Live attenuated rubella vectors expressing SIV and HIV vaccine antigens replicate and elicit durable immune responses in rhesus macaques

PubMed Central

2013-01-01

Background Live attenuated viruses are among our most potent and effective vaccines. For human immunodeficiency virus, however, a live attenuated strain could present substantial safety concerns. We have used the live attenuated rubella vaccine strain RA27/3 as a vector to express SIV and HIV vaccine antigens because its safety and immunogenicity have been demonstrated in millions of children. One dose protects for life against rubella infection. In previous studies, rubella vectors replicated to high titers in cell culture while stably expressing SIV and HIV antigens. Their viability in vivo, however, as well as immunogenicity and antibody persistence, were unknown. Results This paper reports the first successful trial of rubella vectors in rhesus macaques, in combination with DNA vaccines in a prime and boost strategy. The vectors grew robustly in vivo, and the protein inserts were highly immunogenic. Antibody titers elicited by the SIV Gag vector were greater than or equal to those elicited by natural SIV infection. The antibodies were long lasting, and they were boosted by a second dose of replication-competent rubella vectors given six months later, indicating the induction of memory B cells. Conclusions Rubella vectors can serve as a vaccine platform for safe delivery and expression of SIV and HIV antigens. By presenting these antigens in the context of an acute infection, at a high level and for a prolonged duration, these vectors can stimulate a strong and persistent immune response, including maturation of memory B cells. Rhesus macaques will provide an ideal animal model for demonstrating immunogenicity of novel vectors and protection against SIV or SHIV challenge. PMID:24041113

Novel formulations enhance the thermal stability of live-attenuated flavivirus vaccines

PubMed Central

Wiggan, O’Neil; Silengo, Shawn J.; Kinney, Richard M.; Osorio, Jorge E.; Huang, Claire Y.-H.; Stinchcomb, Dan T.

2011-01-01

Thermal stability is important for the manufacture, distribution and administration of vaccines, especially in tropical developing countries, where particularly adverse field conditions exist. Current live-attenuated flavivirus vaccines exhibit relatively poor liquid stability in clinical settings, and clinicians are instructed to discard the yellow fever vaccine 1h after reconstitution. We have identified novel combinations of excipients that greatly enhance the thermal stability of live-attenuated DEN-2 PDK-53-based flavivirus vaccine candidates. Liquid formulations comprising a sugar, albumin and a pluronic polymer minimized the loss of flavivirus infectious titer to less than 0.5log(10)pfu after storage for at least 8h at 37°C, 7 days at room temperature or at least 11 weeks at 4°C. Additionally, these formulations prevented reduction of viral infectivity after two freeze-thaw cycles of virus. Formulated candidate vaccines were readily lyophilized and reconstituted with minimal loss of viral titers. In mice, the formulations were safe and did not hinder the ability of the vaccine virus to generate a potent, protective immune response. These formulations provided significantly greater liquid-phase stability than has been reported previously for other flavivirus vaccine formulations. The enhanced thermal stability provided by the formulations described here will facilitate the effective distribution of flavivirus vaccines worldwide. PMID:21803103

Live attenuated tetravalent dengue vaccine.

PubMed

Bhamarapravati, N; Sutee, Y

2000-05-26

The development of a live attenuated tetravalent dengue vaccine is currently the best strategy to obtain a vaccine against dengue viruses. The Mahidol University group developed candidate live attenuated vaccines by attenuation through serial passages in certified primary cell cultures. Dengue serotype 1, 2 and 4 viruses were developed in primary dog kidney cells, whereas dengue serotype 3 was serially passaged in primary African green monkey kidney cells. Tissue culture passaged strain viruses were subjected to biological marker studies. Candidate vaccines have been tested as monovalent (single virus), bivalent (two viruses), trivalent (three viruses) and tetravalent (all four serotype viruses) vaccines in Thai volunteers. They were found to be safe and immunogenic in both adults and children. The Mahidol live attenuated dengue 2 virus was also tested in American volunteers and resulted in good immune response indistinguishable from those induced in Thai volunteers. The master seeds from the four live attenuated virus strains developed were provided to Pasteur Merieux Connaught of France for production on an industrial scale following good manufacturing practice guidelines.

Prior DNA vaccination does not interfere with the live-attenuated measles vaccine.

PubMed

Premenko-Lanier, Mary; Rota, Paul; Rhodes, Gary; Bellini, William; McChesney, Michael

2004-01-26

The currently used live-attenuated measles vaccine is very effective although maternal antibody prevents its administration prior to 6 months of age. We are investigating the ability of a DNA vaccine encoding the measles viral hemagglutinin, fusion and nucleoprotein to protect newborn infants from measles. Here, we show that a measles DNA vaccine protects juvenile macaques from pathogenic measles virus challenge and that macaques primed and boosted with this DNA vaccine have anemnestic antibody and cell-mediated responses after vaccination with a live-attenuated canine distemper-measles vaccine. Therefore, this DNA vaccine administered to newborn infants may not hinder the subsequent use of live-attenuated measles vaccine.

In elderly persons live attenuated influenza A virus vaccines do not offer an advantage over inactivated virus vaccine in inducing serum or secretory antibodies or local immunologic memory.

PubMed Central

Powers, D C; Fries, L F; Murphy, B R; Thumar, B; Clements, M L

1991-01-01

In a double-blind, randomized trial, 102 healthy elderly subjects were inoculated with one of four preparations: (i) intranasal bivalent live attenuated influenza vaccine containing cold-adapted A/Kawasaki/86 (H1N1) and cold-adapted A/Bethesda/85 (H3N2) viruses; (ii) parenteral trivalent inactivated subvirion vaccine containing A/Taiwan/86 (H1N1), A/Leningrad/86 (H3N2), and B/Ann Arbor/86 antigens; (iii) both vaccines; or (iv) placebo. To determine whether local or systemic immunization augmented mucosal immunologic memory, all volunteers were challenged intranasally 12 weeks later with the inactivated virus vaccine. We used a hemagglutination inhibition assay to measure antibodies in sera and a kinetic enzyme-linked immunosorbent assay to measure immunoglobulin G (IgG) and IgA antibodies in sera and nasal washes, respectively. In comparison with the live virus vaccine, the inactivated virus vaccine elicited higher and more frequent rises of serum antibodies, while nasal wash antibody responses were similar. The vaccine combination induced serum and local antibodies slightly more often than the inactivated vaccine alone did. Coadministration of live influenza A virus vaccine did not alter the serum antibody response to the influenza B virus component of the inactivated vaccine. The anamnestic nasal antibody response elicited by intranasal inactivated virus challenge did not differ in the live, inactivated, or combined vaccine groups from that observed in the placebo group not previously immunized. These results suggest that in elderly persons cold-adapted influenza A virus vaccines offer little advantage over inactivated virus vaccines in terms of inducing serum or secretory antibody or local immunological memory. Studies are needed to determine whether both vaccines in combination are more efficacious than inactivated vaccine alone in people in this age group. PMID:2037667

Deep sequencing reveals persistence of cell-associated mumps vaccine virus in chronic encephalitis.

PubMed

Morfopoulou, Sofia; Mee, Edward T; Connaughton, Sarah M; Brown, Julianne R; Gilmour, Kimberly; Chong, W K 'Kling'; Duprex, W Paul; Ferguson, Deborah; Hubank, Mike; Hutchinson, Ciaran; Kaliakatsos, Marios; McQuaid, Stephen; Paine, Simon; Plagnol, Vincent; Ruis, Christopher; Virasami, Alex; Zhan, Hong; Jacques, Thomas S; Schepelmann, Silke; Qasim, Waseem; Breuer, Judith

2017-01-01

Routine childhood vaccination against measles, mumps and rubella has virtually abolished virus-related morbidity and mortality. Notwithstanding this, we describe here devastating neurological complications associated with the detection of live-attenuated mumps virus Jeryl Lynn (MuV JL5 ) in the brain of a child who had undergone successful allogeneic transplantation for severe combined immunodeficiency (SCID). This is the first confirmed report of MuV JL5 associated with chronic encephalitis and highlights the need to exclude immunodeficient individuals from immunisation with live-attenuated vaccines. The diagnosis was only possible by deep sequencing of the brain biopsy. Sequence comparison of the vaccine batch to the MuV JL5 isolated from brain identified biased hypermutation, particularly in the matrix gene, similar to those found in measles from cases of SSPE. The findings provide unique insights into the pathogenesis of paramyxovirus brain infections.

Yellow fever vector live-virus vaccines: West Nile virus vaccine development.

PubMed

Arroyo, J; Miller, C A; Catalan, J; Monath, T P

2001-08-01

By combining molecular-biological techniques with our increased understanding of the effect of gene sequence modification on viral function, yellow fever 17D, a positive-strand RNA virus vaccine, has been manipulated to induce a protective immune response against viruses of the same family (e.g. Japanese encephalitis and dengue viruses). Triggered by the emergence of West Nile virus infections in the New World afflicting humans, horses and birds, the success of this recombinant technology has prompted the rapid development of a live-virus attenuated candidate vaccine against West Nile virus.

Immunization with Eimeria ninakohlyakimovae-live attenuated oocysts protect goat kids from clinical coccidiosis.

PubMed

Ruiz, Antonio; Muñoz, María Carmen; Molina, José Manuel; Hermosilla, Carlos; Andrada, Marisa; Lara, Pedro; Bordón, Elisa; Pérez, Davinia; López, Adassa María; Matos, Lorena; Guedes, Aránzazu Carmen; Falcón, Soraya; Falcón, Yaiza; Martín, Sergio; Taubert, Anja

2014-01-17

Caprine coccidiosis, affecting mainly young goat kids around the weaning period, is worldwide the most important disease in the goat industry. Control of caprine coccidiosis is increasingly hampered by resistances developed against coccidiostatic drugs leading to an enhanced need for anticoccidial vaccines. In the current study we conducted an oral immunization trial with live attenuated sporulated Eimeria ninakohlyakimovae oocysts. Sporulated E. ninakohlyakimovae oocysts were attenuated by X-irradiation technique. The experimental design included a total of 18 goat kids divided into the following groups: (i) animals immunized with attenuated E. ninakohlyakimovae oocysts at 5 weeks of age and challenged 3 weeks later with non-irradiated homologous oocysts (group 1); (ii) animals infected with non-attenuated E. ninakohlyakimovae oocysts at 5 weeks of age and challenged 3 weeks later with non-attenuated homologous oocysts (group 2); (iii) animals primary-infected with untreated E. ninakohlyakimovae oocysts at 8 weeks of age (control of the challenge infection, group 3); (iv) non-infected control animals (group 4). Goat kids immunized with live attenuated E. ninakohlyakimovae oocysts (group 1) excreted significantly less oocysts in the faeces (95.3% reduction) than kids infected with non-attenuated ones (group 2). Furthermore, immunization with live but attenuated oocysts resulted in ameliorated clinical coccidiosis compared to goat kids infected with untreated oocysts (group 2) and resulted in equally reduced signs of coccidiosis after challenge infection compared to acquired immunity driven by non-attenuated oocysts. Overall, the present study demonstrates for the first time that live attenuated E. ninakohlyakimovae oocysts orally administered showed almost no pathogenicity but enough immunogenicity in terms of immunoprotection. Importantly, vaccinated animals still shed low amounts of oocysts, guaranteeing environmental contamination and consecutive booster infections to sustain ongoing immunity. Copyright © 2013 Elsevier B.V. All rights reserved.

Revaccination of Guinea Pigs With the Live Attenuated Mycobacterium tuberculosis Vaccine MTBVAC Improves BCG's Protection Against Tuberculosis.

PubMed

Clark, Simon; Lanni, Faye; Marinova, Dessislava; Rayner, Emma; Martin, Carlos; Williams, Ann

2017-09-01

The need for an effective vaccine against human tuberculosis has driven the development of different candidates and vaccination strategies. Novel live attenuated vaccines are being developed that promise greater safety and efficacy than BCG against tuberculosis. We combined BCG with the vaccine MTBVAC to evaluate whether the efficacy of either vaccine would be affected upon revaccination. In a well-established guinea pig model of aerosol infection with Mycobacterium tuberculosis, BCG and MTBVAC delivered via various prime-boost combinations or alone were compared. Efficacy was determined by a reduction in bacterial load 4 weeks after challenge. Efficacy data suggests MTBVAC-associated immunity is longer lasting than that of BCG when given as a single dose. Long and short intervals between BCG prime and MTBVAC boost resulted in improved efficacy in lungs, compared with BCG given alone. A shorter interval between MTBVAC prime and BCG boost resulted in improved efficacy in lungs, compared with BCG given alone. A longer interval resulted in protection equivalent to that of BCG given alone. These data indicate that, rather than boosting the waning efficacy of BCG, a vaccination schedule involving a combination of the 2 vaccines yielded stronger immunity to M. tuberculosis infection. This work supports development of MTBVAC use as a revaccination strategy to improve on the effects of BCG in vaccinated people living in tuberculosis-endemic countries. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

Urgent challenges in implementing live attenuated influenza vaccine.

PubMed

Singanayagam, Anika; Zambon, Maria; Lalvani, Ajit; Barclay, Wendy

2018-01-01

Conflicting reports have emerged about the effectiveness of the live attenuated influenza vaccine. The live attenuated influenza vaccine appears to protect particularly poorly against currently circulating H1N1 viruses that are derived from the 2009 pandemic H1N1 viruses. During the 2015-16 influenza season, when pandemic H1N1 was the predominant virus, studies from the USA reported a complete lack of effectiveness of the live vaccine in children. This finding led to a crucial decision in the USA to recommend that the live vaccine not be used in 2016-17 and to switch to the inactivated influenza vaccine. Other countries, including the UK, Canada, and Finland, however, have continued to recommend the use of the live vaccine. This policy divergence and uncertainty has far reaching implications for the entire global community, given the importance of the production capabilities of the live attenuated influenza vaccine for pandemic preparedness. In this Personal View, we discuss possible explanations for the observed reduced effectiveness of the live attenuated influenza vaccine and highlight the underpinning scientific questions. Further research to understand the reasons for these observations is essential to enable informed public health policy and commercial decisions about vaccine production and development in coming years. Copyright © 2018 Elsevier Ltd. All rights reserved.

Dose reduction in fluoroscopic interventions using a combination of a region of interest (ROI) x-ray attenuator and spatially different, temporally variable temporal filtering

NASA Astrophysics Data System (ADS)

Swetadri Vasan, S. N.; Pope, Liza; Ionita, Ciprian N.; Titus, A. H.; Bednarek, D. R.; Rudin, S.

2013-03-01

A novel dose reduction technique for fluoroscopic interventions involving a combination of a material x-ray region of interest (ROI) attenuator and spatially different, temporally variable ROI temporal recursive filter, was used to guide the catheter to the ROI in three live animal studies, two involving rabbits and one involving a sheep. In the two rabbit studies presented , a catheter was guided to the entrance of the carotid artery. With the added ROI attenuator the image under the high attenuation region is very noisy. By using temporal filtering with a filter weight of 0.6 on previous frames, the noise is reduced. In the sheep study the catheter was guided to the descending aorta of the animal. The sheep offered a relatively higher attenuation to the incident x-rays and thus a higher temporal filter weight of 0.8 on previous frames was used during the procedure to reduce the noise to levels acceptable by the interventionalist. The image sequences from both studies show that significant dose reduction of 5-6 times can be achieved with acceptable image quality outside the ROI by using the above mentioned technique. Even though the temporal filter weighting outside the ROI is higher, the consequent lag does not prevent perception of catheter movement.

Identifying Attenuating Mutations: Tools for a New Vaccine Design against Flaviviruses.

PubMed

Khou, Cécile; Pardigon, Nathalie

2017-01-01

Emerging Flaviviruses pose an increasing threat to global human health. To date, human vaccines against yellow fever virus (YFV), Japanese encephalitis virus (JEV), dengue virus (DV), and tick-borne encephalitis virus (TBEV) exist. However, there is no human vaccine against other Flaviviruses such as Zika virus (ZIKV) and West Nile virus (WNV). In order to restrict their spread and to protect populations against the diseases they induce, vaccines against these emerging viruses must be designed. Obtaining new live attenuated Flavivirus vaccines using molecular biology methods is now possible. Molecular infectious clones of the parental viruses are relatively easy to generate. Key mutations present in live attenuated vaccines or mutations known to have a key role in the Flavivirus life cycle and/or interactions with their hosts can be identified by sequencing, and are then inserted in infectious clones by site-directed mutagenesis. More recently, the use of chimeric viruses and large-scale reencoding and introduction of microRNA target sequences have also been tested. Indeed, a combination of these methods will help in designing new generations of vaccines against emerging and reemerging Flaviviruses. © 2017 S. Karger AG, Basel.

Five-year antibody persistence in children after one dose of inactivated or live attenuated hepatitis A vaccine.

PubMed

Zhang, Zhilun; Zhu, Xiangjun; Hu, Yuansheng; Liang, Miao; Sun, Jin; Song, Yufei; Yang, Qi; Ji, Haiquan; Zeng, Gang; Song, Lifei; Chen, Jiangting

2017-06-03

In China, both inactivated hepatitis A (HA) vaccine and live attenuated HA vaccine are available. We conducted a trial to evaluate 5-year immune persistence induced by one dose of inactivated or live attenuated HA vaccines in children. Subjects with no HA vaccination history had randomly received one dose of inactivated or live attenuated HA vaccine at 18-60 months of age. Anti-HAV antibody concentrations were measured before vaccination and at the first, second, and fifth year after vaccination. Suspected cases of hepatitis A were monitored during the study period. A total of 332 subjects were enrolled and 182 provided evaluable serum samples at all planned time points. seropositive rate at 5 y was 85.9% in the inactivated HA vaccine group and 90.7% in the live attenuated HA vaccine group. GMCs were 76.3% mIU/ml (95% CI: 61.7 - 94.4) and 66.8mIU/ml (95% CI: 57.8 - 77.3), respectively. No significant difference in antibody persistence between 2 groups was found. No clinical hepatitis A case was reported. A single dose of an inactivated or live attenuated HA vaccine at 18-60 months of age resulted in high HAV seropositive rate and anti-HAV antibody concentrations that lasted for at least 5 y.

Efficacy of a live attenuated Edwardsiella ictaluri oral vaccine in channel and hybrid catfish

USDA-ARS?s Scientific Manuscript database

This study evaluated the efficacy of an oral live-attenuated Edwardsiella ictaluri vaccine against enteric septicemia of catfish (ESC) in channel and hybrid catfish. The vaccine was delivered orally by feeding fish a diet coated with an attenuated E. ictaluri isolate at four doses to deliver betwee...

Yersinia pestis CO92 delta yopH is a potent live, attenuated plague vaccine.

PubMed

Bubeck, Sarah S; Dube, Peter H

2007-09-01

An in-frame deletion of the yopH gene in Yersinia pestis CO92 attenuates virulence in both bubonic and pneumonic plague models. When it is used as a live, attenuated vaccine, CO92 delta yopH provides a high degree of protection from parental and respiratory challenge with Y. pestis CO92.

78 FR 43219 - Prospective Grant of Exclusive License: Live Attenuated Dengue Tetravalent Vaccine Containing a...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-19

... Exclusive License: Live Attenuated Dengue Tetravalent Vaccine Containing a Common 30 Nucleotide Deletion in the 3'-UTR of Dengue Types 1, 2, 3, and 4 AGENCY: National Institutes of Health, HHS. ACTION: Notice...) E-120-2001/0, Whitehead et al., ``Development of Mutations Useful for Attenuating Dengue Viruses and...

Comparison of the Live Attenuated Yellow Fever Vaccine 17D-204 Strain to Its Virulent Parental Strain Asibi by Deep Sequencing

PubMed Central

Beck, Andrew; Tesh, Robert B.; Wood, Thomas G.; Widen, Steven G.; Ryman, Kate D.; Barrett, Alan D. T.

2014-01-01

Background. The first comparison of a live RNA viral vaccine strain to its wild-type parental strain by deep sequencing is presented using as a model the yellow fever virus (YFV) live vaccine strain 17D-204 and its wild-type parental strain, Asibi. Methods. The YFV 17D-204 vaccine genome was compared to that of the parental strain Asibi by massively parallel methods. Variability was compared on multiple scales of the viral genomes. A modeled exploration of small-frequency variants was performed to reconstruct plausible regions of mutational plasticity. Results. Overt quasispecies diversity is a feature of the parental strain, whereas the live vaccine strain lacks diversity according to multiple independent measurements. A lack of attenuating mutations in the Asibi population relative to that of 17D-204 was observed, demonstrating that the vaccine strain was derived by discrete mutation of Asibi and not by selection of genomes in the wild-type population. Conclusions. Relative quasispecies structure is a plausible correlate of attenuation for live viral vaccines. Analyses such as these of attenuated viruses improve our understanding of the molecular basis of vaccine attenuation and provide critical information on the stability of live vaccines and the risk of reversion to virulence. PMID:24141982

Comparison of the live attenuated yellow fever vaccine 17D-204 strain to its virulent parental strain Asibi by deep sequencing.

PubMed

Beck, Andrew; Tesh, Robert B; Wood, Thomas G; Widen, Steven G; Ryman, Kate D; Barrett, Alan D T

2014-02-01

The first comparison of a live RNA viral vaccine strain to its wild-type parental strain by deep sequencing is presented using as a model the yellow fever virus (YFV) live vaccine strain 17D-204 and its wild-type parental strain, Asibi. The YFV 17D-204 vaccine genome was compared to that of the parental strain Asibi by massively parallel methods. Variability was compared on multiple scales of the viral genomes. A modeled exploration of small-frequency variants was performed to reconstruct plausible regions of mutational plasticity. Overt quasispecies diversity is a feature of the parental strain, whereas the live vaccine strain lacks diversity according to multiple independent measurements. A lack of attenuating mutations in the Asibi population relative to that of 17D-204 was observed, demonstrating that the vaccine strain was derived by discrete mutation of Asibi and not by selection of genomes in the wild-type population. Relative quasispecies structure is a plausible correlate of attenuation for live viral vaccines. Analyses such as these of attenuated viruses improve our understanding of the molecular basis of vaccine attenuation and provide critical information on the stability of live vaccines and the risk of reversion to virulence.

The influence of the multi-basic cleavage site of the H5 hemagglutinin on the attenuation, immunogenicity and efficacy of a live attenuated influenza A h5N1 cold-adapted vaccine virus

USDA-ARS?s Scientific Manuscript database

A recombinant live attenuated influenza virus (LAIV) deltaH5N1 vaccine with a modified hemagglutinin (HA) and intact neuraminidase genes from A/Vietnam/1203/04 (H5N1) and the six remaining genome segments from A/Ann Arbor/6/60 (H2N2) cold-adapted (AA ca) virus was attenuated in chickens, mice and fe...

A live-attenuated and an inactivated chimeric porcine circovirus (PCV)1-2 vaccine are both effective at inducing a humoral immune response and reducing PCV2 viremia and intrauterine infection in female swine of breeding age.

PubMed

Hemann, Michelle; Beach, Nathan M; Meng, Xiang-Jin; Wang, Chong; Halbur, Patrick G; Opriessnig, Tanja

2014-01-01

The objective of this pilot study was to determine the efficacy of inactivated (1 or 2 dose) and live-attenuated chimeric porcine circovirus (PCV)1-2 vaccines in sows using the PCV2-spiked semen model. Thirty-five sows were randomly divided into 6 groups: negative and positive controls, 1 dose inactivated PCV1-2 vaccine challenged (1-VAC-PCV2), 2 dose inactivated PCV1-2 vaccine challenged (2-VAC-PCV2), 1 dose live-attenuated PCV1-2 vaccine unchallenged (1-LIVE-VAC), and 1 dose live-attenuated PCV1-2 vaccine challenged (1-LIVE-VAC-PCV2). The inactivated PCV1-2 vaccine induced higher levels of PCV2-specific antibodies in dams. All vaccination strategies provided good protection against PCV2 viremia in dams, whereas the majority of the unvaccinated sows were viremic. Four of the 35 dams became pregnant: a negative control, a positive control, a 2-VAC-PCV2 sow, and a 1-LIVE-VAC-PCV2 sow. The PCV2 DNA was detected in 100%, 67%, and 29% of the fetuses obtained from the positive control, inactivated vaccinated, or live-attenuated vaccinated dams, respectively. The PCV2 antigen in hearts was only detectable in the positive control litter (23% of the fetuses). The PCV1-2 DNA was detected in 29% of the fetuses in the litter from the 1-LIVE-VAC-PCV2 dam. Under the conditions of this pilot study, both vaccines protected against PCV2 viremia in breeding age animals; however, vertical transmission was not prevented.

A live-attenuated and an inactivated chimeric porcine circovirus (PCV)1-2 vaccine are both effective at inducing a humoral immune response and reducing PCV2 viremia and intrauterine infection in female swine of breeding age

PubMed Central

Hemann, Michelle; Beach, Nathan M.; Meng, Xiang-Jin; Wang, Chong; Halbur, Patrick G.; Opriessnig, Tanja

2014-01-01

The objective of this pilot study was to determine the efficacy of inactivated (1 or 2 dose) and live-attenuated chimeric porcine circovirus (PCV)1-2 vaccines in sows using the PCV2-spiked semen model. Thirty-five sows were randomly divided into 6 groups: negative and positive controls, 1 dose inactivated PCV1-2 vaccine challenged (1-VAC-PCV2), 2 dose inactivated PCV1-2 vaccine challenged (2-VAC-PCV2), 1 dose live-attenuated PCV1-2 vaccine unchallenged (1-LIVE-VAC), and 1 dose live-attenuated PCV1-2 vaccine challenged (1-LIVE-VAC-PCV2). The inactivated PCV1-2 vaccine induced higher levels of PCV2-specific antibodies in dams. All vaccination strategies provided good protection against PCV2 viremia in dams, whereas the majority of the unvaccinated sows were viremic. Four of the 35 dams became pregnant: a negative control, a positive control, a 2-VAC-PCV2 sow, and a 1-LIVE-VAC-PCV2 sow. The PCV2 DNA was detected in 100%, 67%, and 29% of the fetuses obtained from the positive control, inactivated vaccinated, or live-attenuated vaccinated dams, respectively. The PCV2 antigen in hearts was only detectable in the positive control litter (23% of the fetuses). The PCV1-2 DNA was detected in 29% of the fetuses in the litter from the 1-LIVE-VAC-PCV2 dam. Under the conditions of this pilot study, both vaccines protected against PCV2 viremia in breeding age animals; however, vertical transmission was not prevented. PMID:24396175

Trivalent live attenuated intranasal influenza vaccine administered during the 2003-2004 influenza type A (H3N2) outbreak provided immediate, direct, and indirect protection in children.

PubMed

Piedra, Pedro A; Gaglani, Manjusha J; Kozinetz, Claudia A; Herschler, Gayla B; Fewlass, Charles; Harvey, Dianne; Zimmerman, Nadine; Glezen, W Paul

2007-09-01

Live attenuated influenza vaccine may protect against wild-type influenza illness shortly after vaccine administration by innate immunity. The 2003-2004 influenza A (H3N2) outbreak arrived early, and the circulating strain was antigenically distinct from the vaccine strain. The objective of this study was to determine the effectiveness of influenza vaccines for healthy school-aged children when administered during the influenza outbreak. An open-labeled, nonrandomized, community-based influenza vaccine trial was conducted in children 5 to 18 years old. Age-eligible healthy children received trivalent live attenuated influenza vaccine. Trivalent inactivated influenza vaccine was given to children with underlying health conditions. Influenza-positive illness was compared between vaccinated and nonvaccinated children. Medically attended acute respiratory illness and pneumonia and influenza rates for Scott and White Health Plan vaccinees were compared with age-eligible Scott and White Health Plan nonparticipants in the intervention communities. Herd protection was assessed by comparing age-specific medically attended acute respiratory illness rates in Scott and White Health Plan members in the intervention and comparison communities. We administered 1 dose of trivalent live attenuated influenza vaccine or trivalent inactivated influenza vaccine to 6569 and 1040 children, respectively (31.5% vaccination coverage), from October 10 to December 30, 2003. The influenza outbreak occurred from October 12 to December 20, 2003. Significant protection against influenza-positive illness (37.3%) and pneumonia and influenza events (50%) was detected in children who received trivalent live attenuated influenza vaccine but not trivalent inactivated influenza vaccine. Trivalent live attenuated influenza vaccine recipients had similar protection against influenza-positive illness within 14 days compared with >14 days (10 of 25 vs 9 of 30) after vaccination. Indirect effectiveness against medically attended acute respiratory illness was detected in children 5 to 11 and adults 35 to 44 years of age. One dose of trivalent live attenuated influenza vaccine was efficacious in children even when administered during an influenza outbreak and when the dominant circulating influenza virus was antigenically distinct from the vaccine strain. We hypothesize that trivalent live attenuated influenza vaccine provides protection against influenza by both innate and adaptive immune mechanisms.

A Recombinant Respiratory Syncytial Virus Vaccine Candidate Attenuated by a Low-Fusion F Protein Is Immunogenic and Protective against Challenge in Cotton Rats

PubMed Central

Rostad, Christina A.; Stobart, Christopher C.; Gilbert, Brian E.; Pickles, Ray J.; Hotard, Anne L.; Meng, Jia; Blanco, Jorge C. G.; Moin, Syed M.; Graham, Barney S.; Piedra, Pedro A.

2016-01-01

ABSTRACT Although respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in infants, a safe and effective vaccine is not yet available. Live-attenuated vaccines (LAVs) are the most advanced vaccine candidates in RSV-naive infants. However, designing an LAV with appropriate attenuation yet sufficient immunogenicity has proven challenging. In this study, we implemented reverse genetics to address these obstacles with a multifaceted LAV design that combined the codon deoptimization of genes for nonstructural proteins NS1 and NS2 (dNS), deletion of the small hydrophobic protein (ΔSH) gene, and replacement of the wild-type fusion (F) protein gene with a low-fusion RSV subgroup B F consensus sequence of the Buenos Aires clade (BAF). This vaccine candidate, RSV-A2-dNS-ΔSH-BAF (DB1), was attenuated in two models of primary human airway epithelial cells and in the upper and lower airways of cotton rats. DB1 was also highly immunogenic in cotton rats and elicited broadly neutralizing antibodies against a diverse panel of recombinant RSV strains. When vaccinated cotton rats were challenged with wild-type RSV A, DB1 reduced viral titers in the upper and lower airways by 3.8 log10 total PFU and 2.7 log10 PFU/g of tissue, respectively, compared to those in unvaccinated animals (P < 0.0001). DB1 was thus attenuated, highly immunogenic, and protective against RSV challenge in cotton rats. DB1 is the first RSV LAV to incorporate a low-fusion F protein as a strategy to attenuate viral replication and preserve immunogenicity. IMPORTANCE RSV is a leading cause of infant hospitalizations and deaths. The development of an effective vaccine for this high-risk population is therefore a public health priority. Although live-attenuated vaccines have been safely administered to RSV-naive infants, strategies to balance vaccine attenuation with immunogenicity have been elusive. In this study, we introduced a novel strategy to attenuate a recombinant RSV vaccine by incorporating a low-fusion, subgroup B F protein in the genetic background of codon-deoptimized nonstructural protein genes and a deleted small hydrophobic protein gene. The resultant vaccine candidate, DB1, was attenuated, highly immunogenic, and protective against RSV challenge in cotton rats. PMID:27279612

A Recombinant Respiratory Syncytial Virus Vaccine Candidate Attenuated by a Low-Fusion F Protein Is Immunogenic and Protective against Challenge in Cotton Rats.

PubMed

Rostad, Christina A; Stobart, Christopher C; Gilbert, Brian E; Pickles, Ray J; Hotard, Anne L; Meng, Jia; Blanco, Jorge C G; Moin, Syed M; Graham, Barney S; Piedra, Pedro A; Moore, Martin L

2016-08-15

Although respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in infants, a safe and effective vaccine is not yet available. Live-attenuated vaccines (LAVs) are the most advanced vaccine candidates in RSV-naive infants. However, designing an LAV with appropriate attenuation yet sufficient immunogenicity has proven challenging. In this study, we implemented reverse genetics to address these obstacles with a multifaceted LAV design that combined the codon deoptimization of genes for nonstructural proteins NS1 and NS2 (dNS), deletion of the small hydrophobic protein (ΔSH) gene, and replacement of the wild-type fusion (F) protein gene with a low-fusion RSV subgroup B F consensus sequence of the Buenos Aires clade (BAF). This vaccine candidate, RSV-A2-dNS-ΔSH-BAF (DB1), was attenuated in two models of primary human airway epithelial cells and in the upper and lower airways of cotton rats. DB1 was also highly immunogenic in cotton rats and elicited broadly neutralizing antibodies against a diverse panel of recombinant RSV strains. When vaccinated cotton rats were challenged with wild-type RSV A, DB1 reduced viral titers in the upper and lower airways by 3.8 log10 total PFU and 2.7 log10 PFU/g of tissue, respectively, compared to those in unvaccinated animals (P < 0.0001). DB1 was thus attenuated, highly immunogenic, and protective against RSV challenge in cotton rats. DB1 is the first RSV LAV to incorporate a low-fusion F protein as a strategy to attenuate viral replication and preserve immunogenicity. RSV is a leading cause of infant hospitalizations and deaths. The development of an effective vaccine for this high-risk population is therefore a public health priority. Although live-attenuated vaccines have been safely administered to RSV-naive infants, strategies to balance vaccine attenuation with immunogenicity have been elusive. In this study, we introduced a novel strategy to attenuate a recombinant RSV vaccine by incorporating a low-fusion, subgroup B F protein in the genetic background of codon-deoptimized nonstructural protein genes and a deleted small hydrophobic protein gene. The resultant vaccine candidate, DB1, was attenuated, highly immunogenic, and protective against RSV challenge in cotton rats. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Low-fidelity Venezuelan equine encephalitis virus polymerase mutants to improve live-attenuated vaccine safety and efficacy

PubMed Central

Kautz, Tiffany F; Guerbois, Mathilde; Khanipov, Kamil; Yun, Ruimei; Warmbrod, Kelsey L; Fofanov, Yuriy; Weaver, Scott C; Forrester, Naomi L

2018-01-01

Abstract During RNA virus replication, there is the potential to incorporate mutations that affect virulence or pathogenesis. For live-attenuated vaccines, this has implications for stability, as replication may result in mutations that either restore the wild-type phenotype via reversion or compensate for the attenuating mutations by increasing virulence (pseudoreversion). Recent studies have demonstrated that altering the mutation rate of an RNA virus is an effective attenuation tool. To validate the safety of low-fidelity mutations to increase vaccine attenuation, several mutations in the RNA-dependent RNA-polymerase (RdRp) were tested in the live-attenuated Venezuelan equine encephalitis virus vaccine strain, TC-83. Next generation sequencing after passage in the presence of mutagens revealed a mutant containing three mutations in the RdRp, TC-83 3x, to have decreased replication fidelity, while a second mutant, TC-83 4x displayed no change in fidelity, but shared many phenotypic characteristics with TC-83 3x. Both mutants exhibited increased, albeit inconsistent attenuation in an infant mouse model, as well as increased immunogenicity and complete protection against lethal challenge of an adult murine model compared with the parent TC-83. During serial passaging in a highly permissive model, the mutants increased in virulence but remained less virulent than the parent TC-83. These results suggest that the incorporation of low-fidelity mutations into the RdRp of live-attenuated vaccines for RNA viruses can confer increased immunogenicity whilst showing some evidence of increased attenuation. However, while in theory such constructs may result in more effective vaccines, the instability of the vaccine phenotype decreases the likelihood of this being an effective vaccine strategy. PMID:29593882

Improved hatchability and efficient protection after in ovo vaccination with live-attenuated H7N2 and H9N2 avian influenza viruses

PubMed Central

2011-01-01

Mass in ovo vaccination with live attenuated viruses is widely used in the poultry industry to protect against various infectious diseases. The worldwide outbreaks of low pathogenic and highly pathogenic avian influenza highlight the pressing need for the development of similar mass vaccination strategies against avian influenza viruses. We have previously shown that a genetically modified live attenuated avian influenza virus (LAIV) was amenable for in ovo vaccination and provided optimal protection against H5 HPAI viruses. However, in ovo vaccination against other subtypes resulted in poor hatchability and, therefore, seemed impractical. In this study, we modified the H7 and H9 hemagglutinin (HA) proteins by substituting the amino acids at the cleavage site for those found in the H6 HA subtype. We found that with this modification, a single dose in ovo vaccination of 18-day old eggs provided complete protection against homologous challenge with low pathogenic virus in ≥70% of chickens at 2 or 6 weeks post-hatching. Further, inoculation of 19-day old egg embryos with 106 EID50 of LAIVs improved hatchability to ≥90% (equivalent to unvaccinated controls) with similar levels of protection. Our findings indicate that the strategy of modifying the HA cleavage site combined with the LAIV backbone could be used for in ovo vaccination against avian influenza. Importantly, with protection conferred as early as 2 weeks post-hatching, with this strategy birds would be protected prior to or at the time of delivery to a farm or commercial operation. PMID:21255403

Particle-based vaccines for HIV-1 infection.

PubMed

Young, Kelly R; Ross, Ted M

2003-06-01

The use of live-attenuated viruses as vaccines has been successful for the control of viral infections. However, the development of an effective vaccine against the human immunodeficiency virus (HIV) has proven to be a challenge. HIV infects cells of the immune system and results in a severe immunodeficiency. In addition, the ability of the virus to adapt to immune pressure and the ability to reside in an integrated form in host cells present hurdles for vaccinologists to overcome. A particle-based vaccine strategy has promise for eliciting high titer, long-lived, immune responses to a diverse number of viral epitopes from different HIV antigens. Live-attenuated viruses are effective at generating both cellular and humoral immunity, however, a live-attenuated vaccine for HIV is problematic. The possibility of a live-attenuated vaccine to revert to a pathogenic form or recombine with a wild-type or defective virus in an infected individual is a drawback to this approach. Therefore, these vaccines are currently only being tested in non-human primate models. Live-attenuated vaccines are effective in stimulating immunity, however challenged animals rarely clear viral infection and the degree of attenuation directly correlates with the protection of animals from disease. Another particle-based vaccine approach for HIV involves the use of virus-like particles (VLPs). VLPs mimic the viral particle without causing an immunodeficiency disease. HIV-like particles (HIV-LP) are defined as self-assembling, non-replicating, nonpathogenic, genomeless particles that are similar in size and conformation to intact virions. A variety of VLPs for both HIV and SIV are currently in pre-clinical and clinical trials. This review focuses on the current knowledge regarding the immunogenicity and safety of particle-based vaccine strategies for HIV-1.

Biomarkers of Safety and Immune Protection for Genetically Modified Live Attenuated Leishmania Vaccines Against Visceral Leishmaniasis – Discovery and Implications

PubMed Central

Gannavaram, Sreenivas; Dey, Ranadhir; Avishek, Kumar; Selvapandiyan, Angamuthu; Salotra, Poonam; Nakhasi, Hira L.

2014-01-01

Despite intense efforts there is no safe and efficacious vaccine against visceral leishmaniasis, which is fatal and endemic in many tropical countries. A major shortcoming in the vaccine development against blood-borne parasitic agents such as Leishmania is the inadequate predictive power of the early immune responses mounted in the host against the experimental vaccines. Often immune correlates derived from in-bred animal models do not yield immune markers of protection that can be readily extrapolated to humans. The limited efficacy of vaccines based on DNA, subunit, heat killed parasites has led to the realization that acquisition of durable immunity against the protozoan parasites requires a controlled infection with a live attenuated organism. Recent success of irradiated malaria parasites as a vaccine candidate further strengthens this approach to vaccination. We developed several gene deletion mutants in Leishmania donovani as potential live attenuated vaccines and reported extensively on the immunogenicity of LdCentrin1 deleted mutant in mice, hamsters, and dogs. Additional limited studies using genetically modified live attenuated Leishmania parasites as vaccine candidates have been reported. However, for the live attenuated parasite vaccines, the primary barrier against widespread use remains the absence of clear biomarkers associated with protection and safety. Recent studies in evaluation of vaccines, e.g., influenza and yellow fever vaccines, using systems biology tools demonstrated the power of such strategies in understanding the immunological mechanisms that underpin a protective phenotype. Applying similar tools in isolated human tissues such as PBMCs from healthy individuals infected with live attenuated parasites such as LdCen−/− in vitro followed by human microarray hybridization experiments will enable us to understand how early vaccine-induced gene expression profiles and the associated immune responses are coordinately regulated in normal individuals. In addition, comparative analysis of biomarkers in PBMCs from asymptomatic or healed visceral leishmaniasis individuals in response to vaccine candidates including live attenuated parasites may provide clues about determinants of protective immunity and be helpful in shaping the final Leishmania vaccine formulation in the clinical trials. PMID:24904589

Biomarkers of safety and immune protection for genetically modified live attenuated leishmania vaccines against visceral leishmaniasis - discovery and implications.

PubMed

Gannavaram, Sreenivas; Dey, Ranadhir; Avishek, Kumar; Selvapandiyan, Angamuthu; Salotra, Poonam; Nakhasi, Hira L

2014-01-01

Despite intense efforts there is no safe and efficacious vaccine against visceral leishmaniasis, which is fatal and endemic in many tropical countries. A major shortcoming in the vaccine development against blood-borne parasitic agents such as Leishmania is the inadequate predictive power of the early immune responses mounted in the host against the experimental vaccines. Often immune correlates derived from in-bred animal models do not yield immune markers of protection that can be readily extrapolated to humans. The limited efficacy of vaccines based on DNA, subunit, heat killed parasites has led to the realization that acquisition of durable immunity against the protozoan parasites requires a controlled infection with a live attenuated organism. Recent success of irradiated malaria parasites as a vaccine candidate further strengthens this approach to vaccination. We developed several gene deletion mutants in Leishmania donovani as potential live attenuated vaccines and reported extensively on the immunogenicity of LdCentrin1 deleted mutant in mice, hamsters, and dogs. Additional limited studies using genetically modified live attenuated Leishmania parasites as vaccine candidates have been reported. However, for the live attenuated parasite vaccines, the primary barrier against widespread use remains the absence of clear biomarkers associated with protection and safety. Recent studies in evaluation of vaccines, e.g., influenza and yellow fever vaccines, using systems biology tools demonstrated the power of such strategies in understanding the immunological mechanisms that underpin a protective phenotype. Applying similar tools in isolated human tissues such as PBMCs from healthy individuals infected with live attenuated parasites such as LdCen(-/-) in vitro followed by human microarray hybridization experiments will enable us to understand how early vaccine-induced gene expression profiles and the associated immune responses are coordinately regulated in normal individuals. In addition, comparative analysis of biomarkers in PBMCs from asymptomatic or healed visceral leishmaniasis individuals in response to vaccine candidates including live attenuated parasites may provide clues about determinants of protective immunity and be helpful in shaping the final Leishmania vaccine formulation in the clinical trials.

Genetically Modified Live Attenuated Leishmania donovani Parasites Induce Innate Immunity through Classical Activation of Macrophages That Direct the Th1 Response in Mice

PubMed Central

Bhattacharya, Parna; Dey, Ranadhir; Dagur, Pradeep K.; Kruhlak, Michael; Ismail, Nevien; Debrabant, Alain; Joshi, Amritanshu B.; Akue, Adovi; Kukuruga, Mark; Takeda, Kazuyo; Selvapandiyan, Angamuthu; McCoy, John Philip

2015-01-01

Visceral leishmaniasis (VL) causes significant mortality and there is no effective vaccine. Previously, we have shown that genetically modified Leishmania donovani parasites, here described as live attenuated parasites, induce a host protective adaptive immune response in various animal models. In this study, we demonstrate an innate immune response upon infection with live attenuated parasites in macrophages from BALB/c mice both in vitro and in vivo. In vitro infection of macrophages with live attenuated parasites (compared to that with wild-type [WT] L. donovani parasites) induced significantly higher production of proinflammatory cytokines (tumor necrosis factor alpha [TNF-α], interleukin-12 [IL-12], gamma interferon [IFN-γ], and IL-6), chemokines (monocyte chemoattractant protein 1/CCL-2, macrophage inflammatory protein 1α/CCL-3, and IP-10), reactive oxygen species (ROS), and nitric oxide, while concomitantly reducing anti-inflammatory cytokine IL-10 and arginase-1 activities, suggesting a dominant classically activated/M1 macrophage response. The classically activated response in turn helps in presenting antigen to T cells, as observed with robust CD4+ T cell activation in vitro. Similarly, parasitized splenic macrophages from live attenuated parasite-infected mice also demonstrated induction of an M1 macrophage phenotype, indicated by upregulation of IL-1β, TNF-α, IL-12, and inducible nitric oxide synthase 2 and downregulation of genes associated with the M2 phenotype, i.e., the IL-10, YM1, Arg-1, and MRC-1 genes, compared to WT L. donovani-infected mice. Furthermore, an ex vivo antigen presentation assay showed macrophages from live attenuated parasite-infected mice induced higher IFN-γ and IL-2 but significantly less IL-10 production by ovalbumin-specific CD4+ T cells, resulting in proliferation of Th1 cells. These data suggest that infection with live attenuated parasites promotes a state of classical activation (M1 dominant) in macrophages that leads to the generation of protective Th1 responses in BALB/c mice. PMID:26169275

Influenza Vaccine Effectiveness in the United States during the 2015-2016 Season.

PubMed

Jackson, Michael L; Chung, Jessie R; Jackson, Lisa A; Phillips, C Hallie; Benoit, Joyce; Monto, Arnold S; Martin, Emily T; Belongia, Edward A; McLean, Huong Q; Gaglani, Manjusha; Murthy, Kempapura; Zimmerman, Richard; Nowalk, Mary P; Fry, Alicia M; Flannery, Brendan

2017-08-10

The A(H1N1)pdm09 virus strain used in the live attenuated influenza vaccine was changed for the 2015-2016 influenza season because of its lack of effectiveness in young children in 2013-2014. The Influenza Vaccine Effectiveness Network evaluated the effect of this change as part of its estimates of influenza vaccine effectiveness in 2015-2016. We enrolled patients 6 months of age or older who presented with acute respiratory illness at ambulatory care clinics in geographically diverse U.S. sites. Using a test-negative design, we estimated vaccine effectiveness as (1-OR)×100, in which OR is the odds ratio for testing positive for influenza virus among vaccinated versus unvaccinated participants. Separate estimates were calculated for the inactivated vaccines and the live attenuated vaccine. Among 6879 eligible participants, 1309 (19%) tested positive for influenza virus, predominantly for A(H1N1)pdm09 (11%) and influenza B (7%). The effectiveness of the influenza vaccine against any influenza illness was 48% (95% confidence interval [CI], 41 to 55; P<0.001). Among children 2 to 17 years of age, the inactivated influenza vaccine was 60% effective (95% CI, 47 to 70; P<0.001), and the live attenuated vaccine was not observed to be effective (vaccine effectiveness, 5%; 95% CI, -47 to 39; P=0.80). Vaccine effectiveness against A(H1N1)pdm09 among children was 63% (95% CI, 45 to 75; P<0.001) for the inactivated vaccine, as compared with -19% (95% CI, -113 to 33; P=0.55) for the live attenuated vaccine. Influenza vaccines reduced the risk of influenza illness in 2015-2016. However, the live attenuated vaccine was found to be ineffective among children in a year with substantial inactivated vaccine effectiveness. Because the 2016-2017 A(H1N1)pdm09 strain used in the live attenuated vaccine was unchanged from 2015-2016, the Advisory Committee on Immunization Practices made an interim recommendation not to use the live attenuated influenza vaccine for the 2016-2017 influenza season. (Funded by the Centers for Disease Control and Prevention and the National Institutes of Health.).

Genetically Modified Live Attenuated Leishmania donovani Parasites Induce Innate Immunity through Classical Activation of Macrophages That Direct the Th1 Response in Mice.

PubMed

Bhattacharya, Parna; Dey, Ranadhir; Dagur, Pradeep K; Kruhlak, Michael; Ismail, Nevien; Debrabant, Alain; Joshi, Amritanshu B; Akue, Adovi; Kukuruga, Mark; Takeda, Kazuyo; Selvapandiyan, Angamuthu; McCoy, John Philip; Nakhasi, Hira L

2015-10-01

Visceral leishmaniasis (VL) causes significant mortality and there is no effective vaccine. Previously, we have shown that genetically modified Leishmania donovani parasites, here described as live attenuated parasites, induce a host protective adaptive immune response in various animal models. In this study, we demonstrate an innate immune response upon infection with live attenuated parasites in macrophages from BALB/c mice both in vitro and in vivo. In vitro infection of macrophages with live attenuated parasites (compared to that with wild-type [WT] L. donovani parasites) induced significantly higher production of proinflammatory cytokines (tumor necrosis factor alpha [TNF-α], interleukin-12 [IL-12], gamma interferon [IFN-γ], and IL-6), chemokines (monocyte chemoattractant protein 1/CCL-2, macrophage inflammatory protein 1α/CCL-3, and IP-10), reactive oxygen species (ROS), and nitric oxide, while concomitantly reducing anti-inflammatory cytokine IL-10 and arginase-1 activities, suggesting a dominant classically activated/M1 macrophage response. The classically activated response in turn helps in presenting antigen to T cells, as observed with robust CD4(+) T cell activation in vitro. Similarly, parasitized splenic macrophages from live attenuated parasite-infected mice also demonstrated induction of an M1 macrophage phenotype, indicated by upregulation of IL-1β, TNF-α, IL-12, and inducible nitric oxide synthase 2 and downregulation of genes associated with the M2 phenotype, i.e., the IL-10, YM1, Arg-1, and MRC-1 genes, compared to WT L. donovani-infected mice. Furthermore, an ex vivo antigen presentation assay showed macrophages from live attenuated parasite-infected mice induced higher IFN-γ and IL-2 but significantly less IL-10 production by ovalbumin-specific CD4(+) T cells, resulting in proliferation of Th1 cells. These data suggest that infection with live attenuated parasites promotes a state of classical activation (M1 dominant) in macrophages that leads to the generation of protective Th1 responses in BALB/c mice. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Combination therapy of 15-epi-lipoxin A4 with antibiotics protects mice from Escherichia coli-induced sepsis*.

PubMed

Ueda, Tomomi; Fukunaga, Koichi; Seki, Hiroyuki; Miyata, Jun; Arita, Makoto; Miyasho, Taku; Obata, Toru; Asano, Koichiro; Betsuyaku, Tomoko; Takeda, Junzo

2014-04-01

Inflammation occurs along with infection during sepsis. 15-Epi-lipoxin A4 has protective and resolving effects in experimental models of infection. In this study, we examined the effects of 15-epi-lipoxin A4 combined with antibiotics on Escherichia coli-induced peritonitis. Prospective experimental study. University research laboratory. Male C57BL/6 mice. Mice were injected with E. coli to induce peritonitis and were given either 15-epi-lipoxin A4 (1 μg/mouse) or placebo (saline) with antibiotics (ceftazidime). The effects of 15-epi-lipoxin A4 on peritoneal cell populations, bacterial burden, and cytokine production were assessed. Survival rates were observed for up to 7 days. In addition, we examined the effects of 15-epi-lipoxin A4 on peritoneal macrophages stimulated with lipopolysaccharide, CpG DNA, or live E. coli. Treatment with 15-epi-lipoxin A4 significantly reduced the number of neutrophils in the peritoneum, inhibited production of cytokines and chemokines, and decreased bacterial load in the serum. Combined treatment of 15-epi-lipoxin A4 with antibiotics significantly improved survival in E. coli-infected mice. 15-Epi-lipoxin A4 also attenuated the production of interleukin-6 and tumor necrosis factor-α by lipopolysaccharide- or CpG DNA-stimulated peritoneal macrophages. Furthermore, 15-epi-lipoxin A4 combined with antibiotics synergistically reduced the production of interleukin-6 and tumor necrosis factor-α by peritoneal macrophages stimulated with live E. coli. 15-Epi-lipoxin A4 combined with antibiotics attenuated systemic inflammation, inhibited bacteria dissemination, and improved survival in E. coli-infected mice. The reduced production of interleukin-6 and tumor necrosis factor-α by peritoneal macrophages suggested that 15-epi-lipoxin A4 blocked the initial proinflammatory response. Taken together, these data suggested that 15-epi-lipoxin A4 combined with antibiotics was beneficial in regulating the proinflammatory response in sepsis without exacerbating infection.

Attempt to develop live attenuated bacterial vaccines by selecting resistance to gossypol, proflavine hemisulfate, novobiocin, or ciprofloxacin

USDA-ARS?s Scientific Manuscript database

In an attempt to develop attenuated bacteria as potential live vaccines, four chemicals (gossypol, proflavine hemisulfate, novobiocin, and ciprofloxacin) were used to modify the following four genera of bacteria through chemical-resistance strategy: 1) Aeromonas hydrophila (9 isolates); 2) Edwardsie...

Attempt to develop live attenuated bacterial vaccines by selecting resistance to gossypol, proflavine hemisulfate, novobiocin, or ciprofloxacin

USDA-ARS?s Scientific Manuscript database

In an attempt to develop attenuated bacteria as potential live vaccines, four chemicals (gossypol, proflavine hemisulfate, novobiocin, and ciprofloxacin) were used to modify the following four genera of bacteria through chemical-resistance strategy: (1) Aeromonas hydrophila (9 isolates); (2) Edwards...

Efficacy of a live attenuated Edwardsiella ictaluri oral vaccine in channel and hybrid catfish

USDA-ARS?s Scientific Manuscript database

Intensive fish production systems resort to higher stocking densities and feeding rates in culture conditions to manifest suboptimal conditions to facilitate disease outbreaks leading to production losses. This study was conducted to evaluate the efficacy of an oral live-attenuated Edwardsiella ict...

A comparative study of live attenuated F strain-derived Mycoplasma gallisepticum vaccines

USDA-ARS?s Scientific Manuscript database

Commercially available attenuated strains of Mycoplasma gallisepticum (MG) are commonly used within the layer industry to control MG-induced mycoplasmosis. Among these are two live MG vaccines derived from the moderately pathogenic MG “chick F” strain. In the present study, the commercially availa...

aroA-Deficient Salmonella enterica Serovar Typhimurium Is More Than a Metabolically Attenuated Mutant

PubMed Central

Frahm, Michael; Kocijancic, Dino; Rohde, Manfred; Eckweiler, Denitsa; Bielecka, Agata; Bueno, Emilio; Cava, Felipe; Abraham, Wolf-Rainer; Curtiss, Roy; Häussler, Susanne; Erhardt, Marc; Weiss, Siegfried

2016-01-01

ABSTRACT Recombinant attenuated Salmonella enterica serovar Typhimurium strains are believed to act as powerful live vaccine carriers that are able to elicit protection against various pathogens. Auxotrophic mutations, such as a deletion of aroA, are commonly introduced into such bacteria for attenuation without incapacitating immunostimulation. In this study, we describe the surprising finding that deletion of aroA dramatically increased the virulence of attenuated Salmonella in mouse models. Mutant bacteria lacking aroA elicited increased levels of the proinflammatory cytokine tumor necrosis factor alpha (TNF-α) after systemic application. A detailed genetic and phenotypic characterization in combination with transcriptomic and metabolic profiling demonstrated that ΔaroA mutants display pleiotropic alterations in cellular physiology and lipid and amino acid metabolism, as well as increased sensitivity to penicillin, complement, and phagocytic uptake. In concert with other immunomodulating mutations, deletion of aroA affected flagellin phase variation and gene expression of the virulence-associated genes arnT and ansB. Finally, ΔaroA strains displayed significantly improved tumor therapeutic activity. These results highlight the importance of a functional shikimate pathway to control homeostatic bacterial physiology. They further highlight the great potential of ΔaroA-attenuated Salmonella for the development of vaccines and cancer therapies with important implications for host-pathogen interactions and translational medicine. PMID:27601574

Persistence of poliovirus-neutralizing antibodies 2-16 years after immunization with live attenuated vaccine. A seroepidemiologic survey in the mainland of Venice.

PubMed Central

Trivello, R.; Renzulli, G.; Farisano, G.; Bonello, C.; Moschen, M.; Gasparini, V.; Benussi, G.

1988-01-01

A seroepidemiological survey was conducted on subjects who had received a full vaccination course with live attenuated poliovirus 2-16 years before. For strains 1 and 2 prevalence of seropositives and median values dropped gradually during the first 10 years; strain 3 showed a much earlier decline. Environmental displacement of wild poliovirus by the attenuated, less immunogenic strain might eventually induce a 'gap', should complacency hamper needed vaccination efforts. PMID:2850939

Live Attenuated Influenza Vaccines by Computer-Aided Rational Design

PubMed Central

Mueller, Steffen; Coleman, J. Robert; Papamichail, Dimitris; Ward, Charles B.; Nimnual, Anjaruwee; Futcher, Bruce; Skiena, Steven; Wimmer, Eckard

2010-01-01

Influenza claims 250,000 - 500,000 lives annually worldwide. Despite existing vaccines and enormous efforts in biomedical research, these staggering numbers have not changed significantly over the last two decades1, motivating the search for new, more effective, vaccines that can be rapidly designed and easily produced. Using influenza virus strain A/PR/8/34, we describe a systematic, rational approach, termed Synthetic Attenuated Virus Engineering (SAVE), to develop new, efficacious live attenuated influenza virus vaccine candidates through genome-scale changes in codon pair bias. Attenuation is based on many hundreds of nucleotide changes across the viral genome, offering high genetic stability and a wide margin of safety. The method can be applied rapidly to any emerging influenza virus in its entirety, an advantage that is significant for dealing with seasonal epidemics and pandemic threats, such as H5N1- or 2009-H1N1 influenza. PMID:20543832

Retrofitted green roofs and walls and improvements in thermal comfort

NASA Astrophysics Data System (ADS)

Feitosa, Renato Castiglia; Wilkinson, Sara

2017-06-01

Increased urbanization has led to a worsening in the quality of life for many people living in large cities in respect of the urban heat island effect and increases of indoor temperatures in housing and other buildings. A solution may be to retrofit existing environments to their former conditions, with a combination of green infrastructures applied to existing walls and rooftops. Retrofitted green roofs may attenuate housing temperature. However, with tall buildings, facade areas are much larger compared to rooftop areas, the role of green walls in mitigating extreme temperatures is more pronounced. Thus, the combination of green roofs and green walls is expected to promote a better thermal performance in the building envelope. For this purpose, a modular vegetated system is adopted for covering both walls and rooftops. Rather than temperature itself, the heat index, which comprises the combined effect of temperature and relative humidity is used in the evaluation of thermal comfort in small scale experiments performed in Sydney - Australia, where identical timber framed structures prototypes (vegetated and non-vegetated) are compared. The results have shown a different understanding of thermal comfort improvement regarding heat index rather than temperature itself. The combination of green roof and walls has a valid role to play in heat index attenuation.

Early protection events in swine immunized with an experimental live attenuated classical swine fever marker vaccine, FlagT4G

USDA-ARS?s Scientific Manuscript database

Prophylactic vaccination using live attenuated classical swine fever (CSF) vaccines has been a very effective method to control disease in endemic regions and during outbreaks in previously disease-free areas. These vaccines confer effective protection against the disease at early times post-vaccina...

Laboratory and field investigations of wave attenuation by live marsh vegetation

USDA-ARS?s Scientific Manuscript database

Wave attenuation by live marsh vegetation was investigated experimentally in this study. Laboratory experiments were conducted in a 20.6 m long, 0.69 m wide and 1.22 m deep wave flume under regular and random waves. The vegetation species used are Spartina alterniflora and Juncus roemerianus, which ...

Development of live attenuated sparfloxacin-resistant Streptococcus agalactiae polyvalent vaccines to protect Nile tilapia

USDA-ARS?s Scientific Manuscript database

To develop attenuated bacteria as potential live vaccines, sparfloxacin was used in this study to modify 40 isolates of Streptococcus agalactiae. Majority of S. agalactiae used in this study were able to develop at least 80-fold resistance to sparfloxacin. When the virulence of the sparfloxacin-resi...

Development of live attenuated Streptococcus agalactiae as potential vaccines by selecting for resistance to sparfloxacin

USDA-ARS?s Scientific Manuscript database

To develop attenuated bacteria as potential live vaccines, sparfloxacin was used in this study to modify 40 isolates of Streptococcus agalactiae. Majority of S. agalactiae used in this study were able to develop at least 80-fold resistance to sparfloxacin. When the virulence of the sparfloxacin-resi...

Evaluation of live attenuated S79 mumps vaccine effectiveness in mumps outbreaks: a matched case-control study.

PubMed

Fu, Chuan-xi; Nie, Jun; Liang, Jian-hua; Wang, Ming

2009-02-05

Mumps virus infection is a potentially serious viral infection of childhood and early adulthood. In China, live attenuated S(79) mumps vaccine has been licensed for pediatric use since 1990. The objective of this study was to determine the effectiveness of live attenuated S(79) mumps vaccine against clinical mumps in outbreaks. Cases were selected from mumps outbreaks in schools in Guangzhou between 2004 and 2005. Each case was matched by gender, age and classroom. Vaccination information was obtained from Children's EPI Administrative Computerized System. Vaccine effectiveness (VE) was calculated for 1 or 2 doses of S(79) vaccine with 95% confidence intervals (CI). One hundred and ninety-four cases and 194 controls were enrolled into the study. VE of the S(79) mumps vaccine for 1 dose versus 0 confer protection 80.4% (95% CI, 60.0%-90.4%) and VEs against mumps in outbreaks for 1 dose of mumps vaccine are similar among those children aged 4-9 years and aged over 10 years old. The live attenuated S(79) mumps vaccine can be effective in preventing clinical mumps outbreaks.

Evaluation of the thermal stability of a novel strain of live-attenuated mumps vaccine (RS-12 strain) lyophilized in different stabilizers.

PubMed

Jamil, Razieh Kamali; Taqavian, Mohammad; Sadigh, Zohreh-Azita; Shahkarami, Mohammad-Kazem; Esna-Ashari, Fatemeh; Hamkar, Rasool; Hosseini, Seyedeh-Marzieh; Hatami, Alireza

2014-04-01

The stability of live-attenuated viral vaccines is important for immunization efficacy. Here, the thermostabilities of lyophilized live-attenuated mumps vaccine formulations in two different stabilizers, a trehalose dihydrate-based stabilizer and a stabilizer containing sucrose, human serum albumin and sorbitol were investigated using accelerated stability tests at 4°C, 25°C and 37°C at time points between 4h (every 4h for the first 24h) and 1 week. Even under the harshest storage conditions of 37°C for 1 week, the 50% cell culture infective dose (CCID50) determined from titrations in Vero cells dropped by less than 10-fold using each stabilizer formulation and thus complied with the World Health Organization's requirements for the potency of live-attenuated mumps vaccines. However, as the half-life of the RS-12 strain mumps virus infectivity was lengthened substantially at elevated temperatures using the trehalose dihydrate (TD)-based stabilizer, this stabilizer is recommended for vaccine use. Copyright © 2013 Elsevier B.V. All rights reserved.

Evaluation of the immune response in Shitou geese (Anser anser domesticus) following immunization with GPV-VP1 DNA-based and live attenuated vaccines.

PubMed

Deng, Shu-xuan; Cai, Ming-sheng; Cui, Wei; Huang, Jin-lu; Li, Mei-li

2014-01-01

Goose parvovirus (GPV) is a highly contagious and deadly disease for goslings and Muscovy ducklings. To compare the differences in immune response of geese immunized with GPV-VP1 DNA-based and live attenuated vaccines. Shitou geese were immunized once with either 20 μg pcDNA-GPV-VP1 DNA gene vaccine by gene gun bombardment via intramuscular injection, or 300 μg by i.m. injection, or 300 μL live attenuated vaccine by i.m. injection, whereas 300 μg pcDNA3.1 (+) i.m. or 300 μL saline i.m. were used as positive and negative controls, respectively. Each group comprised 28 animals. Peripheral blood samples were collected from 2-210 days after immunization and the proliferation of T lymphocytes, the number of CD4(+) and CD8(+) T cells and the level of IgG assessed. Statistical analysis was performed using a one-way analysis of variance with group multiple comparisons via Tukey's test. The pcDNA-GPV-VP1 DNA and attenuated vaccine induced cellular and humoral responses, and there were no differences between the 20 and 300 μg group in the responses of proliferation of T lymphocyte and the CD8(+) T-cell. However, as to CD4(+) T-cell response and humoral immunity, the 20 μg group performed better than the 300 μg group, which induced better cellular and humoral immunity than live attenuated vaccine. This study showed that it is possible to induce both cellular and humoral response using DNA-based vaccines and that the pcDNA-GPV-VP1 DNA gene vaccine induced better cellular and humoral immunity than live attenuated vaccine.

Evaluation of Immunostimulatory Effects of N-(2-Hydroxy) Propyl-3-Trimethylammonium Chitosan Chloride for Improving Live Attenuated Hepatitis A Virus Vaccine Efficacy.

PubMed

Tao, Wei; Fu, Ting; He, Zhuojing; Hu, Ruxi; Jia, Lan; Hong, Yan

2017-03-01

This study was to evaluate the immunostimulatory effects of N-(2-hydroxy) propyl-3-trimethylammonium chitosan chloride (HTCC) as an adjuvant for improving a commercial live attenuated hepatitis A virus (HAV) vaccine efficacy in mice. Mice in the experimental group were intraperitoneally immunized with a solution of HTCC and live attenuated HAV vaccine. And for those injected with sterile water, HTCC or live attenuated HAV vaccine were treated as mock group, negative group, and positive group in turn. The serum HAV-specific IgG titers and the ratios of the serum HAV-specific IgG2a/IgG1 in the experimental group were significantly increased (p = 0.00042 and p = 0.040, respectively). Splenocyte proliferation stimulation index in experimental group was higher than positive group (p = 0.021), and significantly higher than mock group and negative group (p = 0.0078 and p = 0.0050, respectively). The percentages of CD4 + T lymphocytes in the peripheral blood in experimental group were significantly higher than positive group, negative group, and mock group (p = 0.012, p = 0.012, and p = 0.045, respectively). Compared to the other three groups, experimental group showed a slightly higher ratio of CD4 + /CD8 + , but there were no significant differences (p > 0.05). In the percentages of CD8 + T lymphocytes, there were no significant differences among the four groups (p > 0.05). HTCC can enhance live attenuated HAV vaccine to generate stronger humoral responses and induce a Th1-biased immune response, as well as IgG2a class switching, compared with the live attenuated HAV vaccine alone. This study validated an important concept for further development of a safe and potent vaccine adjuvant.

Natural attenuation, biostimulation and bioaugmentation of landfill leachate management

NASA Astrophysics Data System (ADS)

Er, X. Y.; Seow, T. W.; Lim, C. K.; Ibrahim, Z.

2018-04-01

Landfills used for solid waste management will lead to leachate production. Proper leachate management is highly essential to be paid attention to protect the environment and living organisms’ health and safety. In this study, the remedial strategies used for leachate management were natural attenuation, biostimulation and bioaugmentation. All treatment samples were treated via 42-days combined anaerobic-aerobic treatment and the treatment efficiency was studied by measuring the removal rate of COD and ammonia nitrogen. In this study, all remedial strategies showed different degrees of contaminants removal. Lowest contaminants removal rate was achieved via bioaugmentation of B. panacihumi strain ZB1, which were 39.4% of COD and 37.6% of ammonia nitrogen removed from the leachate sample. Higher contaminants removal rate was achieved via natural attenuation and biostimulation. Native microbial population was able to remove 41% of COD and 59% of ammonia nitrogen from the leachate sample. The removal efficiency could be further improved via biostimulation to trigger microbial growth and decontamination rate. Through biostimulation, 58% of COD and 51.8% of ammonia nitrogen were removed from the leachate sample. In conclusion, natural attenuation and biostimulation should be the main choice for leachate management to avoid any unexpected impacts due to introduction of exogenous species.

A replication-deficient rabies virus vaccine expressing Ebola virus glycoprotein is highly attenuated for neurovirulence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Papaneri, Amy B.; Wirblich, Christoph; Cann, Jennifer A.

We are developing inactivated and live-attenuated rabies virus (RABV) vaccines expressing Ebola virus (EBOV) glycoprotein for use in humans and endangered wildlife, respectively. Here, we further characterize the pathogenesis of the live-attenuated RABV/EBOV vaccine candidates in mice in an effort to define their growth properties and potential for safety. RABV vaccines expressing GP (RV-GP) or a replication-deficient derivative with a deletion of the RABV G gene (RV{Delta}G-GP) are both avirulent after intracerebral inoculation of adult mice. Furthermore, RV{Delta}G-GP is completely avirulent upon intracerebral inoculation of suckling mice unlike parental RABV vaccine or RV-GP. Analysis of RV{Delta}G-GP in the brain bymore » quantitative PCR, determination of virus titer, and immunohistochemistry indicated greatly restricted virus replication. In summary, our findings indicate that RV-GP retains the attenuation phenotype of the live-attenuated RABV vaccine, and RV{Delta}G-GP would appear to be an even safer alternative for use in wildlife or consideration for human use.« less

[A case of orchitis following vaccination with freeze-dried live attenuated mumps vaccine].

PubMed

Suzuki, Masayasu; Takizawa, Akitoshi; Furuta, Akira; Yanada, Shuichi; Iwamuro, Shinya; Tashiro, Kazuya

2002-05-01

In Japan, freeze-dried live attenuated mumps vaccine has been used optionally since 1981. The effectiveness of mumps vaccination has been established by worldwide research since 1971. On the other hand, because of it's live activity several untoward effects have been reported. Vaccination-related mumps orchitis is a rare adverse effect of mumps vaccine. Only 9 cases of vaccination-related mumps orchitis have been reported in Japan. We describe a case of orchitis following mumps vaccination in adolescence. A 16 years-old male has admitted because of acute orchitis with high fever and painful swelling of right testis. The patient had received vaccination with freeze-dried live attenuated mumps vaccine 16 days before admission. After admission, the bed-rest had completely relieved the symptoms on 6th hospital day. The impaired testis has maintained normal size and consistency 6 months after discharge.

Protection Against Dengue Virus by Non-Replicating and Live Attenuated Vaccines Used Together in a Prime Boost Vaccination Strategy

DTIC Science & Technology

2010-01-01

vaccines primed rhesus maca - ques for an immune response to a tetravalent live attenuated virus (TLAV) vaccine. An initial experiment was performed in 16...and 4 and no measurable increase for DENV 1. These two experiments clearly demonstrated that rhesus maca - ques could be successfully immunized and

A novel live attenuated anthrax spore vaccine based on an acapsular Bacillus anthracis Sterne strain with mutations in the htrA, lef and cya genes.

PubMed

Chitlaru, Theodor; Israeli, Ma'ayan; Rotem, Shahar; Elia, Uri; Bar-Haim, Erez; Ehrlich, Sharon; Cohen, Ofer; Shafferman, Avigdor

2017-10-20

We recently reported the development of a novel, next-generation, live attenuated anthrax spore vaccine based on disruption of the htrA (High Temperature Requirement A) gene in the Bacillus anthracis Sterne veterinary vaccine strain. This vaccine exhibited a highly significant decrease in virulence in murine, guinea pig and rabbit animal models yet preserved the protective value of the parental Sterne strain. Here, we report the evaluation of additional mutations in the lef and cya genes, encoding for the toxin components lethal factor (LF) and edema factor (EF), to further attenuate the SterneΔhtrA strain and improve its compatibility for human use. Accordingly, we constructed seven B. anthracis Sterne-derived strains exhibiting different combinations of mutations in the htrA, cya and lef genes. The various strains were indistinguishable in growth in vitro and in their ability to synthesise the protective antigen (PA, necessary for the elicitation of protection). In the sensitive murine model, we observed a gradual increase (ΔhtrA<ΔhtrAΔcya<ΔhtrAΔlef<ΔhtrAΔlefΔcya) in attenuation - up to 10 8 -fold relative to the parental Sterne vaccine strain. Most importantly, all various SterneΔhtrA derivative strains did not differ in their ability to elicit protective immunity in guinea pigs. Immunisation of guinea pigs with a single dose (10 9 spores) or double doses (>10 7 spores) of the most attenuated triple mutant strain SterneΔhtrAlef MUT Δcya induced a robust immune response, providing complete protection against a subsequent respiratory lethal challenge. Partial protection was observed in animals vaccinated with a double dose of as few as 10 5 spores. Furthermore, protective immune status was maintained in all vaccinated guinea pigs and rabbits for at least 40 and 30weeks, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

Live vaccines for human metapneumovirus designed by reverse genetics.

PubMed

Buchholz, Ursula J; Nagashima, Kunio; Murphy, Brian R; Collins, Peter L

2006-10-01

Human metapneumovirus (HMPV) was first described in 2001 and has quickly become recognized as an important cause of respiratory tract disease worldwide, especially in the pediatric population. A vaccine against HMPV is required to prevent severe disease associated with infection in infancy. The primary strategy is to develop a live-attenuated virus for intranasal immunization, which is particularly well suited against a respiratory virus. Reverse genetics provides a means of developing highly characterized 'designer' attenuated vaccine candidates. To date, several promising vaccine candidates have been developed, each using a different mode of attenuation. One candidate involves deletion of the G glycoprotein, providing attenuation that is probably based on reduced efficiency of attachment. A second candidate involves deletion of the M2-2 protein, which participates in regulating RNA synthesis and whose deletion has the advantageous property of upregulating transcription and increasing antigen synthesis. A third candidate involves replacing the P protein gene of HMPV with its counterpart from the related avian metapneumovirus, thereby introducing attenuation owing to its chimeric nature and host range restriction. Another live vaccine strategy involves using an attenuated parainfluenza virus as a vector to express HMPV protective antigens, providing a bivalent pediatric vaccine. Additional modifications to provide improved vaccines will also be discussed.

Attenuation of the influenza virus by microRNA response element in vivo and protective efficacy against 2009 pandemic H1N1 virus in mice.

PubMed

Feng, Chunlai; Tan, Mingming; Sun, Wenkui; Shi, Yi; Xing, Zheng

2015-09-01

The 2009 influenza pandemics underscored the need for effective vaccines to block the spread of influenza virus infection. Most live attenuated vaccines utilize cold-adapted, temperature-sensitive virus. An alternative to live attenuated virus is presented here, based on microRNA-induced gene silencing. In this study, miR-let-7b target sequences were inserted into the H1N1 genome to engineer a recombinant virus - miRT-H1N1. Female BALB/c mice were vaccinated intranasally with the miRT-H1N1 and challenged with a lethal dose of homologous virus. This miRT-H1N1 virus was attenuated in mice, while it exhibited wild-type characteristics in chicken embryos. Mice vaccinated intranasally with the miRT-H1N1 responded with robust immunity that protected the vaccinated mice from a lethal challenge with the wild-type 2009 pandemic H1N1 virus. These results indicate that the influenza virus containing microRNA response elements (MREs) is attenuated in vivo and can be used to design a live attenuated vaccine. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

A Bivalent Typhoid Live Vector Vaccine Expressing both Chromosome- and Plasmid-Encoded Yersinia pestis Antigens Fully Protects against Murine Lethal Pulmonary Plague Infection

PubMed Central

Wang, Jin Yuan; Carrasco, Jose A.; Lloyd, Scott A.; Mellado-Sanchez, Gabriela; Diaz-McNair, Jovita; Franco, Olga; Buskirk, Amanda D.; Nataro, James P.; Pasetti, Marcela F.

2014-01-01

Live attenuated bacteria hold great promise as multivalent mucosal vaccines against a variety of pathogens. A major challenge of this approach has been the successful delivery of sufficient amounts of vaccine antigens to adequately prime the immune system without overattenuating the live vaccine. Here we used a live attenuated Salmonella enterica serovar Typhi strain to create a bivalent mucosal plague vaccine that produces both the protective F1 capsular antigen of Yersinia pestis and the LcrV protein required for secretion of virulence effector proteins. To reduce the metabolic burden associated with the coexpression of F1 and LcrV within the live vector, we balanced expression of both antigens by combining plasmid-based expression of F1 with chromosomal expression of LcrV from three independent loci. The immunogenicity and protective efficacy of this novel vaccine were assessed in mice by using a heterologous prime-boost immunization strategy and compared to those of a conventional strain in which F1 and LcrV were expressed from a single low-copy-number plasmid. The serum antibody responses to lipopolysaccharide (LPS) induced by the optimized bivalent vaccine were indistinguishable from those elicited by the parent strain, suggesting an adequate immunogenic capacity maintained through preservation of bacterial fitness; in contrast, LPS titers were 10-fold lower in mice immunized with the conventional vaccine strain. Importantly, mice receiving the optimized bivalent vaccine were fully protected against lethal pulmonary challenge. These results demonstrate the feasibility of distributing foreign antigen expression across both chromosomal and plasmid locations within a single vaccine organism for induction of protective immunity. PMID:25332120

Safety and tolerability of a live oral Salmonella typhimurium vaccine candidate in SIV-infected nonhuman primates.

PubMed

Ault, Alida; Tennant, Sharon M; Gorres, J Patrick; Eckhaus, Michael; Sandler, Netanya G; Roque, Annelys; Livio, Sofie; Bao, Saran; Foulds, Kathryn E; Kao, Shing-Fen; Roederer, Mario; Schmidlein, Patrick; Boyd, Mary Adetinuke; Pasetti, Marcela F; Douek, Daniel C; Estes, Jacob D; Nabel, Gary J; Levine, Myron M; Rao, Srinivas S

2013-12-02

Nontyphoidal Salmonella (NTS) serovars are a common cause of acute food-borne gastroenteritis worldwide and can cause invasive systemic disease in young infants, the elderly, and immunocompromised hosts, accompanied by high case fatality. Vaccination against invasive NTS disease is warranted where the disease incidence and mortality are high and multidrug resistance is prevalent, as in sub-Saharan Africa. Live-attenuated vaccines that mimic natural infection constitute one strategy to elicit protection. However, they must particularly be shown to be adequately attenuated for consideration of immunocompromised subjects. Accordingly, we examined the safety and tolerability of an oral live attenuated Salmonella typhimurium vaccine candidate, CVD 1921, in an established chronic simian immunodeficiency virus (SIV)-infected rhesus macaque model. We evaluated clinical parameters, histopathology, and measured differences in mucosal permeability to wild-type and vaccine strains. Compared to the wild-type S. typhimurium strain I77 in both SIV-infected and SIV-uninfected nonhuman primate hosts, this live-attenuated vaccine shows reduced shedding and systemic spread, exhibits limited pathological disease manifestations in the digestive tract, and induces low levels of cellular infiltration in tissues. Furthermore, wild-type S. typhimurium induces increased intestinal epithelial damage and permeability, with infiltration of neutrophils and macrophages in both SIV-infected and SIV-uninfected nonhuman primates compared to the vaccine strain. Based on shedding, systemic spread, and histopathology, the live-attenuated S. typhimurium strain CVD 1921 appears to be safe and well-tolerated in the nonhuman primate model, including chronically SIV-infected rhesus macaques. Copyright © 2013. Published by Elsevier Ltd.

Temperature-sensitive mutations for live-attenuated Rift Valley fever vaccines: implications from other RNA viruses

PubMed Central

Nishiyama, Shoko; Ikegami, Tetsuro

2015-01-01

Rift Valley fever (RVF) is a mosquito-borne zoonotic disease endemic to the African continent. RVF is characterized by high rate of abortions in ruminants and hemorrhagic fever, encephalitis, or blindness in humans. RVF is caused by the Rift Valley fever virus (RVFV: genus Phlebovirus, family Bunyaviridae). Vaccination is the only known effective strategy to prevent the disease, but there are no licensed RVF vaccines available for humans. A live-attenuated vaccine candidate derived from the wild-type pathogenic Egyptian ZH548 strain, MP-12, has been conditionally licensed for veterinary use in the U.S. MP-12 displays a temperature-sensitive (ts) phenotype and does not replicate at 41°C. The ts mutation limits viral replication at a specific body temperature and may lead to an attenuation of the virus. Here we will review well-characterized ts mutations for RNA viruses, and further discuss the potential in designing novel live-attenuated vaccines for RVF. PMID:26322023

Live attenuated measles vaccine expressing HIV-1 Gag virus like particles covered with gp160DELTAV1V2 is strongly immunogenic

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guerbois, Mathilde; Moris, Arnaud; Combredet, Chantal

Although a live attenuated HIV vaccine is not currently considered for safety reasons, a strategy inducing both T cells and neutralizing antibodies to native assembled HIV-1 particles expressed by a replicating virus might mimic the advantageous characteristics of live attenuated vaccine. To this aim, we generated a live attenuated recombinant measles vaccine expressing HIV-1 Gag virus-like particles (VLPs) covered with gp160DELTAV1V2 Env protein. The measles-HIV virus replicated efficiently in cell culture and induced the intense budding of HIV particles covered with Env. In mice sensitive to MV infection, this recombinant vaccine stimulated high levels of cellular and humoral immunity tomore » both MV and HIV with neutralizing activity. The measles-HIV virus infected human professional antigen-presenting cells, such as dendritic cells and B cells, and induced efficient presentation of HIV-1 epitopes and subsequent activation of human HIV-1 Gag-specific T cell clones. This candidate vaccine will be next tested in non-human primates. As a pediatric vaccine, it might protect children and adolescents simultaneously from measles and HIV.« less

Developing live vaccines against Yersinia pestis

PubMed Central

Sun, Wei; Roland, Kenneth L.; Curtiss, Roy

2014-01-01

Three great plague pandemics caused by the gram-negative bacterium Yersinia pestis have killed nearly 200 million people and it has been linked to biowarfare in the past. Plague is endemic in many parts of the world. In addition, the risk of plague as a bioweapon has prompted increased research to develop plague vaccines against this disease. Injectable subunit vaccines are being developed in the United States and United Kingdom. However, the live attenuated Y. pestis-EV NIIEG strain has been used as a vaccine for more than 70 years in the former Soviet Union and in some parts of Asia and provides a high degree of efficacy against plague. This vaccine has not gained general acceptance because of safety concerns. In recent years, modern molecular biological techniques have been applied to Y. pestis to construct strains with specific defined mutations designed to create safe, immunogenic vaccines with potential for use in humans and as bait vaccines to reduce the load of Y. pestis in the environment. In addition, a number of live, vectored vaccines have been reported using attenuated viral vectors or attenuated Salmonella strains to deliver plague antigens. Here we summarize the progress of live attenuated vaccines against plague. PMID:21918302

Type III Interferon-Mediated Signaling Is Critical for Controlling Live Attenuated Yellow Fever Virus Infection In Vivo.

PubMed

Douam, Florian; Soto Albrecht, Yentli E; Hrebikova, Gabriela; Sadimin, Evita; Davidson, Christian; Kotenko, Sergei V; Ploss, Alexander

2017-08-15

Yellow fever virus (YFV) is an arthropod-borne flavivirus, infecting ~200,000 people worldwide annually and causing about 30,000 deaths. The live attenuated vaccine strain, YFV-17D, has significantly contributed in controlling the global burden of yellow fever worldwide. However, the viral and host contributions to YFV-17D attenuation remain elusive. Type I interferon (IFN-α/β) signaling and type II interferon (IFN-γ) signaling have been shown to be mutually supportive in controlling YFV-17D infection despite distinct mechanisms of action in viral infection. However, it remains unclear how type III IFN (IFN-λ) integrates into this antiviral system. Here, we report that while wild-type (WT) and IFN-λ receptor knockout (λR -/- ) mice were largely resistant to YFV-17D, deficiency in type I IFN signaling resulted in robust infection. Although IFN-α/β receptor knockout (α/βR -/- ) mice survived the infection, mice with combined deficiencies in both type I signaling and type III IFN signaling were hypersusceptible to YFV-17D and succumbed to the infection. Mortality was associated with viral neuroinvasion and increased permeability of the blood-brain barrier (BBB). α/βR -/- λR -/- mice also exhibited distinct changes in the frequencies of multiple immune cell lineages, impaired T-cell activation, and severe perturbation of the proinflammatory cytokine balance. Taken together, our data highlight that type III IFN has critical immunomodulatory and neuroprotective functions that prevent viral neuroinvasion during active YFV-17D replication. Type III IFN thus likely represents a safeguard mechanism crucial for controlling YFV-17D infection and contributing to shaping vaccine immunogenicity. IMPORTANCE YFV-17D is a live attenuated flavivirus vaccine strain recognized as one of the most effective vaccines ever developed. However, the host and viral determinants governing YFV-17D attenuation and its potent immunogenicity are still unknown. Here, we analyzed the role of type III interferon (IFN)-mediated signaling, a host immune defense mechanism, in controlling YFV-17D infection and attenuation in different mouse models. We uncovered a critical role of type III IFN-mediated signaling in preserving the integrity of the blood-brain barrier and preventing viral brain invasion. Type III IFN also played a major role in regulating the induction of a potent but balanced immune response that prevented viral evasion of the host immune system. An improved understanding of the complex mechanisms regulating YFV-17D attenuation will provide insights into the key virus-host interactions that regulate host immune responses and infection outcomes as well as open novel avenues for the development of innovative vaccine strategies. Copyright © 2017 Douam et al.

Enrollment in YFV Vaccine Trial: An Evaluation of Recruitment Outcomes Associated with a Randomized Controlled Double-Blind Trial of a Live Attenuated Yellow Fever Vaccine.

PubMed

Frew, Paula M; Shapiro, Eve T; Lu, Lu; Edupuganti, Srilatha; Keyserling, Harry L; Mulligan, Mark J

2013-04-15

This investigation evaluated several factors associated with diverse participant enrollment of a clinical trial assessing safety, immunogenicity, and comparative viremia associated with administration of 17-D live, attenuated yellow fever vaccine given alone or in combination with human immune globulin. We obtained baseline participant information (e.g., sociodemographic, medical) and followed recruitment outcomes from 2005 to 2007. Of 355 potential Yellow Fever vaccine study participants, 231 cases were analyzed. Strong interest in study participation was observed among racial and ethnically diverse persons with 36.34% eligible following initial study screening, resulting in 18.75% enrollment. The percentage of white participants increased from 63.66% (prescreened sample) to 81.25% (enrollment group). The regression model was significant with white race as a predictor of enrollment (OR=2.744, 95% CI=1.415-5.320, p=0.003).In addition, persons were more likely to enroll via direct outreach and referral mechanisms compared to mass advertising (OR=2.433, 95% CI=1.102-5.369). The findings indicate that racially diverse populations can be recruited to vaccine clinical trials, yet actual enrollment may not reflect that diversity.

A review of immunogenicity and tolerability of live attenuated Hepatitis A vaccine in children.

PubMed

Rao, Sameer; Mao, J S; Motlekar, Salman; Fangcheng, Zhuang; Kadhe, Ganesh

2016-12-01

Changing epidemiology of Hepatitis A virus (HAV) has led to an increased susceptibility of adolescents and adults to the infection. Vaccination can remarkably reduce the incidence and associated morbidity of HAV infection. This review is focused on the safety and efficacy of H2 strain derived live attenuated Hepatitis A vaccine. We found the vaccine to be highly immunogenic with minimal or negligible safety issues. Moreover, a single dose of live attenuated vaccine persists a long term immune response and can be a preferred option for developing countries. In 2014, Indian Academy of Paediatrics (IAP) also updated their recommendations for H2 vaccine as a single dose as against the previous 2 dose schedule. A focused approach to include the vaccine in national immunization program should be explored.

Vaccination with recombinant Modified Vaccinia Ankara (MVA) viruses expressing single African horse sickness virus VP2 antigens induced cross-reactive virus neutralising antibodies (VNAb) in horses when administered in combination.

PubMed

Manning, Nicola Mary; Bachanek-Bankowska, Katarzyna; Mertens, Peter Paul Clement; Castillo-Olivares, Javier

2017-10-20

African horse sickness is a lethal viral disease of equids transmitted by biting midges of the Genus Culicoides. The disease is endemic to sub-Saharan Africa but outbreaks of high mortality and economic impact have occurred in the past in non-endemic regions of Africa, Asia and Southern Europe. Vaccination is critical for the control of this disease but only live attenuated vaccines are currently available. However, there are bio-safety concerns over the use of this type of vaccines, especially in non-endemic countries, and live attenuated vaccines do not have DIVA (Differentiation of Infected from Vaccinated Animals) capacity. In addition, large scale manufacturing of live attenuated vaccines of AHSV represents a significant environmental and health risk and level 3 bio-safety containment facilities are required for their production. A variety of different technologies have been investigated over the years to develop alternative AHSV vaccines, including the use of viral vaccine vectors such Modified Vaccinia Ankara virus (MVA). In previous studies we demonstrated that recombinant MVA expressing outer capsid protein AHSV-VP2 induced virus neutralising antibodies and protection against virulent challenge both in a mouse model and in the horse. However, AHSV-VP2 is antigenically variable and determines the existence of 9 different AHSV serotypes. Immunity against AHSV is serotype-specific and there is limited cross-reactivity between certain AHSV serotypes: 1 and 2, 3 and 7, 5 and 8, 6 and 9. In Africa, multiple serotypes circulate simultaneously and a polyvalent attenuated vaccine comprising different AHSV serotypes is used. We investigated the potential of a polyvalent AHSV vaccination strategy based on combinations of MVA-VP2 viruses each expressing a single VP2 antigen from a specific serotype. We showed that administration of 2 different recombinant MVA viruses, each expressing a single VP2 protein from AHSV serotype 4 or 9, denoted respectively as MVA-VP2(4) and MVA-VP2(9), induced virus neutralising antibodies against the homologous AHSV serotypes. Vaccination was more efficient when vaccines were administered simultaneously than when they were administered sequentially. A third and fourth dose of a different MVA expressing VP2 of AHSV serotype 5, given 4months later to ponies previously vaccinated with MVA-VP2(4) and MVA-VP2(9), resulted in the induction of VNAb against serotypes 4, 5, 6, 8 and 9. The anamnestic antibody response against AHSV 9 and AHSV 4 following the MVA-VP2(5) boost suggests that it is possible some shared epitopes exist between different serotypes. In conclusion this study showed that it is feasible to develop a polyvalent AHSV vaccination regime based on the use of combinations of MVA-VP2 viruses. Copyright © 2017. Published by Elsevier Ltd.

Methyl tert‐butyl ether degradation in the unsaturated zone and the relation between MTBE in the atmosphere and shallow groundwater

USGS Publications Warehouse

Baehr, Arthur L.; Charles, Emmanuel G.; Baker, Ronald J.

2001-01-01

Atmospheric methyl tert‐butyl ether (MTBE) concentrations in southern New Jersey generally exceeded concentrations in samples taken from the unsaturated zone. A simple unsaturated zone transport model indicates that MTBE degradation can explain the attenuation with half‐lives from a few months to a couple of years. Tert‐butyl alcohol (TBA), a possible degradation product of MTBE, was detected in unsaturated‐zone samples at concentrations exceeding atmospheric levels at some sites, suggesting the possible conversion of MTBE to TBA. At sites where MTBE was detected in shallow groundwater, the concentration was typically higher than the overlying unsaturated‐zone concentration. This observation is consistent with outgassing from the aquifer and combined with the unsaturated‐zone attenuation suggests some of the MTBE detections in shallow groundwater are nonatmospheric in origin, coming from leaking tanks, road runoff, or other sources. The identification of sources of MTBE in groundwater and attenuation mechanisms through the hydrologic cycle is critical in developing an understanding of the long‐term effect of MTBE releases.

An Overview of Live Attenuated Recombinant Pseudorabies Viruses for Use as Novel Vaccines

PubMed Central

Dong, Bo; Zarlenga, Dante S.; Ren, Xiaofeng

2014-01-01

Pseudorabies virus (PRV) is a double-stranded, DNA-based swine virus with a genome approximating 150 kb in size. PRV has many nonessential genes which can be replaced with genes encoding heterologous antigens but without deleterious effects on virus propagation. Recombinant PRVs expressing both native and foreign antigens are able to stimulate immune responses. In this paper, we review the current status of live attenuated recombinant PRVs and live PRV-based vector vaccines with potential for controlling viral infections in animals. PMID:24995348

Attenuation of Marek's disease virus by codon pair deoptimization of a core gene

USDA-ARS?s Scientific Manuscript database

Marek’s disease virus (MDV) is an oncogenic alphaherpesvirus of Gallus gallus, the domesticated chicken. Control strategies rely upon comprehensive vaccination in ovo with live attenuated virus vaccines consisting of antigenically similar avian herpesviruses or attenuated strains of MDV. Recent stud...

A systematic review of human-to-human transmission of measles vaccine virus.

PubMed

Greenwood, Kathryn P; Hafiz, Radwan; Ware, Robert S; Lambert, Stephen B

2016-05-17

Measles is one of the most contagious human diseases. Administration of the live attenuated measles vaccine has substantially reduced childhood mortality and morbidity since its licensure in 1963. The live but attenuated form of the vaccine describes a virus poorly adapted to replicating in human tissue, but with a replication yield sufficient to elicit an immune response for long-term protection. Given the high transmissibility of the wild-type virus and that transmission of other live vaccine viruses has been documented, we conducted a systematic review to establish if there is any evidence of human-to-human transmission of the live attenuated measles vaccine virus. We reviewed 773 articles for genotypic confirmation of a vaccine virus transmitted from a recently vaccinated individual to a susceptible close contact. No evidence of human-to-human transmission of the measles vaccine virus has been reported amongst the thousands of clinical samples genotyped during outbreaks or endemic transmission and individual case studies worldwide. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Evaluation on the effect of immunization and safety of live attenuated and inactivated hepatitis A vaccine in China].

PubMed

Li, Hui; Zhang, Xiao-shu; An, Jing

2013-01-01

To evaluate the safety of both domestic live attenuated and inactivated hepatitis A vaccines, and to provide reference for emergent vaccination after hepatitis A outbreaks. 493 children aged 6 - 9 with negative antibody to HAV (produced by Abbott) were randomly divided into four groups as vaccinated with domestic live attenuated hepatitis A vaccine (Group A), domestic inactivated hepatitis A vaccine (Group B), imported inactivated hepatitis A vaccine (Group C) and hepatitis B vaccine (Group D) respectively. Adverse events following the immunization were observed 30 minutes, 24, 48 and 72 hours after the vaccination, under double-blind method. The main AEFIs were: fever, local pain and scleroma but no other severe AEFIs were observed. The rates of AEFIs were 13.95% in Group A, 15.25% in group B, 16.80% in group C and 25.62% in group D, with no statistical differences between these groups (χ(2) = 6.953, P > 0.05). 2 weeks after the vaccination, the positive conversion rates of domestic live attenuated hepatitis A vaccine and domestic inactivated hepatitis A vaccine were 85.0% and 94.59% respectively. The rate of domestic inactivated hepatitis A vaccine reached 100% at 4 weeks after the vaccination. The antibody levels of HAV-IgG of Group A and B in 2, 4 and 12 weeks of vaccination and of Group C were higher than that of Group D. After 12 weeks of vaccination, the antibody level of group B became higher than it was Group C. There were no differences on safety among domestic live attenuated hepatitis A vaccine, domestic inactivated hepatitis A vaccine or imported inactivated hepatitis A vaccine under routine or emergency vaccination. All the vaccines showed satisfactory effects.

A review of immunogenicity and tolerability of live attenuated Hepatitis A vaccine in children

PubMed Central

Rao, Sameer; Mao, J. S.; Motlekar, Salman; Fangcheng, Zhuang; Kadhe, Ganesh

2016-01-01

ABSTRACT Changing epidemiology of Hepatitis A virus (HAV) has led to an increased susceptibility of adolescents and adults to the infection. Vaccination can remarkably reduce the incidence and associated morbidity of HAV infection. This review is focused on the safety and efficacy of H2 strain derived live attenuated Hepatitis A vaccine. We found the vaccine to be highly immunogenic with minimal or negligible safety issues. Moreover, a single dose of live attenuated vaccine persists a long term immune response and can be a preferred option for developing countries. In 2014, Indian Academy of Paediatrics (IAP) also updated their recommendations for H2 vaccine as a single dose as against the previous 2 dose schedule. A focused approach to include the vaccine in national immunization program should be explored. PMID:27532370

Preliminary development of a live attenuated canine parvovirus vaccine from an isolate of British origin.

PubMed

Churchill, A E

1987-04-04

Canine parvovirus isolated from a case of haemorrhagic enteritis in a breeding kennel in England was passaged and cloned in cultured feline and canine cells. No significant evidence of pathogenicity was found during six serial passages of the modified virus back through young dogs. The attenuated virus was excreted by inoculated animals and spread rapidly to uninoculated animals held in contact. When high titre attenuated virus was given to the six-week-old offspring of a seropositive dam a prompt seroconversion was observed. When the attenuated virus was used as an experimental vaccine in 108 pups in an infected breeding colony a highly significant improvement was obtained in the accumulated morbidity and mortality compared with a parallel group vaccinated with modified live feline panleucopenia virus.

Dose-response assessment for influenza A virus based on data sets of infection with its live attenuated reassortants.

PubMed

Watanabe, Toru; Bartrand, Timothy A; Omura, Tatsuo; Haas, Charles N

2012-03-01

Reported data sets on infection of volunteers challenged with wild-type influenza A virus at graded doses are few. Alternatively, we aimed at developing a dose-response assessment for this virus based on the data sets for its live attenuated reassortants. Eleven data sets for live attenuated reassortants that were fit to beta-Poisson and exponential dose-response models. Dose-response relationships for those reassortants were characterized by pooling analysis of the data sets with respect to virus subtype (H1N1 or H3N2), attenuation method (cold-adapted or avian-human gene reassortment), and human age (adults or children). Furthermore, by comparing the above data sets to a limited number of reported data sets for wild-type virus, we quantified the degree of attenuation of wild-type virus with gene reassortment and estimated its infectivity. As a result, dose-response relationships of all reassortants were best described by a beta-Poisson model. Virus subtype and human age were significant factors determining the dose-response relationship, whereas attenuation method affected only the relationship of H1N1 virus infection to adults. The data sets for H3N2 wild-type virus could be pooled with those for its reassortants on the assumption that the gene reassortment attenuates wild-type virus by at least 63 times and most likely 1,070 times. Considering this most likely degree of attenuation, 10% infectious dose of H3N2 wild-type virus for adults was estimated at 18 TCID50 (95% CI = 8.8-35 TCID50). The infectivity of wild-type H1N1 virus remains unknown as the data set pooling was unsuccessful. © 2011 Society for Risk Analysis.

Attempt to develop live attenuated bacterial vaccines by selecting resistance to gossypol, proflavine hemisulfate, novobiocin, or ciprofloxacin.

PubMed

Pridgeon, Julia W; Klesius, Phillip H; Yildirim-Aksoy, Mediha

2013-04-26

In an attempt to develop attenuated bacteria as potential live vaccines, four chemicals (gossypol, proflavine hemisulfate, novobiocin, and ciprofloxacin) were used to modify the following four genera of bacteria through chemical-resistance strategy: (1) Aeromonas hydrophila (9 isolates); (2) Edwardsiella tarda (9 isolates); (3) Streptococcus iniae (9 isolates); and (4) S. agalactiae (11 isolates). All bacteria used in this study were able to develop high resistance to gossypol. However, only some bacteria were able to develop resistance to proflavine hemisulfate, novobiocin, or ciprofloxacin. When the virulence of resistant bacteria was tested in tilapia or catfish, none of the gossypol-resistant isolate was attenuated, whereas majority of the proflavine hemisulfate-resistant isolates were attenuated. However, all proflavine hemisulfate-attenuated bacteria failed to provide significant protection to fish. Eight novobiocin- or ciprofloxacin-resistant Gram-positive bacteria (S. agalactiae and S. inaie) were found to be attenuated. However, none of them offered protection higher than 70%. Of seven attenuated novobiocin- or ciprofloxacin-resistant Gram-negative isolates (A. hydrophila and E. tarda), only one (novobiocin-resistant E. tarda 30305) was found to safe and highly efficacious. When E. tarda 30305-novo vaccinated Nile tilapia were challenged by its virulent E. tarda 30305, relative percent of survival of vaccinated fish at 14- and 28-days post vaccination (dpv) was 100% and 92%, respectively. Similarly, E. tarda 30305-novo offered 100% protection to channel catfish against challenges with virulent parent isolate E. tarda 30305 at both 14- and 28-dpv. Our results suggest that the development of live attenuated bacterial vaccines that are safe and efficacious is challenging, although it is feasible. Published by Elsevier Ltd.

Applications and challenges of multivalent recombinant vaccines

PubMed Central

Naim, Hussein Y.

2013-01-01

The exceptional discoveries of antigen/gene delivery systems have allowed the development of novel prophylactic and therapeutic vaccine candidates. The vaccine candidates employ various antigen-delivery systems, particularly recombinant viral vectors. Recombinant viral vectors are experimental vaccines similar to DNA vaccines, but they use attenuated viruses or bacterium as a carrier “vector” to introduce microbial DNA to cells of the body. They closely mimic a natural infection and therefore can efficiently stimulate the immune system. Although such recombinant vectors may face extensive preclinical testing and will possibly have to meet stringent regulatory requirements, some of these vectors (e.g. measles virus vectors) may benefit from the profound industrial and clinical experience of the parent vaccine. Most notably, novel vaccines based on live attenuated viruses combine the induction of broad, strong and persistent immune responses with acceptable safety profiles. We assess certain technologies in light of their use against human immunodeficiency virus (HIV). PMID:23249651

Outbreak and genotyping of canine distemper virus in captive Siberian tigers and red pandas.

PubMed

Zhang, He; Shan, Fen; Zhou, Xia; Li, Bing; Zhai, Jun-Qiong; Zou, Shu-Zhan; Wu, Meng-Fan; Chen, Wu; Zhai, Shao-Lun; Luo, Man-Lin

2017-08-15

In this study, four canine distemper virus (CDV) strains were isolated from captive Siberian tigers (Panthera tigris altaica) and red pandas (Ailurus fulgens) during two separate CDV outbreaks in a zoo in Guangdong province, China. Sequence alignment and phylogenetic analyses based on the full-length hemagglutinin (H) and fusion (F) genes showed that they were closely identical to genotype Asia-1. Prior to confirmation of CDV in Siberian tigers, to control spread of the disease, a live attenuated combination CDV vaccine was used among almost all carnivore animals except for red pandas in which another recombinant combination CDV vaccine was used. However, about two months later, CDV re-emerged and caused the death among red pandas. Based on the vaccination records, the live combination vaccine could be considered an ideal weapon against CDV in zoo carnivore animals. Although the recombinant combination CDV vaccine was safe for red pandas, its protection effectiveness remains to be further investigated. Moreover, according to the outbreak interval time and sequence characterization, we suspected that stray cats circulating in the zoo were the intermediate host, which contributed to CDV spread from stray dogs to zoo animals. This study revealed the importance of vaccination and biosecurity for zoo animals.

Clinical experience with respiratory syncytial virus vaccines.

PubMed

Piedra, Pedro A

2003-02-01

Respiratory syncytial virus (RSV) infection is at times associated with life-threatening lower respiratory tract illness in infancy. Severe infection during the first year of life may be an important risk factor or indicator for the development of asthma in early childhood. Severe infections primarily occur in healthy infants, and young infants and children with specific risk factors. However, RSV causes respiratory infections in all age groups. Indeed it is now recognized that RSV disease is responsible for significant morbidity and mortality in the geriatric population. RSV infection remains difficult to treat, and prevention is a worldwide goal. For this reason there has been an intensive effort to develop an effective and safe RSV vaccine. Initial infection with RSV affords limited protection to reinfection, yet repeated episodes decrease the risk for lower respiratory tract illness. In the 20 years from 1960 to 1980, trials of several candidate RSV vaccines failed to attain the desired safety and protection against natural infection. Some vaccine types either failed to elicit immunogenicity, as with the live subcutaneous vaccine, or resulted in exaggerated disease on natural exposure to the virus, as with the formalin-inactivated (FI) type. Currently vaccine candidates are being developed based on the molecular virology of RSV. Recent formulations of candidate RSV vaccines have focused on subunit vaccines [such as purified fusion protein (PFP)], subunit vaccines combined with nonspecific immune activating adjuvants, live attenuated vaccines (including cold passaged, temperature-sensitive or cpts mutants), genetically engineered live attenuated vaccines and polypeptide vaccines.

Vaccination in paediatric patients with auto-immune rheumatic diseases: a systemic literature review for the European League against Rheumatism evidence-based recommendations.

PubMed

Heijstek, M W; Ott de Bruin, L M; Borrow, R; van der Klis, F; Koné-Paut, I; Fasth, A; Minden, K; Ravelli, A; Abinun, M; Pileggi, G; Borte, M; Bijl, M; Wulffraat, N M

2011-12-01

To analyze available evidence on vaccinations in paediatric patients with rheumatic and autoinflammatory diseases. This evidence formed the basis of the recently constructed European League against Rheumatism (EULAR) recommendations for vaccination of these patients. A systematic literature review in the MEDLINE and EMBASE databases was conducted using various terms for vaccinations, paediatric rheumatic and autoinflammatory diseases and immunosuppressive drugs. Only papers on paediatric patients (<18 years of age) were selected. A panel of 13 experts in the field graded methodological quality and extracted data using predefined criteria. 27 papers were available. No studies were found on autoinflammatory diseases. 14 studies considered live-attenuated vaccines. Evidence so far supports the safety and immunogenicity of non-live composite vaccines, although studies were underpowered to accurately assess safety. Live-attenuated vaccines did not cause disease flares or severe adverse events, not even in patients on methotrexate and low dose glucocorticosteroids. Seven patients on anti-TNFalpha therapy were described receiving the live-attenuated measles, mumps, rubella (n=5) or varicella (n=2) booster without severe adverse events. Data on safety and efficacy of vaccinations in paediatric patients with rheumatic diseases is reassuring, but too limited to draw definite conclusions. More research is needed on the safety and efficacy of especially live-attenuated vaccines in patients with rheumatic and autoinflammatory diseases using high dose immunosuppressive drugs. Copyright © 2011 Elsevier B.V. All rights reserved.

Comparison of the immune responses in BALB/c mice following immunization with DNA-based and live attenuated vaccines delivered via different routes.

PubMed

Cai, Ming-sheng; Deng, Shu-xuan; Li, Mei-li

2013-02-18

The objective of this study was to compare immune responses induced in BALB/c mice following immunization with pcDNA-GPV-VP2 DNA by gene gun bombardment (6 μg) or by intramuscular (im) injection (100 μg) with the responses to live attenuated vaccine by im injection (100 μl). pcDNA3.1 (+) and physiological saline were used as controls. Peripheral blood samples were collected at 3, 7, 14, 21, 28, 35, 49, 63, 77 and 105 d after immunization. T lymphocyte proliferation was analyzed by MTT assay and enumeration of CD4(+), and CD8(+) T cell populations in peripheral blood was performed by flow cytometric analysis. Indirect ELISA was used to detect IgG levels. Cellular and humoral responses were induced by pcDNA-GPV-VP2 DNA and live virus vaccines. No differences were observed in T cell proliferation and CD8(+) T cell responses induced by the genetic vaccine regardless of the route of delivery. However, CD4(+) T cell responses and humoral immunity were enhanced in following gene gun immunization compared with im injection of the genetic vaccine. Cellular and humoral immunity was enhanced in following gene gun delivery of the genetic vaccine compared with the live attenuated vaccine. In conclusion, the pcDNA-GPV-VP2 DNA vaccine induced enhanced cellular and humoral immunity compared with that induced by the live attenuated vaccine. Copyright © 2012 Elsevier Ltd. All rights reserved.

Evolutionary characteristics of morbilliviruses during serial passages in vitro: Gradual attenuation of virus virulence.

PubMed

Liu, Fuxiao; Wu, Xiaodong; Li, Lin; Zou, Yanli; Liu, Shan; Wang, Zhiliang

2016-08-01

The genus Morbillivirus is classified into the family Paramyxoviridae, and is composed of 6 members, namely measles virus (MV), rinderpest virus (RPV), peste-des-petits-ruminants virus (PPRV), canine distemper virus (CDV), phocine distemper virus (PDV) and cetacean morbillivirus (CeMV). The MV, RPV, PPRV and CDV have been successfully attenuated through their serial passages in vitro for the production of live vaccines. It has been demonstrated that the morbilliviral virulence in animals was progressively attenuated with their consecutive passages in vitro. However, only a few reports were involved in explanation of an attenuation-related mechanism on them until many years after the establishment of a quasispecies theory. RNA virus quasispecies arise from rapid evolution of viruses with high mutation rate during genomic replication, and play an important role in gradual loss of viral virulence by serial passages. Here, we overviewed the development of live-attenuated vaccine strains against morbilliviruses by consecutive passages in vitro, and further discussed a related mechanism concerning the relationship between virulence attenuation and viral evolution. Copyright © 2016 Elsevier Ltd. All rights reserved.

Stinging nettle and neem enhance antibody response to local killed and imported live infectious bursal disease vaccines in indigenous chicken in Kenya.

PubMed

Bwana, M O; Njagi, L W; Nyaga, P N; Mbuthia, P G; Bebora, L C; Wahome, M W; Mutinda, W U; Kitala, P M

2018-02-01

Immune responses are critical for protection of chickens from infectious bursal disease (IBD). In this study, the antibody response-enhancing effect of drinking water supplementation of 1% stinging nettle and neem on different IBD vaccines and vaccination regimes was evaluated, using 36 (n = 36) specific antibody negative indigenous chicks. The birds were allocated into 3 groups as follows: 1A-C, 2A-C, and 3A-B, while group 3C acted as the unvaccinated non-supplemented control. A local inactivated K1 and imported live attenuated D78 IBD vaccines were given to groups 1A-C and 3A-B at 14 and 28 d of age, respectively. A combination of K1 and D78 vaccines was given 30 d apart to groups 2A and 2B (D78 at 14 and 21 d and K1 at 44 d of age) and on the same d to group 2C at 14 and 28 d of age. Stinging nettle was given in water to groups 1B, 2B, and 2C, and neem to groups 1C, 2A, and 3B. Birds were bled weekly and immune responses monitored using indirect ELISA. Both neem and stinging nettle had antibody response-enhancing effects in groups 1B and 1C, receiving the local inactivated K1 vaccine. There were significant differences (P < 0.05) in antibody titers between groups 1A and 2C. Stinging nettle induced earlier onset of high antibody responses in group 2C and persistent titers (>3.8 log10) from the third week in group 2B. Imported live D78 vaccine induced higher antibody titers compared to the local inactivated K1 vaccine. Groups 2B and 2C receiving a combination of the local K1 and imported live attenuated D78 vaccines had the highest antibody titers. Adoption of stinging nettle supplementation and a prime-boost program involving use of a local virus isolates-derived vaccine is recommended. © 2017 Poultry Science Association Inc.

Evaluation of protective efficacy of live attenuated Salmonella enterica serovar Gallinarum vaccine strains against fowl typhoid in chickens.

PubMed

Laniewski, Paweł; Mitra, Arindam; Karaca, Kemal; Khan, Ayub; Prasad, Rajeev; Curtiss, Roy; Roland, Kenneth L

2014-09-01

Salmonella enterica serovar Gallinarum is the etiological agent of fowl typhoid, which constitutes a considerable economic problem for poultry growers in developing countries. The vaccination of chickens seems to be the most effective strategy to control the disease in those areas. We constructed S. Gallinarum strains with a deletion of the global regulatory gene fur and evaluated their virulence and protective efficacy in Rhode Island Red chicks and Brown Leghorn layers. The fur deletion mutant was avirulent and, when delivered orally to chicks, elicited excellent protection against lethal S. Gallinarum challenge. It was not as effective when given orally to older birds, although it was highly immunogenic when delivered by intramuscular injection. We also examined the effect of a pmi mutant and a combination of fur deletions with mutations in the pmi and rfaH genes, which affect O-antigen synthesis, and ansB, whose product inhibits host T-cell responses. The S. Gallinarum Δpmi mutant was only partially attenuated, and the ΔansB mutant was fully virulent. The Δfur Δpmi and Δfur ΔansB double mutants were attenuated but not protective when delivered orally to the chicks. However, a Δpmi Δfur strain was highly immunogenic when administered intramuscularly. All together, our results show that the fur gene is essential for the virulence of S. Gallinarum, and the fur mutant is effective as a live recombinant vaccine against fowl typhoid. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

A live attenuated H7N7 candidate vaccine virus induces neutralizing antibody that confers protection from challenge in mice, ferrets and monkeys

USDA-ARS?s Scientific Manuscript database

A live attenuated H7N7 candidate vaccine virus was generated by reverse genetics using the modified hemagglutinin (HA) and neuraminidase (NA) genes of HP A/Netherlands/219/03 (NL/03) (H7N7) wild-type (wt) virus and the six internal protein genes of the cold-adapted (ca) A/Ann Arbor/6/60 ca (AA ca) (...

Yersinia pestis caf1 variants and the limits of plague vaccine protection.

PubMed

Quenee, Lauriane E; Cornelius, Claire A; Ciletti, Nancy A; Elli, Derek; Schneewind, Olaf

2008-05-01

Yersinia pestis, the highly virulent agent of plague, is a biological weapon. Strategies that prevent plague have been sought for centuries, and immunization with live, attenuated (nonpigmented) strains or subunit vaccines with F1 (Caf1) antigen is considered effective. We show here that immunization with live, attenuated strains generates plague-protective immunity and humoral immune responses against F1 pilus antigen and LcrV. Y. pestis variants lacking caf1 (F1 pili) are not only fully virulent in animal models of bubonic and pneumonic plague but also break through immune responses generated with live, attenuated strains or F1 subunit vaccines. In contrast, immunization with purified LcrV, a protein at the tip of type III needles, generates protective immunity against the wild-type and the fully virulent caf1 mutant strain, in agreement with the notion that LcrV can elicit vaccine protection against both types of virulent plague strains.

Antigen-specific B memory cell responses to lipopolysaccharide (LPS) and invasion plasmid antigen (Ipa) B elicited in volunteers vaccinated with live-attenuated Shigella flexneri 2a vaccine candidates.

PubMed

Simon, J K; Wahid, R; Maciel, M; Picking, W L; Kotloff, K L; Levine, M M; Sztein, M B

2009-01-22

We evaluated B memory responses in healthy adult volunteers who received one oral dose of live-attenuated Shigella flexneri 2a vaccine. LPS-specific B(M) cells increased from a median of 0 at baseline to 20 spot forming cells (SFC)/10(6) expanded cells following vaccination (p=0.008). A strong correlation was found between post-vaccination anti-LPS B(M) cell counts and peak serum anti-LPS IgG titers (rs=0.95, p=0.0003). Increases in B(M) specific for IpaB approaching significance were also observed. In sum, oral vaccination with live-attenuated S. flexneri 2a elicits B(M) cells to LPS and IpaB, suggesting that B(M) responses to Shigella antigens should be further studied as a suitable surrogate of protection in shigellosis.

Antigen-specific B memory cell responses to lipopolysaccharide (LPS) and invasion plasmid antigen (Ipa) B elicited in volunteers vaccinated with live-attenuated Shigella flexneri 2a vaccine candidates

PubMed Central

Simon, J.K.; Wahid, R.; Maciel, M.; Picking, W.L.; Kotloff, K.L.; Levine, M.M.; Sztein, M.B.

2013-01-01

We evaluated B memory responses in healthy adult volunteers who received one oral dose of live-attenuated Shigella flexneri 2a vaccine. LPS-specific BM cells increased from a median of 0 at baseline to 20 spot forming cells (SFC)/106 expanded cells following vaccination (p = 0.008). A strong correlation was found between post-vaccination anti-LPS BM cell counts and peak serum anti-LPS IgG titers (rs = 0.95, p = 0.0003). Increases in BM specific for IpaB approaching significance were also observed. In sum, oral vaccination with live-attenuated S. flexneri 2a elicits BM cells to LPS and IpaB, suggesting that BM responses to Shigella antigens should be further studied as a suitable surrogate of protection in shigellosis. PMID:19022324

Current Efforts and Future Prospects in the Development of Live Mycobacteria as Vaccines

PubMed Central

Porcelli, Steven A.; Ng, Tony W.; Saavedra-Avila, Noemi A; Kennedy, Steven C.; Carreno, Leandro J.

2016-01-01

Summary The development of more effective vaccines against Mycobacterium tuberculosis (Mtb) remains a major goal in the effort to reduce the enormous global burden of disease caused by this pathogen. Whole-cell vaccines based on live mycobacteria with attenuated virulence represent an appealing approach, providing broad antigen exposure and intrinsic adjuvant properties to prime durable immune responses. However, designing vaccine strains with an optimal balance between attenuation and immunogenicity has proven to be extremely challenging. Recent basic and clinical research efforts have broadened our understanding of Mtb pathogenesis and created numerous new vaccine candidates that are designed to overcome different aspects of immune evasion by Mtb. In this review, we provide an overview of current efforts to create improved vaccines against tuberculosis based on modifications of live attenuated mycobacteria. In addition, we discuss the use of such vaccine strains as vectors for stimulating protective immunity against other infectious diseases and cancers. PMID:26366616

Comparison of Immunogenicity Between Inactivated and Live Attenuated Hepatitis A Vaccines Among Young Adults: A 3-Year Follow-up Study.

PubMed

Liu, Xue-en; Chen, Hai-ying; Liao, Zheng; Zhou, Yisheng; Wen, Hairong; Peng, Shihui; Liu, Yan; Li, Rui; Li, Jie; Zhuang, Hui

2015-10-15

A randomized clinical trial of hepatitis A vaccines (1 or 2 doses of inactivated vaccine [Healive] or 1 dose of live attenuated vaccine [Biovac]) was conducted among adults to evaluate seroprotection rates and geometric mean concentrations of antibody against hepatitis A virus for 36 months. High rates of seroprotection persisted for at least 36 months among adults who received 1 or 2 doses of inactivated hepatitis A vaccine but not among adults who received 1 dose of live attenuated hepatitis A vaccine. The long-term serial monitoring of immunogenicity induced by 1 dose of inactivated hepatitis A vaccine is needed to determine an effective alternative to a 2-dose schedule. NCT01865968. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Cellular Immune Responses to Live Attenuated Japanese Encephalitis (JE) Vaccine SA14-14-2 in Adults in a JE/Dengue Co-Endemic Area.

PubMed

Turtle, Lance; Tatullo, Filippo; Bali, Tanushka; Ravi, Vasanthapuram; Soni, Mohammed; Chan, Sajesh; Chib, Savita; Venkataswamy, Manjunatha M; Fadnis, Prachi; Yaïch, Mansour; Fernandez, Stefan; Klenerman, Paul; Satchidanandam, Vijaya; Solomon, Tom

2017-01-01

Japanese encephalitis (JE) virus (JEV) causes severe epidemic encephalitis across Asia, for which the live attenuated vaccine SA14-14-2 is being used increasingly. JEV is a flavivirus, and is closely related to dengue virus (DENV), which is co-endemic in many parts of Asia, with clinically relevant interactions. There is no information on the human T cell response to SA14-14-2, or whether responses to SA14-14-2 cross-react with DENV. We used live attenuated JE vaccine SA14-14-2 as a model for studying T cell responses to JEV infection in adults, and to determine whether these T cell responses are cross-reactive with DENV, and other flaviviruses. We conducted a single arm, open label clinical trial (registration: clinicaltrials.gov NCT01656200) to study T cell responses to SA14-14-2 in adults in South India, an area endemic for JE and dengue. Ten out of 16 (62.5%) participants seroconverted to JEV SA14-14-2, and geometric mean neutralising antibody (NAb) titre was 18.5. Proliferation responses were commonly present before vaccination in the absence of NAb, indicating a likely high degree of previous flavivirus exposure. Thirteen of 15 (87%) participants made T cell interferon-gamma (IFNγ) responses against JEV proteins. In four subjects tested, at least some T cell epitopes mapped cross-reacted with DENV and other flaviviruses. JEV SA14-14-2 was more immunogenic for T cell IFNγ than for NAb in adults in this JE/DENV co-endemic area. The proliferation positive, NAb negative combination may represent a new marker of long term immunity/exposure to JE. T cell responses can cross-react between JE vaccine and DENV in a co-endemic area, illustrating a need for greater knowledge on such responses to inform the development of next-generation vaccines effective against both diseases. clinicaltrials.gov (NCT01656200).

Estimates of the Public Health Impact of a Pediatric Vaccination Program Using an Intranasal Tetravalent Live-Attenuated Influenza Vaccine in Belgium.

PubMed

Gerlier, Laetitia; Lamotte, Mark; Dos Santos Mendes, Sofia; Damm, Oliver; Schwehm, Markus; Eichner, Martin

2016-08-01

Our objectives were to estimate the public health outcomes of vaccinating Belgian children using an intranasal tetravalent live-attenuated influenza vaccine (QLAIV) combined with current coverage of high-risk/elderly individuals using the trivalent inactivated vaccine. We used a deterministic, age-structured, dynamic model to simulate seasonal influenza transmission in the Belgian population under the current coverage or after extending vaccination with QLAIV to healthy children aged 2-17 years. Differential equations describe demographic changes, exposure to infectious individuals, infection recovery, and immunity dynamics. The basic reproduction number (R 0) was calibrated to the observed number of influenza doctor visits/year. Vaccine efficacy was 80 % (live-attenuated) and 59-68 % (inactivated). The 10-year incidence of symptomatic influenza was calculated with different coverage scenarios (add-on to current coverage). Model calibration yielded R 0 = 1.1. QLAIV coverage of 75 % of those aged 2-17 years averted 374,000 symptomatic cases/year (57 % of the current number), 244,000 of which were among adults (indirect effect). Vaccinating 75 % of those aged 2-11 years and 50 % of those aged 12-17 years averted 333,200 cases/year (213,000 adult cases/year). Vaccinating only healthy children aged 2-5 years generated direct protection but limited indirect protection, even with 90 % coverage (40,800 averted adult cases/year; -8.4 %). Targeting all children averted twice as many high-risk cases as targeting high-risk children only (8485 vs. 4965/year with 75 % coverage). Sensitivity analyses showed the robustness of results. The model highlights the direct and indirect protection benefits when vaccinating healthy children with QLAIV in Belgium. Policies targeting only high-risk individuals or the youngest provide limited herd protection, as school-age children are important influenza vectors in the community.

Rearrangement of Influenza Virus Spliced Segments for the Development of Live-Attenuated Vaccines

PubMed Central

Nogales, Aitor; DeDiego, Marta L.; Topham, David J.

2016-01-01

ABSTRACT Influenza viral infections represent a serious public health problem, with influenza virus causing a contagious respiratory disease which is most effectively prevented through vaccination. Segments 7 (M) and 8 (NS) of the influenza virus genome encode mRNA transcripts that are alternatively spliced to express two different viral proteins. This study describes the generation, using reverse genetics, of three different recombinant influenza A/Puerto Rico/8/1934 (PR8) H1N1 viruses containing M or NS viral segments individually or modified M or NS viral segments combined in which the overlapping open reading frames of matrix 1 (M1)/M2 for the modified M segment and the open reading frames of nonstructural protein 1 (NS1)/nuclear export protein (NEP) for the modified NS segment were split by using the porcine teschovirus 1 (PTV-1) 2A autoproteolytic cleavage site. Viruses with an M split segment were impaired in replication at nonpermissive high temperatures, whereas high viral titers could be obtained at permissive low temperatures (33°C). Furthermore, viruses containing the M split segment were highly attenuated in vivo, while they retained their immunogenicity and provided protection against a lethal challenge with wild-type PR8. These results indicate that influenza viruses can be effectively attenuated by the rearrangement of spliced segments and that such attenuated viruses represent an excellent option as safe, immunogenic, and protective live-attenuated vaccines. Moreover, this is the first time in which an influenza virus containing a restructured M segment has been described. Reorganization of the M segment to encode M1 and M2 from two separate, nonoverlapping, independent open reading frames represents a useful tool to independently study mutations in the M1 and M2 viral proteins without affecting the other viral M product. IMPORTANCE Vaccination represents our best therapeutic option against influenza viral infections. However, the efficacy of current influenza vaccines is suboptimal, and novel approaches are necessary for the prevention of disease caused by this important human respiratory pathogen. In this work, we describe a novel approach to generate safer and more efficient live-attenuated influenza virus vaccines (LAIVs) based on recombinant viruses whose genomes encode nonoverlapping and independent M1/M2 (split M segment [Ms]) or both M1/M2 and NS1/NEP (Ms and split NS segment [NSs]) open reading frames. Viruses containing a modified M segment were highly attenuated in mice but were able to confer, upon a single intranasal immunization, complete protection against a lethal homologous challenge with wild-type virus. Notably, the protection efficacy conferred by our viruses with split M segments was better than that conferred by the current temperature-sensitive LAIV. Altogether, these results open a new avenue for the development of safer and more protective LAIVs on the basis of the reorganization of spliced viral RNA segments in the genome. PMID:27122587

Updated data on effective and safe immunizations with live-attenuated vaccines for children after living donor liver transplantation.

PubMed

Shinjoh, Masayoshi; Hoshino, Ken; Takahashi, Takao; Nakayama, Tetsuo

2015-01-29

Although immunizations using live-attenuated vaccines are not recommended for children post-liver transplant due to their theoretical risks, they will inevitably encounter vaccine-preventable viral diseases upon returning to real-life situations. The window of opportunity for vaccination is usually limited prior to transplantation because these children often have unstable disease courses. Also, vaccine immunity does not always persist after transplantation. Beginning in 2002, subcutaneous immunizations with four individual live-attenuated vaccines (measles, rubella, varicella, and mumps) to pediatric patients following living donor liver transplantation (LDLT) were performed for those who fulfilled the clinical criteria, including humoral and cell-mediated immunity. Written informed consent was collected. We included the study on 70 immunizations for 18 cases that we reported in 2008 (Shinjoh et al., 2008). A total of 196 immunizations were administered to 48 pediatric post-LDLT recipients. Of these, 144 were first immunizations and 52 were repeated immunizations following LDLT. The seroconversion rates at the first dose for measles (AIK-C), rubella (TO-336), varicella (Oka), and mumps (Hoshino) were 100% (36/36), 100% (35/35), 70% (23/33), and 75% (24/32), respectively. Antibody levels did not fall over time in patients immunized with rubella vaccine. Three mild cases of breakthrough varicella were observed. Two cases with transient parotid gland swelling were observed after mumps immunization. Two admissions because of fever at 2-3 weeks after the measles vaccine were reported but the patients had no symptoms of measles. Immunizations using selected live-attenuated vaccines were safe and effective for post-LDLT children who were not severely immunosuppressed. However, with the exception of rubella, repeated immunization may be necessary. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of bright light and melatonin on cognitive and noncognitive function in elderly residents of group care facilities: a randomized controlled trial.

PubMed

Riemersma-van der Lek, Rixt F; Swaab, Dick F; Twisk, Jos; Hol, Elly M; Hoogendijk, Witte J G; Van Someren, Eus J W

2008-06-11

Cognitive decline, mood, behavioral and sleep disturbances, and limitations of activities of daily living commonly burden elderly patients with dementia and their caregivers. Circadian rhythm disturbances have been associated with these symptoms. To determine whether the progression of cognitive and noncognitive symptoms may be ameliorated by individual or combined long-term application of the 2 major synchronizers of the circadian timing system: bright light and melatonin. A long-term, double-blind, placebo-controlled, 2 x 2 factorial randomized trial performed from 1999 to 2004 with 189 residents of 12 group care facilities in the Netherlands; mean (SD) age, 85.8 (5.5) years; 90% were female and 87% had dementia. Random assignment by facility to long-term daily treatment with whole-day bright (+/- 1000 lux) or dim (+/- 300 lux) light and by participant to evening melatonin (2.5 mg) or placebo for a mean (SD) of 15 (12) months (maximum period of 3.5 years). Standardized scales for cognitive and noncognitive symptoms, limitations of activities of daily living, and adverse effects assessed every 6 months. Light attenuated cognitive deterioration by a mean of 0.9 points (95% confidence interval [CI], 0.04-1.71) on the Mini-Mental State Examination or a relative 5%. Light also ameliorated depressive symptoms by 1.5 points (95% CI, 0.24-2.70) on the Cornell Scale for Depression in Dementia or a relative 19%, and attenuated the increase in functional limitations over time by 1.8 points per year (95% CI, 0.61-2.92) on the nurse-informant activities of daily living scale or a relative 53% difference. Melatonin shortened sleep onset latency by 8.2 minutes (95% CI, 1.08-15.38) or 19% and increased sleep duration by 27 minutes (95% CI, 9-46) or 6%. However, melatonin adversely affected scores on the Philadelphia Geriatric Centre Affect Rating Scale, both for positive affect (-0.5 points; 95% CI, -0.10 to -1.00) and negative affect (0.8 points; 95% CI, 0.20-1.44). Melatonin also increased withdrawn behavior by 1.02 points (95% CI, 0.18-1.86) on the Multi Observational Scale for Elderly Subjects scale, although this effect was not seen if given in combination with light. Combined treatment also attenuated aggressive behavior by 3.9 points (95% CI, 0.88-6.92) on the Cohen-Mansfield Agitation Index or 9%, increased sleep efficiency by 3.5% (95% CI, 0.8%-6.1%), and improved nocturnal restlessness by 1.00 minute per hour each year (95% CI, 0.26-1.78) or 9% (treatment x time effect). Light has a modest benefit in improving some cognitive and noncognitive symptoms of dementia. To counteract the adverse effect of melatonin on mood, it is recommended only in combination with light. controlled-trials.com/isrctn Identifier: ISRCTN93133646.

Mutations within ICP4 acquired during in vitro attenuation do not alter virulence of recombinant Marek’s disease viruses in vivo

USDA-ARS?s Scientific Manuscript database

Marek's disease (MD) is a T-cell lymphoma of chickens caused by the oncogenic Marek's disease virus (MDV). MD is primarily controlled by live-attenuated vaccines generated by repeated in vitro serial passage. Previous efforts to characterize attenuated MDVs identified numerous mutations, particularl...

Gamma-interferon exerts a critical early restriction on replication and dissemination of yellow fever virus vaccine strain 17D-204.

PubMed

Lam, L K Metthew; Watson, Alan M; Ryman, Kate D; Klimstra, William B

2018-01-01

Live attenuated viruses are historically among the most effective viral vaccines. Development of a safe vaccine requires the virus to be less virulent, a phenotype that is historically arrived by empirical evaluation often leaving the mechanisms of attenuation unknown. The yellow fever virus 17D live attenuated vaccine strain has been developed as a delivery vector for heterologous antigens; however, the mechanisms of attenuation remain elusive. The successful and safe progress of 17D as a vaccine vector and the development of live attenuated vaccines (LAVs) to related flaviviruses requires an understanding of the molecular mechanisms leading to attenuation. Using subcutaneous infection of interferon-deficient mouse models of wild type yellow fever virus (WT YFV) pathogenesis and 17D-mediated immunity, we found that, in the absence of type I IFN (IFN-α/β), type II interferon (IFN-γ) restricted 17D replication, but not that of WT YFV, by 1-2 days post-infection. In this context, IFN-γ responses protected 17D-infected animals from mortality, largely restricted the virus to lymphoid organs, and eliminated viscerotropic disease signs such as steatosis in the liver and inflammatory cell infiltration into the spleen. However, WT YFV caused a disseminated infection, gross liver pathology, and rapid death of the animals. In vitro, IFN-γ treatment of myeloid cells suppressed the replication of 17D significantly more than that of WT YFV, suggesting a direct differential effect on 17D virus replication. Together these data indicate that an important mechanism of 17D attenuation in vivo is increased sensitivity to IFN-γ stimulated responses elicited early after infection.

Synergy of SOCS-1 Inhibition and Microbial-Based Cancer Vaccines

DTIC Science & Technology

2014-11-01

response without causing additional risk to the patient. The goal of our proposal is to modify a live- attenuated vaccine vector based on the food -borne...response after vaccination with a live-­‐‑attenuated L. monocytogenes. Aim 3: Test the hypothesis that secretion of a SOCS-­‐‑1 small peptide ...efficient internalization of pathogens and dying cells, processing of this material into peptide antigens that are presented in the context of major

Quantitative measurement of permeabilization of living cells by terahertz attenuated total reflection

NASA Astrophysics Data System (ADS)

Grognot, Marianne; Gallot, Guilhem

2015-09-01

Using Attenuated Total Reflection imaging technique in the terahertz domain, we demonstrate non-invasive, non-staining real time measurements of cytoplasm leakage during permeabilization of epithelial cells by saponin. The terahertz signal is mostly sensitive to the intracellular protein concentration in the cells, in a very good agreement with standard bicinchoninic acid protein measurements. It opens the way to in situ real time dynamics of protein content and permeabilization in live cells.

Absence of an N-Linked Glycosylation Motif in the Glycoprotein of the Live-Attenuated Argentine Hemorrhagic Fever Vaccine, Candid #1, Results in Its Improper Processing, and Reduced Surface Expression.

PubMed

Manning, John T; Seregin, Alexey V; Yun, Nadezhda E; Koma, Takaaki; Huang, Cheng; Barral, José; de la Torre, Juan C; Paessler, Slobodan

2017-01-01

Junin virus (JUNV), a highly pathogenic New World arenavirus, is the causative agent of Argentine hemorrhagic fever (AHF). The live-attenuated Candid #1 (Can) strain currently serves as a vaccine for at-risk populations. We have previously shown that the Can glycoprotein (GPC) gene is the primary gene responsible for attenuation in a guinea pig model of AHF. However, the mechanisms through which the GPC contributes to the attenuation of the Can strain remain unknown. A more complete understanding of the mechanisms underlying the attenuation and immunogenicity of the Can strain will potentially allow for the rational design of additional safe and novel vaccines. Here, we provide a detailed comparison of both RNA and protein expression profiles between both inter- and intra-segment chimeric JUNV recombinant clones expressing combinations of genes from the Can strain and the pathogenic Romero (Rom) strain. The recombinant viruses that express Can GPC, which were shown to be attenuated in guinea pigs, displayed different RNA levels and GPC processing patterns as determined by Northern and Western blot analyses, respectively. Analysis of recombinant viruses containing amino acid substitutions selected at different mouse brain passages during the generation of Can revealed that altered Can GPC processing was primarily due to the T168A substitution within G1, which eliminates an N-linked glycosylation motif. Incorporation of the T168A substitution in the Rom GPC resulted in a Can-like processing pattern of Rom GPC. In addition, JUNV GPCs containing T168A substitution were retained within the endoplasmic reticulum (ER) and displayed significantly lower cell surface expression than wild-type Rom GPC. Interestingly, the reversion A168T in Can GPC significantly increased GPC expression at the cell surface. Our results demonstrate that recombinant JUNV (rJUNV) expressing Can GPC display markedly different protein expression and elevated genomic RNA expression when compared to viruses expressing Rom GPC. Additionally, our findings indicate that the N-linked glycosylation motif at amino acid positions 166-168 is important for trafficking of JUNV GPC to the cell surface, and the elimination of this motif interferes with the GPC release from the ER.

Distemper-like disease and encephalitozoonosis in wild dogs (Lycaon pictus).

PubMed

Van Heerden, J; Bainbridge, N; Burroughs, R E; Kriek, N P

1989-01-01

Clinical signs of a fatal disease resembling those of canine distemper were observed in two groups of captive wild dog (Lycaon pictus) pups 13 days after vaccination with a commercially available combination vaccine for dogs which contained a live attenuated strain of canine distemper virus. Histopathological examination of tissues revealed the presence of intranuclear inclusion bodies in neurons and lesions resembling canine distemper as well as colonies of an Encephalitozoon sp. in the central nervous system and kidneys. Lesions were observed in both organs which resembled those described in other species infected with Encephalitozoon cuniculi.

A chimeric measles virus with canine distemper envelope protects ferrets from lethal distemper challenge.

PubMed

Rouxel, Ronan Nicolas; Svitek, Nicholas; von Messling, Veronika

2009-08-06

CDV infects a broad range of carnivores, and over the past decades it has caused outbreaks in a variety of wild carnivore populations. Since the currently available live-attenuated vaccine is not sufficiently safe in these highly susceptible species, we produced a chimeric virus combining the replication complex of the measles Moraten vaccine strain with the envelope of a recent CDV wild type isolate. The resulting virus did not cause disease or immunosuppression in ferrets and conferred protection from challenge with a lethal wild type strain, demonstrating its potential value for wildlife conservation efforts.

Next-Generation Bacillus anthracis Live Attenuated Spore Vaccine Based on the htrA- (High Temperature Requirement A) Sterne Strain

PubMed Central

Chitlaru, Theodor; Israeli, Ma’ayan; Bar-Haim, Erez; Elia, Uri; Rotem, Shahar; Ehrlich, Sharon; Cohen, Ofer; Shafferman, Avigdor

2016-01-01

Anthrax is a lethal disease caused by the gram-positive spore-producing bacterium Bacillus anthracis. Live attenuated vaccines, such as the nonencapsulated Sterne strain, do not meet the safety standards mandated for human use in the Western world and are approved for veterinary purposes only. Here we demonstrate that disrupting the htrA gene, encoding the chaperone/protease HtrA (High Temperature Requirement A), in the virulent Bacillus anthracis Vollum strain results in significant virulence attenuation in guinea pigs, rabbits and mice, underlying the universality of the attenuated phenotype associated with htrA knockout. Accordingly, htrA disruption was implemented for the development of a Sterne-derived safe live vaccine compatible with human use. The novel B. anthracis SterneΔhtrA strain secretes functional anthrax toxins but is 10–104-fold less virulent than the Sterne vaccine strain depending on animal model (mice, guinea pigs, or rabbits). In spite of this attenuation, double or even single immunization with SterneΔhtrA spores elicits immune responses which target toxaemia and bacteremia resulting in protection from subcutaneous or respiratory lethal challenge with a virulent strain in guinea pigs and rabbits. The efficacy of the immune-protective response in guinea pigs was maintained for at least 50 weeks after a single immunization. PMID:26732659

Genetically attenuated Trypanosoma cruzi parasites as a potential vaccination tool

PubMed Central

Brandan, Cecilia Pérez; Basombrío, Miguel Ángel

2012-01-01

Chagas disease is the clinical manifestation of the infection produced by the parasite Trypanosoma cruzi. Currently there is no vaccine to prevent this disease and the protection attained with vaccines containing non-replicating parasites is limited. Genetically attenuated trypanosomatid parasites can be obtained by deletion of selected genes. Gene deletion takes advantage of the fact that this parasite can undergo homologous recombination between endogenous and foreign DNA sequences artificially introduced in the cells. This approach facilitated the discovery of several unknown gene functions, as well as allowing us to speculate about the potential for genetically attenuated live organisms as experimental immunogens. Vaccination with live attenuated parasites has been used effectively in mice to reduce parasitemia and histological damage, and in dogs, to prevent vector-delivered infection in the field. However, the use of live parasites as immunogens is controversial due to the risk of reversion to a virulent phenotype. Herein, we present our results from experiments on genetic manipulation of two T. cruzi strains to produce parasites with impaired replication and infectivity, and using the mutation of the dhfr-ts gene as a safety device against reversion to virulence. PMID:22705838

Vaccination with live attenuated simian immunodeficiency virus causes dynamic changes in intestinal CD4+CCR5+ T cells

PubMed Central

2011-01-01

Background Vaccination with live attenuated SIV can protect against detectable infection with wild-type virus. We have investigated whether target cell depletion contributes to the protection observed. Following vaccination with live attenuated SIV the frequency of intestinal CD4+CCR5+ T cells, an early target of wild-type SIV infection and destruction, was determined at days 3, 7, 10, 21 and 125 post inoculation. Results In naive controls, modest frequencies of intestinal CD4+CCR5+ T cells were predominantly found within the LPL TTrM-1 and IEL TTrM-2 subsets. At day 3, LPL and IEL CD4+CCR5+ TEM cells were dramatically increased whilst less differentiated subsets were greatly reduced, consistent with activation-induced maturation. CCR5 expression remained high at day 7, although there was a shift in subset balance from CD4+CCR5+ TEM to less differentiated TTrM-2 cells. This increase in intestinal CD4+CCR5+ T cells preceded the peak of SIV RNA plasma loads measured at day 10. Greater than 65.9% depletion of intestinal CD4+CCR5+ T cells followed at day 10, but overall CD4+ T cell homeostasis was maintained by increased CD4+CCR5- T cells. At days 21 and 125, high numbers of intestinal CD4+CCR5- naive TN cells were detected concurrent with greatly increased CD4+CCR5+ LPL TTrM-2 and IEL TEM cells at day 125, yet SIV RNA plasma loads remained low. Conclusions This increase in intestinal CD4+CCR5+ T cells, following vaccination with live attenuated SIV, does not correlate with target cell depletion as a mechanism of protection. Instead, increased intestinal CD4+CCR5+ T cells may correlate with or contribute to the protection conferred by vaccination with live attenuated SIV. PMID:21291552

Principles underlying rational design of live attenuated influenza vaccines

PubMed Central

Jang, Yo Han

2012-01-01

Despite recent innovative advances in molecular virology and the developments of vaccines, influenza virus remains a serious burden for human health. Vaccination has been considered a primary countermeasure for prevention of influenza infection. Live attenuated influenza vaccines (LAIVs) are particularly attracting attention as an effective strategy due to several advantages over inactivated vaccines. Cold-adaptation, as a classical means for attenuating viral virulence, has been successfully used for generating safe and effective donor strains of LAIVs against seasonal epidemics and occasional pandemics. Recently, the advent of reverse genetics technique expedited a variety of rational strategies to broaden the pool of LAIVs. Considering the breadth of antigenic diversity of influenza virus, the pool of LAIVs is likely to equip us with better options for controlling influenza pandemics. With a brief reflection on classical attenuating strategies used at the initial stage of development of LAIVs, especially on the principles underlying the development of cold-adapted LAIVs, we further discuss and outline other attenuation strategies especially with respect to the rationales for attenuation, and their practicality for mass production. Finally, we propose important considerations for a rational vaccine design, which will provide us with practical guidelines for improving the safety and effectiveness of LAIVs. PMID:23596576

Identification of sequence changes in live attenuated goose parvovirus vaccine strains developed in Asia and Europe.

PubMed

Shien, J-H; Wang, Y-S; Chen, C-H; Shieh, H K; Hu, C-C; Chang, P-C

2008-10-01

Live attenuated vaccines have been used for control of the disease caused by goose parvovirus (GPV), but the mechanism involved in attenuation of GPV remains elusive. This report presents the complete nucleotide sequences of two live attenuated strains of GPV (82-0321V and VG32/1) that were independently developed in Taiwan and Europe, together with the parental strain of 82-0321V and a field strain isolated in Taiwan in 2006. Sequence comparisons showed that 82-0321V and VG32/1 had multiple deletions and substitutions in the inverted terminal repeats region when compared with their parental strain or the field virus, but these changes did not affect the formation of the hairpin structure essential for viral replication. Moreover, 82-0321V and VG32/1 had five amino acid changes in the non-structural protein, but these changes were located at positions distant from known functional motifs in the non-structural protein. In contrast, 82-0321V had nine changes and VG32/1 had 11 changes in their capsid proteins (VP1), and the majority of these changes occurred at positions close to the putative receptor binding sites of VP1, as predicted using the structure of adeno-associated virus 2 as the model system. Taken together, the results suggest that changes in sequence near the receptor binding sites of VP1 might be responsible for attenuation of GPV. This is the first report of complete nucleotide sequences of GPV other than the virulent B strain, and suggests a possible mechanism for attenuation of GPV.

Genetically Engineered, Live Attenuated Vaccines Protect Nonhuman Primates Against Aerosol Challenge with a Virulent IE Strain of Venezuelan Equine Encephalitis Virus

DTIC Science & Technology

2005-01-21

integrated moving average ( ARIMA ) model [15,19]. Fore- casted values for the postexposure time periods were based on the training model extrapolated...Smith JF. Genetically engineered, live attenuated vaccines or Venezuelan equine encephalitis: testing in animal models . Vaccine 2003;21(25–26):3854–62...encephalitis: testing in animal models . Vaccine 2003;21(25-26):3854-62] and IE strains of VEE viruses. 15. SUBJECT TERMS Venezuelan equine

Human Transcriptome Response to Immunization with Live- Attenuated Venezuelan equine encephalitis Virus Vaccine (TC 83): Analysis of Whole Blood

DTIC Science & Technology

2016-11-21

strain of VEEV though tissue culture in fetal guinea pig heart cells.9 The second, C-84, is a 70 formalin-inactivated version of the TC-83 strain.10...71 Live-attenuated TC-83 has been used extensively in humans and has demonstrated high 72 protective data as measured by the production of...contributing to the lack of 76 neutralizing antibody production for individuals receiving sequential alphavirus immunizations, 77 including circumstances

Co-administration of the broad-spectrum antiviral, brincidofovir (CMX001), with smallpox vaccine does not compromise vaccine protection in mice challenged with ectromelia virus.

PubMed

Parker, Scott; Crump, Ryan; Foster, Scott; Hartzler, Hollyce; Hembrador, Ed; Lanier, E Randall; Painter, George; Schriewer, Jill; Trost, Lawrence C; Buller, R Mark

2014-11-01

Natural orthopoxvirus outbreaks such as vaccinia, cowpox, cattlepox and buffalopox continue to cause morbidity in the human population. Monkeypox virus remains a significant agent of morbidity and mortality in Africa. Furthermore, monkeypox virus's broad host-range and expanding environs make it of particular concern as an emerging human pathogen. Monkeypox virus and variola virus (the etiological agent of smallpox) are both potential agents of bioterrorism. The first line response to orthopoxvirus disease is through vaccination with first-generation and second-generation vaccines, such as Dryvax and ACAM2000. Although these vaccines provide excellent protection, their widespread use is impeded by the high level of adverse events associated with vaccination using live, attenuated virus. It is possible that vaccines could be used in combination with antiviral drugs to reduce the incidence and severity of vaccine-associated adverse events, or as a preventive in individuals with uncertain exposure status or contraindication to vaccination. We have used the intranasal mousepox (ectromelia) model to evaluate the efficacy of vaccination with Dryvax or ACAM2000 in conjunction with treatment using the broad spectrum antiviral, brincidofovir (BCV, CMX001). We found that co-treatment with BCV reduced the severity of vaccination-associated lesion development. Although the immune response to vaccination was quantifiably attenuated, vaccination combined with BCV treatment did not alter the development of full protective immunity, even when administered two days following ectromelia challenge. Studies with a non-replicating vaccine, ACAM3000 (MVA), confirmed that BCV's mechanism of attenuating the immune response following vaccination with live virus was, as expected, by limiting viral replication and not through inhibition of the immune system. These studies suggest that, in the setting of post-exposure prophylaxis, co-administration of BCV with vaccination should be considered a first response to a smallpox emergency in subjects of uncertain exposure status or as a means of reduction of the incidence and severity of vaccine-associated adverse events. Copyright © 2014 Elsevier B.V. All rights reserved.

Current status of flavivirus vaccines.

PubMed

Barrett, A D

2001-12-01

Although there are approximately 68 flaviviruses recognized, vaccines have been developed to control very few human flavivirus diseases. Licensed live attenuated vaccines have been developed for yellow fever (strain 17D) and Japanese encephalitis (strain SA14-14-2) viruses, and inactivated vaccines have been developed for Japanese encephalitis and tick-borne encephalitis viruses. The yellow fever live attenuated 17D vaccine is one of the most efficacious and safe vaccines developed to date and has been used to immunize more than 300 million people. A number of experimental vaccines are being developed, most notably for dengue. Candidate tetravalent live attenuated dengue vaccines are undergoing clinical trials. Other vaccines are being developed using reverse genetics, DNA vaccines, and recombinant immunogens. In addition, the yellow fever 17D vaccine has been used as a backbone to generate chimeric viruses containing the premembrane and envelope protein genes from other flaviviruses. The "Chimerivax" platform has been used to construct chimeric Japanese encephalitis and dengue viruses that are in different phases of development. Similar strategies are being used by other laboratories.

Yellow fever live attenuated vaccine: A very successful live attenuated vaccine but still we have problems controlling the disease.

PubMed

Barrett, Alan D T

2017-10-20

Yellow fever (YF) is regarded as the original hemorrhagic fever and has been a major public health problem for at least 250years. A very effective live attenuated vaccine, strain 17D, was developed in the 1930s and this has proved critical in the control of the disease. There is little doubt that without the vaccine, YF virus would be considered a biosafety level 4 pathogen. Significantly, YF is currently the only disease where an international vaccination certificate is required under the International Health Regulations. Despite having a very successful vaccine, there are occasional issues of supply and demand, such as that which occurred in Angola and Democratic Republic of Congo in 2016 when there was insufficient vaccine available. For the first time fractional dosing of the vaccine was approved on an emergency basis. Thus, continued vigilance and improvements in supply and demand are needed in the future. Copyright © 2017. Published by Elsevier Ltd.

A New Approach to Establish a Cell Line with Reduced Risk of Endogenous Retroviruses

PubMed Central

Fukuma, Aiko; Yoshikawa, Rokusuke; Miyazawa, Takayuki; Yasuda, Jiro

2013-01-01

Endogenous retroviruses (ERVs) are integrated as DNA proviruses in the genomes of all mammalian species. Several ERVs are replication-competent and produced as fully infectious viruses from host cell. Thus, live-attenuated vaccines and biological substances have been prepared using the cell lines which may produce ERV. Indeed, we recently reported that several commercial live-attenuated vaccines for pets were contaminated with the infectious feline endogenous retrovirus, RD-114. In this study, to establish a cell line for vaccine manufacture with reduced risk of ERVs, we generated a cell line stably expressing human tetherin (Teth-CRFK cells). The release of infectious ERV from Teth-CRFK cells was suppressed to undetectable levels, while the production of parvovirus in Teth-CRFK cells was similar to that in parental CRFK cells. These observations suggest that Teth-CRFK cells will be useful as a cell line for the manufacture of live-attenuated vaccines or biological substances with reduced risk of ERV. PMID:23585909

A modified live canine parvovirus strain with novel plaque characteristics. I. Viral attenuation and dog response.

PubMed

Carmichael, L E; Joubert, J C; Pollock, R V

1981-10-01

A canine parvovirus (CPV) strain (C-780916) was found attenuated for pups at 80, but not after 51 serial passages in dog kidney cell (DKC) cultures. A variant viral population ('large plaque') emerged after prolonged cultivation in DKC cultures that may be associated with reduced native virulence. Dogs vaccinated with modified CPV developed high hemagglutination-inhibiting (HI) antibody titers within 4 days of incoluation and antibody persisted. Vaccinated animals shed small amounts of virus in the feces that spread to contact dogs. After five back-passages in dogs the modified strain was not pathogenic for pups and the plaque characteristics of the virus isolated from the feces were typical of the attenuated strain. The modified live CPV did not cause infection of the fetus when inoculated parenterally into pregnant bitches at various stages of gestation. It was not pathogenic for neonatal pups. These results suggest that a safe and effective live homologous (CPV) vaccine has been developed which should aid substantially in controlling CPV infection.

A new approach to establish a cell line with reduced risk of endogenous retroviruses.

PubMed

Fukuma, Aiko; Yoshikawa, Rokusuke; Miyazawa, Takayuki; Yasuda, Jiro

2013-01-01

Endogenous retroviruses (ERVs) are integrated as DNA proviruses in the genomes of all mammalian species. Several ERVs are replication-competent and produced as fully infectious viruses from host cell. Thus, live-attenuated vaccines and biological substances have been prepared using the cell lines which may produce ERV. Indeed, we recently reported that several commercial live-attenuated vaccines for pets were contaminated with the infectious feline endogenous retrovirus, RD-114. In this study, to establish a cell line for vaccine manufacture with reduced risk of ERVs, we generated a cell line stably expressing human tetherin (Teth-CRFK cells). The release of infectious ERV from Teth-CRFK cells was suppressed to undetectable levels, while the production of parvovirus in Teth-CRFK cells was similar to that in parental CRFK cells. These observations suggest that Teth-CRFK cells will be useful as a cell line for the manufacture of live-attenuated vaccines or biological substances with reduced risk of ERV.

The muscle findings in a pediatric patient with live attenuated oral polio vaccine-related flaccid monoplegia.

PubMed

Uchiyama, Shin-ichi; Nishino, Ichizo; Izumi, Tatsuro

2014-09-22

A pediatric patient, who was given live-attenuated oral polio vaccine twice without distinct gait disturbance during infancy, begun to present limp at 3 years. His gait disturbance became remarkable with aging. At 7 years, he was unable to dorsiflex the left ankle, and presented flaccid monoplegia of the left lower extremity, and the left Achilles tendon reflex was diminished. Magnetic resonance imaging revealed multiple crack-lines in the left anterior tibial muscle, but was unable to detect any distinct lesion at responsible level of L4, L5 and S1 anterior horn cells' degeneration. Electromyography showed continuous fibrillation potentials, but muscle biopsy presented nearly normal in this muscle. The serum levels of polio antibody type 1 and type 2 titers were elevated 64× respectively, while the type 3 antibody titer was not elevated 4×. This patient was diagnosed as live attenuated oral polio vaccine-related flaccid monoplegia, with mild clinical course. Copyright © 2014 Elsevier Ltd. All rights reserved.

Type III Interferon-Mediated Signaling Is Critical for Controlling Live Attenuated Yellow Fever Virus Infection In Vivo

PubMed Central

Douam, Florian; Soto Albrecht, Yentli E.; Hrebikova, Gabriela; Sadimin, Evita; Davidson, Christian; Kotenko, Sergei V.

2017-01-01

ABSTRACT Yellow fever virus (YFV) is an arthropod-borne flavivirus, infecting ~200,000 people worldwide annually and causing about 30,000 deaths. The live attenuated vaccine strain, YFV-17D, has significantly contributed in controlling the global burden of yellow fever worldwide. However, the viral and host contributions to YFV-17D attenuation remain elusive. Type I interferon (IFN-α/β) signaling and type II interferon (IFN-γ) signaling have been shown to be mutually supportive in controlling YFV-17D infection despite distinct mechanisms of action in viral infection. However, it remains unclear how type III IFN (IFN-λ) integrates into this antiviral system. Here, we report that while wild-type (WT) and IFN-λ receptor knockout (λR−/−) mice were largely resistant to YFV-17D, deficiency in type I IFN signaling resulted in robust infection. Although IFN-α/β receptor knockout (α/βR−/−) mice survived the infection, mice with combined deficiencies in both type I signaling and type III IFN signaling were hypersusceptible to YFV-17D and succumbed to the infection. Mortality was associated with viral neuroinvasion and increased permeability of the blood-brain barrier (BBB). α/βR−/− λR−/− mice also exhibited distinct changes in the frequencies of multiple immune cell lineages, impaired T-cell activation, and severe perturbation of the proinflammatory cytokine balance. Taken together, our data highlight that type III IFN has critical immunomodulatory and neuroprotective functions that prevent viral neuroinvasion during active YFV-17D replication. Type III IFN thus likely represents a safeguard mechanism crucial for controlling YFV-17D infection and contributing to shaping vaccine immunogenicity. PMID:28811340

Recombinant bovine respiratory syncytial virus with deletion of the SH gene induces increased apoptosis and pro-inflammatory cytokines in vitro, and is attenuated and induces protective immunity in calves

PubMed Central

Wyld, Sara; Valarcher, Jean-Francois; Guzman, Efrain; Thom, Michelle; Widdison, Stephanie; Buchholz, Ursula J.

2014-01-01

Bovine respiratory syncytial virus (BRSV) causes inflammation and obstruction of the small airways, leading to severe respiratory disease in young calves. The virus is closely related to human (H)RSV, a major cause of bronchiolitis and pneumonia in young children. The ability to manipulate the genome of RSV has provided opportunities for the development of stable, live attenuated RSV vaccines. The role of the SH protein in the pathogenesis of BRSV was evaluated in vitro and in vivo using a recombinant (r)BRSV in which the SH gene had been deleted. Infection of bovine epithelial cells and monocytes with rBRSVΔSH, in vitro, resulted in an increase in apoptosis, and higher levels of TNF-α and IL-1β compared with cells infected with parental, wild-type (WT) rBRSV. Although replication of rBRSVΔSH and WT rBRSV, in vitro, were similar, the replication of rBRSVΔSH was moderately reduced in the lower, but not the upper, respiratory tract of experimentally infected calves. Despite the greater ability of rBRSVΔSH to induce pro-inflammatory cytokines, in vitro, the pulmonary inflammatory response in rBRSVΔSH-infected calves was significantly reduced compared with that in calves inoculated with WT rBRSV, 6 days previously. Virus lacking SH appeared to be as immunogenic and effective in inducing resistance to virulent virus challenge, 6 months later, as the parental rBRSV. These findings suggest that rBRSVΔSH may be an ideal live attenuated virus vaccine candidate, combining safety with a high level of immunogenicity. PMID:24700100

Evaluation of an in vitro cell assay to select attenuated bacterial mutants of Aeromonas hydrophila and Edwardsiella tarda to channel catfish

USDA-ARS?s Scientific Manuscript database

To evaluate the feasibility of using an in vitro cell assay to select attenuated bacterial mutants. Using catfish gill cells G1B, the feasibility of using an in vitro assay instead of in vivo virulence assay using live fish to select attenuated bacterial mutants was evaluated in this study. Pearson ...

Live Attenuated Influenza Vaccine Enhances Colonization of Streptococcus pneumoniae and Staphylococcus aureus in Mice

PubMed Central

Mina, Michael J.; McCullers, Jonathan A.; Klugman, Keith P.

2014-01-01

ABSTRACT Community interactions at mucosal surfaces between viruses, like influenza virus, and respiratory bacterial pathogens are important contributors toward pathogenesis of bacterial disease. What has not been considered is the natural extension of these interactions to live attenuated immunizations, and in particular, live attenuated influenza vaccines (LAIVs). Using a mouse-adapted LAIV against influenza A (H3N2) virus carrying the same mutations as the human FluMist vaccine, we find that LAIV vaccination reverses normal bacterial clearance from the nasopharynx and significantly increases bacterial carriage densities of the clinically important bacterial pathogens Streptococcus pneumoniae (serotypes 19F and 7F) and Staphylococcus aureus (strains Newman and Wright) within the upper respiratory tract of mice. Vaccination with LAIV also resulted in 2- to 5-fold increases in mean durations of bacterial carriage. Furthermore, we show that the increases in carriage density and duration were nearly identical in all aspects to changes in bacterial colonizing dynamics following infection with wild-type (WT) influenza virus. Importantly, LAIV, unlike WT influenza viruses, had no effect on severe bacterial disease or mortality within the lower respiratory tract. Our findings are, to the best of our knowledge, the first to demonstrate that vaccination with a live attenuated viral vaccine can directly modulate colonizing dynamics of important and unrelated human bacterial pathogens, and does so in a manner highly analogous to that seen following wild-type virus infection. PMID:24549845

Herpes Simplex Vaccines: Prospects of Live-attenuated HSV Vaccines to Combat Genital and Ocular infections

PubMed Central

Stanfield, Brent; Kousoulas, Konstantin Gus

2015-01-01

Herpes simplex virus type-1 (HSV-1) and its closely related type-2 (HSV-2) viruses cause important clinical manifestations in humans including acute ocular disease and genital infections. These viruses establish latency in the trigeminal ganglionic and dorsal root neurons, respectively. Both viruses are widespread among humans and can frequently reactivate from latency causing disease. Currently, there are no vaccines available against herpes simplex viral infections. However, a number of promising vaccine approaches are being explored in pre-clinical investigations with few progressing to early phase clinical trials. Consensus research findings suggest that robust humoral and cellular immune responses may partially control the frequency of reactivation episodes and reduce clinical symptoms. Live-attenuated viral vaccines have long been considered as a viable option for generating robust and protective immune responses against viral pathogens. Varicella zoster virus (VZV) belongs to the same alphaherpesvirus subfamily with herpes simplex viruses. A live-attenuated VZV vaccine has been extensively used in a prophylactic and therapeutic approach to combat primary and recurrent VZV infection indicating that a similar vaccine approach may be feasible for HSVs. In this review, we summarize pre-clinical approaches to HSV vaccine development and current efforts to test certain vaccine approaches in human clinical trials. Also, we discuss the potential advantages of using a safe, live-attenuated HSV-1 vaccine strain to protect against both HSV-1 and HSV-2 infections. PMID:27114893

A genetically engineered live attenuated vaccine of Coccidioides posadasii protects BALB/c mice against coccidioidomycosis.

PubMed

Xue, Jianmin; Chen, Xia; Selby, Dale; Hung, Chiung-Yu; Yu, Jieh-Juen; Cole, Garry T

2009-08-01

Coccidioidomycosis (also known as San Joaquin Valley fever) is an occupational disease. Workers exposed to outdoor dust which contains spores of the soil-inhabiting fungus have a significantly increased risk of respiratory infection. In addition, people with compromised T-cell immunity, the elderly, and certain racial groups, particularly African-Americans and Filipinos, who live in regions of endemicity in the southwestern United States have an elevated incidence of symptomatic infection caused by inhalation of spores of Coccidioides posadasii or Coccidioides immitis. Recurring epidemics and escalation of medical costs have helped to motivate production of a vaccine against valley fever. The major focus has been the development of a defined, T-cell-reactive, recombinant protein vaccine. However, none of the products described to date have provided full protection to coccidioidal disease-susceptible BALB/c mice. Here we describe the first genetically engineered, live, attenuated vaccine that protects both BALB/c and C57BL/6 mice against coccidioidomycosis. Two chitinase genes (CTS2 and CTS3) were disrupted to yield the attenuated strain, which was unable to endosporulate and was no longer infectious. Vaccinated survivors mounted an immune response characterized by production of both T-helper-1- and T-helper-2-type cytokines. Histology revealed well-formed granulomas and markedly diminished inflammation. Significantly fewer organisms were observed in the lungs of survivors than in those of nonvaccinated mice. Additional investigations are required to further define the nature of the live, attenuated vaccine-induced immunity against Coccidioides infection.

Biological safety concepts of genetically modified live bacterial vaccines.

PubMed

Frey, Joachim

2007-07-26

Live vaccines possess the advantage of having access to induce cell-mediated and antibody-mediated immunity; thus in certain cases they are able to prevent infection, and not only disease. Furthermore, live vaccines, particularly bacterial live vaccines, are relatively cheap to produce and easy to apply. Hence they are suitable to immunize large communities or herds. The induction of both cell-mediated immunity as well as antibody-mediated immunity, which is particularly beneficial in inducing mucosal immune responses, is obtained by the vaccine-strain's ability to colonize and multiply in the host without causing disease. For this reason, live vaccines require attenuation of virulence of the bacterium to which immunity must be induced. Traditionally attenuation was achieved simply by multiple passages of the microorganism on growth medium, in animals, eggs or cell cultures or by chemical or physical mutagenesis, which resulted in random mutations that lead to attenuation. In contrast, novel molecular methods enable the development of genetically modified organisms (GMOs) targeted to specific genes that are particularly suited to induce attenuation or to reduce undesirable effects in the tissue in which the vaccine strains can multiply and survive. Since live vaccine strains (attenuated by natural selection or genetic engineering) are potentially released into the environment by the vaccinees, safety issues concerning the medical as well as environmental aspects must be considered. These involve (i) changes in cell, tissue and host tropism, (ii) virulence of the carrier through the incorporation of foreign genes, (iii) reversion to virulence by acquisition of complementation genes, (iv) exchange of genetic information with other vaccine or wild-type strains of the carrier organism and (v) spread of undesired genes such as antibiotic resistance genes. Before live vaccines are applied, the safety issues must be thoroughly evaluated case-by-case. Safety assessment includes knowledge of the precise function and genetic location of the genes to be mutated, their genetic stability, potential reversion mechanisms, possible recombination events with dormant genes, gene transfer to other organisms as well as gene acquisition from other organisms by phage transduction, transposition or plasmid transfer and cis- or trans-complementation. For this, GMOs that are constructed with modern techniques of genetic engineering display a significant advantage over random mutagenesis derived live organisms. The selection of suitable GMO candidate strains can be made under in vitro conditions using basic knowledge on molecular mechanisms of pathogenicity of the corresponding bacterial species rather than by in vivo testing of large numbers of random mutants. This leads to a more targeted safety testing on volunteers and to a reduction in the use of animal experimentation.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dhondt, Ineke; Petyuk, Vladislav A.; Cai, Huaihan

Most aging hypotheses assume the accumulation of damage, resulting in gradual physiological decline and, ultimately, death. Avoiding protein damage accumulation by enhanced turnover should slow down the aging process and extend the lifespan. But, lowering translational efficiency extends rather than shortens the lifespan in C. elegans. We studied turnover of individual proteins in the long-lived daf-2 mutant by combining SILeNCe (stable isotope labeling by nitrogen in Caenorhabditiselegans) and mass spectrometry. Intriguingly, the majority of proteins displayed prolonged half-lives in daf-2, whereas others remained unchanged, signifying that longevity is not supported by high protein turnover. We found that this slowdown wasmore » most prominent for translation-related and mitochondrial proteins. Conversely, the high turnover of lysosomal hydrolases and very low turnover of cytoskeletal proteins remained largely unchanged. The slowdown of protein dynamics and decreased abundance of the translational machinery may point to the importance of anabolic attenuation in lifespan extension, as suggested by the hyperfunction theory.« less

Generation of growth arrested Leishmania amastigotes: a tool to develop live attenuated vaccine candidates against visceral leishmaniasis.

PubMed

Selvapandiyan, Angamuthu; Dey, Ranadhir; Gannavaram, Sreenivas; Solanki, Sumit; Salotra, Poonam; Nakhasi, Hira L

2014-06-30

Visceral leishmaniasis (VL) is fatal if not treated and is prevalent widely in the tropical and sub-tropical regions of world. VL is caused by the protozoan parasite Leishmania donovani or Leishmania infantum. Although several second generation vaccines have been licensed to protect dogs against VL, there are no effective vaccines against human VL [1]. Since people cured of leishmaniasis develop lifelong protection, development of live attenuated Leishmania parasites as vaccines, which can have controlled infection, may be a close surrogate to leishmanization. This can be achieved by deletion of genes involved in the regulation of growth and/or virulence of the parasite. Such mutant parasites generally do not revert to virulence in animal models even under conditions of induced immune suppression due to complete deletion of the essential gene(s). In the Leishmania life cycle, the intracellular amastigote form is the virulent form and causes disease in the mammalian hosts. We developed centrin gene deleted L. donovani parasites that displayed attenuated growth only in the amastigote stage and were found safe and efficacious against virulent challenge in the experimental animal models. Thus, targeting genes differentially expressed in the amastigote stage would potentially attenuate only the amastigote stage and hence controlled infectivity may be effective in developing immunity. This review lays out the strategies for attenuation of the growth of the amastigote form of Leishmania for use as live vaccine against leishmaniasis, with a focus on visceral leishmaniasis. Copyright © 2014 Elsevier Ltd. All rights reserved.

Low Dose Vaccination with Attenuated Francisella tularensis Strain SchuS4 Mutants Protects against Tularemia Independent of the Route of Vaccination

PubMed Central

Rockx-Brouwer, Dedeke; Chong, Audrey; Wehrly, Tara D.; Child, Robert; Crane, Deborah D.

2012-01-01

Tularemia, caused by the Gram-negative bacterium Francisella tularensis, is a severe, sometimes fatal disease. Interest in tularemia has increased over the last decade due to its history as a biological weapon. In particular, development of novel vaccines directed at protecting against pneumonic tularemia has been an important goal. Previous work has demonstrated that, when delivered at very high inoculums, administration of live, highly attenuated strains of virulent F. tularensis can protect against tularemia. However, lower vaccinating inoculums did not offer similar immunity. One concern of using live vaccines is that the host may develop mild tularemia in response to infection and use of high inoculums may contribute to this issue. Thus, generation of a live vaccine that can efficiently protect against tularemia when delivered in low numbers, e.g. <100 organisms, may address this concern. Herein we describe the ability of three defined, attenuated mutants of F. tularensis SchuS4, deleted for FTT0369c, FTT1676, or FTT0369c and FTT1676, respectively, to engender protective immunity against tularemia when delivered at concentrations of approximately 50 or fewer bacteria. Attenuated strains for use as vaccines were selected by their inability to efficiently replicate in macrophages in vitro and impaired replication and dissemination in vivo. Although all strains were defective for replication in vitro within macrophages, protective efficacy of each attenuated mutant was correlated with their ability to modestly replicate and disseminate in the host. Finally, we demonstrate the parenteral vaccination with these strains offered superior protection against pneumonic tularemia than intranasal vaccination. Together our data provides proof of principle that low dose attenuated vaccines may be a viable goal in development of novel vaccines directed against tularemia. PMID:22662210

Control of poultry coccidiosis: changing trends.

PubMed

Tewari, A K; Maharana, B R

2011-06-01

Coccidiosis is the most important protozoan disease affecting the poultry industry worldwide. Control of poultry coccidiosis is presently based on managerial skills and the use of prophylactic coccidiostatic drugs. With the emergence of drug resistant Eimeria strains, emphasis has been laid on development and use of safer vaccines; some of them have been commercialized successfully. The present review deals with the various factors responsible for the development of clinical coccidiosis in poultry as well as an overview of the currently available inducers and boosters of immunity against coccidiosis. There are three groups of vaccines currently available against coccidiosis which can be distinguished on the basis of characteristics of the Eimeria species included in the respective products, viz. vaccines based on live virulent strains, vaccines based on live attenuated strains, and vaccines based on live strains that are relatively tolerant to the ionophore compounds. The latter vaccine combines the early chemotherapeutic effect of ionophores with the late prophylactic effect of vaccination. Although in the near future more varieties of oocyst based live vaccines are expected, identification of selective coccidian-specific immunoprotective molecules is likely to get more attention to facilitate the sustainable control of poultry coccidiosis.

Combined administration in a single injection of a feline multivalent modified live vaccine against FHV, FCV, and FPLV together with a recombinant FeLV vaccine is both safe and efficacious for all four major feline viral pathogens.

PubMed

Kanellos, Theo; Sutton, David J; Salisbury, Claire F; Chalmers, William Stuart K

2008-08-01

Nobivac Tricat, a lyophilised trivalent modified live attenuated vaccine is routinely used to protect cats against three commonly diagnosed feline viral pathogens namely herpesvirus, calicivirus and panleukopenia virus. The recognition of feline leukaemia virus (FeLV) as an important viral pathogen has prompted the development of an efficacious liquid recombinant subunit FeLV vaccine (p45 envelope protein). Lyophilised Tricat vaccine was dissolved in the liquid FeLV vaccine and no detectable deleterious effect on the titre of any of the live virus components was observed after 2h incubation. In vivo studies where the vaccines were mixed in the same syringe prior to inoculation showed no alteration to the safety profile assessed by repeat and overdose studies. Serological comparisons of the modified live viral antibody titres showed no evidence of reduced responses following administration of the mixed products. Challenge studies using pathogenic herpesvirus and FeLV revealed no difference in the degree of clinical protection. This paper shows that neither safety nor efficacy is adversely affected as a result of mixing the two vaccines.

Attenuated Human Parainfluenza Virus Type 1 (HPIV1) Expressing the Fusion Glycoprotein of Human Respiratory Syncytial Virus (RSV) as a Bivalent HPIV1/RSV Vaccine

PubMed Central

Mackow, Natalie; Amaro-Carambot, Emérito; Liang, Bo; Surman, Sonja; Lingemann, Matthias; Yang, Lijuan; Collins, Peter L.

2015-01-01

ABSTRACT Live attenuated recombinant human parainfluenza virus type 1 (rHPIV1) was investigated as a vector to express the respiratory syncytial virus (RSV) fusion (F) glycoprotein, to provide a bivalent vaccine against RSV and HPIV1. The RSV F gene was engineered to include HPIV1 transcription signals and inserted individually into three gene locations in each of the two attenuated rHPIV1 backbones. Each backbone contained a single previously described attenuating mutation that was stabilized against deattenuation, specifically, a non-temperature-sensitive deletion mutation involving 6 nucleotides in the overlapping P/C open reading frames (ORFs) (CΔ170) or a temperature-sensitive missense mutation in the L ORF (LY942A). The insertion sites in the genome were pre-N (F1), N-P (F2), or P-M (F3) and were identical for both backbones. In vitro, the presence of the F insert reduced the rate of virus replication, but the final titers were the same as the final titer of wild-type (wt) HPIV1. High levels of RSV F expression in cultured cells were observed with rHPIV1-CΔ170-F1, -F2, and -F3 and rHPIV1-LY942A-F1. In hamsters, the rHPIV1-CΔ170-F1, -F2, and -F3 vectors were moderately restricted in the nasal turbinates, highly restricted in lungs, and genetically stable in vivo. Among the CΔ170 vectors, the F1 virus was the most immunogenic and protective against wt RSV challenge. The rHPIV1-LY942A vectors were highly restricted in vivo and were not detectably immunogenic or protective, indicative of overattenuation. The CΔ170-F1 construct appears to be suitably attenuated and immunogenic for further development as a bivalent intranasal pediatric vaccine. IMPORTANCE There are no vaccines for the pediatric respiratory pathogens RSV and HPIV. We are developing live attenuated RSV and HPIV vaccines for use in virus-naive infants. Live attenuated RSV strains in particular are difficult to develop due to their poor growth and physical instability, but these obstacles could be avoided by the use of a vaccine vector. We describe the development and preclinical evaluation of live attenuated rHPIV1 vectors expressing the RSV F protein. Two different attenuated rHPIV1 backbones were each engineered to express RSV F from three different gene positions. The rHPIV1-CΔ170-F1 vector, bearing an attenuating deletion mutation (CΔ170) in the P/C gene and expressing RSV F from the pre-N position, was attenuated, stable, and immunogenic against the RSV F protein and HPIV1 in the hamster model and provided substantial protection against RSV challenge. This study provides a candidate rHPIV1-RSV-F vaccine virus suitable for continued development as a bivalent vaccine against two major childhood pathogens. PMID:26223633

Vaccination Against Tuberculosis With Whole-Cell Mycobacterial Vaccines.

PubMed

Scriba, Thomas J; Kaufmann, Stefan H E; Henri Lambert, Paul; Sanicas, Melvin; Martin, Carlos; Neyrolles, Olivier

2016-09-01

Live attenuated and killed whole-cell vaccines (WCVs) offer promising vaccination strategies against tuberculosis. A number of WCV candidates, based on recombinant bacillus Calmette-Guerin (BCG), attenuated Mycobacterium tuberculosis, or related mycobacterial species are in various stages of preclinical or clinical development. In this review, we discuss the vaccine candidates and key factors shaping the development pathway for live and killed WCVs and provide an update on progress. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

A live-attenuated chimeric PCV2 vaccine based on subtype 2b is transmitted to contact pigs but is not upregulated by concurrent infection with PPV and PRRSV and is efficacious in a triple challenge co-infection model

USDA-ARS?s Scientific Manuscript database

The objective of this study was to determine the safety and efficacy of a new live-attenuated chimeric PCV1/2b vaccine. Forty-six, 21-day-old, PCV2-naïve pigs were randomly assigned to one of six groups (Negative controls, positive controls, Vac-0, Vac-0-PCV2, Contact-PCV2, Vac-28-PCV2). All pigs we...

Studies of parvovirus vaccination in the dog: the performance of live attenuated feline parvovirus vaccines.

PubMed

Thompson, H; McCandlish, I A; Cornwell, H J; Macartney, L; Maxwell, N S; Weipers, A F; Wills, I R; Black, J A; Mackenzie, A C

1988-04-16

The performance of three live attenuated feline parvovirus vaccines licensed for use in the dog was studied. At the end of the primary vaccination course 67 per cent of dogs had inadequate antibody levels (less than or equal to 32) as measured by a haemagglutination inhibition test. Interference by maternal antibody accounted for some of the failures but the fact that there was no significant difference in performance between dogs vaccinated at 12 weeks or 16 weeks of age indicated that maternal antibody was not the only factor.

Live attenuated pre-erythrocytic malaria vaccines.

PubMed

Keitany, Gladys J; Vignali, Marissa; Wang, Ruobing

2014-01-01

Although recent control measures have significantly reduced malaria cases and deaths in many endemic areas, an effective vaccine will be essential to eradicate this parasitic disease. Malaria vaccine strategies developed to date focus on different phases of the parasite's complex life cycle in the human host and mosquito vector, and include both subunit-based and whole-parasite vaccines. This review focuses on the 3 live-attenuated malaria vaccination strategies that have been tested in humans to date, and discusses their progress, challenges and the immune correlates of protection that have been identified.

MicroRNA-Based Attenuation of Influenza Virus across Susceptible Hosts.

PubMed

Waring, Barbara M; Sjaastad, Louisa E; Fiege, Jessica K; Fay, Elizabeth J; Reyes, Ismarc; Moriarity, Branden; Langlois, Ryan A

2018-01-15

Influenza A virus drives significant morbidity and mortality in humans and livestock. Annual circulation of the virus in livestock and waterfowl contributes to severe economic disruption and increases the risk of zoonotic transmission of novel strains into the human population, where there is no preexisting immunity. Seasonal vaccinations in humans help prevent infection and can reduce symptoms when infection does occur. However, current vaccination regimens available for livestock are limited in part due to safety concerns regarding reassortment/recombination with circulating strains. Therefore, inactivated vaccines are used instead of the more immunostimulatory live attenuated vaccines. MicroRNAs (miRNAs) have been used previously to generate attenuated influenza A viruses for use as a vaccine. Here, we systematically targeted individual influenza gene mRNAs using the same miRNA to determine the segment(s) that yields maximal attenuation potential. This analysis demonstrated that targeting of NP mRNA most efficiently ablates replication. We further increased the plasticity of miRNA-mediated attenuation of influenza A virus by exploiting a miRNA, miR-21, that is ubiquitously expressed across influenza-susceptible hosts. In order to construct this targeted virus, we used CRISPR/Cas9 to eliminate the universally expressed miR-21 from MDCK cells. miR-21-targeted viruses were attenuated in human, mouse, canine, and avian cells and drove protective immunity in mice. This strategy has the potential to enhance the safety of live attenuated vaccines in humans and zoonotic reservoirs. IMPORTANCE Influenza A virus circulates annually in both avian and human populations, causing significant morbidity, mortality, and economic burden. High incidence of zoonotic infections greatly increases the potential for transmission to humans, where no preexisting immunity or vaccine exists. There is a critical need for new vaccine strategies to combat emerging influenza outbreaks. MicroRNAs were used previously to attenuate influenza A viruses. We propose the development of a novel platform to produce live attenuated vaccines that are highly customizable, efficacious across a broad species range, and exhibit enhanced safety over traditional vaccination methods. This strategy exploits a microRNA that is expressed abundantly in influenza virus-susceptible hosts. By eliminating this ubiquitous microRNA from a cell line, targeted viruses that are attenuated across susceptible strains can be generated. This approach greatly increases the plasticity of the microRNA targeting approach and enhances vaccine safety. Copyright © 2018 American Society for Microbiology.

The influence of the multi-basic cleavage site of the H5 hemagglutinin on the attenuation, immunogenicity and efficacy of a live attenuated influenza A H5N1 cold-adapted vaccine virus.

PubMed

Suguitan, Amorsolo L; Marino, Michael P; Desai, Purvi D; Chen, Li-Mei; Matsuoka, Yumiko; Donis, Ruben O; Jin, Hong; Swayne, David E; Kemble, George; Subbarao, Kanta

2009-12-20

A recombinant live attenuated influenza virus DeltaH5N1 vaccine with a modified hemagglutinin (HA) and intact neuraminidase genes from A/Vietnam/1203/04 (H5N1) and six remaining genome segments from A/Ann Arbor/6/60 (H2N2) cold-adapted (AA ca) virus was previously shown to be attenuated in chickens, mice and ferrets. Evaluation of the recombinant H5N1 viruses in mice indicated that three independent factors contributed to the attenuation of the DeltaH5N1 vaccine: the attenuating mutations specified by the AA ca loci had the greatest influence, followed by the deletion of the H5 HA multi-basic cleavage site (MBS), and the constellation effects of the AA genes acting in concert with the H5N1 glycoproteins. Restoring the MBS in the H5 HA of the vaccine virus improved its immunogenicity and efficacy, likely as a consequence of increased virus replication, indicating that removal of the MBS had a deleterious effect on the immunogenicity and efficacy of the DeltaH5N1 vaccine in mice.

The influence of the multi-basic cleavage site of the H5 hemagglutinin on the attenuation, immunogenicity and efficacy of a live attenuated influenza A H5N1 cold-adapted vaccine virus

PubMed Central

Suguitan, Amorsolo L.; Marino, Michael P.; Desai, Purvi D.; Chen, Li-Mei; Matsuoka, Yumiko; Donis, Ruben O.; Jin, Hong; Swayne, David E.; Kemble, George; Subbarao, Kanta

2009-01-01

A recombinant live attenuated influenza virus ΔH5N1 vaccine with a modified hemagglutinin (HA) and intact neuraminidase genes from A/Vietnam/1203/04 (H5N1) and six remaining genome segments from A/Ann Arbor/6/60 (H2N2) cold-adapted (AA ca) virus was previously shown to be attenuated in chickens, mice and ferrets. Evaluation of the recombinant H5N1 viruses in mice indicated that three independent factors contributed to the attenuation of the ΔH5N1 vaccine: the attenuating mutations specified by the AA ca loci had the greatest influence, followed by the deletion of the H5 HA multi-basic cleavage site (MBS), and the constellation effects of the AA genes acting in concert with the H5N1 glycoproteins. Restoring the MBS in the H5 HA of the vaccine virus improved its immunogenicity and efficacy, likely as a consequence of increased virus replication, indicating that removal of the MBS had a deleterious effect on the immunogenicity and efficacy of the ΔH5N1 vaccine in mice. PMID:19833372

Attenuation correction strategies for multi-energy photon emitters using SPECT

NASA Astrophysics Data System (ADS)

Pretorius, P. H.; King, M. A.; Pan, T.-S.; Hutton, B. F.

1997-06-01

The aim of this study was to investigate whether the photopeak window projections from different energy photons can be combined into a single window for reconstruction or if it is better to not combine the projections due to differences in the attenuation maps required for each photon energy. The mathematical cardiac torso (MCAT) phantom was modified to simulate the uptake of Ga-67 in the human body. Four spherical hot tumors were placed in locations which challenged attenuation correction. An analytical 3D projector with attenuation and detector response included was used to generate projection sets. Data were reconstructed using filtered backprojection (FBP) reconstruction with Butterworth filtering in conjunction with one iteration of Chang attenuation correction, and with 5 and 10 iterations of ordered-subset maximum-likelihood expectation maximization (ML-OS) reconstruction. To serve as a standard for comparison, the projection sets obtained from the two energies were first reconstructed separately using their own attenuation maps. The emission data obtained from both energies were added and reconstructed using the following attenuation strategies: 1) the 93 keV attenuation map for attenuation correction, 2) the 185 keV attenuation map for attenuation correction, 3) using a weighted mean obtained from combining the 93 keV and 185 keV maps, and 4) an ordered subset approach which combines both energies. The central count ratio (CCR) and total count ratio (TCR) were used to compare the performance of the different strategies. Compared to the standard method, results indicate an over-estimation with strategy 1, an under-estimation with strategy 2 and comparable results with strategies 3 and 4. In all strategies, the CCRs of sphere 4 (in proximity to the liver, spleen and backbone) were under-estimated, although TCRs were comparable to that of the other locations. The weighted mean and ordered subset strategies for attenuation correction were of comparable accuracy to reconstruction of the windows separately. They are recommended for multi-energy photon SPECT imaging quantitation when there is a need to combine the acquisitions of multiple windows.

Comparative study and evaluation of further attenuated, live measles vaccines alone and in combination with mumps and rubella vaccines.

PubMed

Wegmann, A; Glück, R; Just, M; Mischler, R; Paroz, P; Germanier, R

1986-01-01

The further attenuated Enders (FAE) measles vaccine strain and the Edmonston B-Zagreb (EZ) measles vaccine strain were compared. In VERO-cells plaque sizes of FAE varied between 0.5 and 1 mm, those of EZ between 1 and 2 mm in diameter. The lots available in Switzerland during a 2 year period showed virus titers of 10(3.1) to 10(4.0) TCID50 per dose in the one vaccine (FAE) and of 10(3.1) to 10(4.5) TCID50 per dose in the other (EZ). Clinical investigations were performed with FAE and EZ monovalent and trivalent (measles + mumps + rubella) vaccine preparations. The virus titers of the vaccine lots used were 10(3.1) to 10(4.0) TCID50 per dose. The overall seroconversion rates of 96% to 100% indicate that both types of vaccine have comparable immunization properties. Stability tests demonstrated good stability of both the FAE and the EZ vaccines. Thus conservation at 37 degrees C was possible for 2 and 4 weeks, respectively, and at 41 degrees C for 6 and 6 days, respectively, without undue loss of live virus content (less than 1 log 10). Since the EZ vaccine is derived from human diploid cells, it is particularly suitable for the vaccination of persons with a history of allergy to avian proteins.

Concurrent micro-RNA mediated silencing of tick-borne flavivirus replication in tick vector and in the brain of vertebrate host.

PubMed

Tsetsarkin, Konstantin A; Liu, Guangping; Kenney, Heather; Hermance, Meghan; Thangamani, Saravanan; Pletnev, Alexander G

2016-09-13

Tick-borne viruses include medically important zoonotic pathogens that can cause life-threatening diseases. Unlike mosquito-borne viruses, whose impact can be restrained via mosquito population control programs, for tick-borne viruses only vaccination remains the reliable means of disease prevention. For live vaccine viruses a concern exists, that spillovers from viremic vaccinees could result in introduction of genetically modified viruses into sustainable tick-vertebrate host transmission cycle in nature. To restrict tick-borne flavivirus (Langat virus, LGTV) vector tropism, we inserted target sequences for tick-specific microRNAs (mir-1, mir-275 and mir-279) individually or in combination into several distant regions of LGTV genome. This caused selective attenuation of viral replication in tick-derived cells. LGTV expressing combinations of target sequences for tick- and vertebrate CNS-specific miRNAs were developed. The resulting viruses replicated efficiently and remained stable in simian Vero cells, which do not express these miRNAs, however were severely restricted to replicate in tick-derived cells. In addition, simultaneous dual miRNA targeting led to silencing of virus replication in live Ixodes ricinus ticks and abolished virus neurotropism in highly permissive newborn mice. The concurrent restriction of adverse replication events in vertebrate and invertebrate hosts will, therefore, ensure the environmental safety of live tick-borne virus vaccine candidates.

Live bacterial vaccines--a review and identification of potential hazards.

PubMed

Detmer, Ann; Glenting, Jacob

2006-06-23

The use of live bacteria to induce an immune response to itself or to a carried vaccine component is an attractive vaccine strategy. Advantages of live bacterial vaccines include their mimicry of a natural infection, intrinsic adjuvant properties and their possibility to be administered orally. Derivatives of pathogenic and non-pathogenic food related bacteria are currently being evaluated as live vaccines. However, pathogenic bacteria demands for attenuation to weaken its virulence. The use of bacteria as vaccine delivery vehicles implies construction of recombinant strains that contain the gene cassette encoding the antigen. With the increased knowledge of mucosal immunity and the availability of genetic tools for heterologous gene expression the concept of live vaccine vehicles gains renewed interest. However, administration of live bacterial vaccines poses some risks. In addition, vaccination using recombinant bacteria results in the release of live recombinant organisms into nature. This places these vaccines in the debate on application of genetically modified organisms. In this review we give an overview of live bacterial vaccines on the market and describe the development of new live vaccines with a focus on attenuated bacteria and food-related lactic acid bacteria. Furthermore, we outline the safety concerns and identify the hazards associated with live bacterial vaccines and try to give some suggestions of what to consider during their development.

Virus engineering: Fighting HIV at its own game

NASA Astrophysics Data System (ADS)

Lin, Shixian; Chen, Peng R.

2014-07-01

Live-attenuated viruses used in vaccines can regain their virulence, which for deadly viruses such as HIV is an unacceptable risk. Now, attenuated HIV-1 viruses, which include mutations that genetically encode unnatural amino acids and prevent them from replicating in normal cells, have been constructed.

Immune effects of the vaccine of live attenuated Aeromonas hydrophila screened by rifampicin on common carp (Cyprinus carpio L).

PubMed

Jiang, Xinyu; Zhang, Chao; Zhao, Yanjing; Kong, Xianghui; Pei, Chao; Li, Li; Nie, Guoxing; Li, Xuejun

2016-06-08

Aeromonas hydrophila, as a strong Gram-negative bacterium, can infect a wide range of freshwater fish, including common carp Cyprinus carpio, and cause the huge economic loss. To create the effective vaccine is the best way to control the outbreak of the disease caused by A. hydrophila. In this study, a live attenuated A. hydrophila strain, XX1LA, was screened from the pathogenic A. hydrophila strain XX1 cultured on medium containing the antibiotic rifampicin, which was used as a live attenuated vaccine candidate. The immune protection of XX1LA against the pathogen A. hydrophila in common carp was evaluated by the relative percent survival (RPS), the specific IgM antibody titers, serum lysozyme activity and the expression profiles of multiple immune-related genes at the different time points following immunization. The results showed that the variable up-regulations of the immune-related genes, such as the pro-inflammatory cytokine IL-1β, the chemokine IL-10 and IgM, were observed in spleen and liver of common carp injected in the vaccines with the formalin-killed A. hydrophila (FKA) and the live attenuated XX1LA. Specific antibody to A. hydrophila was found to gradually increase during 28 days post-vaccination (dpv), and the RPS (83.7%) in fish vaccinated with XX1LA, was significant higher than that (37.2%) in fish vaccinated with FKA (P<0.05) on Day 28 after challenged by pathogen. It was demonstrated that the remarkable immune protection presented in the group vaccinated with XX1LA. During the late stage of 4-week immunization phase, compared with FKA and the control, specific IgM antibody titers significantly increased (P<0.05) in the XX1LA group. The activity of the lysozyme in serum indicated no significant change among three groups. In summary, the live attenuated bacterial vaccine XX1LA, screened in this study, indicates the better protect effect on common carp against A. hydrophila, which can be applied in aquaculture of common carp to prevent from the disease outbreak in the future. Copyright © 2016 Elsevier Ltd. All rights reserved.

Attenuation correction strategies for multi-energy photon emitters using SPECT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pretorius, P.H.; King, M.A.; Pan, T.S.

1996-12-31

The aim of this study was to investigate whether the photopeak window projections from different energy photons can be combined into a single window for reconstruction or if it is better to not combine the projections due to differences in the attenuation maps required for each photon energy. The mathematical cardiac torso (MCAT) phantom was modified to simulate the uptake of Ga-67 in the human body. Four spherical hot tumors were placed in locations which challenged attenuation correction. An analytical 3D projector with attenuation and detector response included was used to generate projection sets. Data were reconstructed using filtered backprojectionmore » (FBP) reconstruction with Butterworth filtering in conjunction with one iteration of Chang attenuation correction, and with 5 and 10 iterations of ordered-subset maximum-likelihood expectation-maximization reconstruction. To serve as a standard for comparison, the projection sets obtained from the two energies were first reconstructed separately using their own attenuation maps. The emission data obtained from both energies were added and reconstructed using the following attenuation strategies: (1) the 93 keV attenuation map for attenuation correction, (2) the 185 keV attenuation map for attenuation correction, (3) using a weighted mean obtained from combining the 93 keV and 185 keV maps, and (4) an ordered subset approach which combines both energies. The central count ratio (CCR) and total count ratio (TCR) were used to compare the performance of the different strategies. Compared to the standard method, results indicate an over-estimation with strategy 1, an under-estimation with strategy 2 and comparable results with strategies 3 and 4. In all strategies, the CCR`s of sphere 4 were under-estimated, although TCR`s were comparable to that of the other locations. The weighted mean and ordered subset strategies for attenuation correction were of comparable accuracy to reconstruction of the windows separately.« less

Predicted Attenuation Relation and Observed Ground Motion of Gorkha Nepal Earthquake of 25 April 2015

NASA Astrophysics Data System (ADS)

Singh, R. P.; Ahmad, R.

2015-12-01

A comparison of recent observed ground motion parameters of recent Gorkha Nepal earthquake of 25 April 2015 (Mw 7.8) with the predicted ground motion parameters using exitsing attenuation relation of the Himalayan region will be presented. The recent earthquake took about 8000 lives and destroyed thousands of poor quality of buildings and the earthquake was felt by millions of people living in Nepal, China, India, Bangladesh, and Bhutan. The knowledge of ground parameters are very important in developing seismic code of seismic prone regions like Himalaya for better design of buildings. The ground parameters recorded in recent earthquake event and aftershocks are compared with attenuation relations for the Himalayan region, the predicted ground motion parameters show good correlation with the observed ground parameters. The results will be of great use to Civil engineers in updating existing building codes in the Himlayan and surrounding regions and also for the evaluation of seismic hazards. The results clearly show that the attenuation relation developed for the Himalayan region should be only used, other attenuation relations based on other regions fail to provide good estimate of observed ground motion parameters.

ADCC Develops Over Time during Persistent Infection with Live-Attenuated SIV and Is Associated with Complete Protection against SIVmac251 Challenge

PubMed Central

Alpert, Michael D.; Harvey, Jackson D.; Lauer, W. Anderson; Reeves, R. Keith; Piatak, Michael; Carville, Angela; Mansfield, Keith G.; Lifson, Jeffrey D.; Li, Wenjun; Desrosiers, Ronald C.; Johnson, R. Paul; Evans, David T.

2012-01-01

Live-attenuated strains of simian immunodeficiency virus (SIV) routinely confer apparent sterilizing immunity against pathogenic SIV challenge in rhesus macaques. Understanding the mechanisms of protection by live-attenuated SIV may provide important insights into the immune responses needed for protection against HIV-1. Here we investigated the development of antibodies that are functional against neutralization-resistant SIV challenge strains, and tested the hypothesis that these antibodies are associated with protection. In the absence of detectable neutralizing antibodies, Env-specific antibody-dependent cell-mediated cytotoxicity (ADCC) emerged by three weeks after inoculation with SIVΔnef, increased progressively over time, and was proportional to SIVΔnef replication. Persistent infection with SIVΔnef elicited significantly higher ADCC titers than immunization with a non-persistent SIV strain that is limited to a single cycle of infection. ADCC titers were higher against viruses matched to the vaccine strain in Env, but were measurable against viruses expressing heterologous Env proteins. In two separate experiments, which took advantage of either the strain-specificity or the time-dependent maturation of immunity to overcome complete protection against SIVmac251 challenge, measures of ADCC activity were higher among the SIVΔnef-inoculated macaques that remained uninfected than among those that became infected. These observations show that features of the antibody response elicited by SIVΔnef are consistent with hallmarks of protection by live-attenuated SIV, and reveal an association between Env-specific antibodies that direct ADCC and apparent sterilizing protection by SIVΔnef. PMID:22927823

Swine dysentery: protection of pigs by oral and parenteral immunisation with attenuated Treponema hyodysenteriae.

PubMed

Hudson, M J; Alexander, T J; Lysons, R J; Prescott, J F

1976-11-01

An attenuated strain of Treponema hyodysenteriae was used to immunise 18 pigs in three experiments. Live attenuated spirochaetes were dosed orally and injected intra-peritoneally, and killed spirochaetes were injected intramuscularly with adjuvant. The vaccinated pigs, which developed high serum agglutination titres against T hyodysenteriae, and 18 unvaccinated litter-mates were repeatedly challenged with virulent T hyodysenteriae. Nine vaccinated pigs and 16 control pigs developed typical swine dysentery.

Induction of Cell Cycle and NK Cell Responses by Live-Attenuated Oral Vaccines against Typhoid Fever

PubMed Central

Blohmke, Christoph J.; Hill, Jennifer; Darton, Thomas C.; Carvalho-Burger, Matheus; Eustace, Andrew; Jones, Claire; Schreiber, Fernanda; Goodier, Martin R.; Dougan, Gordon; Nakaya, Helder I.; Pollard, Andrew J.

2017-01-01

The mechanisms by which oral, live-attenuated vaccines protect against typhoid fever are poorly understood. Here, we analyze transcriptional responses after vaccination with Ty21a or vaccine candidate, M01ZH09. Alterations in response profiles were related to vaccine-induced immune responses and subsequent outcome after wild-type Salmonella Typhi challenge. Despite broad genetic similarity, we detected differences in transcriptional responses to each vaccine. Seven days after M01ZH09 vaccination, marked cell cycle activation was identified and associated with humoral immunogenicity. By contrast, vaccination with Ty21a was associated with NK cell activity and validated in peripheral blood mononuclear cell stimulation assays confirming superior induction of an NK cell response. Moreover, transcriptional signatures of amino acid metabolism in Ty21a recipients were associated with protection against infection, including increased incubation time and decreased severity. Our data provide detailed insight into molecular immune responses to typhoid vaccines, which could aid the rational design of improved oral, live-attenuated vaccines against enteric pathogens. PMID:29075261

The Molecular Specificity of the Human Antibody Response to Dengue Virus Infections.

PubMed

Gallichotte, Emily N; Baric, Ralph S; de Silva, Aravinda M

2018-01-01

Dengue viruses (DENV) are mosquito-borne positive sense RNA viruses in the family Flaviviridae. The four serotypes of DENV (DENV1, DENV2, DENV3, DENV4) are widely distributed and it is estimated over a third of the world's population is at risk of infection [4]. While the majority of infections are asymptomatic, DENV infection can cause a spectrum of disease, from mild flu-like symptoms, to the more severe DENV hemorrhagic fever and shock syndrome [24]. Over the past 20 years, there have been intense efforts to develop a tetravalent live-attenuated DENV vaccine [36]. The process of vaccine development has been largely empirical, because effective live attenuated vaccines have been developed for other flaviviruses like yellow fever and Japanese encephalitis viruses. However, recent results from phase III live attenuated DENV vaccine efficacy trials are mixed with evidence for efficacy in some populations but not others [20]. In light of unexpected results from DENV vaccine trials, in this chapter we will review recent discoveries about the human antibody response to natural DENV infection and discuss the relevance of this work to understanding vaccine performance.

Engineering nanoparticle-coated bacteria as oral DNA vaccines for cancer immunotherapy.

PubMed

Hu, Qinglian; Wu, Min; Fang, Chun; Cheng, Changyong; Zhao, Mengmeng; Fang, Weihuan; Chu, Paul K; Ping, Yuan; Tang, Guping

2015-04-08

Live attenuated bacteria are of increasing importance in biotechnology and medicine in the emerging field of cancer immunotherapy. Oral DNA vaccination mediated by live attenuated bacteria often suffers from low infection efficiency due to various biological barriers during the infection process. To this end, we herein report, for the first time, a new strategy to engineer cationic nanoparticle-coated bacterial vectors that can efficiently deliver oral DNA vaccine for efficacious cancer immunotherapy. By coating live attenuated bacteria with synthetic nanoparticles self-assembled from cationic polymers and plasmid DNA, the protective nanoparticle coating layer is able to facilitate bacteria to effectively escape phagosomes, significantly enhance the acid tolerance of bacteria in stomach and intestines, and greatly promote dissemination of bacteria into blood circulation after oral administration. Most importantly, oral delivery of DNA vaccines encoding autologous vascular endothelial growth factor receptor 2 (VEGFR2) by this hybrid vector showed remarkable T cell activation and cytokine production. Successful inhibition of tumor growth was also achieved by efficient oral delivery of VEGFR2 with nanoparticle-coated bacterial vectors due to angiogenesis suppression in the tumor vasculature and tumor necrosis. This proof-of-concept work demonstrates that coating live bacterial cells with synthetic nanoparticles represents a promising strategy to engineer efficient and versatile DNA vaccines for the era of immunotherapy.

Immunization in pregnancy.

PubMed

Gruslin, Andrée; Steben, Marc; Halperin, Scott; Money, Deborah M; Yudin, Mark H; Boucher, Marc; Cormier, Beatrice; Ogilvie, Gina; Paquet, Caroline; Steenbeek, Audrey; Van Eyk, Nancy; van Schalkwyk, Julie; Wong, Thomas

2008-12-01

To review the evidence and provide recommendations on immunization in pregnancy. Outcomes evaluated include effectiveness of immunization, and risks and benefits for mother and fetus. The Medline and Cochrane databases were searched for articles published up to June 2007 on the topic of immunization in pregnancy. The evidence obtained was reviewed and evaluated by the Infectious Diseases Committee of the Society of Obstetricians and Gynaecologists of Canada (SOGC) under the leadership of the principal authors, and recommendations were made according to guidelines developed by the Canadian Task Force on Preventive Health Care. Implementation of the recommendations in this guideline should result in more appropriate immunization of pregnant and breastfeeding women, decreased risk of contraindicated immunization, and better disease prevention. Recommendations 1. All women of childbearing age should be evaluated for the possibility of pregnancy before immunization. (III-A) 2. Health care providers should obtain an immunization history from all women accessing prenatal care. (III-A) 3. In general, live and/or live-attenuated virus vaccines are contraindicated during pregnancy, as there is a, largely theoretical, risk to the fetus. (II-3) 4. Women who have inadvertently received immunization with live or live-attenuated vaccines during pregnancy should not be counselled to terminate the pregnancy because of a teratogenic risk. (II-2) 5. Non-pregnant women immunized with a live or live-attenuated vaccine should be counselled to delay pregnancy for at least four weeks. (III) 6. Inactivated viral vaccines, bacterial vaccines, and toxoids are considered safe in pregnancy. (II-1) 7. Women who are breastfeeding can still be immunized (passive-active immunization, live or killed vaccines). (II-1) 8. Pregnant women should be offered the influenza vaccine when pregnant during the influenza season. (II-1).

Live attenuated hepatitis A vaccines developed in China.

PubMed

Xu, Zhi-Yi; Wang, Xuan-Yi

2014-01-01

Two live, attenuated hepatitis A vaccines, H 2 and LA-1 virus strains, were developed through serial passages of the viruses in cell cultures at 32 °C and 35 °C respectively. Both vaccines were safe and immunogenic, providing protection against clinical hepatitis A in 95% of the vaccinees, with a single dose by subcutaneous injection. The vaccine recipients were not protected from asymptomatic, subclinical hepatitis A virus (HAV) infection, which induced a similar antibody response as for unvaccinated subjects. A second dose caused anamnestic response and can be used for boosting. Oral immunization of human with H 2 vaccine or of marmoset with LA-1 vaccine failed, and no evidence was found for person-to-person transmission of the H 2 strain or for marmoset-to-marmoset transmission of LA-1 strain, by close contact. H 2 strain was genetically stable when passaged in marmosets, humans or cell cultures at 37 °C; 3 consecutive passages of the virus in marmosets did not cause virulence mutation. The live vaccines offer the benefits of low cost, single dose injection, long- term protection, and increased duration of immunity through subclinical infection. Improved sanitation and administration of 150 million doses of the live vaccines to children had led to a 90% reduction in the annual national incidence rate of hepatitis A in China during the 16-year period, from 1991 to 2006. Hepatitis A immunization with both live and inactivated HA vaccines was implemented in the national routine childhood immunization program in 2008 and around 92% of the 16 million annual births received the affordable live, attenuated vaccines at 18 months of age. Near elimination of the disease was achieved in China for 14 years following introduction of the H 2 live vaccine into the Expanded Immunization Program (EPI) in 1992.

Comparative Study of Influenza Virus Replication in MDCK Cells and in Primary Cells Derived from Adenoids and Airway Epithelium

PubMed Central

Ikizler, Mine R.; Kawaoka, Yoshihiro; Rudenko, Larisa G.; Treanor, John J.; Subbarao, Kanta; Wright, Peter F.

2012-01-01

Although clinical trials with human subjects are essential for determination of safety, infectivity, and immunogenicity, it is desirable to know in advance the infectiousness of potential candidate live attenuated influenza vaccine strains for human use. We compared the replication kinetics of wild-type and live attenuated influenza viruses, including H1N1, H3N2, H9N2, and B strains, in Madin-Darby canine kidney (MDCK) cells, primary epithelial cells derived from human adenoids, and human bronchial epithelium (NHBE cells). Our data showed that despite the fact that all tissue culture models lack a functional adaptive immune system, differentiated cultures of human epithelium exhibited the greatest restriction for all H1N1, H3N2, and B vaccine viruses studied among three cell types tested and the best correlation with their levels of attenuation seen in clinical trials with humans. In contrast, the data obtained with MDCK cells were the least predictive of restricted viral replication of live attenuated vaccine viruses in humans. We were able to detect a statistically significant difference between the replication abilities of the U.S. (A/Ann Arbor/6/60) and Russian (A/Leningrad/134/17/57) cold-adapted vaccine donor strains in NHBE cultures. Since live attenuated pandemic influenza vaccines may potentially express a hemagglutinin and neuraminidase from a non-human influenza virus, we assessed which of the three cell cultures could be used to optimally evaluate the infectivity and cellular tropism of viruses derived from different hosts. Among the three cell types tested, NHBE cultures most adequately reflected the infectivity and cellular tropism of influenza virus strains with different receptor specificities. NHBE cultures could be considered for use as a screening step for evaluating the restricted replication of influenza vaccine candidates. PMID:22915797

Evaluation of synthetic infection-enhancing lipopeptides as adjuvants for a live-attenuated canine distemper virus vaccine administered intra-nasally to ferrets.

PubMed

Nguyen, D Tien; Ludlow, Martin; van Amerongen, Geert; de Vries, Rory D; Yüksel, Selma; Verburgh, R Joyce; Osterhaus, Albert D M E; Duprex, W Paul; de Swart, Rik L

2012-07-20

Inactivated paramyxovirus vaccines have been associated with hypersensitivity responses upon challenge infection. For measles and canine distemper virus (CDV) safe and effective live-attenuated virus vaccines are available, but for human respiratory syncytial virus and human metapneumovirus development of such vaccines has proven difficult. We recently identified three synthetic bacterial lipopeptides that enhance paramyxovirus infections in vitro, and hypothesized these could be used as adjuvants to promote immune responses induced by live-attenuated paramyxovirus vaccines. Here, we tested this hypothesis using a CDV vaccination and challenge model in ferrets. Three groups of six animals were intra-nasally vaccinated with recombinant (r) CDV(5804P)L(CCEGFPC) in the presence or absence of the infection-enhancing lipopeptides Pam3CSK4 or PHCSK4. The recombinant CDV vaccine virus had previously been described to be over-attenuated in ferrets. A group of six animals was mock-vaccinated as control. Six weeks after vaccination all animals were challenged with a lethal dose of rCDV strain Snyder-Hill expressing the red fluorescent protein dTomato. Unexpectedly, intra-nasal vaccination of ferrets with rCDV(5804P)L(CCEGFPC) in the absence of lipopeptides resulted in good immune responses and protection against lethal challenge infection. However, in animals vaccinated with lipopeptide-adjuvanted virus significantly higher vaccine virus loads were detected in nasopharyngeal lavages and peripheral blood mononuclear cells. In addition, these animals developed significantly higher CDV neutralizing antibody titers compared to animals vaccinated with non-adjuvanted vaccine. This study demonstrates that the synthetic cationic lipopeptides Pam3CSK4 and PHCSK4 not only enhance paramyxovirus infection in vitro, but also in vivo. Given the observed enhancement of immunogenicity their potential as adjuvants for other live-attenuated paramyxovirus vaccines should be considered. Copyright © 2012 Elsevier Ltd. All rights reserved.

Smallpox vaccine: problems and prospects.

PubMed

Poland, Gregory A; Neff, John M

2003-11-01

Smallpox justifiably is feared because of its morbidity and mortality. Wide-spread population-level susceptibility to smallpox exists, and the only effective tool against the virus is a live, attenuated vaccine that is highly reactogenic and controversial. A significant minority of the population has contraindications that prevent preexposure use of this vaccine. Newer, safer, and equally immunogenic vaccines must be developed and licensed. Several live, attenuated vaccines are in clinical trials. Although these vaccines may prove to be less reactogenic, they still may not be administered safely to a significant portion of the population because they contain live, attenuated viruses. Newer vaccines will be needed if routine preexposure vaccination is to be instituted universally. The idea of a subunit or peptide-based vaccine is appealing, because it obviates potential safety concerns. It may be possible to use a more-attenuated, live vaccine strain for a large segment of the population on a preexposure basis and accept the morbidity and mortality that would result from its use on a postexposure basis, if necessary. The need for widespread population-level protection against variola infection is apparent. The use of the new biology tools to predict or define who might experience serious reactions to the smallpox vaccine and why these reactions occur is an area ripe for additional research. The reason why an individual develops postvaccinal encephalitis remains unknown, and the development is unpredictable and untreatable. In the future, if the mechanism behind such adverse events is defined, it may be possible to screen persons who are likely to experience such events. Although the authors remain proponents for use of the vaccine in alignment with the CDC vaccination program and recommendations, the previous concerns indicate that new knowledge must be gained and shared. Further research on attenuated vaccines and nonliving or peptide vaccines with equal efficacy should remain the goal, as it is apparent that smallpox vaccine once again will become part of the vaccinologist's and public health official's armamentarium in the decades to come.

Development of an acid-resistant Salmonella Typhi Ty21a attenuated vector for improved oral vaccine delivery

USDA-ARS?s Scientific Manuscript database

The licensed oral, live-attenuated bacterial vaccine for typhoid fever, Salmonella Typhi strain Ty21a, has also been utilized as a vaccine delivery platform for expression of diverse foreign antigens that stimulate protection against shigellosis, anthrax, plague, or human papilloma virus. However, T...

Association of the host immune response with protection using a live attenuated African swine fever virus model

USDA-ARS?s Scientific Manuscript database

African swine fever virus (ASFV) causes a lethal disease of swine. Infection with attenuated strains protect against challenge but there is limited knowledge of the immune mechanisms generating that protection. ASFV Pret4 produces a fatal disease, while its derivative, lacking virulence-associated g...

Recoding structural glycoprotein E2 in classical swine fever virus (CSFV) produces complete virus attenuation in swine and protects infected animals against disease

USDA-ARS?s Scientific Manuscript database

Controlling classical swine fever (CSF) involves vaccination in endemic regions and preemptive slaughter of infected swine herds during epidemics. Generally, live attenuated vaccines induce solid immunity. Using diverse approaches, reverse genetics has been useful in developing classical swine fever...

Deletion of the thymidine kinase gene induces complete attenuation of the Georgia isolate of African swine fever virus

USDA-ARS?s Scientific Manuscript database

African swine fever virus (ASFV) is the etiological agent of a contagious and often lethal viral disease of domestic pigs. There are no vaccines to control Africa swine fever (ASF). Experimental vaccines have been developed using genetically modified live attenuated ASFVs obtained by specifically de...

Development of a new live attenuated mumps virus vaccine in human diploid cells.

PubMed

Sassani, A; Mirchamsy, H; Shafyi, A; Ahourai, P; Razavi, J; Gholami, M R; Mohammadi, A; Ezzi, A; Rahmani, M; Fateh, G

1991-07-01

A new live attenuated mumps vaccine was developed in human diploid cells. The S-12 virus was isolated from a 10-year-old girl showing typical symptoms of mumps infection, the diagnosis was confirmed by a pediatrician. The virus was isolated in green monkey kidney cells, without passage in chick embryo cavity or chick embryo fibroblasts. Attenuation of the wild virus was performed by serial passages in human diploid cells (MRC-5). The attenuated virus was characterized by identity tests, as well as by a reduction in plaque size, as marker tests. The virus was free from adventitious agents and safe for laboratory animals as well as for monkeys. The reactogenicity and immunogenicity of the S-12 virus for man was investigated by administration of a monovalent vaccine to 20 seronegative adult male volunteers and 30 children aged 1 to 5 years without history of mumps infection or vaccination. Seroconversion was obtained in 95% of the vaccinees. The new vaccine has the advantage of not requiring specific pathogen-free eggs, and being free from avian proteins and therefore can be used in sensitized patients.

Using Cell-Phone Tower Signals for Detecting the Precursors of Fog

NASA Astrophysics Data System (ADS)

David, N.; Gao, H. O.

2018-01-01

In the last decade, published research has indicated the potential of commercial microwave links that comprise the data transmission infrastructure of cellular communication networks as an environmental monitoring technology. Different weather phenomena cause interference in the wireless communication links that can therefore essentially act as a low-cost sensor network, already deployed worldwide, for atmospheric monitoring. In this study we focus on the attenuation effect caused in commercial microwave networks due to gradients in the atmospheric refractive index with altitude as a result of the combination of temperature inversions and falls in the atmospheric humidity trapped beneath them. These conditions, when combined with high relative humidity near ground level, are precursors to the creation of fog. The current work utilizes this novel approach to demonstrate the potential for detecting these preconditions of fog, a phenomenon associated with severe visibility limitations that can lead to dangerous accidents, injuries, and loss of lives.

Impact of Type I Interferon on the Safety and Immunogenicity of an Experimental Live-Attenuated Herpes Simplex Virus 1 Vaccine in Mice

PubMed Central

Royer, Derek J.; Carr, Meghan M.; Chucair-Elliott, Ana J.; Halford, William P.

2017-01-01

ABSTRACT Viral fitness dictates virulence and capacity to evade host immune defenses. Understanding the biological underpinnings of such features is essential for rational vaccine development. We have previously shown that the live-attenuated herpes simplex virus 1 (HSV-1) mutant lacking the nuclear localization signal (NLS) on the ICP0 gene (0ΔNLS) is sensitive to inhibition by interferon beta (IFN-β) in vitro and functions as a highly efficacious experimental vaccine. Here, we characterize the host immune response and in vivo pathogenesis of HSV-1 0ΔNLS relative to its fully virulent parental strain in C57BL/6 mice. Additionally, we explore the role of type 1 interferon (IFN-α/β) signaling on virulence and immunogenicity of HSV-1 0ΔNLS and uncover a probable sex bias in the induction of IFN-α/β in the cornea during HSV-1 infection. Our data show that HSV-1 0ΔNLS lacks neurovirulence even in highly immunocompromised mice lacking the IFN-α/β receptor. These studies support the translational viability of the HSV-1 0ΔNLS vaccine strain by demonstrating that, while it is comparable to a virulent parental strain in terms of immunogenicity, HSV-1 0ΔNLS does not induce significant tissue pathology. IMPORTANCE HSV-1 is a common human pathogen associated with a variety of clinical presentations ranging in severity from periodic “cold sores” to lethal encephalitis. Despite the consistent failures of HSV subunit vaccines in clinical trials spanning the past 28 years, opposition to live-attenuated HSV vaccines predicated on unfounded safety concerns currently limits their widespread acceptance. Here, we demonstrate that a live-attenuated HSV-1 vaccine has great translational potential. PMID:28122977

Oral immunization of wild boar and domestic pigs with attenuated live vaccine protects against Pseudorabies virus infection.

PubMed

Maresch, Christina; Lange, Elke; Teifke, Jens P; Fuchs, Walter; Klupp, Barbara; Müller, Thomas; Mettenleiter, Thomas C; Vahlenkamp, Thomas W

2012-12-28

In domestic pigs strict control measures and the use of gene-deleted marker vaccines resulted in the elimination of pseudorabies virus (PrV) infections in many parts of Europe and North America. In free-roaming feral pigs and wild boar populations, however, serological surveys and monitoring in The Americas, Europe and North Africa provided serological and virological evidence that PrV is more widely distributed than previously assumed. Thus, there is a constant risk of spillover of PrV infection from wild pig populations to domestic animals which could require intervention to limit the infection in wild pigs. To investigate whether oral immunization of wild boar by live-attenuated PrV could be an option, wild boar and domestic pigs were orally immunized with 2×10(6) TCID(50) of the attenuated live PrV vaccine strain Bartha supplied either with a syringe or within a blister, and subsequently intranasally challenged with 10(6) TCID(50) of the highly virulent PrV strain NIA-3. Oral immunization with live-attenuated PrV was able to confer protection against clinical signs in wild boar and against transmission of challenge virus to naïve contact animals. Only two vaccinated domestic pigs developed neurological signs after challenge infection. Our results demonstrate that oral immunization against PrV infection in wild boar is possible. In case increasing PrV infection rates in wild boar may enhance the risk for spillover into domestic pig populations, oral immunization of wild boar against PrV in endemic areas might be a feasible control strategy. Copyright © 2012 Elsevier B.V. All rights reserved.

Current and future vaccines and vaccination strategies against infectious laryngotracheitis (ILT) respiratory disease of poultry.

PubMed

García, Maricarmen

2017-07-01

Infectious laryngotracheitis (ILT) is an economically important respiratory disease of poultry that affects the industry worldwide. Vaccination is the principal tool in the control of the disease. Two types of vaccines, live attenuated and recombinant viral vector, are commercially available. The first generation of GaHV-1 vaccines available since the early 1960's are live viruses, attenuated by continuous passages in cell culture or embryos. These vaccines significantly reduce mortalities and, in particular, the chicken embryo origin (CEO) vaccines have shown to limit outbreaks of the disease. However, the CEO vaccines can regain virulence and become the source of outbreaks. Recombinant viral vector vaccines, the second generation of GaHV-1 vaccines, were first introduced in the early 2000's. These are Fowl Pox virus (FPV) and Herpes virus of turkeys (HVT) vectors expressing one or multiple GaHV-1 immunogenic proteins. Recombinant viral vector vaccines are considered a much safer alternative because they do not regain virulence. In the face of challenge, they improve bird performance and ameliorate clinical signs of the disease but fail to reduce shedding of the challenge virus increasing the likelihood of outbreaks. At the moment, several new strategies are being evaluated to improve both live attenuated and viral vector vaccines. Potential new live vaccines attenuated by deletion of genes associated with virulence or by selection of CEO viral subpopulations that do not exhibit increased virulence upon passages in birds are being evaluated. Also new vector alternatives to express GaHV-1 glycoproteins in Newcastle diseases virus (NDV) or in modified very virulent (vv) serotype I Marek's disease virus (MDV) were developed and evaluated. Copyright © 2016 Elsevier B.V. All rights reserved.

EVALUATION OF TWO CANINE DISTEMPER VIRUS VACCINES IN CAPTIVE TIGERS (PANTHERA TIGRIS).

PubMed

Sadler, Ryan A; Ramsay, Edward; McAloose, Denise; Rush, Robert; Wilkes, Rebecca P

2016-06-01

Canine distemper virus (CDV) has caused clinical disease and death in nondomestic felids in both captive settings and in the wild. Outbreaks resulting in high mortality rates in tigers (Panthera tigris) have prompted some zoos to vaccinate tigers for CDV. In this study, six tigers received a recombinant canarypox-vectored CDV vaccine (1 ml s.c.) and were revaccinated with 3 ml s.c. (mean) 39 days later. Blood collection for CDV antibody detection via serum neutralization was performed on (mean) days 0, 26, and 66 post-initial vaccination. No tigers had detectable antibodies at days 0 or 26, and only two tigers had low (16 and 32) antibody titers at day 66. Eight additional tigers received a live, attenuated CDV vaccine (1 ml s.c.) on day 0 and were revaccinated with 1 ml s.c. (mean) 171 days later. Blood collection for CDV antibody detection via serum neutralization was performed on (mean) days 0, 26, 171, and 196. Seven of eight tigers receiving the live, attenuated vaccine had no detectable titers prior to vaccination, but all animals had titers of >128 (range 128-1,024) at day 26. At 171 days, all tigers still had detectable titers (geometric mean 69.8, range 16-256), and at 196 days (2 wk post-revaccination) all but two showed an increase to >128 (range 32-512). To determine safety, an additional 41 tigers were vaccinated with 2 ml of a recombinant vaccine containing only CDV components, and an additional 38 tigers received 1 ml of the live, attenuated vaccine, administered either subcutaneously or intramuscularly; no serious adverse effects were noted. Although both vaccines appear safe, the live, attenuated vaccine produced a stronger and more consistent serologic response in tigers.

Early Potent Protection against Heterologous SIVsmE660 Challenge Following Live Attenuated SIV Vaccination in Mauritian Cynomolgus Macaques

PubMed Central

Berry, Neil; Ham, Claire; Mee, Edward T.; Rose, Nicola J.; Mattiuzzo, Giada; Jenkins, Adrian; Page, Mark; Elsley, William; Robinson, Mark; Smith, Deborah; Ferguson, Deborah; Towers, Greg; Almond, Neil; Stebbings, Richard

2011-01-01

Background Live attenuated simian immunodeficiency virus (SIV) vaccines represent the most effective means of vaccinating macaques against pathogenic SIV challenge. However, thus far, protection has been demonstrated to be more effective against homologous than heterologous strains. Immune correlates of vaccine-induced protection have also been difficult to identify, particularly those measurable in the peripheral circulation. Methodology/Principal Findings Here we describe potent protection in 6 out of 8 Mauritian-derived cynomolgus macaques (MCM) against heterologous virus challenge with the pathogenic, uncloned SIVsmE660 viral stock following vaccination with live attenuated SIVmac251/C8. MCM provided a characterised host genetic background with limited Major Histocompatibility Complex (MHC) and TRIM5α allelic diversity. Early protection, observed as soon as 3 weeks post-vaccination, was comparable to that of 20 weeks vaccination. Recrudescence of vaccine virus was most pronounced in breakthrough cases where simultaneous identification of vaccine and challenge viruses by virus-specific PCR was indicative of active co-infection. Persistence of the vaccine virus in a range of lymphoid tissues was typified by a consistent level of SIV RNA positive cells in protected vaccinates. However, no association between MHC class I /II haplotype or TRIM5α polymorphism and study outcome was identified. Conclusion/Significance This SIV vaccine study, conducted in MHC-characterised MCM, demonstrated potent protection against the pathogenic, heterologous SIVsmE660 challenge stock after only 3 weeks vaccination. This level of protection against this viral stock by intravenous challenge has not been hitherto observed. The mechanism(s) of protection by vaccination with live attenuated SIV must account for the heterologous and early protection data described in this study, including those which relate to the innate immune system. PMID:21853072

Future Approaches to DNA Vaccination Against Hemorrhagic Fever Viruses.

PubMed

Suschak, John J; Schmaljohn, Connie S

2018-01-01

To date, there is no protective vaccine for Ebola virus infection. Safety concerns have prevented the use of live-attenuated vaccines, and forced researchers to examine new vaccine formulations. DNA vaccination is an attractive method for inducing protective immunity to a variety of pathogens, but the low immunogenicity seen in larger animals and humans has hindered its usage. Various approaches have been used to improve the immunogenicity of DNA vaccines, but the most successful, and widespread, is electroporation. Of increasing interest is the use of molecular adjuvants to produce immunomodulatory signals that can both amplify and direct the immune response. When combined, these approaches have the possibility to push DNA vaccination into the forefront of medicine.

Immunization studies with attenuated strains of Bacillus anthracis.

PubMed Central

Ivins, B E; Ezzell, J W; Jemski, J; Hedlund, K W; Ristroph, J D; Leppla, S H

1986-01-01

Live, attenuated strains of Bacillus anthracis lacking either the capsule plasmid pXO2, the toxin plasmid pXO1, or both were tested for their efficacy as vaccines against intravenous challenge with anthrax toxin in Fischer 344 rats and against aerosol or intramuscular challenge with virulent anthrax spores in Hartley guinea pigs. Animals immunized with toxigenic, nonencapsulated (pXO1+, pXO2-) strains survived toxin and spore challenge and demonstrated postimmunization antibody titers to the three components of anthrax toxin (protective antigen, lethal factor, and edema factor). Immunization with two nontoxigenic, encapsulated (pXO1-, pXO2+), Pasteur vaccine strains neither provided protection nor elicited titers to any of the toxin components. Therefore, to immunize successfully against anthrax toxin or spore challenge, attenuated, live strains of B. anthracis must produce the toxin components specified by the pXO1 plasmid. PMID:3084383

A laboratory study of the perceived benefit of additional noise attenuation by houses

NASA Technical Reports Server (NTRS)

Flindell, I. H.

1983-01-01

Two Experiments were conducted to investigate the perceived benefit of additional house attenuation against aircraft flyover noise. First, subjects made annoyance judgments in a simulated living room while an operative window with real and dummy storm windows was manipulated in full view of those subjects. Second, subjects made annoyance judgments in an anechoic audiometric test chamber of frequency shaped noise signals having spectra closely matched to those of the aircraft flyover noises reproduced in the first experiment. These stimuli represented the aircraft flyover noises in levels and spectra but without the situational and visual cues present in the simulated living room. Perceptual constancy theory implies that annoyance tends to remain constant despite reductions in noise level caused by additional attenuation of which the subjects are fully aware. This theory was supported when account was taken for a reported annoyance overestimation for certain spectra and for a simulated condition cue overreaction.

A systematic approach to the development of a safe live attenuated Zika vaccine.

PubMed

Kwek, Swee Sen; Watanabe, Satoru; Chan, Kuan Rong; Ong, Eugenia Z; Tan, Hwee Cheng; Ng, Wy Ching; Nguyen, Mien T X; Gan, Esther S; Zhang, Summer L; Chan, Kitti W K; Tan, Jun Hao; Sessions, October M; Manuel, Menchie; Pompon, Julien; Chua, Camillus; Hazirah, Sharifah; Tryggvason, Karl; Vasudevan, Subhash G; Ooi, Eng Eong

2018-03-12

Zika virus (ZIKV) is a flavivirus that can cause congenital disease and requires development of an effective long-term preventative strategy. A replicative ZIKV vaccine with properties similar to the yellow fever 17D (YF17D) live-attenuated vaccine (LAV) would be advantageous, as a single dose of YF17D produces lifelong immunity. However, a replicative ZIKV vaccine must also be safe from causing persistent organ infections. Here we report an approach to ZIKV LAV development. We identify a ZIKV variant that produces small plaques due to interferon (IFN)-restricted viral propagation and displays attenuated infection of endothelial cells. We show that these properties collectively reduce the risk of organ infections and vertical transmission in a mouse model but remain sufficiently immunogenic to prevent wild-type ZIKV infection. Our findings suggest a strategy for the development of a safe but efficacious ZIKV LAV.

Effective preexposure and postexposure prophylaxis of rabies with a highly attenuated recombinant rabies virus.

PubMed

Faber, Milosz; Li, Jianwei; Kean, Rhonda B; Hooper, D Craig; Alugupalli, Kishore R; Dietzschold, Bernhard

2009-07-07

Rabies remains an important public health problem with more than 95% of all human rabies cases caused by exposure to rabid dogs in areas where effective, inexpensive vaccines are unavailable. Because of their ability to induce strong innate and adaptive immune responses capable of clearing the infection from the CNS after a single immunization, live-attenuated rabies virus (RV) vaccines could be particularly useful not only for the global eradication of canine rabies but also for late-stage rabies postexposure prophylaxis of humans. To overcome concerns regarding the safety of live-attenuated RV vaccines, we developed the highly attenuated triple RV G variant, SPBAANGAS-GAS-GAS. In contrast to most attenuated recombinant RVs generated thus far, SPBAANGAS-GAS-GAS is completely nonpathogenic after intracranial infection of mice that are either developmentally immunocompromised (e.g., 5-day-old mice) or have inherited deficits in immune function (e.g., antibody production or type I IFN signaling), as well as normal adult animals. In addition, SPBAANGAS-GAS-GAS induces immune mechanisms capable of containing a CNS infection with pathogenic RV, thereby preventing lethal rabies encephalopathy. The lack of pathogenicity together with excellent immunogenicity and the capacity to deliver immune effectors to CNS tissues makes SPBAANGAS-GAS-GAS a promising vaccine candidate for both the preexposure and postexposure prophylaxis of rabies.

A novel, live-attenuated vesicular stomatitis virus vector displaying conformationally intact, functional HIV-1 envelope trimers that elicits potent cellular and humoral responses in mice.

PubMed

Rabinovich, Svetlana; Powell, Rebecca L R; Lindsay, Ross W B; Yuan, Maoli; Carpov, Alexei; Wilson, Aaron; Lopez, Mary; Coleman, John W; Wagner, Denise; Sharma, Palka; Kemelman, Marina; Wright, Kevin J; Seabrook, John P; Arendt, Heather; Martinez, Jennifer; DeStefano, Joanne; Chiuchiolo, Maria J; Parks, Christopher L

2014-01-01

Though vaccination with live-attenuated SIV provides the greatest protection from progressive disease caused by SIV challenge in rhesus macaques, attenuated HIV presents safety concerns as a vaccine; therefore, live viral vectors carrying HIV immunogens must be considered. We have designed a replication-competent vesicular stomatitis virus (VSV) displaying immunogenic HIV-1 Env trimers and attenuating quantities of the native surface glycoprotein (G). The clade B Env immunogen is an Env-VSV G hybrid (EnvG) in which the transmembrane and cytoplasmic tail regions are derived from G. Relocation of the G gene to the 5'terminus of the genome and insertion of EnvG into the natural G position induced a ∼1 log reduction in surface G, significant growth attenuation compared to wild-type, and incorporation of abundant EnvG. Western blot analysis indicated that ∼75% of incorporated EnvG was a mature proteolytically processed form. Flow cytometry showed that surface EnvG bound various conformationally- and trimer-specific antibodies (Abs), and in-vitro growth assays on CD4+CCR5+ cells demonstrated EnvG functionality. Neither intranasal (IN) or intramuscular (IM) administration in mice induced any observable pathology and all regimens tested generated potent Env-specific ELISA titers of 10(4)-10(5), with an IM VSV prime/IN VSV boost regimen eliciting the highest binding and neutralizing Ab titers. Significant quantities of Env-specific CD4+ T cells were also detected, which were augmented as much as 70-fold by priming with IM electroporated plasmids encoding EnvG and IL-12. These data suggest that our novel vector can achieve balanced safety and immunogenicity and should be considered as an HIV vaccine platform.

Rational design of human metapneumovirus live attenuated vaccine candidates by inhibiting viral mRNA cap methyltransferase.

PubMed

Zhang, Yu; Wei, Yongwei; Zhang, Xiaodong; Cai, Hui; Niewiesk, Stefan; Li, Jianrong

2014-10-01

The paramyxoviruses human respiratory syncytial virus (hRSV), human metapneumovirus (hMPV), and human parainfluenza virus type 3 (hPIV3) are responsible for the majority of pediatric respiratory diseases and inflict significant economic loss, health care costs, and emotional burdens. Despite major efforts, there are no vaccines available for these viruses. The conserved region VI (CR VI) of the large (L) polymerase proteins of paramyxoviruses catalyzes methyltransferase (MTase) activities that typically methylate viral mRNAs at positions guanine N-7 (G-N-7) and ribose 2'-O. In this study, we generated a panel of recombinant hMPVs carrying mutations in the S-adenosylmethionine (SAM) binding site in CR VI of L protein. These recombinant viruses were specifically defective in ribose 2'-O methylation but not G-N-7 methylation and were genetically stable and highly attenuated in cell culture and viral replication in the upper and lower respiratory tracts of cotton rats. Importantly, vaccination of cotton rats with these recombinant hMPVs (rhMPVs) with defective MTases triggered a high level of neutralizing antibody, and the rats were completely protected from challenge with wild-type rhMPV. Collectively, our results indicate that (i) amino acid residues in the SAM binding site in the hMPV L protein are essential for 2'-O methylation and (ii) inhibition of mRNA cap MTase can serve as a novel target to rationally design live attenuated vaccines for hMPV and perhaps other paramyxoviruses, such as hRSV and hPIV3. Human paramyxoviruses, including hRSV, hMPV, and hPIV3, cause the majority of acute upper and lower respiratory tract infections in humans, particularly in infants, children, the elderly, and immunocompromised individuals. Currently, there is no licensed vaccine available. A formalin-inactivated vaccine is not suitable for these viruses because it causes enhanced lung damage upon reinfection with the same virus. A live attenuated vaccine is the most promising vaccine strategy for human paramyxoviruses. However, it remains a challenge to identify an attenuated virus strain that has an optimal balance between attenuation and immunogenicity. Using reverse genetics, we generated a panel of recombinant hMPVs that were specifically defective in ribose 2'-O methyltransferase (MTase) but not G-N-7 MTase. These MTase-defective hMPVs were genetically stable and sufficiently attenuated but retained high immunogenicity. This work highlights a critical role of 2'-O MTase in paramyxovirus replication and pathogenesis and a new avenue for the development of safe and efficacious live attenuated vaccines for hMPV and other human paramyxoviruses. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

A combination in-ovo vaccine for avian influenza virus and Newcastle disease virus.

PubMed

Steel, John; Burmakina, Svetlana V; Thomas, Colleen; Spackman, Erica; García-Sastre, Adolfo; Swayne, David E; Palese, Peter

2008-01-24

The protection of poultry from H5N1 highly pathogenic avian influenza A (HPAI) and Newcastle disease virus (NDV) can be achieved through vaccination, as part of a broader disease control strategy. We have previously generated a recombinant influenza virus expressing, (i) an H5 hemagglutinin protein, modified by the removal of the polybasic cleavage peptide and (ii) the ectodomain of the NDV hemagglutinin-neuraminidase (HN) protein in the place of the ectodomain of influenza neuraminidase (Park MS, et al. Proc Natl Acad Sci USA 2006;103(21):8203-8). Here we show this virus is attenuated in primary normal human bronchial epithelial (NHBE) cell culture, and demonstrate protection of C57BL/6 mice from lethal challenge with an H5 HA-containing influenza virus through immunisation with the recombinant virus. In addition, in-ovo vaccination of 18-day-old embryonated chicken eggs provided 90% and 80% protection against highly stringent lethal challenge by NDV and H5N1 virus, respectively. We propose that this virus has potential as a safe in-ovo live, attenuated, bivalent avian influenza and Newcastle disease virus vaccine.

Molecular and immunological characterization of a DNA-launched yellow fever virus 17D infectious clone.

PubMed

Jiang, Xiaohong; Dalebout, Tim J; Lukashevich, Igor S; Bredenbeek, Peter J; Franco, David

2015-04-01

Yellow fever virus (YFV)-17D is an empirically developed, highly effective live-attenuated vaccine that has been administered to human beings for almost a century. YFV-17D has stood as a paradigm for a successful viral vaccine, and has been exploited as a potential virus vector for the development of recombinant vaccines against other diseases. In this study, a DNA-launched YFV-17D construct (pBeloBAC-FLYF) was explored as a new modality to the standard vaccine to combine the commendable features of both DNA vaccine and live-attenuated viral vaccine. The DNA-launched YFV-17D construct was characterized extensively both in cell culture and in mice. High titres of YFV-17D were generated upon transfection of the DNA into cells, whereas a mutant with deletion in the capsid-coding region (pBeloBAC-YF/ΔC) was restricted to a single round of infection, with no release of progeny virus. Homologous prime-boost immunization of AAD mice with both pBeloBAC-FLYF and pBeloBAC-YF/ΔC elicited specific dose-dependent cellular immune response against YFV-17D. Vaccination of A129 mice with pBeloBAC-FLYF resulted in the induction of YFV-specific neutralizing antibodies in all vaccinated subjects. These promising results underlined the potential of the DNA-launched YFV both as an alternative to standard YFV-17D vaccination and as a vaccine platform for the development of DNA-based recombinant YFV vaccines. © 2015.

A bivalent live-attenuated influenza vaccine for the control and prevention of H3N8 and H3N2 canine influenza viruses.

PubMed

Rodriguez, Laura; Nogales, Aitor; Murcia, Pablo R; Parrish, Colin R; Martínez-Sobrido, Luis

2017-08-03

Canine influenza viruses (CIVs) cause a contagious respiratory disease in dogs. CIV subtypes include H3N8, which originated from the transfer of H3N8 equine influenza virus (EIV) to dogs; and the H3N2, which is an avian-origin virus adapted to infect dogs. Only inactivated influenza vaccines (IIVs) are currently available against the different CIV subtypes. However, the efficacy of these CIV IIVs is not optimal and improved vaccines are necessary for the efficient prevention of disease caused by CIVs in dogs. Since live-attenuated influenza vaccines (LAIVs) induce better immunogenicity and protection efficacy than IIVs, we have combined our previously described H3N8 and H3N2 CIV LAIVs to create a bivalent vaccine against both CIV subtypes. Our findings show that, in a mouse model of infection, the bivalent CIV LAIV is safe and able to induce, upon a single intranasal immunization, better protection than that induced by a bivalent CIV IIV against subsequent challenge with H3N8 or H3N2 CIVs. These protection results also correlated with the ability of the bivalent CIV LAIV to induce better humoral immune responses. This is the first description of a bivalent LAIV for the control and prevention of H3N8 and H3N2 CIV infections in dogs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Molecular and immunological characterization of a DNA-launched yellow fever virus 17D infectious clone

PubMed Central

Jiang, Xiaohong; Dalebout, Tim J.; Lukashevich, Igor S.; Bredenbeek, Peter J.

2015-01-01

Yellow fever virus (YFV)-17D is an empirically developed, highly effective live-attenuated vaccine that has been administered to human beings for almost a century. YFV-17D has stood as a paradigm for a successful viral vaccine, and has been exploited as a potential virus vector for the development of recombinant vaccines against other diseases. In this study, a DNA-launched YFV-17D construct (pBeloBAC-FLYF) was explored as a new modality to the standard vaccine to combine the commendable features of both DNA vaccine and live-attenuated viral vaccine. The DNA-launched YFV-17D construct was characterized extensively both in cell culture and in mice. High titres of YFV-17D were generated upon transfection of the DNA into cells, whereas a mutant with deletion in the capsid-coding region (pBeloBAC-YF/ΔC) was restricted to a single round of infection, with no release of progeny virus. Homologous prime–boost immunization of AAD mice with both pBeloBAC-FLYF and pBeloBAC-YF/ΔC elicited specific dose-dependent cellular immune response against YFV-17D. Vaccination of A129 mice with pBeloBAC-FLYF resulted in the induction of YFV-specific neutralizing antibodies in all vaccinated subjects. These promising results underlined the potential of the DNA-launched YFV both as an alternative to standard YFV-17D vaccination and as a vaccine platform for the development of DNA-based recombinant YFV vaccines. PMID:25516543

Markerless attenuation correction for carotid MRI surface receiver coils in combined PET/MR imaging

NASA Astrophysics Data System (ADS)

Eldib, Mootaz; Bini, Jason; Robson, Philip M.; Calcagno, Claudia; Faul, David D.; Tsoumpas, Charalampos; Fayad, Zahi A.

2015-06-01

The purpose of the study was to evaluate the effect of attenuation of MR coils on quantitative carotid PET/MR exams. Additionally, an automated attenuation correction method for flexible carotid MR coils was developed and evaluated. The attenuation of the carotid coil was measured by imaging a uniform water phantom injected with 37 MBq of 18F-FDG in a combined PET/MR scanner for 24 min with and without the coil. In the same session, an ultra-short echo time (UTE) image of the coil on top of the phantom was acquired. Using a combination of rigid and non-rigid registration, a CT-based attenuation map was registered to the UTE image of the coil for attenuation and scatter correction. After phantom validation, the effect of the carotid coil attenuation and the attenuation correction method were evaluated in five subjects. Phantom studies indicated that the overall loss of PET counts due to the coil was 6.3% with local region-of-interest (ROI) errors reaching up to 18.8%. Our registration method to correct for attenuation from the coil decreased the global error and local error (ROI) to 0.8% and 3.8%, respectively. The proposed registration method accurately captured the location and shape of the coil with a maximum spatial error of 2.6 mm. Quantitative analysis in human studies correlated with the phantom findings, but was dependent on the size of the ROI used in the analysis. MR coils result in significant error in PET quantification and thus attenuation correction is needed. The proposed strategy provides an operator-free method for attenuation and scatter correction for a flexible MRI carotid surface coil for routine clinical use.

Influenza Vaccination Strategies: Comparing Inactivated and Live Attenuated Influenza Vaccines

PubMed Central

Sridhar, Saranya; Brokstad, Karl A.; Cox, Rebecca J.

2015-01-01

Influenza is a major respiratory pathogen causing annual outbreaks and occasional pandemics. Influenza vaccination is the major method of prophylaxis. Currently annual influenza vaccination is recommended for groups at high risk of complications from influenza infection such as pregnant women, young children, people with underlying disease and the elderly, along with occupational groups such a healthcare workers and farm workers. There are two main types of vaccines available: the parenteral inactivated influenza vaccine and the intranasal live attenuated influenza vaccine. The inactivated vaccines are licensed from 6 months of age and have been used for more than 50 years with a good safety profile. Inactivated vaccines are standardized according to the presence of the viral major surface glycoprotein hemagglutinin and protection is mediated by the induction of vaccine strain specific antibody responses. In contrast, the live attenuated vaccines are licensed in Europe for children from 2–17 years of age and provide a multifaceted immune response with local and systemic antibody and T cell responses but with no clear correlate of protection. Here we discuss the immunological immune responses elicited by the two vaccines and discuss future work to better define correlates of protection. PMID:26343192

FOXO/DAF-16 Activation Slows Down Turnover of the Majority of Proteins in C. elegans

DOE PAGES

Dhondt, Ineke; Petyuk, Vladislav A.; Cai, Huaihan; ...

2016-09-13

Most aging hypotheses assume the accumulation of damage, resulting in gradual physiological decline and, ultimately, death. Avoiding protein damage accumulation by enhanced turnover should slow down the aging process and extend the lifespan. But, lowering translational efficiency extends rather than shortens the lifespan in C. elegans. We studied turnover of individual proteins in the long-lived daf-2 mutant by combining SILeNCe (stable isotope labeling by nitrogen in Caenorhabditiselegans) and mass spectrometry. Intriguingly, the majority of proteins displayed prolonged half-lives in daf-2, whereas others remained unchanged, signifying that longevity is not supported by high protein turnover. We found that this slowdown wasmore » most prominent for translation-related and mitochondrial proteins. Conversely, the high turnover of lysosomal hydrolases and very low turnover of cytoskeletal proteins remained largely unchanged. The slowdown of protein dynamics and decreased abundance of the translational machinery may point to the importance of anabolic attenuation in lifespan extension, as suggested by the hyperfunction theory.« less

Association of the host immune response with protection using a live attenuated African swine fever virus model

USDA-ARS?s Scientific Manuscript database

African swine fever (ASF) is a lethal hemorrhagic disease of swine caused by a double-stranded DNA virus, African Swine Fever Virus (ASFV). There is no vaccine to prevent the disease and current control measures are limited to culling and restricted animal movement. Swine infected with attenuated st...

Divergent immune responses and disease outcomes in piglets immunized with inactivated and attenuated H3N2 swine influenza vaccines in the presence of maternally-derived antibodies

USDA-ARS?s Scientific Manuscript database

Vaccine-associated enhanced respiratory disease (VAERD) can occur in pigs immunized with whole-inactivated influenza virus (WIV) vaccine and subsequently infected with an antigenically divergent virus of the same HA subtype. Live-attenuated influenza virus (LAIV) vaccines administered intranasally h...

Attenuation and protective efficacy of Rift Valley fever phlebovirus rMP12-GM50 strain.

PubMed

Ly, Hoai J; Nishiyama, Shoko; Lokugamage, Nandadeva; Smith, Jennifer K; Zhang, Lihong; Perez, David; Juelich, Terry L; Freiberg, Alexander N; Ikegami, Tetsuro

2017-12-04

Rift Valley fever (RVF) is a mosquito-borne zoonotic disease endemic to Africa and the Arabian Peninsula that affects sheep, cattle, goats, camels, and humans. Effective vaccination of susceptible ruminants is important for the prevention of RVF outbreaks. Live-attenuated RVF vaccines are in general highly immunogenic in ruminants, whereas residual virulence might be a concern for vulnerable populations. It is also important for live-attenuated strains to encode unique genetic markers for the differentiation from wild-type RVFV strains. In this study, we aimed to strengthen the attenuation profile of the MP-12 vaccine strain via the introduction of 584 silent mutations. To minimize the impact on protective efficacy, codon usage and codon pair bias were not de-optimized. The resulting rMP12-GM50 strain showed 100% protective efficacy with a single intramuscular dose, raising a 1:853 mean titer of plaque reduction neutralization test. Moreover, outbred mice infected with one of three pathogenic reassortant ZH501 strains, which encoded rMP12-GM50 L-, M-, or S-segments, showed 90%, 50%, or 30% survival, respectively. These results indicate that attenuation of the rMP12-GM50 strain is significantly attenuated via the L-, M-, and S-segments. Recombinant RVFV vaccine strains encoding similar silent mutations will be also useful for the surveillance of reassortant strains derived from vaccine strains in endemic countries. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Live Attenuated Actinobacillus pleuropneumoniae Triple-Deletion Mutant ΔapxIC ΔapxIIC ΔapxIV-ORF1 Strain, SLW05, Immunizes Pigs against Lethal Challenge with Haemophilus parasuis

PubMed Central

Fu, Shulin; Ou, Jiwen; Zhang, Minmin; Xu, Juan; Liu, Huazhen; Liu, Jinlin; Yuan, Fangyan; Chen, Huanchun

2013-01-01

Haemophilus parasuis and Actinobacillus pleuropneumoniae both belong to the family Pasteurellaceae and are major respiratory pathogens that cause large economic losses in the pig industry worldwide. We previously constructed an attenuated A. pleuropneumoniae serovar 1 live vaccine prototype, SLW05 (ΔapxIC ΔapxIIC ΔapxIV-ORF1), which is able to produce nontoxic but immunogenic ApxIA, ApxIIA, and ApxIVA. This triple-deletion mutant strain was shown to elicit protective immunity against virulent A. pleuropneumoniae. In the present study, we investigated whether immunization with SLW05 could also protect against lethal challenge with virulent H. parasuis SH0165 (serovar 5) or MD0322 (serovar 4). The SLW05 strain was found to elicit a strong humoral antibody response in pigs and to confer significant protection against challenge with a lethal dose of H. parasuis SH0165 or MD0322. IgG subtype analysis revealed that SLW05 induces a bias toward a Th1-type immune response and stimulates interleukin 2 (IL-2) and gamma interferon (IFN-γ) production. Moreover, antisera from SLW05-vaccinated pigs efficiently inhibited both A. pleuropneumoniae and H. parasuis growth in a whole-blood assay. This is the first report that a live attenuated A. pleuropneumoniae vaccine with SLW05 can protect against lethal H. parasuis infection, which provides a novel approach for developing an attenuated H. parasuis vaccine. PMID:23220998

The live attenuated Actinobacillus pleuropneumoniae triple-deletion mutant ΔapxIC ΔapxIIC ΔapxIV-ORF1 strain, SLW05, Immunizes pigs against lethal challenge with Haemophilus parasuis.

PubMed

Fu, Shulin; Ou, Jiwen; Zhang, Minmin; Xu, Juan; Liu, Huazhen; Liu, Jinlin; Yuan, Fangyan; Chen, Huanchun; Bei, Weicheng

2013-02-01

Haemophilus parasuis and Actinobacillus pleuropneumoniae both belong to the family Pasteurellaceae and are major respiratory pathogens that cause large economic losses in the pig industry worldwide. We previously constructed an attenuated A. pleuropneumoniae serovar 1 live vaccine prototype, SLW05 (ΔapxIC ΔapxIIC ΔapxIV-ORF1), which is able to produce nontoxic but immunogenic ApxIA, ApxIIA, and ApxIVA. This triple-deletion mutant strain was shown to elicit protective immunity against virulent A. pleuropneumoniae. In the present study, we investigated whether immunization with SLW05 could also protect against lethal challenge with virulent H. parasuis SH0165 (serovar 5) or MD0322 (serovar 4). The SLW05 strain was found to elicit a strong humoral antibody response in pigs and to confer significant protection against challenge with a lethal dose of H. parasuis SH0165 or MD0322. IgG subtype analysis revealed that SLW05 induces a bias toward a Th1-type immune response and stimulates interleukin 2 (IL-2) and gamma interferon (IFN-γ) production. Moreover, antisera from SLW05-vaccinated pigs efficiently inhibited both A. pleuropneumoniae and H. parasuis growth in a whole-blood assay. This is the first report that a live attenuated A. pleuropneumoniae vaccine with SLW05 can protect against lethal H. parasuis infection, which provides a novel approach for developing an attenuated H. parasuis vaccine.

Dextromethorphan attenuated inflammation and combined opioid use in humans undergoing methadone maintenance treatment.

PubMed

Chen, Shiou-Lan; Lee, Sheng-Yu; Tao, Pao-Luh; Chang, Yun-Hsuan; Chen, Shih-Heng; Chu, Chun-Hsien; Chen, Po See; Lee, I Hui; Yeh, Tzung Lieh; Yang, Yen Kuang; Hong, Jau-Shyong; Lu, Ru-Band

2012-12-01

Recent studies show that proinflammatory cytokines might be related to the development of opioid dependence (physiological, psychological, or both). In a double-blind, randomly stratified clinical trial investigating whether add-on dextromethorphan (60-120 mg/day) attenuated inflammation and the combined use of opioids in heroin-dependent patients undergoing methadone maintenance treatment, we evaluated whether inflammation is related to the progression of opioid dependence. All participants (107 heroin-dependent patients and 84 nondependent healthy controls) were recruited from National Cheng Kung University Hospital. Their plasma cytokine levels were measured to evaluate the effect of add-on dextromethorphan. Plasma TNF-α and IL-8 levels were significantly higher in long-term heroin-dependent patients than in healthy controls (p < 0.001). Chronic heroin-use-induced TNF-α and IL-8 levels were significantly (p < 0.05) attenuated in patients treated for 12 weeks with add-on dextromethorphan. Moreover, both tolerance to methadone and the combined use of opioids were significantly (p < 0.05) attenuated in patients taking dextromethorphan. We conclude that dextromethorphan might be a feasible adjuvant therapeutic for attenuating inflammation and inhibiting methadone tolerance and combined opioid use in heroin-dependent patients.

Recombination of Globally Circulating Varicella-Zoster Virus

PubMed Central

Depledge, Daniel P.; Kundu, Samit; Atkinson, Claire; Brown, Julianne; Haque, Tanzina; Hussaini, Yusuf; MacMahon, Eithne; Molyneaux, Pamela; Papaevangelou, Vassiliki; Sengupta, Nitu; Koay, Evelyn S. C.; Tang, Julian W.; Underhill, Gillian S.; Grahn, Anna; Studahl, Marie; Breuer, Judith; Bergström, Tomas

2015-01-01

ABSTRACT Varicella-zoster virus (VZV) is a human herpesvirus, which during primary infection typically causes varicella (chicken pox) and establishes lifelong latency in sensory and autonomic ganglia. Later in life, the virus may reactivate to cause herpes zoster (HZ; also known as shingles). To prevent these diseases, a live-attenuated heterogeneous vaccine preparation, vOka, is used routinely in many countries worldwide. Recent studies of another alphaherpesvirus, infectious laryngotracheitis virus, demonstrate that live-attenuated vaccine strains can recombine in vivo, creating virulent progeny. These findings raised concerns about using attenuated herpesvirus vaccines under conditions that favor recombination. To investigate whether VZV may undergo recombination, which is a prerequisite for VZV vaccination to create such conditions, we here analyzed 115 complete VZV genomes. Our results demonstrate that recombination occurs frequently for VZV. It thus seems that VZV is fully capable of recombination if given the opportunity, which may have important implications for continued VZV vaccination. Although no interclade vaccine-wild-type recombinant strains were found, intraclade recombinants were frequently detected in clade 2, which harbors the vaccine strains, suggesting that the vaccine strains have already been involved in recombination events, either in vivo or in vitro during passages in cell culture. Finally, previous partial and complete genomic studies have described strains that do not cluster phylogenetically to any of the five established clades. The additional VZV strains sequenced here, in combination with those previously published, have enabled us to formally define a novel sixth VZV clade. IMPORTANCE Although genetic recombination has been demonstrated to frequently occur for other human alphaherpesviruses, herpes simplex viruses 1 and 2, only a few ancient and isolated recent recombination events have hitherto been demonstrated for VZV. In the present study, we demonstrate that VZV also frequently undergoes genetic recombination, including strains belonging to the clade containing the vOKA strain. PMID:25926648

Comparison of impact force attenuation by various combinations of hip protector and flooring material using a simplified fall-impact simulation device.

PubMed

Li, Ning; Tsushima, Eiki; Tsushima, Hitoshi

2013-04-05

Use of hip protectors and compliant flooring has been recommended for preventing hip fracture due to falls. We aimed to identify the factors attenuating forces in falls by comparing and analyzing the impact forces occurring with various combinations of hip protectors and flooring materials. We designed a simplified pendulum device to simulate the impact force at the hip during falling. The impact force was measured on pressure-sensitive recording film under combined conditions of two kinds of hip protector (hard or soft shell) and three kinds of floor material (concrete, wooden, or tatami matting). We then calculated the percentage force attenuation under each test condition compared with the use of a concrete floor and no hip protector. All the tests using tatami matting reduced the impact to below the average fracture threshold of elderly people (3472N). A combination of tatami and soft hip protector provided the best attenuation (72.5%). Multiple regression analyses showed that use of tatami matting and a soft hip protector had the biggest force-attenuation effect. The soft hip protector gave better percentage force attenuation than did the hard one. Use of tatami matting as a flooring material could be an effective strategy for helping prevent hip fractures. Copyright © 2013 Elsevier Ltd. All rights reserved.

Pan-Influenza A Protection by Prime-Boost Vaccination with Cold-Adapted Live-Attenuated Influenza Vaccine in a Mouse Model.

PubMed

Jang, Yo Han; Kim, Joo Young; Byun, Young Ho; Son, Ahyun; Lee, Jeong-Yoon; Lee, Yoon Jae; Chang, Jun; Seong, Baik Lin

2018-01-01

Influenza virus infections continually pose a major public health threat with seasonal epidemics and sporadic pandemics worldwide. While currently licensed influenza vaccines provide only strain-specific protection, antigenic drift and shift occasionally render the viruses resistant to the host immune responses, which highlight the need for a vaccine that provides broad protection against multiple subtypes. In this study, we suggest a vaccination strategy using cold-adapted, live attenuated influenza vaccines (CAIVs) to provide a broad, potent, and safe cross-protection covering antigenically distinct hemagglutinin (HA) groups 1 and 2 influenza viruses. Using a mouse model, we tested different prime-boost combinations of CAIVs for their ability to induce humoral and T-cell responses, and protective efficacy against H1 and H5 (HA group 1) as well as H3 and H7 (HA group 2) influenza viruses. Notably, even in the absence of antibody-mediated neutralizing activity or HA inhibitory activity in vitro , CAIVs provided a potent protection against heterologous and heterosubtypic lethal challenges in vivo . Heterologous combination of prime (H1)-boost (H5) vaccine strains showed the most potent cross-protection efficacy. In vivo depletion experiments demonstrated not only that T cells and natural killer cells contributed to the cross-protection, but also the involvement of antibody-dependent mechanisms for the cross-protection. Vaccination-induced antibodies did not enhance the infectivity of heterologous viruses, and prime vaccination did not interfere with neutralizing antibody generation by the boost vaccination, allaying vaccine safety concerns associated with heterogeneity between the vaccines and challenge strains. Our data show that CAIV-based strategy can serve as a simple but powerful option for developing a "truly" universal influenza vaccine providing pan-influenza A protection, which has not been achieved yet by other vaccine strategies. The promising results of potency, breadth, and safety demonstrated in the mouse model support further studies in higher animal models for clinical relevance.

Pan-Influenza A Protection by Prime–Boost Vaccination with Cold-Adapted Live-Attenuated Influenza Vaccine in a Mouse Model

PubMed Central

Jang, Yo Han; Kim, Joo Young; Byun, Young Ho; Son, Ahyun; Lee, Jeong-Yoon; Lee, Yoon Jae; Chang, Jun; Seong, Baik Lin

2018-01-01

Influenza virus infections continually pose a major public health threat with seasonal epidemics and sporadic pandemics worldwide. While currently licensed influenza vaccines provide only strain-specific protection, antigenic drift and shift occasionally render the viruses resistant to the host immune responses, which highlight the need for a vaccine that provides broad protection against multiple subtypes. In this study, we suggest a vaccination strategy using cold-adapted, live attenuated influenza vaccines (CAIVs) to provide a broad, potent, and safe cross-protection covering antigenically distinct hemagglutinin (HA) groups 1 and 2 influenza viruses. Using a mouse model, we tested different prime–boost combinations of CAIVs for their ability to induce humoral and T-cell responses, and protective efficacy against H1 and H5 (HA group 1) as well as H3 and H7 (HA group 2) influenza viruses. Notably, even in the absence of antibody-mediated neutralizing activity or HA inhibitory activity in vitro, CAIVs provided a potent protection against heterologous and heterosubtypic lethal challenges in vivo. Heterologous combination of prime (H1)–boost (H5) vaccine strains showed the most potent cross-protection efficacy. In vivo depletion experiments demonstrated not only that T cells and natural killer cells contributed to the cross-protection, but also the involvement of antibody-dependent mechanisms for the cross-protection. Vaccination-induced antibodies did not enhance the infectivity of heterologous viruses, and prime vaccination did not interfere with neutralizing antibody generation by the boost vaccination, allaying vaccine safety concerns associated with heterogeneity between the vaccines and challenge strains. Our data show that CAIV-based strategy can serve as a simple but powerful option for developing a “truly” universal influenza vaccine providing pan-influenza A protection, which has not been achieved yet by other vaccine strategies. The promising results of potency, breadth, and safety demonstrated in the mouse model support further studies in higher animal models for clinical relevance. PMID:29449842

Live attenuated hepatitis A vaccines developed in China

PubMed Central

Xu, Zhi-Yi; Wang, Xuan-Yi

2014-01-01

Two live, attenuated hepatitis A vaccines, H2 and LA-1 virus strains, were developed through serial passages of the viruses in cell cultures at 32 °C and 35 °C respectively. Both vaccines were safe and immunogenic, providing protection against clinical hepatitis A in 95% of the vaccinees, with a single dose by subcutaneous injection. The vaccine recipients were not protected from asymptomatic, subclinical hepatitis A virus (HAV) infection, which induced a similar antibody response as for unvaccinated subjects. A second dose caused anamnestic response and can be used for boosting. Oral immunization of human with H2 vaccine or of marmoset with LA-1 vaccine failed, and no evidence was found for person-to-person transmission of H2 strain or for marmoset-to-marmoset transmission of LA-1 strain by close contact. H2 strain was genetically stable when passaged in marmosets, humans or cell cultures at 37 °C; 3 consecutive passages of the virus in marmosets did not cause virulence mutation. The live vaccines offer the benefits of low cost, single dose injection, long- term protection, and increased duration of immunity through subclinical infection. Improved sanitation and administration of 150 million doses of the live vaccines to children had led to a 90% reduction in the annual national incidence rate of hepatitis A in China during the 16-year period, from 1991 to 2006. Hepatitis A (HA) immunization with both live and inactivated HA vaccines was implemented in the national routine childhood immunization program in 2008 and around 92% of the 16 million annual births received the affordable live, attenuated vaccines at 18 months of age. Near elimination of the disease was achieved in a county of China for 14 years following introduction of the H2 live vaccine into the Expanded Immunization Program (EPI) in 1992. PMID:24280971

Decreased accumulation of subgenomic RNA in human cells infected with vaccine candidate DEN4Δ30 increases viral susceptibility to type I interferon.

PubMed

Bustos-Arriaga, José; Gromowski, Gregory D; Tsetsarkin, Konstantin A; Firestone, Cai-Yen; Castro-Jiménez, Tannya; Pletnev, Alexander G; Cedillo-Barrón, Leticia; Whitehead, Stephen S

2018-06-07

The NIH has developed live attenuated dengue virus (DENV) vaccine candidates by deletion of 30 nucleotides (Δ30) from the untranslated region of the viral genome. Although this attenuation strategy has proven to be effective in generating safe and immunogenic vaccine strains, the molecular mechanism of attenuation is largely unknown. To examine the mediators of the observed attenuation phenotype, differences in translation efficiency, genome replication, cytotoxicity, and type I interferon susceptibility were compared between wild type parental DENV and DENVΔ30 attenuated vaccine candidates. We observed that decreased accumulation of subgenomic RNA (sfRNA) from the vaccine candidates in infected human cells causes increased type I IFN susceptibility and propose this as one of the of attenuation mechanisms produced by the 3' UTR Δ30 mutation. Copyright © 2018 Elsevier Ltd. All rights reserved.

Laboratory tests for mumps vaccines.

PubMed

Minor, P D

1997-03-01

The action of live attenuated vaccines against mumps is poorly understood although their clinical efficacy is beyond doubt. The attenuated character of the vaccine is assured by consistency of production related to clinical trials, and limited studies of vaccine seeds in primates. Potency is assessed by infectivity in vitro and is subject to poorly understood sources of variation. Molecular biological studies are at an early stage.

A live attenuated cold-adapted influenza A H7N3 virus vaccine provides protection against homologous and heterologous H7 viruses in mice and ferrets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Joseph, Tomy; MedImmune Inc., Mountain View, CA 94043; McAuliffe, Josephine

2008-08-15

The appearance of human infections caused by avian influenza A H7 subtype viruses underscores their pandemic potential and the need to develop vaccines to protect humans from viruses of this subtype. A live attenuated H7N3 virus vaccine was generated by reverse genetics using the HA and NA genes of a low pathogenicity A/chicken/BC/CN-6/04 (H7N3) virus and the six internal protein genes of the cold-adapted A/Ann Arbor/6/60 ca (H2N2) virus. The reassortant H7N3 BC 04 ca vaccine virus was temperature sensitive and showed attenuation in mice and ferrets. Intranasal immunization with one dose of the vaccine protected mice and ferrets whenmore » challenged with homologous and heterologous H7 viruses. The reassortant H7N3 BC 04 ca vaccine virus showed comparable levels of attenuation, immunogenicity and efficacy in mice and ferret models. The safety, immunogenicity, and efficacy of this vaccine in mice and ferrets support the evaluation of this vaccine in clinical trials.« less

A live attenuated cold adapted influenza A H7N3 virus vaccine provides protection against homologous and heterologous H7 viruses in mice and ferrets

PubMed Central

Joseph, Tomy; McAuliffe, Josephine; Lu, Bin; Vogel, Leatrice; Swayne, David; Jin, Hong; Kemble, George; Subbarao, Kanta

2008-01-01

The appearance of human infections caused by avian influenza A H7 subtype viruses underscore their pandemic potential and the need to develop vaccines to protect humans from viruses of this subtype. A live attenuated H7N3 virus vaccine was generated by reverse genetics using the HA and NA genes of a low pathogenicity A/chicken/BC/CN-6/04 (H7N3) virus and the six internal protein genes of the cold-adapted A/Ann Arbor/6/60 ca (H2N2) virus. The reassortant H7N3 BC 04 ca vaccine virus was temperature sensitive and showed attenuation in mice and ferrets. Intranasal immunization with one dose of the vaccine protected mice and ferrets when challenged with homologous and heterologous H7 viruses. The reassortant H7N3 BC 04 ca vaccine virus showed comparable levels of attenuation, immunogenicity and efficacy in mice and ferret models. The safety, immunogenicity, and efficacy of this vaccine in mice and ferrets support the evaluation of this vaccine in clinical trials. PMID:18585748

Phosphorous Attenuation in Urban Best Management (BMP) and Low Impact Development (LID) Practices

EPA Science Inventory

While all living organisms require phosphorous (P) to live and grow, adding too much P to the environment can cause unintended and undesirable effects, such as eutrophication of surface waters and harmful algal blooms. Urban best management (BMP) and low impact development (LI...

Pets or People: Another Research Note.

ERIC Educational Resources Information Center

Goldmeier, John

1986-01-01

Compared four samples of elderly women: living alone, with other persons, and with and without a pet. Pets only made a difference for those living alone. At best, pets only attenuate the sense of loneliness. In intervention with the elderly, the provision of human supports should remain a priority. (Author/BL)

The L, M, and S Segments of Rift Valley Fever Virus MP-12 Vaccine Independently Contribute to a Temperature-Sensitive Phenotype

PubMed Central

Nishiyama, Shoko; Lokugamage, Nandadeva

2016-01-01

ABSTRACT Rift Valley fever (RVF) is endemic to Africa, and the mosquito-borne disease is characterized by “abortion storms” in ruminants and by hemorrhagic fever, encephalitis, and blindness in humans. Rift Valley fever virus (RVFV; family Bunyaviridae, genus Phlebovirus) has a tripartite negative-stranded RNA genome (L, M, and S segments). A live-attenuated vaccine for RVF, the MP-12 vaccine, is conditionally licensed for veterinary use in the United States. MP-12 is fully attenuated by the combination of the partially attenuated L, M, and S segments. Temperature sensitivity (ts) limits viral replication at a restrictive temperature and may be involved with viral attenuation. In this study, we aimed to characterize the ts mutations for MP-12. The MP-12 vaccine showed restricted replication at 38°C and replication shutoff (100-fold or greater reduction in virus titer compared to that at 37°C) at 39°C in Vero and MRC-5 cells. Using rZH501 reassortants with either the MP-12 L, M, or S segment, we found that all three segments encode a temperature-sensitive phenotype. However, the ts phenotype of the S segment was weaker than that of the M or L segment. We identified Gn-Y259H, Gc-R1182G, L-V172A, and L-M1244I as major ts mutations for MP-12. The ts mutations in the L segment decreased viral RNA synthesis, while those in the M segment delayed progeny production from infected cells. We also found that a lack of NSs and/or 78kD/NSm protein expression minimally affected the ts phenotype. Our study revealed that MP-12 is a unique vaccine carrying ts mutations in the L, M, and S segments. IMPORTANCE Rift Valley fever (RVF) is a mosquito-borne viral disease endemic to Africa, characterized by high rates of abortion in ruminants and severe diseases in humans. Vaccination is important to prevent the spread of disease, and a live-attenuated MP-12 vaccine is currently the only vaccine with a conditional license in the United States. This study determined the temperature sensitivity (ts) of MP-12 vaccine to understand virologic characteristics. Our study revealed that MP-12 vaccine contains ts mutations independently in the L, M, and S segments and that MP-12 displays a restrictive replication at 38°C. PMID:26819307

The L, M, and S Segments of Rift Valley Fever Virus MP-12 Vaccine Independently Contribute to a Temperature-Sensitive Phenotype.

PubMed

Nishiyama, Shoko; Lokugamage, Nandadeva; Ikegami, Tetsuro

2016-01-27

Rift Valley fever (RVF) is endemic to Africa, and the mosquito-borne disease is characterized by "abortion storms" in ruminants and by hemorrhagic fever, encephalitis, and blindness in humans. Rift Valley fever virus (RVFV; family Bunyaviridae, genus Phlebovirus) has a tripartite negative-stranded RNA genome (L, M, and S segments). A live-attenuated vaccine for RVF, the MP-12 vaccine, is conditionally licensed for veterinary use in the United States. MP-12 is fully attenuated by the combination of the partially attenuated L, M, and S segments. Temperature sensitivity (ts) limits viral replication at a restrictive temperature and may be involved with viral attenuation. In this study, we aimed to characterize the ts mutations for MP-12. The MP-12 vaccine showed restricted replication at 38°C and replication shutoff (100-fold or greater reduction in virus titer compared to that at 37°C) at 39°C in Vero and MRC-5 cells. Using rZH501 reassortants with either the MP-12 L, M, or S segment, we found that all three segments encode a temperature-sensitive phenotype. However, the ts phenotype of the S segment was weaker than that of the M or L segment. We identified Gn-Y259H, Gc-R1182G, L-V172A, and L-M1244I as major ts mutations for MP-12. The ts mutations in the L segment decreased viral RNA synthesis, while those in the M segment delayed progeny production from infected cells. We also found that a lack of NSs and/or 78kD/NSm protein expression minimally affected the ts phenotype. Our study revealed that MP-12 is a unique vaccine carrying ts mutations in the L, M, and S segments. Rift Valley fever (RVF) is a mosquito-borne viral disease endemic to Africa, characterized by high rates of abortion in ruminants and severe diseases in humans. Vaccination is important to prevent the spread of disease, and a live-attenuated MP-12 vaccine is currently the only vaccine with a conditional license in the United States. This study determined the temperature sensitivity (ts) of MP-12 vaccine to understand virologic characteristics. Our study revealed that MP-12 vaccine contains ts mutations independently in the L, M, and S segments and that MP-12 displays a restrictive replication at 38°C. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Influence of seasonality and vegetation on the attenuation of emerging contaminants in wastewater effluent-dominated streams. A preliminary study.

PubMed

Matamoros, Víctor; Rodríguez, Yolanda

2017-11-01

Treated wastewater from small communities is discharged into rivers or streams with a high biodiversity value. This is particularly important in Mediterranean countries, where most of the streams are dry almost all year round. This preliminary study assessed the occurrence and attenuation of 23 emerging contaminants (ECs) in 4 wastewater-dominated streams in which treated wastewater accounted for the entire stream flow. The concentration of ECs was monitored in the warm and cold seasons in the wastewater treatment plant (WWTP) effluent and at 6 downstream locations. The concentration of ECs in the WWTP effluents ranged from undetected to 12 μg L -1 . The attenuation of ECs 1 km downstream ranged from no removal to up to 80% (48% on average). The half-lives of ECs in the 4 streams ranged from 0.4 to 20 h (3.9 ± 3.5 h on average). Compounds such as benzodiazepine drugs and flame retardants were the most recalcitrant (half-lives >5 h). The highest attenuation of ECs and ammonia was observed in the stream completely covered by vegetation. The cumulative hazardous quotient 1 km downstream was reduced on average by more than 60%. Therefore, the results suggest that both seasonality and vegetation play an important role in in-stream attenuation of ECs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Single dose of SA 14-14-2 vaccine provides long-term protection against Japanese encephalitis: a case-control study in Nepalese children 5 years after immunization. drjbtandan@yahoo.com.

PubMed

Tandan, J B; Ohrr, Heechoul; Sohn, Young Mo; Yoksan, Sutee; Ji, Min; Nam, Chung Mo; Halstead, Scott B

2007-06-28

In July 1999, a single dose of live-attenuated SA 14-14-2 Japanese encephalitis (JE) vaccine was administered to children living in the Bardiya, Banke and Kailali districts of Nepal. In 2004, the original vaccinated population experienced a fifth seasonal exposure to JE. We performed a case-control study comparing the prevalence of the administration of vaccine in patients with JE hospitalized in the Bardiya and Bheri Zonal hospitals and in age-sex matched controls resident in the Bardiya district. Among the 219 village controls, 114 had been vaccinated (52.1%) while only one of 20 JE cases had received live-attenuated JE vaccine. Five years after administration of a single dose, SA 14-14-2 provided a protective efficacy of 96.2% (CI 73.1-99.9%).

Live attenuated human rotavirus vaccine, Rotarix.

PubMed

Bernstein, David I

2006-10-01

Rotavirus infections are the leading cause of severe gastroenteritis in young children worldwide. Recently two new rotavirus vaccines have entered the world market. This review provides a summary of the rationale, development, and evaluation of one of these vaccines, Rotarix. Rotarix is a live oral rotavirus vaccine developed from a single protective human strain following multiple passages in tissue culture to attenuate the strain. The vaccine is administered as two oral doses at approximately 2 and 4 months of age. Large safety and efficacy trials have shown the vaccine is safe, not associated with intussusception, and effective against the most common circulating human serotypes. Efficacy against severe rotavirus gastroenteritis and hospitalization have ranged from 85 to 100 percent.

Development of a human live attenuated West Nile infectious DNA vaccine: Suitability of attenuating mutations found in SA14-14-2 for WN vaccine design

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamshchikov, Vladimir, E-mail: yaximik@gmail.com; Manuvakhova, Marina; Rodriguez, Efrain

Direct attenuation of West Nile (WN) virus strain NY99 for the purpose of vaccine development is not feasible due to its high virulence and pathogenicity. Instead, we created highly attenuated chimeric virus W1806 with the serological identity of NY99. To further attenuate W1806, we investigated effects of mutations found in Japanese encephalitis virus vaccine SA14-14-2. WN viruses carrying all attenuating mutations lost infectivity in mammalian, but not in mosquito cells. No single reversion restored infectivity in mammalian cells, although increased infectivity in mosquito cells was observed. To identify a subset of mutations suitable for further attenuation of W1806, we analyzedmore » effects of E{sub 138}K and K{sub 279}M changes on virulence, growth properties, and immunogenicity of derivatized W956, from which chimeric W1806 inherited its biological properties and attenuation profile. Despite strong dominant attenuating effect, introduction of only two mutations was not sufficient for attenuating W1806 to the safety level acceptable for human use. - Highlights: • Further attenuation of a WN vaccine precursor is outlined. • Effect of SA14-14-2 attenuating mutations is tested. • Mechanism of attenuation is proposed and illustrated. • The need for additional attenuating mutations is justified.« less

Development of a chimeric Zika vaccine using a licensed live-attenuated flavivirus vaccine as backbone.

PubMed

Li, Xiao-Feng; Dong, Hao-Long; Wang, Hong-Jiang; Huang, Xing-Yao; Qiu, Ye-Feng; Ji, Xue; Ye, Qing; Li, Chunfeng; Liu, Yang; Deng, Yong-Qiang; Jiang, Tao; Cheng, Gong; Zhang, Fu-Chun; Davidson, Andrew D; Song, Ya-Jun; Shi, Pei-Yong; Qin, Cheng-Feng

2018-02-14

The global spread of Zika virus (ZIKV) and its unexpected association with congenital defects necessitates the rapid development of a safe and effective vaccine. Here we report the development and characterization of a recombinant chimeric ZIKV vaccine candidate (termed ChinZIKV) that expresses the prM-E proteins of ZIKV using the licensed Japanese encephalitis live-attenuated vaccine SA14-14-2 as the genetic backbone. ChinZIKV retains its replication activity and genetic stability in vitro, while exhibiting an attenuation phenotype in multiple animal models. Remarkably, immunization of mice and rhesus macaques with a single dose of ChinZIKV elicits robust and long-lasting immune responses, and confers complete protection against ZIKV challenge. Significantly, female mice immunized with ChinZIKV are protected against placental and fetal damage upon ZIKV challenge during pregnancy. Overall, our study provides an alternative vaccine platform in response to the ZIKV emergency, and the safety, immunogenicity, and protection profiles of ChinZIKV warrant further clinical development.

Genetic engineering of live attenuated influenza viruses.

PubMed

Jin, Hong; Chen, Zhongying; Liu, Jonathan; Kemble, George

2012-01-01

The first live attenuated influenza vaccine (LAIV) was licensed in the USA in 2003; it is a trivalent vaccine composed of two type A (H1N1 and H3N2) and one type B influenza virus each at 10(7) fluorescent focus units (FFU). Each influenza vaccine strain is a reassortant virus that contains the hemagglutinin (HA) and neuraminidase (NA) gene segments from a wild-type influenza virus and the six internal protein gene segments from a master donor virus (MDV) of either cold-adapted A/Ann Arbor/6/60 or B/Ann Arbor/1/66. MDV confers the cold-adapted, temperature-sensitive, and attenuation phenotypes to the vaccine strains. The reassortant vaccine seeds are currently produced by reverse genetics and amplified in specific pathogen-free (SPF) 9-11 days old embryonated chicken eggs for manufacture. In addition, MDCK cell culture manufacture processes have been developed to produce LAIV for research use and with modifications for clinical and/or commercial grade material production.

A clinical trial of WRL 105 strain live attenuated influenza vaccine comparing four methods of intranasal vaccination.

PubMed Central

Freestone, D. S.; Bowker, C. H.; Letley, E.; Ferris, R. D.; White, W. G.; Barnes, G. M.

1976-01-01

A single intranasal dose of 10(7-0) EID50 recombinant WRL 105 strain live attenuated influenza vaccine was administered intranasally to 193 volunteers either as nose drops or by one of three spray devices which produced sprays of differing physical characteristics. In volunteers with homologous haemagglutinating inhibiting antibody titres of less than or equal to 20 before vaccination, seroconversion rates varied widely from 80% following the administration of drops to 71%, 57% and 28% with the three spray devices. In the week following vaccination 16 (22%) of 74 volunteers who were found to show a fourfold or greater antibody response to took analgesics to control symptoms in comparison with 4 (7%) of 58 volunteers who exhibited no serological response to vaccination (P less than 0-05). However, neither the occurrence of upper respiratory nor systemic symptoms were significantly different in these two groups and the degree of attenuation of the recombinant WRL 105 strain appears to be acceptable for future use. PMID:1064672

Pet Ownership may Attenuate Loneliness Among Older Adult Primary Care Patients Who Live Alone

PubMed Central

Stanley, Ian H.; Conwell, Yeates; Bowen, Connie; Van Orden, Kimberly A.

2013-01-01

Objectives Older adults who report feelings of loneliness are at increased risk for a range of negative physical and mental health outcomes, including early mortality. Identifying potential sources of social connectedness, such as pet ownership, could add to the understanding of how to promote health and well-being in older adults. The aim of this study is to describe the association of pet ownership and loneliness. Methods The current study utilizes cross-sectional survey data from a sample (N = 830) of older adult primary care patients (age > 60 years). Results Pet owners were 36% less likely than non-pet owners to report loneliness, in a model controlling for age, living status (i.e., alone vs. not alone), happy mood, and seasonal residency (adjOR = 0.64, 95% CI = 0.41-0.98, p <.05). An interaction was found between pet ownership and living status (b = −1.60, p < .001) in which living alone and not owning a pet was associated with the greatest odds of reporting feelings of loneliness. Conclusions Findings suggest that pet ownership may confer benefits for well-being, including attenuating feelings of loneliness and its related sequelae, among older adults who live alone. PMID:24047314

Pet ownership may attenuate loneliness among older adult primary care patients who live alone.

PubMed

Stanley, Ian H; Conwell, Yeates; Bowen, Connie; Van Orden, Kimberly A

2014-01-01

Older adults who report feelings of loneliness are at increased risk for a range of negative physical and mental health outcomes, including early mortality. Identifying potential sources of social connectedness, such as pet ownership, could add to the understanding of how to promote health and well-being in older adults. The aim of this study is to describe the association of pet ownership and loneliness. The current study utilizes cross-sectional survey data from a sample (N = 830) of older adult primary care patients (age ≥ 60 years). Pet owners were 36% less likely than non-pet owners to report loneliness, in a model controlling for age, living status (i.e., alone vs. not alone), happy mood, and seasonal residency (adjOR = 0.64, 95% CI = 0.41-0.98, p < 0.05). An interaction was found between pet ownership and living status (b = -1.60, p < 0.001) in which living alone and not owning a pet was associated with the greatest odds of reporting feelings of loneliness. The findings suggest that pet ownership may confer benefits for well-being, including attenuating feelings of loneliness and its related sequelae, among older adults who live alone.

Attenuation by intravenous 2-chloroadenosine of acute lung injury induced by live escherichia coli or latex particles added to endotoxin in the neutropenic state.

PubMed

Sakamaki, Fumio; Ishizaka, Akitoshi; Urano, Tetsuya; Sayama, Koichi; Nakamura, Hidetoshi; Terashima, Takeshi; Waki, Yasuhiro; Soejima, Kenzo; Tasaka, Sadatomo; Sawafuji, Makoto; Kobayashi, Kouichi; Yamaguchi, Kazuhiro; Kanazawa, Minoru

2003-08-01

Although neutrophil depletion can reduce the level of acute lung injury (ALI) induced by Escherichia coli endotoxin, that induced by live E coli cannot be attenuated even in neutropenia. This suggests that live E coli cause ALI by way of an mechanism independent of circulating neutrophil. Tumor necrosis factor-alpha (TNF-alpha), which is released from monocytes and macrophages, is a proinflammatory cytokine that is recognized as a central mediator of several forms of inflammation. In this controlled experimental study, we examined the effects of an adenosine-receptor agonist, 2-chloroadenosine (2CA), that has suppressive effects on various cell types and TNF-alpha, on endotoxin plus latex particles, and on ALI induced by live E coli in the neutropenic state. We studied 42 guinea pigs rendered neutropenic by means of intraperitoneal cyclophosphamide administration. Experimental groups consisted of (1) a saline-solution control group; (2) an endotoxin (0.2 mg/kg)-treated group; (3) a group treated with endotoxin plus 2CA (10 micro g/kg); (4) a group treated with latex (2 x 10(9)/kg); (5) a group exposed to endotoxin and latex; (6) a group exposed to endotoxin, latex, and 2CA; (7) a group exposed to E coli (2 x 10(9)/kg); and (8) a group exposed to E coli and 2CA. The injection of endotoxin alone in neutropenic animals did not increase the indexes of ALI (lung tissue/plasma ratio [T/P] and lung wet weight/dry weight ratio [W/D], calculated with the use of iodine 125-labeled albumin). In contrast, these indexes were increased in the endotoxin-and-latex groups compared with those of the control group. ALI in the endotoxin-and-latex group was attenuated by intravenous 2CA. The intravenous injection of live E coli also caused increases in T/P, W/D, and plasma TNF-alpha, but thse were limited by 2CA. In summary, ALI induced by latex particles added to endotoxin and live E coli in the neutropenic state was attenuated by 2CA, suggesting a partial contribution of various cell types or humoral mediators as a neutrophil-independent pathway in its pathogenesis.

The Live Attenuated Cholera Vaccine CVD 103-HgR Primes Responses to the Toxin-Coregulated Pilus Antigen TcpA in Subjects Challenged with Wild-Type Vibrio cholerae.

PubMed

Mayo-Smith, Leslie M; Simon, Jakub K; Chen, Wilbur H; Haney, Douglas; Lock, Michael; Lyon, Caroline E; Calderwood, Stephen B; Kirkpatrick, Beth D; Cohen, Mitchell; Levine, Myron M; Gurwith, Marc; Harris, Jason B

2017-01-01

One potential advantage of live attenuated bacterial vaccines is the ability to stimulate responses to antigens which are only expressed during the course of infection. To determine whether the live attenuated cholera vaccine CVD 103-HgR (Vaxchora) results in antibody responses to the in vivo-induced toxin-coregulated pilus antigen TcpA, we measured IgA and IgG responses to Vibrio cholerae O1 El Tor TcpA in a subset of participants in a recently reported experimental challenge study. Participants were challenged with V. cholerae O1 El Tor Inaba N16961 either 10 days or 90 days after receiving the vaccine or a placebo. Neither vaccination nor experimental infection with V. cholerae alone resulted in a robust TcpA IgG or IgA response, but each did elicit a strong response to cholera toxin. However, compared to placebo recipients, vaccinees had a marked increase in IgG TcpA antibodies following the 90-day challenge, suggesting that vaccination with CVD 103-HgR resulted in priming for a subsequent response to TcpA. No such difference between vaccine and placebo recipients was observed for volunteers challenged 10 days after vaccination, indicating that this was insufficient time for vaccine-induced priming of the TcpA response. The priming of the response to TcpA and potentially other antigens expressed in vivo by attenuated V. cholerae may have relevance to the maintenance of immunity in areas where cholera is endemic. Copyright © 2017 American Society for Microbiology.

[Immune response to one booster dose of inactivated hepatitis A vaccine in college students].

PubMed

Liao, Z; Feng, X W; Liu, X E; Zhou, Y S; Wen, H R; Peng, S H; Zhang, Y X; Xu, B; Zhuang, H; Chen, H Y

2017-05-10

Objective: To evaluate the safety and immunogenicity of one booster dose of inactivated hepatitis A vaccine in young adults. Methods: The subjects were selected from participants in the clinical trial of immunogenicity of inactivated and attenuated live hepatitis A vaccine in young adults. Eligible subjects were those who had received one dose of inactivated or attenuated hepatitis A vaccine, could be contacted and were sero-negative before primary vaccination. All qualified subjects were immunized with one booster dose of inactivated hepatitis A vaccine. The blood samples were collected before booster dose vaccination and 28 days after the immunization. Anti-HAV antibody titer ≥20 mIU/ml was considered to be sero-protected against hepatitis A virus. Results: The GMCs in the inactivated HAV vaccine group and attenuated live vaccine group before booster dose vaccination were 70.80 mIU/ml and 50.12 mIU/ml, respectively, and the sero-protection rates were 94.7 % and 65.0 % , respectively. After the vaccination of the booster dose, the sero-protection rates in both groups were 100.0 % , and the GMCs were 2 816.09 mIU/ml and 2 654.55 mIU/ml, respectively. Conclusion: The GMCs and sero-protection rates of anti-HAV antibody in young adults declined after three years of the primary vaccination. However, the higher GMC and sero-protection rate were observed in the inactivated vaccine group than in the attenuated live vaccine group. Significant increases of GMC levels were observed in both groups after one booster dose vaccination.

A single-dose live-attenuated vaccine prevents Zika virus pregnancy transmission and testis damage.

PubMed

Shan, Chao; Muruato, Antonio E; Jagger, Brett W; Richner, Justin; Nunes, Bruno T D; Medeiros, Daniele B A; Xie, Xuping; Nunes, Jannyce G C; Morabito, Kaitlyn M; Kong, Wing-Pui; Pierson, Theodore C; Barrett, Alan D; Weaver, Scott C; Rossi, Shannan L; Vasconcelos, Pedro F C; Graham, Barney S; Diamond, Michael S; Shi, Pei-Yong

2017-09-22

Zika virus infection during pregnancy can cause congenital abnormities or fetal demise. The persistence of Zika virus in the male reproductive system poses a risk of sexual transmission. Here we demonstrate that live-attenuated Zika virus vaccine candidates containing deletions in the 3' untranslated region of the Zika virus genome (ZIKV-3'UTR-LAV) prevent viral transmission during pregnancy and testis damage in mice, as well as infection of nonhuman primates. After a single-dose vaccination, pregnant mice challenged with Zika virus at embryonic day 6 and evaluated at embryonic day 13 show markedly diminished levels of viral RNA in maternal, placental, and fetal tissues. Vaccinated male mice challenged with Zika virus were protected against testis infection, injury, and oligospermia. A single immunization of rhesus macaques elicited a rapid and robust antibody response, conferring complete protection upon challenge. Furthermore, the ZIKV-3'UTR-LAV vaccine candidates have a desirable safety profile. These results suggest that further development of ZIKV-3'UTR-LAV is warranted for humans.Zika virus infection can result in congenital disorders and cause disease in adults, and there is currently no approved vaccine. Here Shan et al. show that a single dose of a live-attenuated Zika vaccine prevents infection, testis damage and transmission to the fetus during pregnancy in different animal models.

Live Attenuated Influenza Virus Increases Pneumococcal Translocation and Persistence Within the Middle Ear

PubMed Central

Mina, Michael J.; Klugman, Keith P.; Rosch, Jason W.; McCullers, Jonathan A.

2015-01-01

Background. Infection with influenza A virus (IAV) increases susceptibility to respiratory bacterial infections, resulting in increased bacterial carriage and complications such acute otitis media, pneumonia, bacteremia, and meningitis. Recently, vaccination with live attenuated influenza virus (LAIV) was reported to enhance subclinical bacterial colonization within the nasopharynx, similar to IAV. Although LAIV does not predispose to bacterial pneumonia, whether it may alter bacterial transmigration toward the middle ear, where it could have clinically relevant implications, has not been investigated. Methods. BALB/c mice received LAIV or phosphate-buffered saline 1 or 7 days before or during pneumococcal colonization with either of 2 clinical isolates, 19F or 7F. Middle ear bacterial titers were monitored daily via in vivo imaging. Results. LAIV increased bacterial transmigration to and persistence within the middle ear. When colonization followed LAIV inoculation, a minimum LAIV incubation period of 4 days was required before bacterial transmigration commenced. Conclusions. While LAIV vaccination is safe and effective at reducing IAV and coinfection with influenza virus and bacteria, LAIV may increase bacterial transmigration to the middle ear and could thus increase the risk of clinically relevant acute otitis media. These data warrant further investigations into interactions between live attenuated viruses and naturally colonizing bacterial pathogens. PMID:25505300

Matched Case-Control Study of Effectiveness of Live, Attenuated S79 Mumps Virus Vaccine against Clinical Mumps▿

PubMed Central

Fu, Chuanxi; Liang, Jianhua; Wang, Ming

2008-01-01

Mumps virus infection is a potentially serious viral infection of childhood and early adulthood. In China, live, attenuated S79 mumps virus vaccine has been licensed for pediatric use since 1990. There has been no assessment of its efficacy. Thus, the objective of this study was to determine the effectiveness of live, attenuated S79 mumps virus vaccine against clinical mumps. Cases were selected from the China Information System for Disease Control and Prevention during September 2004 to March 2005. Each case was matched to a control by gender, age, and area of residency. In all, 469 cases and 469 controls were enrolled in the study. Vaccination information was obtained from the Children's EPI Administrative Computerized System. Vaccine effectiveness (VE) was calculated for one or two doses of S79 vaccine, with 95% confidence intervals (CI). VE of mumps virus vaccine for one dose versus none was protection of 86.0% (95% CI, 77.2% to 91.5%) of recipients, and VE was much higher in the first 4 years than in the 5 to 12 years after vaccination. The S79 vaccine can effectively prevent clinical mumps, and a second dose of mumps virus vaccine is necessary for the protection of children in China. PMID:18667635

Combined genetic and pharmacological inhibition of TRPV1 and P2X3 attenuates colorectal hypersensitivity and afferent sensitization

PubMed Central

Kiyatkin, Michael E.; Feng, Bin; Schwartz, Erica S.

2013-01-01

The ligand-gated channels transient receptor potential vanilloid 1 (TRPV1) and P2X3 have been reported to facilitate colorectal afferent neuron sensitization, thus contributing to organ hypersensitivity and pain. In the present study, we hypothesized that TRPV1 and P2X3 cooperate to modulate colorectal nociception and afferent sensitivity. To test this hypothesis, we employed TRPV1-P2X3 double knockout (TPDKO) mice and channel-selective pharmacological antagonists and evaluated combined channel contributions to behavioral responses to colorectal distension (CRD) and afferent fiber responses to colorectal stretch. Baseline responses to CRD were unexpectedly greater in TPDKO compared with control mice, but zymosan-produced CRD hypersensitivity was absent in TPDKO mice. Relative to control mice, proportions of mechanosensitive and -insensitive pelvic nerve afferent classes were not different in TPDKO mice. Responses of mucosal and serosal class afferents to mechanical probing were unaffected, whereas responses of muscular (but not muscular/mucosal) afferents to stretch were significantly attenuated in TPDKO mice; sensitization of both muscular and muscular/mucosal afferents by inflammatory soup was also significantly attenuated. In pharmacological studies, the TRPV1 antagonist A889425 and P2X3 antagonist TNP-ATP, alone and in combination, applied onto stretch-sensitive afferent endings attenuated responses to stretch; combined antagonism produced greater attenuation. In the aggregate, these observations suggest that 1) genetic manipulation of TRPV1 and P2X3 leads to reduction in colorectal mechanosensation peripherally and compensatory changes and/or disinhibition of other channels centrally, 2) combined pharmacological antagonism produces more robust attenuation of mechanosensation peripherally than does antagonism of either channel alone, and 3) the relative importance of these channels appears to be enhanced in colorectal hypersensitivity. PMID:23989007

Genomic changes in an attenuated genotype I Japanese encephalitis virus and comparison with virulent parental strain.

PubMed

Zhou, Yuyong; Wu, Rui; Feng, Yao; Zhao, Qin; Wen, Xintian; Huang, Xiaobo; Wen, Yiping; Yan, Qigui; Huang, Yong; Ma, Xiaoping; Han, Xinfeng; Cao, Sanjie

2018-06-01

Genotype I Japanese encephalitis virus (JEV) strain SCYA201201 was previously isolated from brain tissues of aborted piglets. In this study, we obtained an attenuated SCYA201201-0901 strain by serial passage of strain SCYA201201-1 in Syrian baby hamster kidney cells, combined with multiple plaque purifications and selection for virulence in mice. We investigated the genetic changes associated with attenuation by comparing the entire genomes of SCYA201201-0901 and SCYA201201-1. Sequence comparisons identified 14 common amino acid substitutions in the coding region, with two nucleotide point mutations in the 5'-untranslated region (UTR) and another three in the 3'-UTR, which differed between the attenuated and virulent strains. In addition, a total of 13 silent nucleotide mutations were found after attenuation. These substitutions, alone or in combination, may be responsible for the attenuated phenotype of the SCYA201201-0901 strain in mice. This information will contribute to our understanding of attenuation and of the molecular basis of virulence in genotype I strains such as SCYA201201-0901, as well as aiding the development of safer JEV vaccines.

Enhancing the Thermostability and Immunogenicity of a Respiratory Syncytial Virus (RSV) Live-Attenuated Vaccine by Incorporating Unique RSV Line19F Protein Residues.

PubMed

Rostad, Christina A; Stobart, Christopher C; Todd, Sean O; Molina, Samuel A; Lee, Sujin; Blanco, Jorge C G; Moore, Martin L

2018-03-15

Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in infants, and an effective vaccine is not yet available. We previously generated an RSV live-attenuated vaccine (LAV) candidate, DB1, which was attenuated by a low-fusion subgroup B F protein (BAF) and codon-deoptimized nonstructural protein genes. DB1 was immunogenic and protective in cotton rats but lacked thermostability and stability of the prefusion conformation of F compared to strains with the line19F gene. We hypothesized that substitution of unique residues from the thermostable A2-line19F strain could thermostabilize DB1 and boost its immunogenicity. We therefore substituted 4 unique line19F residues into the BAF protein of DB1 by site-directed mutagenesis and rescued the recombinant virus, DB1-QUAD. Compared to DB1, DB1-QUAD had improved thermostability at 4°C and higher levels of prefusion F as measured by enzyme-linked immunosorbent assays (ELISAs). DB1-QUAD was attenuated in normal human bronchial epithelial cells, in BALB/c mice, and in cotton rats but grew to wild-type titers in Vero cells. In mice, DB1-QUAD was highly immunogenic and generated significantly higher neutralizing antibody titers to a panel of RSV A and B strains than did DB1. DB1-QUAD was also efficacious against wild-type RSV challenge in mice and cotton rats. Thus, substitution of unique line19F residues into RSV LAV DB1 enhanced vaccine thermostability, incorporation of prefusion F, and immunogenicity and generated a promising vaccine candidate that merits further investigation. IMPORTANCE We boosted the thermostability and immunogenicity of an RSV live-attenuated vaccine candidate by substituting 4 unique residues from the RSV line19F protein into the F protein of the heterologous vaccine strain DB1. The resultant vaccine candidate, DB1-QUAD, was thermostable, attenuated in vivo , highly immunogenic, and protective against RSV challenge in mice and cotton rats. Copyright © 2018 American Society for Microbiology.

Development of a dual-protective live attenuated vaccine against H5N1 and H9N2 avian influenza viruses by modifying the NS1 gene.

PubMed

Choi, Eun-hye; Song, Min-Suk; Park, Su-Jin; Pascua, Philippe Noriel Q; Baek, Yun Hee; Kwon, Hyeok-il; Kim, Eun-Ha; Kim, Semi; Jang, Hyung-Kwan; Poo, Haryoung; Kim, Chul-Joong; Choi, Young Ki

2015-07-01

An increasing number of outbreaks of avian influenza H5N1 and H9N2 viruses in poultry have caused serious economic losses and raised concerns for human health due to the risk of zoonotic transmission. However, licensed H5N1 and H9N2 vaccines for animals and humans have not been developed. Thus, to develop a dual H5N1 and H9N2 live-attenuated influenza vaccine (LAIV), the HA and NA genes from a virulent mouse-adapted avian H5N2 (A/WB/Korea/ma81/06) virus and a recently isolated chicken H9N2 (A/CK/Korea/116/06) virus, respectively, were introduced into the A/Puerto Rico/8/34 backbone expressing truncated NS1 proteins (NS1-73, NS1-86, NS1-101, NS1-122) but still possessing a full-length NS gene. Two H5N2/NS1-LAIV viruses (H5N2/NS1-86 and H5N2/NS1-101) were highly attenuated compared with the full-length and remaining H5N2/NS-LAIV viruses in a mouse model. Furthermore, viruses containing NS1 modifications were found to induce more IFN-β activation than viruses with full-length NS1 proteins and were correspondingly attenuated in mice. Intranasal vaccination with a single dose (10(4.0) PFU/ml) of these viruses completely protected mice from a lethal challenge with the homologous A/WB/Korea/ma81/06 (H5N2), heterologous highly pathogenic A/EM/Korea/W149/06 (H5N1), and heterosubtypic highly virulent mouse-adapted H9N2 viruses. This study clearly demonstrates that the modified H5N2/NS1-LAIV viruses attenuated through the introduction of mutations in the NS1 coding region display characteristics that are desirable for live attenuated vaccines and hold potential as vaccine candidates for mammalian hosts.

Protection of chickens against infectious bronchitis by a recombinant fowlpox virus co-expressing IBV-S1 and chicken IFNgamma.

PubMed

Wang, Yun-Feng; Sun, Yong-Ke; Tian, Zhan-Cheng; Shi, Xing-Ming; Tong, Guang-Zhi; Liu, Sheng-Wang; Zhi, Hai-Dong; Kong, Xian-Gang; Wang, Mei

2009-11-23

A fowlpox virus expressing the chicken infectious bronchitis virus (IBV) S1 gene of the LX4 strain (rFPV-IBVS1) and a fowlpox virus co-expressing the S1 gene and the chicken type II interferon gene (rFPV-IBVS1-ChIFNgamma) were constructed. These viruses were assessed for their immunological efficacy on specific-pathogen-free (SPF) chickens challenged with a virulent IBV. Although the antibody levels in the rFPV-IBVS1-ChIFNgamma-vaccinated group were lower than those in the attenuated live IB vaccine H120 group and the rFPV-IBVS1 group, the rFPV-IBVS1-ChIFNgamma provided the strongest protection against an IBV LX4 virus challenge (15 out of 16 chickens immunized with rFPV-IBVS1-ChIFNgamma were protected), followed by the attenuated live IB vaccine (13/16 protected) and the rFPV-IBVS1 (12/16 protected). Compared to those of the rFPV-IBVS1 and the attenuated live IB vaccine groups, chickens in the rFPV-IBVS1-ChIFNgamma group eliminated virus more quickly and decreased the presence of viral antigen more significantly in renal tissue. Examination of affected tissues revealed abnormalities in the liver, spleen, kidney, lung and trachea of chickens vaccinated with the attenuated live IB vaccine and the rFPV-IBVS1 vaccine. In rFPV-IBVS1-ChIFNgamma-vaccinated chickens, pathological changes were also observed in those organs, but were milder and lasted shorter. The lesions in the mock control group were the most severe and lasted for at least 20 days. This study demonstrated that chicken type II interferon increased the immunoprotective efficacy of rFPV-IBVS1-ChIFNgamma and normal weight gain in vaccinated chickens although it inhibited serum antibody production.

Live attenuated H5N1 vaccine with H9N2 internal genes protects chickens from infections by both Highly Pathogenic H5N1 and H9N2 Influenza Viruses

PubMed Central

Nang, Nguyen Tai; Song, Byung Min; Kang, Young Myong; Kim, Heui Man; Kim, Hyun Soo; Seo, Sang Heui

2012-01-01

Please cite this paper as: Nang et al. (2013) Live attenuated H5N1 vaccine with H9N2 internal genes protects chickens from infections by both Highly Pathogenic H5N1 and H9N2 Influenza Viruses. Influenza and Other Respiratory Viruses 7(2) 120–131. Background  The highly pathogenic H5N1 and H9N2 influenza viruses are endemic in many countries around the world and have caused considerable economic loss to the poultry industry. Objectives  We aimed to study whether a live attenuated H5N1 vaccine comprising internal genes from a cold‐adapted H9N2 influenza virus could protect chickens from infection by both H5N1 and H9N2 viruses. Methods  We developed a cold‐adapted H9N2 vaccine virus expressing hemagglutinin and neuraminidase derived from the highly pathogenic H5N1 influenza virus using reverse genetics. Results and Conclusions  Chickens immunized with the vaccine were protected from lethal infections with homologous and heterologous H5N1 or H9N2 influenza viruses. Specific antibody against H5N1 virus was detected up to 11 weeks after vaccination (the endpoint of this study). In vaccinated chickens, IgA and IgG antibody subtypes were induced in lung and intestinal tissue, and CD4+ and CD8+ T lymphocytes expressing interferon‐gamma were induced in the splenocytes. These data suggest that a live attenuated H5N1 vaccine with cold‐adapted H9N2 internal genes can protect chickens from infection with H5N1 and H9N2 influenza viruses by eliciting humoral and cellular immunity. PMID:22487301

Middle East Respiratory Syndrome Coronavirus Nonstructural Protein 16 Is Necessary for Interferon Resistance and Viral Pathogenesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Menachery, Vineet D.; Gralinski, Lisa E.; Mitchell, Hugh D.

ABSTRACT Coronaviruses (CoVs) encode a mixture of highly conserved and novel genes, as well as genetic elements necessary for infection and pathogenesis, raising the possibility of common targets for attenuation and therapeutic design. In this study, we focused on highly conserved nonstructural protein 16 (NSP16), a viral 2'O-methyltransferase (2'O-MTase) that encodes critical functions in immune modulation and infection. Using reverse genetics, we disrupted a key motif in the conserved KDKE motif of Middle East respiratory syndrome CoV (MERS-CoV) NSP16 (D130A) and evaluated the effect on viral infection and pathogenesis. While the absence of 2'O-MTase activity had only a marginal impactmore » on propagation and replication in Vero cells, dNSP16 mutant MERS-CoV demonstrated significant attenuation relative to the control both in primary human airway cell cultures andin vivo. Further examination indicated that dNSP16 mutant MERS-CoV had a type I interferon (IFN)-based attenuation and was partially restored in the absence of molecules of IFN-induced proteins with tetratricopeptide repeats. Importantly, the robust attenuation permitted the use of dNSP16 mutant MERS-CoV as a live attenuated vaccine platform protecting from a challenge with a mouse-adapted MERS-CoV strain. These studies demonstrate the importance of the conserved 2'O-MTase activity for CoV pathogenesis and highlight NSP16 as a conserved universal target for rapid live attenuated vaccine design in an expanding CoV outbreak setting. IMPORTANCECoronavirus (CoV) emergence in both humans and livestock represents a significant threat to global public health, as evidenced by the sudden emergence of severe acute respiratory syndrome CoV (SARS-CoV), MERS-CoV, porcine epidemic diarrhea virus, and swine delta CoV in the 21st century. These studies describe an approach that effectively targets the highly conserved 2'O-MTase activity of CoVs for attenuation. With clear understanding of the IFN/IFIT (IFN-induced proteins with tetratricopeptide repeats)-based mechanism, NSP16 mutants provide a suitable target for a live attenuated vaccine platform, as well as therapeutic development for both current and future emergent CoV strains. Importantly, other approaches targeting other conserved pan-CoV functions have not yet proven effective against MERS-CoV, illustrating the broad applicability of targeting viral 2'O-MTase function across CoVs.« less

Middle East Respiratory Syndrome Coronavirus Nonstructural Protein 16 Is Necessary for Interferon Resistance and Viral Pathogenesis

PubMed Central

Menachery, Vineet D.; Gralinski, Lisa E.; Mitchell, Hugh D.; Dinnon, Kenneth H.; Leist, Sarah R.; Yount, Boyd L.; Graham, Rachel L.; McAnarney, Eileen T.; Stratton, Kelly G.; Cockrell, Adam S.; Debbink, Kari; Sims, Amy C.; Waters, Katrina M.

2017-01-01

ABSTRACT Coronaviruses (CoVs) encode a mixture of highly conserved and novel genes, as well as genetic elements necessary for infection and pathogenesis, raising the possibility of common targets for attenuation and therapeutic design. In this study, we focused on highly conserved nonstructural protein 16 (NSP16), a viral 2′O-methyltransferase (2′O-MTase) that encodes critical functions in immune modulation and infection. Using reverse genetics, we disrupted a key motif in the conserved KDKE motif of Middle East respiratory syndrome CoV (MERS-CoV) NSP16 (D130A) and evaluated the effect on viral infection and pathogenesis. While the absence of 2′O-MTase activity had only a marginal impact on propagation and replication in Vero cells, dNSP16 mutant MERS-CoV demonstrated significant attenuation relative to the control both in primary human airway cell cultures and in vivo. Further examination indicated that dNSP16 mutant MERS-CoV had a type I interferon (IFN)-based attenuation and was partially restored in the absence of molecules of IFN-induced proteins with tetratricopeptide repeats. Importantly, the robust attenuation permitted the use of dNSP16 mutant MERS-CoV as a live attenuated vaccine platform protecting from a challenge with a mouse-adapted MERS-CoV strain. These studies demonstrate the importance of the conserved 2′O-MTase activity for CoV pathogenesis and highlight NSP16 as a conserved universal target for rapid live attenuated vaccine design in an expanding CoV outbreak setting. IMPORTANCE Coronavirus (CoV) emergence in both humans and livestock represents a significant threat to global public health, as evidenced by the sudden emergence of severe acute respiratory syndrome CoV (SARS-CoV), MERS-CoV, porcine epidemic diarrhea virus, and swine delta CoV in the 21st century. These studies describe an approach that effectively targets the highly conserved 2′O-MTase activity of CoVs for attenuation. With clear understanding of the IFN/IFIT (IFN-induced proteins with tetratricopeptide repeats)-based mechanism, NSP16 mutants provide a suitable target for a live attenuated vaccine platform, as well as therapeutic development for both current and future emergent CoV strains. Importantly, other approaches targeting other conserved pan-CoV functions have not yet proven effective against MERS-CoV, illustrating the broad applicability of targeting viral 2′O-MTase function across CoVs. PMID:29152578

Fatal vaccine-induced canine distemper virus infection in black-footed ferrets

USGS Publications Warehouse

Carpenter, J.W.; Appel, M.J.G.; Erickson, R.C.; Novilla, M.N.

1976-01-01

Four black-footed ferrets that were live-trapped in South Dakota and transported to the Patuxent Wildlife Research Center died within 21 days after vaccination with modified live canine distemper virus. Immunofluorescence, European ferret inoculation, virus isolation attempts, and serum-neutralization tests indicated insufficient attenuation of the vaccine for this species.

Fatal vaccine-induced canine distemper virus infection in black-footed ferrets.

PubMed

Carpenter, J W; Appel, M J; Erickson, R C; Novilla, M N

1976-11-01

Four black-footed ferrets that were live-trapped in South Dakota and transported to the Patuxent Wildlife Research Center died within 21 days after vaccination with modified live canine distemper virus. Immunofluorescence, European ferret inoculation, virus isolation attempts, and serum-neutralization tests indicated insufficient attenuation of the vaccine for this species.

Evaluation of the attenuation, immunogenicity, and efficacy of a live virus vaccine generated by codon-pair bias de-optimization of the 2009 pandemic H1N1 influenza virus, in ferrets

PubMed Central

Broadbent, Andrew J.; Santos, Celia P.; Anafu, Amanda; Wimmer, Eckard; Mueller, Steffen; Subbarao, Kanta

2015-01-01

Codon-pair bias de-optimization (CPBD) of viruses involves re-writing viral genes using statistically underrepresented codon pairs, without any changes to the amino acid sequence or codon usage. Previously, this technology has been used to attenuate the influenza A/Puerto Rico/8/34 (H1N1) virus. The de-optimized virus was immunogenic and protected inbred mice from challenge. In order to assess whether CPBD could be used to produce a live vaccine against a clinically relevant influenza virus, we generated an influenza A/California/07/2009 pandemic H1N1 (2009 pH1N1) virus with de-optimized HA and NA gene segments (2009 pH1N1-(HA+NA)Min), and evaluated viral replication and protein expression in MDCK cells, and attenuation, immunogenicity, and efficacy in outbred ferrets. The 2009 pH1N1-(HA+NA)Min virus grew to a similar titer as the 2009 pH1N1 wild type (wt) virus in MDCK cells (~106 TCID50/ml), despite reduced HA and NA protein expression on western blot. In ferrets, intranasal inoculation of 2009 pH1N1-(HA+NA)Min virus at doses ranging from 103 to 105 TCID50 led to seroconversion in all animals and protection from challenge with the 2009 pH1N1 wt virus 28 days later. The 2009 pH1N1-(HA+NA)Min virus did not cause clinical illness in ferrets, but replicated to a similar titer as the wt virus in the upper and lower respiratory tract, suggesting that de-optimization of additional gene segments may be warranted for improved attenuation. Taken together, our data demonstrate the potential of using CPBD technology for the development of a live influenza virus vaccine if the level of attenuation is optimized. PMID:26655630

Comparison of immunogenicity between inactivated and live attenuated hepatitis A vaccines: a single-blind, randomized, parallel-group clinical trial among children in Xinjiang Uighur Autonomous Region, China.

PubMed

Liu, Xue-En; Wushouer, Fuerhati; Gou, Aili; Kuerban, Mahemuti; Li, Xinlan; Sun, Yubo; Zhang, Jiamin; Liu, Yan; Li, Jie; Zhuang, Hui

2013-07-01

To compare immunogenicity among an inactivated hepatitis A vaccine (Healive(®)) with one-dose and two-dose regimens, and three kinds of live attenuated vaccines in children. A single-blind, randomized, parallel-group clinical trial was conducted among healthy children aged 1.5-6 y in Xinjiang Uighur Autonomous Region, China. Subjects were randomly assigned to 5 groups. Two groups were administered one-dose or two-dose inactivated vaccine and the remaining groups were immunized with one of three kinds of attenuated vaccines, respectively. Serum samples were collected at 6- and 12-mo follow-ups. Anti-HAV IgG was measured with a microparticle enzyme immunoassay. No significant differences were observed in seroconversion rates (seroprotection rates) among the five groups at 6 or 12 mo (p>0.05). The geometric mean concentration (GMC) of anti-HAV IgG was significantly higher in the two-dose Healive(®) group than in the one-dose Healive(®) group and the attenuated vaccine groups at 12 mo (932.4 vs. 112.7, 135.8, 203.3, 212.8 mIU/ml, respectively, p<0.05). In the one-dose Healive(®) group, the GMC was significantly lower than that in the attenuated vaccine B and C groups at 6 mo (152.6 vs. 212, 204 mIU/ml, p<0.05) and at 12 mo (112.7 vs. 203.3, 212.8, p<0.05), but was similar to the attenuated vaccine A group at 12 mo (112.7 vs. 135.8 mIU/ml, p>0.05). The GMCs were significantly higher in the 1-2 y of age group than in the 3-6 y of age group for all types of vaccines except the attenuated vaccine C (p<0.05) at 12 mo. A higher GMC of anti-HAV IgG was induced in the two-dose Healive(®) than in the one-dose and the attenuated vaccines at 12 mo. The attenuated vaccine B or C produced higher GMCs than the one-dose Healive(®) at 6-12 mo after vaccination.

A Combination in-ovo Vaccine for Avian Influenza Virus and Newcastle Disease Virus

PubMed Central

Steel, John; Burmakina, Svetlana V.; Thomas, Colleen; Spackman, Erica; García-Sastre, Adolfo; Swayne, David E.; Palese, Peter

2008-01-01

The protection of poultry from H5N1 highly pathogenic avian influenza A (HPAI) and Newcastle disease virus (NDV) can be achieved through vaccination, as part of a broader disease control strategy. We have previously generated a recombinant influenza virus expressing; (i) an H5 hemagglutinin protein, modified by the removal of the polybasic cleavage peptide and (ii) the ectodomain of the NDV hemagglutinin – neuraminidase (HN) protein in the place of the ectodomain of influenza neuraminidase (Park, M.S., et al., 2006. Proc Natl Acad Sci U S A, 103 (21), 8203–8208). Here we show this virus is attenuated in primary normal human bronchial epithelial (NHBE) cell culture, and demonstrate protection of C57BL/6 mice from lethal challenge with an H5 HA-containing influenza virus through immunisation with the recombinant virus. In addition, in-ovo vaccination of 18-day-old embryonated chicken eggs provided 90% and 80% protection against highly stringent lethal challenge by NDV and H5N1 virus respectively. We propose that this virus has potential as a safe in-ovo live, attenuated, bivalent avian influenza and Newcastle disease virus vaccine. PMID:18093698

Advances in the development of bacterial vector technology.

PubMed

Kochi, Sims K; Killeen, Kevin P; Ryan, Una S

2003-02-01

The demand for new and improved vaccines against human diseases has continued unabated over the past century. While the need continues for traditional vaccines in areas such as infectious diseases, there is an increasing demand for new therapies in nontraditional areas, such as cancer treatment, bioterrorism and food safety. Prompted by these changes, there has been a renewed interest in the application and development of live, attenuated bacteria expressing foreign antigens as vaccines. The application of bacterial vector vaccines to human maladies has been studied most extensively in attenuted strains of Salmonella. Live, attenuated strains of Shigella, Listeria monocytogenes, Mycobacterium bovis-BCG and Vibrio cholerae provide unique alternatives in terms of antigen delivery and immune presentation, however and also show promise as potentially useful bacterial vectors.

Hereditary Hemochromatosis Restores the Virulence of Plague Vaccine Strains

PubMed Central

Quenee, Lauriane E.; Hermanas, Timothy M.; Ciletti, Nancy; Louvel, Helene; Miller, Nathan C.; Elli, Derek; Blaylock, Bill; Mitchell, Anthony; Schroeder, Jay; Krausz, Thomas; Kanabrocki, Joseph; Schneewind, Olaf

2012-01-01

Nonpigmented Yersinia pestis (pgm) strains are defective in scavenging host iron and have been used in live-attenuated vaccines to combat plague epidemics. Recently, a Y. pestis pgm strain was isolated from a researcher with hereditary hemochromatosis who died from laboratory-acquired plague. We used hemojuvelin-knockout (Hjv−/−) mice to examine whether iron-storage disease restores the virulence defects of nonpigmented Y. pestis. Unlike wild-type mice, Hjv−/− mice developed lethal plague when challenged with Y. pestis pgm strains. Immunization of Hjv−/− mice with a subunit vaccine that blocks Y. pestis type III secretion generated protection against plague. Thus, individuals with hereditary hemochromatosis may be protected with subunit vaccines but should not be exposed to live-attenuated plague vaccines. PMID:22896664

Live attenuated vaccines: Historical successes and current challenges.

PubMed

Minor, Philip D

2015-05-01

Live attenuated vaccines against human viral diseases have been amongst the most successful cost effective interventions in medical history. Smallpox was declared eradicated in 1980; poliomyelitis is nearing global eradication and measles has been controlled in most parts of the world. Vaccines function well for acute diseases such as these but chronic infections such as HIV are more challenging for reasons of both likely safety and probable efficacy. The derivation of the vaccines used has in general not been purely rational except in the sense that it has involved careful clinical trials of candidates and subsequent careful follow up in clinical use; the identification of the candidates is reviewed. Copyright © 2015 The Author. Published by Elsevier Inc. All rights reserved.

A Safe Bacterial Microsyringe for In Vivo Antigen Delivery and Immunotherapy

PubMed Central

Le Gouëllec, Audrey; Chauchet, Xavier; Laurin, David; Aspord, Caroline; Verove, Julien; Wang, Yan; Genestet, Charlotte; Trocme, Candice; Ahmadi, Mitra; Martin, Sandrine; Broisat, Alexis; Cretin, François; Ghezzi, Catherine; Polack, Benoit; Plumas, Joël; Toussaint, Bertrand

2013-01-01

The industrial development of active immunotherapy based on live-attenuated bacterial vectors has matured. We developed a microsyringe for antigen delivery based on the type III secretion system (T3SS) of P. aeruginosa. We applied the “killed but metabolically active” (KBMA) attenuation strategy to make this bacterial vector suitable for human use. We demonstrate that attenuated P. aeruginosa has the potential to deliver antigens to human antigen-presenting cells in vitro via T3SS with considerable attenuated cytotoxicity as compared with the wild-type vector. In a mouse model of cancer, we demonstrate that this KBMA strain, which cannot replicate in its host, efficiently disseminates into lymphoid organs and delivers its heterologous antigen. The attenuated strain effectively induces a cellular immune response to the cancerous cells while lowering the systemic inflammatory response. Hence, a KBMA P. aeruginosa microsyringe is an efficient and safe tool for in vivo antigen delivery. PMID:23531551

[Studying of molecular mechanisms of rubella virus attenuation evidence from Russian strain C-77].

PubMed

Dmitriev, G V; Borisova, T K; Faĭzuloev, E B; Zabiiaka, Iu I; Desiatskova, R G; Zverev, V V

2012-01-01

Live attenuated rubella vaccine is used for vaccination. Temperature-sensitive (ts) phenotype was proved for almost all rubella vaccine strains, and the acquisition of the ts phenotype during cold adaptation was strongly correlated with the attenuation of the wild-type viruses. Nevertheless, the molecular mechanisms of the attenuation have been insufficiently understood for rubella virus. Study ofthese mechanisms, identifying genotypic markers of attenuation, which together with the sequence analyses could be used for genetic stability control of vaccine strains, is still of current interest. In this work, we determined nearly complete genome sequences of attenuated (ca) and the wildtype progenitor (wt) of the rubella virus strain C-77 isolated in Russia. Possible genetic determinants of attenuation were detected. Thus, 13 nucleotide differences leading to 6 amino acid substitutions were found. Four amino acid substitutions were found to be almost unique. Special consideration should be given to Tyr1042Cys substitution in the protease domain of C-77 strain, because it most probably plays the crucial role in acquisition of ts-phenotype.

Oral fluids as a live-animal sample for evaluating cross-reactivity and cross-protection following intranasal influenza A virus vaccination in pigs

USDA-ARS?s Scientific Manuscript database

In North American swine there are numerous antigenically distinct influenza A virus (IAV) H1 subtypes currently circulating, making vaccine development difficult due to the inability to formulate a vaccine that provides broad cross-protection. Live-attenuated influenza virus (LAIV) vaccines provide ...

Direct Reconstruction of CT-Based Attenuation Correction Images for PET With Cluster-Based Penalties

NASA Astrophysics Data System (ADS)

Kim, Soo Mee; Alessio, Adam M.; De Man, Bruno; Kinahan, Paul E.

2017-03-01

Extremely low-dose (LD) CT acquisitions used for PET attenuation correction have high levels of noise and potential bias artifacts due to photon starvation. This paper explores the use of a priori knowledge for iterative image reconstruction of the CT-based attenuation map. We investigate a maximum a posteriori framework with cluster-based multinomial penalty for direct iterative coordinate decent (dICD) reconstruction of the PET attenuation map. The objective function for direct iterative attenuation map reconstruction used a Poisson log-likelihood data fit term and evaluated two image penalty terms of spatial and mixture distributions. The spatial regularization is based on a quadratic penalty. For the mixture penalty, we assumed that the attenuation map may consist of four material clusters: air + background, lung, soft tissue, and bone. Using simulated noisy sinogram data, dICD reconstruction was performed with different strengths of the spatial and mixture penalties. The combined spatial and mixture penalties reduced the root mean squared error (RMSE) by roughly two times compared with a weighted least square and filtered backprojection reconstruction of CT images. The combined spatial and mixture penalties resulted in only slightly lower RMSE compared with a spatial quadratic penalty alone. For direct PET attenuation map reconstruction from ultra-LD CT acquisitions, the combination of spatial and mixture penalties offers regularization of both variance and bias and is a potential method to reconstruct attenuation maps with negligible patient dose. The presented results, using a best-case histogram suggest that the mixture penalty does not offer a substantive benefit over conventional quadratic regularization and diminishes enthusiasm for exploring future application of the mixture penalty.

Galileo: The Added Value for Integrity in Harsh Environments.

PubMed

Borio, Daniele; Gioia, Ciro

2016-01-16

A global navigation satellite system (GNSS)-based navigation is a challenging task in a signal-degraded environments where GNSS signals are distorted by multipath and attenuated by fading effects: the navigation solution may be inaccurate or unavailable. A possible approach to improve accuracy and availability is the joint use of measurements from different GNSSs and quality check algorithms; this approach is investigated here using live GPS and Galileo signals. A modified receiver autonomous integrity monitoring (RAIM) algorithm, including geometry and separability checks, is proposed to detect and exclude erroneous measurements: the multi-constellation approach provides redundant measurements, and RAIM exploits them to exclude distorted observations. The synergy between combined GPS/Galileo navigation and RAIM is analyzed using live data; the performance is compared to the accuracy and availability of a GPS-only solution. The tests performed demonstrate that the methods developed are effective techniques for GNSS-based navigation in signal-degraded environments. The joint use of the multi-constellation approach and of modified RAIM algorithms improves the performance of the navigation system in terms of both accuracy and availability.

Galileo: The Added Value for Integrity in Harsh Environments

PubMed Central

Borio, Daniele; Gioia, Ciro

2016-01-01

A global navigation satellite system (GNSS)-based navigation is a challenging task in a signal-degraded environments where GNSS signals are distorted by multipath and attenuated by fading effects: the navigation solution may be inaccurate or unavailable. A possible approach to improve accuracy and availability is the joint use of measurements from different GNSSs and quality check algorithms; this approach is investigated here using live GPS and Galileo signals. A modified receiver autonomous integrity monitoring (RAIM) algorithm, including geometry and separability checks, is proposed to detect and exclude erroneous measurements: the multi-constellation approach provides redundant measurements, and RAIM exploits them to exclude distorted observations. The synergy between combined GPS/Galileo navigation and RAIM is analyzed using live data; the performance is compared to the accuracy and availability of a GPS-only solution. The tests performed demonstrate that the methods developed are effective techniques for GNSS-based navigation in signal-degraded environments. The joint use of the multi-constellation approach and of modified RAIM algorithms improves the performance of the navigation system in terms of both accuracy and availability. PMID:26784205

Evaluation of a Salmonella Strain Lacking the Secondary Messenger C-di-GMP and RpoS as a Live Oral Vaccine

PubMed Central

García, Begoña; Gil, Carmen; García-Ona, Enrique; Burgui, Saioa; Casares, Noelia; Hervás-Stubbs, Sandra; Lasarte, Juan José; Lasa, Iñigo

2016-01-01

Salmonellosis is one of the most important bacterial zoonotic diseases transmitted through the consumption of contaminated food, with chicken and pig related products being key reservoirs of infection. Although numerous studies on animal vaccination have been performed in order to reduce Salmonella prevalence, there is still a need for an ideal vaccine. Here, with the aim of constructing a novel live attenuated Salmonella vaccine candidate, we firstly analyzed the impact of the absence of cyclic-di-GMP (c-di-GMP) in Salmonella virulence. C-di-GMP is an intracellular second messenger that controls a wide range of bacterial processes, including biofilm formation and synthesis of virulence factors, and also modulates the host innate immune response. Our results showed that a Salmonella multiple mutant in the twelve genes encoding diguanylate cyclase proteins that, as a consequence, cannot synthesize c-di-GMP, presents a moderate attenuation in a systemic murine infection model. An additional mutation of the rpoS gene resulted in a synergic attenuating effect that led to a highly attenuated strain, referred to as ΔXIII, immunogenic enough to protect mice against a lethal oral challenge of a S. Typhimurium virulent strain. ΔXIII immunogenicity relied on activation of both antibody and cell mediated immune responses characterized by the production of opsonizing antibodies and the induction of significant levels of IFN-γ, TNF-α, IL-2, IL-17 and IL-10. ΔXIII was unable to form a biofilm and did not survive under desiccation conditions, indicating that it could be easily eliminated from the environment. Moreover, ΔXIII shows DIVA features that allow differentiation of infected and vaccinated animals. Altogether, these results show ΔXIII as a safe and effective live DIVA vaccine. PMID:27537839

An infant with acute gastroenteritis caused by a secondary infection with a Rotarix-derived strain.

PubMed

Sakon, Naomi; Miyamoto, Ryohei; Komano, Jun

2017-09-01

Rotavirus vaccines have been successful in controlling severe diarrhea and have decreased deaths of young children globally. Rotarix and RotaTeq are the two currently available live-attenuated rotavirus vaccines. The vaccine virus can grow in a recipient's gut and spread from the vaccinee to naïve individuals. The potential for the emergence of revertant viruses is a concern with live-attenuated vaccines. We identified a previously healthy infant with severe acute gastroenteritis that was positive for rotavirus in a non-endemic season. A whole genome sequencing revealed that all of the viral genome segments were highly similar to those of the Rotarix virus, with the exception of five amino acid mutations in viral genes that could be associated with virulence. The younger sibling of this patient was administered Rotarix before the onset of disease in this patient, although no gastrointestinal symptoms were reported. Epidemiological data, circumstantial evidence, and the genome analysis suggest that the vaccine virus was transmitted from the vaccinee to the patient. This is a severe acute gastroenteritis case most probably attributed to the secondary infection of Rotarix-related virus without underlying diseases. The importance of molecular surveillance of rotavirus infections is discussed. What is Known: • The live-attenuated rotavirus vaccines, Rotarix and RotaTeq, have been successful in controlling severe diarrhea and have decreased deaths of young children globally. • Attenuated vaccine virus can grow in a recipient's gut and spread to naïve individuals and may revert to cause secondary symptomatic infections. What is New: • This is the first report describing a Rotarix-associated secondary infection resulting in severe acute gastroenteritis in an infant without underlying diseases. • Amino acid mutations that might contribute to viral pathogenesis were identified by whole genome sequencing.

Immunization in pregnancy.

PubMed

Gruslin, Andrée; Steben, Marc; Halperin, Scott; Money, Deborah M; Yudin, Mark H

2009-11-01

To review the evidence and provide recommendations on immunization in pregnancy. Outcomes evaluated include effectiveness of immunization, risks and benefits for mother and fetus. The Medline and Cochrane databases were searched for articles published up to June 2008 on the topic of immunization in pregnancy. The evidence obtained was reviewed and evaluated by the Infectious Diseases Committee of the Society of Obstetricians and Gynaecologists of Canada (SOGC) under the leadership of the principal authors, and recommendations were made according to guidelines developed by the Canadian Task Force on Preventive Health Care. Implementation of the recommendations in this guideline should result in more appropriate immunization of pregnant and breastfeeding women, decreased risk of contraindicated immunization, and better disease prevention. The quality of evidence reported in this document has been assessed using the evaluation of evidence criteria in the Report of the Canadian Task Force on Preventive Health Care (Table 1). (1) All women of childbearing age should be evaluated for the possibility of pregnancy before immunization. (III-A). (2) Health care providers should obtain a relevant immunization history from all women accessing prenatal care. (III-A). (3) In general, live and/or live-attenuated virus vaccines should not be administered during pregnancy, as there is a, largely theoretical, risk to the fetus. (II-3B). (4) Women who have inadvertently received immunization with live or live-attenuated vaccines during pregnancy should not be counselled to terminate the pregnancy because of a teratogenic risk. (II-2A). (5) Non-pregnant women immunized with a live or live-attenuated vaccine should be counselled to delay pregnancy for at least four weeks. (III-B). (6) Inactivated viral vaccines, bacterial vaccines, and toxoids can be used safely in pregnancy. (II-1A). (7) Women who are breastfeeding can still be immunized (passive-active immunization, live or killed vaccines). (II-1A) (8) Pregnant women should be offered the influenza vaccine (including H1N1 vaccine, when it is available) when they are pregnant during the influenza season. (II-1A). (9) Pregnant women with suspected or documented H1N1 infection should be treated with oseltamivir (Tamiflu, 75 mg twice daily for 5 days) within 48 hours of onset of symptoms. (III-B).

Safety and efficacy of an attenuated Chinese QX-like infectious bronchitis virus strain as a candidate vaccine.

PubMed

Zhao, Ye; Cheng, Jin-long; Liu, Xiao-yu; Zhao, Jing; Hu, Yan-xin; Zhang, Guo-zhong

2015-10-22

Infectious bronchitis (IB) is a highly contagious respiratory and urogenital disease of chickens caused by infectious bronchitis virus (IBV). This disease is of considerable economic importance and is primarily controlled through biosecurity and immunization with live attenuated and inactivated IB vaccines of various serotypes. In the present study, we tested the safety and efficacy of an attenuated predominant Chinese QX-like IBV strain. The results revealed that the attenuated strain has a clear decrease in pathogenicity for specific-pathogen-free (SPF) chickens compared with the parent strain. Strain YN-inoculated birds had clinical signs of varying severity with 30% mortality, while the attenuated group appeared healthy, with less tissue damage. The attenuated strain also had relatively low tissue replication rates and higher antibody levels. The superior protective efficacy of the attenuated strain was observed when vaccinated birds were challenged with a homologous or heterologous field IBV strain, indicating the potential of the attenuated YN (aYN) as a vaccine. Producing a vaccine targeting the abundant serotype in China is essential to reducing the economic impact of IB on the poultry industry. Copyright © 2015 Elsevier B.V. All rights reserved.

24 CFR 51.101 - General policy.

Code of Federal Regulations, 2013 CFR

2013-04-01

... to save lives, protect property, protect public health and safety, remove debris and wreckage, or... noise sensitive interior spaces such as bedrooms. Minimum attenuation requirements are prescribed in...

24 CFR 51.101 - General policy.

Code of Federal Regulations, 2011 CFR

2011-04-01

... to save lives, protect property, protect public health and safety, remove debris and wreckage, or... noise sensitive interior spaces such as bedrooms. Minimum attenuation requirements are prescribed in...

24 CFR 51.101 - General policy.

Code of Federal Regulations, 2014 CFR

2014-04-01

... to save lives, protect property, protect public health and safety, remove debris and wreckage, or... noise sensitive interior spaces such as bedrooms. Minimum attenuation requirements are prescribed in...

24 CFR 51.101 - General policy.

Code of Federal Regulations, 2012 CFR

2012-04-01

... to save lives, protect property, protect public health and safety, remove debris and wreckage, or... noise sensitive interior spaces such as bedrooms. Minimum attenuation requirements are prescribed in...

Protection from SARS coronavirus conferred by live measles vaccine expressing the spike glycoprotein.

PubMed

Escriou, Nicolas; Callendret, Benoît; Lorin, Valérie; Combredet, Chantal; Marianneau, Philippe; Février, Michèle; Tangy, Frédéric

2014-03-01

The recent identification of a novel human coronavirus responsible of a SARS-like illness in the Middle-East a decade after the SARS pandemic, demonstrates that reemergence of a SARS-like coronavirus from an animal reservoir remains a credible threat. Because SARS is contracted by aerosolized contamination of the respiratory tract, a vaccine inducing mucosal long-term protection would be an asset to control new epidemics. To this aim, we generated live attenuated recombinant measles vaccine (MV) candidates expressing either the membrane-anchored SARS-CoV spike (S) protein or its secreted soluble ectodomain (Ssol). In mice susceptible to measles virus, recombinant MV expressing the anchored full-length S induced the highest titers of neutralizing antibodies and fully protected immunized animals from intranasal infectious challenge with SARS-CoV. As compared to immunization with adjuvanted recombinant Ssol protein, recombinant MV induced stronger and Th1-biased responses, a hallmark of live attenuated viruses and a highly desirable feature for an antiviral vaccine. Copyright © 2014 Elsevier Inc. All rights reserved.

Post-marketing surveillance of live-attenuated Japanese encephalitis vaccine safety in China.

PubMed

Wang, Yali; Dong, Duo; Cheng, Gang; Zuo, Shuyan; Liu, Dawei; Du, Xiaoxi

2014-10-07

Japanese encephalitis (JE) is the most severe form of viral encephalitis in Asia and no specific treatment is available. Vaccination provides an effective intervention to prevent JE. In this paper, surveillance data for adverse events following immunization (AEFI) related to SA-14-14-2 live-attenuated Japanese encephalitis vaccine (Chengdu Institute of Biological Products) was presented. This information has been routinely generated by the Chinese national surveillance system for the period 2009-2012. There were 6024 AEFI cases (estimated reported rate 96.55 per million doses). Most common symptoms of adverse events were fever, redness, induration and skin rash. There were 70 serious AEFI cases (1.12 per million doses), including 9 cases of meningoencephalitis and 4 cases of death. The post-marketing surveillance data add the evidence that the Chengdu institute live attenutated vaccine has a reasonable safety profile. The relationship between encephalitis and SA-14-14-2 vaccination should be further studied. Copyright © 2014 Elsevier Ltd. All rights reserved.

Optical coefficient measurements using bulk living tissue by an optical fiber puncture with FOV change

NASA Astrophysics Data System (ADS)

Nakazawa, Haruna; Doi, Marika; Ogawa, Emiyu; Arai, Tsunenori

2018-02-01

To avoid an instability of the optical coefficient measurement using sliced tissue preparation, we proposed the combination of light intensity measurement through an optical fiber puncturing into a bulk tissue varying field of view (FOV) and ray tracing calculation using Monte-Carlo method. The optical coefficients of myocardium such as absorption coefficient μa, scattering coefficient μs, and anisotropic parameter g are used in the myocardium optical propagation. Since optical coefficients obtained using thin sliced tissue could be instable because they are affected by dehydration and intracellular fluid effusion on the sample surface, variety of coefficients have been reported over individual optical differences of living samples. The proposed method which combined the experiment using the bulk tissue with ray tracing calculation were performed. In this method, a 200 μmΦ high-NA silica fiber installed in a 21G needle was punctured up to the bottom of the myocardial bulk tissue over 3 cm in thickness to measure light intensity changing the fiber-tip depth and FOV. We found that the measured attenuation coefficients decreased as the FOV increased. The ray trace calculation represented the same FOV dependence in above mentioned experimental result. We think our particular fiber punctured measurement using bulk tissue varying FOV with Inverse Monte-Carlo method might be useful to obtain the optical coefficients to avoid sample preparation instabilities.

Attenuation-emission alignment in cardiac PET∕CT based on consistency conditions

PubMed Central

Alessio, Adam M.; Kinahan, Paul E.; Champley, Kyle M.; Caldwell, James H.

2010-01-01

Purpose: In cardiac PET and PET∕CT imaging, misaligned transmission and emission images are a common problem due to respiratory and cardiac motion. This misalignment leads to erroneous attenuation correction and can cause errors in perfusion mapping and quantification. This study develops and tests a method for automated alignment of attenuation and emission data. Methods: The CT-based attenuation map is iteratively transformed until the attenuation corrected emission data minimize an objective function based on the Radon consistency conditions. The alignment process is derived from previous work by Welch et al. [“Attenuation correction in PET using consistency information,” IEEE Trans. Nucl. Sci. 45, 3134–3141 (1998)] for stand-alone PET imaging. The process was evaluated with the simulated data and measured patient data from multiple cardiac ammonia PET∕CT exams. The alignment procedure was applied to simulations of five different noise levels with three different initial attenuation maps. For the measured patient data, the alignment procedure was applied to eight attenuation-emission combinations with initially acceptable alignment and eight combinations with unacceptable alignment. The initially acceptable alignment studies were forced out of alignment a known amount and quantitatively evaluated for alignment and perfusion accuracy. The initially unacceptable studies were compared to the proposed aligned images in a blinded side-by-side review. Results: The proposed automatic alignment procedure reduced errors in the simulated data and iteratively approaches global minimum solutions with the patient data. In simulations, the alignment procedure reduced the root mean square error to less than 5 mm and reduces the axial translation error to less than 1 mm. In patient studies, the procedure reduced the translation error by >50% and resolved perfusion artifacts after a known misalignment for the eight initially acceptable patient combinations. The side-by-side review of the proposed aligned attenuation-emission maps and initially misaligned attenuation-emission maps revealed that reviewers preferred the proposed aligned maps in all cases, except one inconclusive case. Conclusions: The proposed alignment procedure offers an automatic method to reduce attenuation correction artifacts in cardiac PET∕CT and provides a viable supplement to subjective manual realignment tools. PMID:20384256

[Antibody persistence following on different vaccination strategies of domestic measles, mumps and rubella combined attenuated live vaccine: a 3-year follow-up study].

PubMed

He, H Q; Li, Q; Yan, R; Zhou, Y; Tang, X W; Deng, X; Xie, S Y; Chen, Z P

2017-04-06

Objective: To assess the 3-year antibody persistence after vaccination of domestic measles, mumps and rubella combined attenuated live vaccine (MMR) with different program. Methods: Children from three different vaccination strategies (Group 8 m MR: 8 months and 18 months vaccinated with measles-rubella combined attenuated live vaccine and domestic MMR,respectively; Group 8 m MMR: 8 months and 18 months both vaccinated with domestic MMR; Group 12 m MMR: 12 months and 22 months both vaccinated with domestic MMR ) were followed up in Zhejiang province in July 2015. There were 170 participants in Group 8 m MR, 171 participants in Group 8 m MMR and 173 participants in Group 12 m MMR selected by simple random sampling method .Blood samples (venous blood 2-3 ml) were collected 1 month after the first dose vaccination of MMR (only in Group 8 m MMR and Group 12 m MMR) and 3 years (36-38 months) after the last dose vaccination of MMR and tested for antibody IgG against Measles, Mumps and Rubella using ELISA. Seropostive rate and Geometric mean concentration (GMC) were calculated and compared among different groups by Chi-square test or Fisher exact test and Kruskal-Wallis H test. Results: A total of 514 participants (8 m MR: 170; 8 m MMR:171; 12 m MMR:173) were enrolled. The overall seropositivity rate of measles, mumps and rubella was 98.1% (504), 93.4% (480) and 88.1% (453), respectively, with corresponding GMC was 1 012.33 mU/ml, 502.87 U/ml and 50.53 U/ml respectively. There was no significant difference of seropositivity rate for measles among three groups (all groups were>97%). The highest seropositivity rate for mumps was found in the Group 12 m MMR with the rate of 98.8% (171/173), followed by Group 8 m MMR and Group 8 m MR with 93.0% (159/171) and 88.2%(150/170) respectively (Fisher exact test, P< 0.001). The highest seropositivity rate for rubella was also found in the Group 12 m MMR with the rate of 94.8% (164/173), followed by Group 8 m MMR and Group 8 m MR with 86.6%(148/171) and 82.9%(141/170) respectively (Fisher exact test, P= 0.002). The highest GMC of antibody against measles, mumps and rubella were all found in Group 12 m MMR, with 1 217.30 (1 119.35-1 323.82) mU/ml, 717.07 (643.83-798.65) U/ml and 62.54(56.21-69.58) U/ml respectively. The lowest GMC of antibody against measles and mumps were both in Group 12 m MR with 812.01 (734.52-897.67) mU/ml and 363.28 (305.42-432.11) U/ml respectively. The lowest GMC of antibody against rubella was in Group 8 m MMR with 44.10 (39.08-49.76) U/ml. These differences of GMCs among three groups were all reach significant means ( P< 0.05). Conclusion: High level seropostive rates and GMCs were exist against measles and rubella after 3-year vaccination of domestic MMR among different program. Higher antibody level against mumps were found in those children with two doses vaccination of MMR.

CHRONOVAC VOYAGEUR: A study of the immune response to yellow fever vaccine among infants previously immunized against measles.

PubMed

Goujon, Catherine; Gougeon, Marie-Lise; Tondeur, Laura; Poirier, Béatrice; Seffer, Valérie; Desprès, Philippe; Consigny, Paul-Henri; Vray, Muriel

2017-10-27

For administration of multiple live attenuated vaccines, the Advisory Committee on Immunization Practices recommends either simultaneous immunization or period of at least 28days between vaccines, due to a possible reduction in the immune response to either vaccine. The main objective of this study was to compare the immune response to measles (alone or combined with mumps and rubella) and yellow fever vaccines among infants aged 6-24months living in a yellow fever non-endemic country who had receivedmeasles and yellow fever vaccines before travelling to a yellow fever endemic area. A retrospective, multicenter case-control study was carried out in 7 travel clinics in the Paris area from February 1st 2011 to march 31, 2015. Cases were defined as infants immunized with the yellow fever vaccine and with the measles vaccine, either alone or in combination with mumps and rubella vaccine, with a period of 1-27days between each immunization. For each case, two controls were matched based on sex and age: a first control group (control 1) was defined as infants having received the measles vaccine and the yellow fever vaccine simultaneously; a second control group (control 2) was defined as infants who had a period of more than 27days between receiving the measles vaccine and yellow fever vaccine. The primary endpoint of the study was the percentage of infants with protective immunity against yellow fever, measured by the titer of neutralizing antibodies in a venous blood sample. One hundred and thirty-one infants were included in the study (62 cases, 50 infants in control 1 and 19 infants in control 2). Of these, 127 (96%) were shown to have a protective titer of yellow fever antibodies. All 4 infants without a protective titer of yellow fever antibodies were part of control group 1. The measles vaccine, alone or combined with mumps and rubella vaccines, appears to have no influence on humoral immune response to the yellow fever vaccine when administered between 1 and 27days. The absence of protective antibodies against yellow fever was observed only among infants who received both vaccines simultaneously. These results may support a revision of current vaccination recommendations concerning the administration of these two live attenuated vaccines either on the same day or at least 28days apart. Our findings show no statistically significant difference if the interval between both vaccines is more than 24 h, but the immune response seems to be reduced when the two vaccines are given at the same time. Copyright © 2017 Elsevier Ltd. All rights reserved.

Live attenuated influenza virus increases pneumococcal translocation and persistence within the middle ear.

PubMed

Mina, Michael J; Klugman, Keith P; Rosch, Jason W; McCullers, Jonathan A

2015-07-15

Infection with influenza A virus (IAV) increases susceptibility to respiratory bacterial infections, resulting in increased bacterial carriage and complications such acute otitis media, pneumonia, bacteremia, and meningitis. Recently, vaccination with live attenuated influenza virus (LAIV) was reported to enhance subclinical bacterial colonization within the nasopharynx, similar to IAV. Although LAIV does not predispose to bacterial pneumonia, whether it may alter bacterial transmigration toward the middle ear, where it could have clinically relevant implications, has not been investigated. BALB/c mice received LAIV or phosphate-buffered saline 1 or 7 days before or during pneumococcal colonization with either of 2 clinical isolates, 19F or 7F. Middle ear bacterial titers were monitored daily via in vivo imaging. LAIV increased bacterial transmigration to and persistence within the middle ear. When colonization followed LAIV inoculation, a minimum LAIV incubation period of 4 days was required before bacterial transmigration commenced. While LAIV vaccination is safe and effective at reducing IAV and coinfection with influenza virus and bacteria, LAIV may increase bacterial transmigration to the middle ear and could thus increase the risk of clinically relevant acute otitis media. These data warrant further investigations into interactions between live attenuated viruses and naturally colonizing bacterial pathogens. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Suppressing active replication of a live attenuated simian immunodeficiency virus vaccine does not abrogate protection from challenge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gabriel, Benjamin; Fiebig, Uwe; Hohn, Oliver

Although safety concerns preclude the use of live attenuated HIV vaccines in humans, they provide a useful system for identifying the elusive correlates of protective immunity in the SIV/macaque animal model. However, a number of pieces of evidence suggest that protection may result from prior occupancy of susceptible target cells by the vaccine virus rather than the immune response. To address this, we developed a Nef-deletion variant of an RT-SHIV whose active replication could be shut off by treatment with RT-inhibitors. Groups of macaques were inoculated with the ∆Nef-RT-SHIV and immune responses allowed to develop before antiretroviral treatment and subsequentmore » challenge with wild-type SIVmac239. Vaccinated animals either resisted infection fully or significantly controlled the subsequent viremia. However, there was no difference between animals undergoing replication of the vaccine virus and those without. This strongly suggests that competition for available target cells does not play a role in protection. - Highlights: • A Nef-deleted RT-SHIV was used as a live attenuated vaccine in macaques. • Vaccine virus replication was shut down to investigate its role in protection. • Ongoing vaccine virus replication did not appear to be necessary for protection. • An analysis of T- and B-cell responses failed to identify a correlate of protection.« less

Titration of individual strains in trivalent live-attenuated influenza vaccine without neutralization.

PubMed

Sirinonthanawech, Naraporn; Surichan, Somchaiya; Namsai, Aphinya; Puthavathana, Pilaipan; Auewarakul, Prasert; Kongchanagul, Alita

2016-11-01

Formulation and quality control of trivalent live-attenuated influenza vaccine requires titration of infectivity of individual strains in the trivalent mix. This is usually performed by selective neutralization of two of the three strains and titration of the un-neutralized strain in cell culture or embryonated eggs. This procedure requires standard sera with high neutralizing titer against each of the three strains. Obtaining standard sera, which can specifically neutralize only the corresponding strain of influenza viruses and is able to completely neutralize high concentration of virus in the vaccine samples, can be a problem for many vaccine manufacturers as vaccine stocks usually have very high viral titers and complete neutralization may not be obtained. Here an alternative approach for titration of individual strain in trivalent vaccine without the selective neutralization is presented. This was done by detecting individual strains with specific antibodies in an end-point titration of a trivalent vaccine in cell culture. Similar titers were observed in monovalent and trivalent vaccines for influenza A H3N2 and influenza B strains, whereas the influenza A H1N1 strain did not grow well in cell culture. Viral interference among the vaccine strains was not observed. Therefore, providing that vaccine strains grow well in cell culture, this assay can reliably determine the potency of individual strains in trivalent live-attenuated influenza vaccines. Copyright © 2016 Elsevier B.V. All rights reserved.

A Yersinia pestis YscN ATPase mutant functions as a live attenuated vaccine against bubonic plague in mice.

PubMed

Bozue, Joel; Cote, Christopher K; Webster, Wendy; Bassett, Anthony; Tobery, Steven; Little, Stephen; Swietnicki, Wieslaw

2012-07-01

Yersinia pestis is the causative agent responsible for bubonic and pneumonic plague. The bacterium uses the pLcr plasmid-encoded type III secretion system to deliver virulence factors into host cells. Delivery requires ATP hydrolysis by the YscN ATPase encoded by the yscN gene also on pLcr. A yscN mutant was constructed in the fully virulent CO92 strain containing a nonpolar, in-frame internal deletion within the gene. We demonstrate that CO92 with a yscN mutation was not able to secrete the LcrV protein (V-Antigen) and attenuated in a subcutaneous model of plague demonstrating that the YscN ATPase was essential for virulence. However, if the yscN mutant was complemented with a functional yscN gene in trans, virulence was restored. To evaluate the mutant as a live vaccine, Swiss-Webster mice were vaccinated twice with the ΔyscN mutant at varying doses and were protected against bubonic plague in a dose-dependent manner. Antibodies to F1 capsule but not to LcrV were detected in sera from the vaccinated mice. These preliminary results suggest a proof-of-concept for an attenuated, genetically engineered, live vaccine effective against bubonic plague. Published 2012. This article is a US Government work and is in the public domain in the USA.

The delicate balance in genetically engineering live vaccines

PubMed Central

Galen, James E.; Curtiss, Roy

2014-01-01

Contemporary vaccine development relies less on empirical methods of vaccine construction, and now employs a powerful array of precise engineering strategies to construct immunogenic live vaccines. In this review, we will survey various engineering techniques used to create attenuated vaccines, with an emphasis on recent advances and insights. We will further explore the adaptation of attenuated strains to create multivalent vaccine platforms for immunization against multiple unrelated pathogens. These carrier vaccines are engineered to deliver sufficient levels of protective antigens to appropriate lymphoid inductive sites to elicit both carrier-specific and foreign antigen-specific immunity. Although many of these technologies were originally developed for use in Salmonella vaccines, application of the essential logic of these approaches will be extended to development of other enteric vaccines where possible. A central theme driving our discussion will stress that the ultimate success of an engineered vaccine rests on achieving the proper balance between attenuation and immunogenicity. Achieving this balance will avoid over-activation of inflammatory responses, which results in unacceptable reactogenicity, but will retain sufficient metabolic fitness to enable the live vaccine to reach deep tissue inductive sites and trigger protective immunity. The breadth of examples presented herein will clearly demonstrate that genetic engineering offers the potential for rapidly propelling vaccine development forward into novel applications and therapies which will significantly expand the role of vaccines in public health. PMID:24370705

Live Attenuated B. pertussis as a Single-Dose Nasal Vaccine against Whooping Cough

PubMed Central

Mielcarek, Nathalie; Debrie, Anne-Sophie; Raze, Dominique; Bertout, Julie; Rouanet, Carine; Younes, Amena Ben; Creusy, Colette; Engle, Jacquelyn; Goldman, William E; Locht, Camille

2006-01-01

Pertussis is still among the principal causes of death worldwide, and its incidence is increasing even in countries with high vaccine coverage. Although all age groups are susceptible, it is most severe in infants too young to be protected by currently available vaccines. To induce strong protective immunity in neonates, we have developed BPZE1, a live attenuated Bordetella pertussis strain to be given as a single-dose nasal vaccine in early life. BPZE1 was developed by the genetic inactivation or removal of three major toxins. In mice, BPZE1 was highly attenuated, yet able to colonize the respiratory tract and to induce strong protective immunity after a single nasal administration. Protection against B. pertussis was comparable to that induced by two injections of acellular vaccine (aPV) in adult mice, but was significantly better than two administrations of aPV in infant mice. Moreover, BPZE1 protected against Bordetella parapertussis infection, whereas aPV did not. BPZE1 is thus an attractive vaccine candidate to protect against whooping cough by nasal, needle-free administration early in life, possibly at birth. PMID:16839199

[Immune response to live influenza vaccine].

PubMed

Naĭkhin, A N; Rekstin, A R; Barantseva, I B; Donina, S A; Desheva, Iu A; Grigor'eva, E P; Kiseleva, I V; Rudenko, L G

2002-01-01

Priority data on the induction, by using a Russian live cold-adapted reassortant influenza vaccine (LIV), of the cellular and humoral immunity with regard for attenuation and genetic reassortment of vaccine stains as well as with regard for the age of vaccinated persons and the production of Th1 (IFNY, IL-2) and Th2 (IL-4) cytokine markers in vitro are presented. It was demonstrated in vivo that a pathogenic virus of the A group by far more actively induced the lymphocyte apoptosis as compared with attenuated genetically reassorted stains. Unlike the influenza pathogenic virus, the genetically attenuated and reassorted strain did not produce any negative effects on the induction of cellular immunity. A comparative study of the LIV immunogenic properties in vaccinated persons showed an advantage of LIV over inactivated influenza vaccine (IIV) in stimulating the cellular and local immunity in the elderly. Unlike IIV, LIV induced an active and balanced immune response developing due to Th1 and Th2 activation. LIV was found to stimulate well enough the production of IFN and IL-2 in both young and old persons.

Oral vaccination with LcrV from Yersinia pestis KIM delivered by live attenuated Salmonella enterica serovar Typhimurium elicits a protective immune response against challenge with Yersinia pseudotuberculosis and Yersinia enterocolitica.

PubMed

Branger, Christine G; Torres-Escobar, Ascención; Sun, Wei; Perry, Robert; Fetherston, Jacqueline; Roland, Kenneth L; Curtiss, Roy

2009-08-27

The use of live recombinant attenuated Salmonella vaccines (RASV) synthesizing Yersinia proteins is a promising approach for controlling infection by Yersinia species. In this study, we constructed attenuated Salmonella strains which synthesize a truncated form of LcrV, LcrV196 and evaluated the immune response and protective efficacy elicited by these strains in mice against two other major species of Yersinia: Yersinia pseudotuberculosis and Yersinia enterocolitica. Surprisingly, we found that the RASV strain alone was sufficient to afford nearly full protection against challenge with Y. pseudotuberculosis, indicating the likelihood that Salmonella produces immunogenic cross-protective antigens. In contrast, lcrV196 expression was required for protection against challenge with Y. enterocolitica strain 8081, but was not sufficient to achieve significant protection against challenge with Y. enterocolitica strain WA, which expressed a divergent form of lcrV. Nevertheless, we are encouraged by these findings to continue pursuing our long-term goal of developing a single vaccine to protect against all three human pathogenic species of Yersinia.

THE ATTENUATING EFFECT OF EMPOWERMENT ON IPV-RELATED PTSD SYMPTOMS IN BATTERED WOMEN LIVING IN DOMESTIC VIOLENCE SHELTERS

PubMed Central

Perez, Sara; Johnson, Dawn M.; Wright, Caroline Vaile

2010-01-01

Intimate partner violence (IPV) is associated with significant psychological distress, including posttraumatic stress disorder (PTSD). However, factors that attenuate the impact of IPV on PTSD remain largely unknown. Using hierarchical regression, this investigation explored the impact of resource acquisition and empowerment on the relationship between IPV and PTSD. Empowerment demonstrated greater relative importance over resource acquisition. Specifically, empowerment was found to attenuate the impact of IPV severity on PTSD at low and moderate levels of violence. The importance of fostering empowerment and addressing PTSD in addition to provision of resources in battered women is discussed. PMID:22411301

Quantification of live Lactobacillus acidophilus in mixed populations of live and killed by application of attenuated reflection Fourier transform infrared spectroscopy combined with chemometrics.

PubMed

Toziou, Peristera-Maria; Barmpalexis, Panagiotis; Boukouvala, Paraskevi; Verghese, Susan; Nikolakakis, Ioannis

2018-05-30

Since culture-based methods are costly and time consuming, alternative methods are investigated for the quantification of probiotics in commercial products. In this work ATR- FTIR vibration spectroscopy was applied for the differentiation and quantification of live Lactobacillus (La 5) in mixed populations of live and killed La 5, in the absence and in the presence of enteric polymer Eudragit ® L 100-55. Suspensions of live (La 5_L) and killed in acidic environment bacillus (La 5_K) were prepared and binary mixtures of different percentages were used to grow cell cultures for colony counting and spectral analysis. The increase in the number of colonies with added%La 5_L to the mixture was log-linear (r 2  = 0.926). Differentiation of La 5_L from La 5_K was possible directly from the peak area at 1635 cm -1 (amides of proteins and peptides) and a linear relationship between%La 5_L and peak area in the range 0-95% was obtained. Application of partial least squares regression (PLSR) gave reasonable prediction of%La 5_L (RMSEp = 6.48) in binary mixtures of live and killed La 5 but poor prediction (RMSEp = 11.75) when polymer was added to the La 5 mixture. Application of artificial neural networks (ANNs) improved greatly the predictive ability for%La 5_L both in the absence and in the presence of polymer (RMSEp = 8.11 × 10 -8 for La 5 only mixtures and RMSEp = 8.77 × 10 -8 with added polymer) due to their ability to express in the calibration models more hidden spectral information than PLSR. Copyright © 2018 Elsevier B.V. All rights reserved.

[History of development of the live poliomyelitis vaccine from Sabin attenuated strains in 1959 and idea of poliomyelitis eradication].

PubMed

Lashkevich, V A

2013-01-01

In 1958 Poliomyelitis Institute in Moscow and Institute of Experimental Medicine in St. Petersburg received from A. Sabin the attenuated strains of poliomyelitis virus. The characteristics of the strains were thoroughly studied by A. A. Smorodintsev and coworkers. They found that the virulence of the strains fluctuated slightly in 10 consecutive passages through the intestine of the non-immune children. A part of the Sabin material was used by A. A. Smorodintsev and M. P. Chumakov in the beginning of 1959 for immunizing approximately 40000 children in Estonia, Lithuania, and Latvia. Epidemic poliomyelitis rate in these republics decreased from approximately 1000 cases yearly before vaccination to less than 20 in the third quarter of 1959. This was a convincing proof of the efficacy and safety of the vaccine from the attenuated Sabin strains. In 1959, according to A. Sabin's recommendation, a technology of live vaccine production was developed at the Poliomyelitis Institute, and several experimental lots of vaccine were prepared. In the second part of 1959, 13.5 million children in USSR were immunized. The epidemic poliomyelitis rate decreased 3-5 times in different regions without paralytic cases, which could be attributed to the vaccination. These results were the final proof of high efficiency and safety of live poliomyelitis vaccine from the attenuated Sabin strains. Based on these results, A. Sabin and M. P. Chumakov suggested in 1960 the idea of poliomyelitis eradication using mass immunization of children with live vaccine. 72 million persons up to 20 years old were vaccinated in USSR in 1960 with a 5 times drop in the paralytic rate. 50-year-long use of live vaccine results in poliomyelitis eradication in almost all countries worldwide. More than 10 million children were rescued from the death and palsy. Poliomyelitis eradication in a few countries where it still exists depends not on medical services but is defined by the attitude of their leaders to fight against poliomyelitis. In some developing countries the vaccination data are falsified, thereby threatening the polio epidemics reappearance and the virus spreading to other countries. Methods must be developed for detection and dealing with extremely rare persistent virus carriers. Because of all these constraints the outcome of poliomyelitis eradication at present is uncertain and vaccination must be continued. The world has become poliovaccine dependent.

Age-specific reproductive success in a long-lived bird: do older parents resist stress better?

PubMed

Angelier, Frederic; Moe, Børge; Weimerskirch, Henri; Chastel, Olivier

2007-11-01

In many vertebrates, reproductive performance increases with advancing age but mechanisms involved in such a pattern remain poorly studied. One potential mechanism may be the hormonal stress response, which shifts energy investment away from reproduction and redirects it towards survival. In birds, this stress response is achieved through a release of corticosterone and is also accompanied by a decrease in circulating prolactin, a hormone involved widely in regulating parental cares. It has been predicted that, when the value of the current reproduction is high relative to the value of future reproduction and survival, as it is expected to be in older adults, the stress response should be attenuated to ensure that reproduction is not inhibited. We tested this hypothesis by measuring the corticosterone and prolactin responses of known-age (8-36 years old) incubating snow petrels (Pagadroma nivea) to a standardized capture/handling stress protocol. We also investigated whether an attenuation of the stress responses will correlate with a lower occurrence of egg neglect, a frequently observed behaviour in snow petrels. The probability of successfully fledging a chick increased from 6 years to 12 years before stabilizing after 12 years of age. Corticosterone response to stress was unaffected by age. Prolactin response to stress, however, was influenced clearly by age: in both sexes older breeders had higher stress-induced prolactin levels than younger ones. This was due to an increasing attenuation of the prolactin response to stress with advancing age in females, and in males this was due to a probably higher intrinsic capacity of older males to secrete prolactin. Moreover, higher stress-induced prolactin levels were correlated with a lower probability of neglecting the egg. In young breeders, the combination of a robust corticosterone increase with a lower ability to maintain prolactin secretion during acute stress is probably one of the functional causes of their lower incubation commitment. We suggest that the ability to maintain a threshold level of prolactin during a stressful situation may be an important physiological mechanism involved in the improvement of reproductive performance with advancing age in long-lived birds.

Comparative Neuropathogenesis and Neurovirulence of Attenuated Flaviviruses in Nonhuman Primates▿ †

PubMed Central

Maximova, Olga A.; Ward, Jerrold M.; Asher, David M.; St. Claire, Marisa; Finneyfrock, Brad W.; Speicher, James M.; Murphy, Brian R.; Pletnev, Alexander G.

2008-01-01

Based on previous preclinical evaluation in mice and monkeys, the chimeric TBEV/DEN4Δ30 virus, carrying the prM and E protein genes from a highly virulent Far Eastern strain of tick-borne encephalitis virus (TBEV) on the backbone of a nonneuroinvasive dengue type 4 virus (DEN4), has been identified as a promising live attenuated virus vaccine candidate against disease caused by TBEV. However, prior to use of this vaccine candidate in humans, its neurovirulence in nonhuman primates needed to be evaluated. In the present study, we compared the neuropathogeneses of the chimeric TBEV/DEN4Δ30 virus; Langat virus (LGTV), a former live TBEV vaccine; and yellow fever 17D virus vaccine (YF 17D) in rhesus monkeys inoculated intracerebrally. TBEV/DEN4Δ30 and YF 17D demonstrated remarkably similar spatiotemporal profiles of virus replication and virus-associated histopathology in the central nervous system (CNS) that were high in cerebral hemispheres but progressively decreased toward the spinal cord. In contrast, the neurovirulence of LGTV exhibited the reverse profile, progressing from the site of inoculation toward the cerebellum and spinal cord. Analysis of the spatiotemporal distribution of viral antigens in the CNS of monkeys revealed a prominent neurotropism associated with all three attenuated viruses. Nevertheless, TBEV/DEN4Δ30 virus exhibited higher neurovirulence in monkeys than either LGTV or YF 17D, suggesting insufficient attenuation. These results provide insight into the neuropathogenesis associated with attenuated flaviviruses that may guide the design of safe vaccines. PMID:18353947

Attenuation of Recombinant Yellow Fever 17D Viruses Expressing Foreign Protein Epitopes at the Surface

PubMed Central

Bonaldo, Myrna C.; Garratt, Richard C.; Marchevsky, Renato S.; Coutinho, Evandro S. F.; Jabor, Alfredo V.; Almeida, Luís F. C.; Yamamura, Anna M. Y.; Duarte, Adriana S.; Oliveira, Prisciliana J.; Lizeu, Jackeline O. P.; Camacho, Luiz A. B.; Freire, Marcos S.; Galler, Ricardo

2005-01-01

The yellow fever (YF) 17D vaccine is a live attenuated virus. Three-dimensional (3D) homology modeling of the E protein structure from YF 17D virus and its comparison with that from tick-borne encephalitis virus revealed that it is possible to accommodate inserts of different sizes and amino acid compositions in the flavivirus E protein fg loop. This is consistent with the 3D structures of both the dimeric and trimeric forms in which the fg loop lies exposed to solvents. We demonstrate here that YF 17D viruses bearing foreign humoral (17D/8) and T-cell (17D/13) epitopes, which vary in sequence and length, displayed growth restriction. It is hypothesized that interference with the dimer-trimer transition and with the formation of a ring of such trimers in order to allow fusion compromises the capability of the E protein to induce fusion of viral and endosomal membranes, and a slower rate of fusion may delay the extent of virus production. This would account for the lower levels of replication in cultured cells and of viremia in monkeys, as well as for the more attenuated phenotype of the recombinant viruses in monkeys. Testing of both recombinant viruses (17D/8 and 17D/13) for monkey neurovirulence also suggests that insertion at the 17D E protein fg loop does not compromise the attenuated phenotype of YF 17D virus, further confirming the potential use of this site for the development of new live attenuated 17D virus-based vaccines. PMID:15956601

A Novel Self-Replicating Chimeric Lentivirus-Like Particle

PubMed Central

Young, Kelly R.; Madden, Victoria J.; Johnson, Philip R.; Johnston, Robert E.

2012-01-01

Successful live attenuated vaccines mimic natural exposure to pathogens without causing disease and have been successful against several viruses. However, safety concerns prevent the development of attenuated human immunodeficiency virus (HIV) as a vaccine candidate. If a safe, replicating virus vaccine could be developed, it might have the potential to offer significant protection against HIV infection and disease. Described here is the development of a novel self-replicating chimeric virus vaccine candidate that is designed to provide natural exposure to a lentivirus-like particle and to incorporate the properties of a live attenuated virus vaccine without the inherent safety issues associated with attenuated lentiviruses. The genome from the alphavirus Venezuelan equine encephalitis virus (VEE) was modified to express SHIV89.6P genes encoding the structural proteins Gag and Env. Expression of Gag and Env from VEE RNA in primate cells led to the assembly of particles that morphologically and functionally resembled lentivirus virions and that incorporated alphavirus RNA. Infection of CD4+ cells with chimeric lentivirus-like particles was specific and productive, resulting in RNA replication, expression of Gag and Env, and generation of progeny chimeric particles. Further genome modifications designed to enhance encapsidation of the chimeric virus genome and to express an attenuated simian immunodeficiency virus (SIV) protease for particle maturation improved the ability of chimeric lentivirus-like particles to propagate in cell culture. This study provides proof of concept for the feasibility of creating chimeric virus genomes that express lentivirus structural proteins and assemble into infectious particles for presentation of lentivirus immunogens in their native and functional conformation. PMID:22013035

A novel self-replicating chimeric lentivirus-like particle.

PubMed

Jurgens, Christy K; Young, Kelly R; Madden, Victoria J; Johnson, Philip R; Johnston, Robert E

2012-01-01

Successful live attenuated vaccines mimic natural exposure to pathogens without causing disease and have been successful against several viruses. However, safety concerns prevent the development of attenuated human immunodeficiency virus (HIV) as a vaccine candidate. If a safe, replicating virus vaccine could be developed, it might have the potential to offer significant protection against HIV infection and disease. Described here is the development of a novel self-replicating chimeric virus vaccine candidate that is designed to provide natural exposure to a lentivirus-like particle and to incorporate the properties of a live attenuated virus vaccine without the inherent safety issues associated with attenuated lentiviruses. The genome from the alphavirus Venezuelan equine encephalitis virus (VEE) was modified to express SHIV89.6P genes encoding the structural proteins Gag and Env. Expression of Gag and Env from VEE RNA in primate cells led to the assembly of particles that morphologically and functionally resembled lentivirus virions and that incorporated alphavirus RNA. Infection of CD4⁺ cells with chimeric lentivirus-like particles was specific and productive, resulting in RNA replication, expression of Gag and Env, and generation of progeny chimeric particles. Further genome modifications designed to enhance encapsidation of the chimeric virus genome and to express an attenuated simian immunodeficiency virus (SIV) protease for particle maturation improved the ability of chimeric lentivirus-like particles to propagate in cell culture. This study provides proof of concept for the feasibility of creating chimeric virus genomes that express lentivirus structural proteins and assemble into infectious particles for presentation of lentivirus immunogens in their native and functional conformation.

Attenuation of Ricin Toxin under Ambient Conditions and ...

EPA Pesticide Factsheets

Report This study focused on the attenuation of ricin toxin on six types of materials representative of a mail sorting facility and/or indoor building materials. Attenuation tests were conducted under various combinations of temperature, relative humidity (RH), and contact time, using two forms of ricin toxin: a commercially-available pure preparation and a crude preparation from castor beans.

Live attenuated herpes zoster vaccine for HIV-infected adults.

PubMed

Shafran, S D

2016-04-01

Multiple guidelines exist for the use of live viral vaccines for measles-mumps-rubella (MMR), varicella and yellow fever in people with HIV infections, but these guidelines do not make recommendations regarding live attenuated herpes zoster vaccine (LAHZV), which is approved for people over 50 years in the general population. LAHZV is made with the same virus used in varicella vaccine. The incidence of herpes zoster remains increased in people with HIV infection, even when on suppressive antiretroviral therapy, and a growing proportion of HIV-infected patients are over 50 years of age. The purpose of this article is to review the use of varicella vaccine and LAHZV in people with HIV infection and to make recommendations about the use of LAHZV in adults with HIV infection. A PubMed search was undertaken using the terms 'herpes zoster AND HIV' and 'varicella AND HIV'. Reference lists were also reviewed for pertinent citations. Varicella vaccine is recommended in varicella-susceptible adults, as long as they have a CD4 count > 200 cells/μL, the same CD4 threshold used for MMR and yellow fever vaccines. No transmission of vaccine strain Varicella zoster virus has been documented in people with HIV infections with a CD4 count above this threshold. LAHZV was administered to 295 HIV-infected adults with a CD4 count > 200 cells/μL, and was safe and immunogenic with no cases of vaccine strain infection. It is recommended that LAHZV be administered to HIV-infected adults with a CD4 count above 200 cells/μL, the same CD4 threshold used for other live attenuated viral vaccines. © 2015 British HIV Association.

Safety of live, attenuated oral vaccines in HIV-infected Zambian adults

PubMed Central

Banda, Rose; Yambayamba, Vera; Lalusha, Bwalya Daka; Sinkala, Edford; Kapulu, Melissa Chola; Kelly, Paul

2012-01-01

Background Current recommendations are that HIV-infected persons should not be given live vaccines. We set out to assess potential toxicity of three live, attenuated oral vaccines (against rotavirus, typhoid and ETEC) in a phase 1 study. Methods Two commercially available oral vaccines against rotavirus (Rotarix) and typhoid (Vivotif) and one candidate vaccine against Enterotoxigenic Escherichia coli (ACAM2017) were given to HIV seropositive (n = 42) and HIV seronegative (n = 59) adults. Gastrointestinal symptoms were sought actively by weekly interview up to 1 month of vaccination. In rotavirus vaccine recipients, intestinal biopsies were collected by endoscopy and evaluated for expression of IL-8 and pro-inflammatory cytokines. Results No difference was observed between symptoms in HIV infected and HIV uninfected vaccinees, except for diarrhoea reported more than 7 days after the last dose of vaccine. If only diarrhoea episodes within 7 days of vaccination are included, diarrhoea was not more frequent in HIV seropositive than in HIV seronegative vaccinees (OR 6.7, 95% CI 1.2–67; P = 0.09). However, if later episodes of diarrhoea are included, a significant increase in diarrhoea was demonstrated (OR 5.3, 95% CI 0.98–53; P = 0.04). All episodes were mild and transient. IL-8 was slowly up-regulated over the week following vaccination (P = 0.02), but IL-β, IFNγ or TNFα were not. Conclusions No evidence was found of adverse events following administration of these three vaccines, except for late episodes of diarrhoea which may not be attributable to vaccination. Our data do not support the need for a prohibition on oral administration of live, attenuated vaccines to all HIV infected adults, though further work on severely immunocompromised adults and children are required. PMID:22789509

A Live-Attenuated HSV-2 ICP0 − Virus Elicits 10 to 100 Times Greater Protection against Genital Herpes than a Glycoprotein D Subunit Vaccine

PubMed Central

Halford, William P.; Püschel, Ringo; Gershburg, Edward; Wilber, Andrew; Gershburg, Svetlana; Rakowski, Brandon

2011-01-01

Glycoprotein D (gD-2) is the entry receptor of herpes simplex virus 2 (HSV-2), and is the immunogen in the pharmaceutical industry's lead HSV-2 vaccine candidate. Efforts to prevent genital herpes using gD-2 subunit vaccines have been ongoing for 20 years at a cost in excess of $100 million. To date, gD-2 vaccines have yielded equivocal protection in clinical trials. Therefore, using a small animal model, we sought to determine if a live-attenuated HSV-2 ICP0 − virus would elicit better protection against genital herpes than a gD-2 subunit vaccine. Mice immunized with gD-2 and a potent adjuvant (alum+monophosphoryl lipid A) produced high titers of gD-2 antibody. While gD-2-immunized mice possessed significant resistance to HSV-2, only 3 of 45 gD-2-immunized mice survived an overwhelming challenge of the vagina or eyes with wild-type HSV-2 (MS strain). In contrast, 114 of 115 mice immunized with a live HSV-2 ICP0 − virus, 0ΔNLS, survived the same HSV-2 MS challenges. Likewise, 0ΔNLS-immunized mice shed an average 125-fold less HSV-2 MS challenge virus per vagina relative to gD-2-immunized mice. In vivo imaging demonstrated that a luciferase-expressing HSV-2 challenge virus failed to establish a detectable infection in 0ΔNLS-immunized mice, whereas the same virus readily infected naïve and gD-2-immunized mice. Collectively, these results suggest that a HSV-2 vaccine might be more likely to prevent genital herpes if it contained a live-attenuated HSV-2 virus rather than a single HSV-2 protein. PMID:21412438

Immunogenicity and protective efficacy of an elastase-dependent live attenuated swine influenza virus vaccine administered intranasally in pigs.

PubMed

Masic, Aleksandar; Lu, Xinya; Li, Junwei; Mutwiri, George K; Babiuk, Lorne A; Brown, Earl G; Zhou, Yan

2010-10-08

Influenza A virus is an important respiratory pathogen of swine that causes significant morbidity and economic impact on the swine industry. Vaccination is the first choice for prevention and control of influenza infections. Live attenuated influenza vaccines (LAIV) are approved for use in humans and horses and their application provides broad protective immunity, however no LAIV against swine influenza virus (SIV) exists in the market. Previously we reported that an elastase-dependent mutant SIV A/Sw/Sk-R345V (R345V) derived from A/Sw/Saskatchewan/18789/02 (H1N1) (SIV/Sk02) is highly attenuated in pigs. Two intratracheal administrations of R345V induced strong cell-mediated and humoral immune responses and provided a high degree of protection to antigenically different SIV infection in pigs. Here we evaluated the immunogenicity and the protective efficacy of R345V against SIV infection by intranasal administration, the more practical route for vaccination of pigs in the field. Our data showed that intranasally administered R345V live vaccine is capable of inducing strong antigen-specific IFN-γ response from local tracheo-bronchial lymphocytes and antibody responses in serum and respiratory mucosa after two applications. Intranasal vaccination of R345V provided pigs with complete protection not only from parental wild type virus infection, but also from homologous antigenic variant A/Sw/Indiana/1726/88 (H1N1) infection. Moreover, intranasal administration of R345V conferred partial protection from heterologous subtypic H3N2 SIV infection in pigs. Thus, R345V elastase-dependent mutant SIV can serve as a live vaccine against antigenically different swine influenza viruses in pigs. Copyright © 2010 Elsevier Ltd. All rights reserved.

The development of immune responses in Balb/c mice following inoculation with attenuated or virulent Neospora caninum tachyzoites.

PubMed

Bartley, P M; Wright, S E; Maley, S W; Buxton, D; Nath, M; Innes, E A

2009-07-01

Balb/c mice were inoculated intraperitoneally (i.p.) with either 5 x 10(6) live virulent (group 1) or 5 x 10(6) live attenuated (group 2) tachyzoites, or Vero cells (group 3). Animals were killed at 0, 14, 28 and 42 days post-inoculation (p.i.), with the remaining mice receiving a lethal challenge on day 48 p.i. Serum, spleen and brain samples were collected post-mortem to examine humoral and cell-mediated immune responses as well as pathological lesions and to quantify parasite loads. On day 14 p.i. group 2 (attenuated) demonstrated statistically significant (P < 0.001) lower levels of mean morbidity and weight loss, while also showing significantly (P = 0.01) higher levels of splenocyte proliferation and IFN-gamma production (P = 0.003), compared to group 1 (virulent). Histology of brain samples showed milder lesions and a lower incidence of positive immunohistochemistry, demonstrating tachyzoites and tissue cysts, and statistically significant (P = 0.03) lower mean burdens of parasite DNA in group 2 (attenuated) compared to group 1 (virulent). All mice in group 2 were protected following challenge on day 48 p.i. whereas naïve control mice succumbed to the challenge. No mice from group 1 (virulent) survived beyond day 24 p.i. so they were not included in the challenge.

A Live Attenuated Equine H3N8 Influenza Vaccine Is Highly Immunogenic and Efficacious in Mice and Ferrets

PubMed Central

Baz, Mariana; Paskel, Myeisha; Matsuoka, Yumiko; Zengel, James; Cheng, Xing; Treanor, John J.; Jin, Hong

2014-01-01

ABSTRACT Equine influenza viruses (EIV) are responsible for rapidly spreading outbreaks of respiratory disease in horses. Although natural infections of humans with EIV have not been reported, experimental inoculation of humans with these viruses can lead to a productive infection and elicit a neutralizing antibody response. Moreover, EIV have crossed the species barrier to infect dogs, pigs, and camels and therefore may also pose a threat to humans. Based on serologic cross-reactivity of H3N8 EIV from different lineages and sublineages, A/equine/Georgia/1/1981 (eq/GA/81) was selected to produce a live attenuated candidate vaccine by reverse genetics with the hemagglutinin and neuraminidase genes of the eq/GA/81 wild-type (wt) virus and the six internal protein genes of the cold-adapted (ca) A/Ann Arbor/6/60 (H2N2) vaccine donor virus, which is the backbone of the licensed seasonal live attenuated influenza vaccine. In both mice and ferrets, intranasal administration of a single dose of the eq/GA/81 ca vaccine virus induced neutralizing antibodies and conferred complete protection from homologous wt virus challenge in the upper respiratory tract. One dose of the eq/GA/81 ca vaccine also induced neutralizing antibodies and conferred complete protection in mice and nearly complete protection in ferrets upon heterologous challenge with the H3N8 (eq/Newmarket/03) wt virus. These data support further evaluation of the eq/GA/81 ca vaccine in humans for use in the event of transmission of an equine H3N8 influenza virus to humans. IMPORTANCE Equine influenza viruses have crossed the species barrier to infect other mammals such as dogs, pigs, and camels and therefore may also pose a threat to humans. We believe that it is important to develop vaccines against equine influenza viruses in the event that an EIV evolves, adapts, and spreads in humans, causing disease. We generated a live attenuated H3N8 vaccine candidate and demonstrated that the vaccine was immunogenic and protected mice and ferrets against homologous and heterologous EIV. PMID:25410860

Pulse transducer with artifact signal attenuator. [heart rate sensors

NASA Technical Reports Server (NTRS)

Cash, W. H., Jr.; Polhemus, J. T. (Inventor)

1980-01-01

An artifact signal attenuator for a pulse rate sensor is described. The circuit for attenuating background noise signals is connected with a pulse rate transducer which has a light source and a detector for light reflected from blood vessels of a living body. The heart signal provided consists of a modulated dc signal voltage indicative of pulse rate. The artifact signal resulting from light reflected from the skin of the body comprises both a constant dc signal voltage and a modulated dc signal voltage. The amplitude of the artifact signal is greater and the frequency less than that of the heart signal. The signal attenuator circuit includes an operational amplifier for canceling the artifact signal from the output signal of the transducer and has the capability of meeting packaging requirements for wrist-watch-size packages.

Plasmid DNA initiates replication of yellow fever vaccine in vitro and elicits virus-specific immune response in mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tretyakova, Irina; Nickols, Brian; Hidajat, Rachmat

Yellow fever (YF) causes an acute hemorrhagic fever disease in tropical Africa and Latin America. To develop a novel experimental YF vaccine, we applied iDNA infectious clone technology. The iDNA represents plasmid that encodes the full-length RNA genome of 17D vaccine downstream from a cytomegalovirus (CMV) promoter. The vaccine was designed to transcribe the full-length viral RNA and to launch 17D vaccine virus in vitro and in vivo. Transfection with 10 ng of iDNA plasmid was sufficient to start replication of vaccine virus in vitro. Safety of the parental 17D and iDNA-derived 17D viruses was confirmed in AG129 mice deficientmore » in receptors for IFN-α/β/γ. Finally, direct vaccination of BALB/c mice with a single 20 μg dose of iDNA plasmid resulted in seroconversion and elicitation of virus-specific neutralizing antibodies in animals. We conclude that iDNA immunization approach combines characteristics of DNA and attenuated vaccines and represents a promising vaccination strategy for YF. - Highlights: • The iDNA{sup ®} platform combines advantages of DNA and live attenuated vaccines. • Yellow fever (YF) 17D vaccine was launched from iDNA plasmid in vitro and in vivo. • Safety of iDNA-generated 17D virus was confirmed in AG129 mice. • BALB/c mice seroconverted after a single-dose vaccination with iDNA. • YF virus-neutralizing response was elicited in iDNA-vaccinated mice.« less

Optimization of Enzyme-Substrate Pairing for Bioluminescence Imaging of Gene Transfer Using Renilla and Gaussia Luciferases

PubMed Central

Kimura, Takahiro; Hiraoka, Kei; Kasahara, Noriyuki; Logg, Christopher R.

2010-01-01

Background Bioluminescence imaging (BLI) permits the noninvasive quantitation and localization of transduction and expression by gene transfer vectors. The tendency of tissue to attenuate light in the optical region, however, limits the sensitivity of BLI. Improvements in light output from bioluminescent reporter systems would allow the detection of lower levels of expression, smaller numbers of cells and expression from deeper and more attenuating tissues within an animal. Methods With the goal of identifying substrates that allow improved sensitivity with Renilla luciferase (RLuc) and Gaussia luciferase (GLuc) reporter genes, we evaluated native coelenterazine and three of its most promising derivatives in BLI of cultured cells transduced with retroviral vectors encoding these reporters. Of the eight enzyme-substrate pairs tested, the two that performed best were further evaluated in mice to compare their effectiveness for imaging vector-modified cells in live animals. Results In cell culture, we observed striking differences in luminescence levels from the various enzyme-substrate combinations and found that the two luciferases exhibited markedly distinct abilities to generate light with the substrates. The most effective pairs were RLuc with the synthetic coelenterazine derivative ViviRen, and GLuc with native coelenterazine. In animals, these two pairs allowed similar detection sensitivities, which were 8–15 times higher than that of the prototypical RLuc-native coelenterazine combination. Conclusions Our results demonstrate that substrate selection can dramatically influence the detection sensitivity of RLuc and GLuc and that appropriate selection of substrate can greatly improve the performance of reporter genes encoding these enzymes for monitoring gene transfer by BLI. PMID:20527045

Optimization of enzyme-substrate pairing for bioluminescence imaging of gene transfer using Renilla and Gaussia luciferases.

PubMed

Kimura, Takahiro; Hiraoka, Kei; Kasahara, Noriyuki; Logg, Christopher R

2010-06-01

Bioluminescence imaging (BLI) permits the non-invasive quantification and localization of transduction and expression by gene transfer vectors. The tendency of tissue to attenuate light in the optical region, however, limits the sensitivity of BLI. Improvements in light output from bioluminescent reporter systems would allow the detection of lower levels of expression, smaller numbers of cells and expression from deeper and more attenuating tissues within an animal. With the goal of identifying substrates that allow improved sensitivity with Renilla luciferase (RLuc) and Gaussia luciferase (GLuc) reporter genes, we evaluated native coelenterazine and three of its most promising derivatives in BLI of cultured cells transduced with retroviral vectors encoding these reporters. Of the eight enzyme-substrate pairs tested, the two that performed best were further evaluated in mice to compare their effectiveness for imaging vector-modified cells in live animals. In cell culture, we observed striking differences in luminescence levels from the various enzyme-substrate combinations and found that the two luciferases exhibited markedly distinct abilities to generate light with the substrates. The most effective pairs were RLuc with the synthetic coelenterazine derivative ViviRen, and GLuc with native coelenterazine. In animals, these two pairs allowed similar detection sensitivities, which were eight- to 15-fold higher than that of the prototypical RLuc-native coelenterazine combination. Substrate selection can dramatically influence the detection sensitivity of RLuc and GLuc and appropriate choice of substrate can greatly improve the performance of reporter genes encoding these enzymes for monitoring gene transfer by BLI.

Mucosal and Parenteral Vaccination against Acute and Latent Murine Cytomegalovirus (MCMV) Infection by Using an Attenuated MCMV Mutant

PubMed Central

MacDonald, Margaret R.; Li, Xi-Yang; Stenberg, Richard M.; Campbell, Ann E.; Virgin, Herbert W.

1998-01-01

We used a live attenuated murine cytomegalovirus (MCMV) mutant to analyze mechanisms of vaccination against acute and latent CMV infection. We selected MCMV mutant RV7 as a vaccine candidate since this virus grows well in tissue culture but is profoundly attenuated for growth in normal and severe combined immunodeficient (SCID) mice (V. J. Cavanaugh et al., J. Virol. 70:1365–1374, 1996). BALB/c mice were immunized twice (0 and 14 days) subcutaneously (s.c.) with tissue culture-passaged RV7 and then challenged with salivary gland-passaged wild-type MCMV (sgMCMV) intraperitoneally (i.p.) on day 28. RV7 vaccination protected mice against challenge with 105 PFU of sgMCMV, a dose that killed 100% of mock-vaccinated mice. RV7 vaccination reduced MCMV replication 100- to 500-fold in the spleen between 1 and 8 days after challenge. We used the capacity to control replication of MCMV in the spleen 4 days after challenge as a surrogate for protection. Protection was antigen specific and required both live RV7 and antigen-specific lymphocytes. Interestingly, RV7 was effective when administered s.c., i.p., perorally, intranasally, and intragastrically, demonstrating that attenuated CMV applied to mucosal surfaces can elicit protection against parenteral virus challenge. B cells and immunoglobulin G were not essential for RV7-induced immunity since B-cell-deficient mice were effectively vaccinated by RV7. CD8 T cells, but not CD4 T cells, were critical for RV7-induced protection. Depletion of CD8 T cells by passive transfer of monoclonal anti-CD8 (but not anti-CD4) antibody abrogated RV7-mediated protection, and RV7 vaccination was less efficient in CD8 T-cell-deficient mice with a targeted mutation in the β2-microglobulin gene. Although gamma interferon is important for innate resistance to MCMV, it was not essential for RV7 vaccination since gamma interferon receptor-deficient mice were protected by RV7 vaccination. Establishment of and/or reactivation from latency by sgMCMV was decreased by RV7 vaccination, as measured by diminished reactivation of MCMV from splenic explants. We found no evidence for establishment of splenic latency by RV7 after s.c. vaccination. We conclude that RV7 administered through both systemic and mucosal routes is an effective vaccine against MCMV infection. It may be possible to design human CMV vaccines with similar properties. PMID:9420244

Intravital microscopy of biosensor activities and intrinsic metabolic states

PubMed Central

Winfree, Seth; Hato, Takashi; Day, Richard N.

2018-01-01

Intravital microscopy (IVM) is an imaging tool that is capable of detecting subcellular signaling or metabolic events as they occur in tissues in the living animal. Imaging in highly scattering biological tissues, however, is challenging because of the attenuation of signal in images acquired at increasing depths. Depth-dependent signal attenuation is the major impediment to IVM, limiting the depth from which significant data can be obtained. Therefore, making quantitative measurements by IVM requires methods that use internal calibration, or alternatively, a completely different way of evaluating the signals. Here, we describe how ratiometric imaging of genetically encoded biosensor probes can be used to make quantitative measurements of changes in the activity of cell signaling pathways. Then, we describe how fluorescence lifetime imaging can be used for label-free measurements of the metabolic states of cells within the living animal. PMID:28434902

Oral poliovirus vaccination and pregnancy complications.

PubMed

Harjulehto-Mervaala, T; Hovi, T; Aro, T; Saxén, H; Hiilesmaa, V K

1995-04-01

To determine whether the effect of live attenuated oral polio virus vaccine given to pregnant women increases pregnancy complications. A study of women who had been vaccinated against poliovirus during a national vaccination campaign and who had delivered by cesarean section in three obstetrical hospitals in southern Finland. One thousand seven hundred and forty-seven vaccinated women (in three study cohorts), and their 2293 nonvaccinated controls (in two reference cohorts) were analyzed. Subjects are out of 22,000 deliveries evaluated earlier. Vaccinated sectioned women did not show an excess of pregnancy complications. The mean rate of cesarean sections was 18.4% in the study cohorts and 18.9% in the reference cohorts counted from the 22,000 deliveries. Oral live attenuated polio virus vaccine does not increase pregnancy complications and is considered a safe alternative for vaccinating pregnant women.

Application of Droplet Digital PCR to Validate Rift Valley Fever Vaccines.

PubMed

Ly, Hoai J; Lokugamage, Nandadeva; Ikegami, Tetsuro

2016-01-01

Droplet Digital™ polymerase chain reaction (ddPCR™) is a promising technique that quantitates the absolute concentration of nucleic acids in a given sample. This technique utilizes water-in-oil emulsion technology, a system developed by Bio-Rad Laboratories that partitions a single sample into thousands of nanoliter-sized droplets and counts nucleic acid molecules encapsulated in each individual particle as one PCR reaction. This chapter discusses the applications and methodologies of ddPCR for development of Rift Valley fever (RVF) vaccine, using an example that measures RNA copy numbers of a live-attenuated MP-12 vaccine from virus stocks, infected cells, or animal blood. We also discuss how ddPCR detects a reversion mutant of MP-12 from virus stocks accurately. The use of ddPCR improves the quality control of live-attenuated vaccines in the seed lot systems.

Development and biological properties of a new live attenuated mumps vaccine.

PubMed

Saika, Shizuko; Kidokoro, Minoru; Kubonoya, Hiroko; Ito, Kozo; Ohkawa, Tokitada; Aoki, Athuko; Nagata, Noriyo; Suzuki, Kazuyoshi

2006-01-01

To develop a new live attenuated mumps vaccine, a wild mumps Y7 strain isolated from a patient who developed mild parotitis was treated with nitrosoguanidine and ultraviolet, followed by selection of a temperature-sensitive clone. The selected clone, Y125, showed stable temperature-sensitivity in Vero cells. Intraspinal inoculation of marmosets with the Y125 produced only minimal histopathological changes, while intracerebral inoculation of neonatal rats revealed that the Y125 did not cause hydrocephalus. Both these effects of the Y125 were similar to those of the non-neurovirulent Jeryl Lynn strain. Furthermore, subcutaneous inoculation of the Y125 induced high levels of neutralizing antibodies in all Cercopithecus monkeys examined. Although the safety and immunogenicity should be confirmed in further field trials in humans, the present results indicate that the Y125 could be a promising vaccine candidate.

Evaluation of Mycoplasma gallisepticum (MG) ts-304 vaccine as a live attenuated vaccine in turkeys.

PubMed

Kanci, Anna; Wijesurendra, Dinidu S; Wawegama, Nadeeka K; Underwood, Gregory J; Noormohammadi, Amir H; Markham, Philip F; Browning, Glenn F

2018-04-25

Mycoplasma gallisepticum (MG) is an important pathogen of poultry worldwide that causes chronic respiratory disease (CRD) in chickens and infectious sinusitis in turkeys. Vaxsafe MG (strain ts-11) is a live attenuated temperature sensitive vaccine that has been proven to be effective in controlling CRD in chickens, but it is not efficacious in turkeys. The gapA gene, which encodes a mature cytadhesin protein with a molecular weight of approximately 105 kDa, is not expressed in strain ts-11 because a 20 base pair reiterated sequence introduces a frame shift and causes premature truncation of the translated peptide. A GapA positive clone, MG ts-304, isolated from strain ts-11 has been shown to have enhanced efficacy in chickens. Here we describe studies we conducted to assess the safety and efficacy of the MG ts-304 vaccine candidate in turkeys. We found that MG ts-304 was able to colonise the trachea of 3-week-old turkeys and was safe, even at a tenfold overdose, inducing no adverse clinical signs of respiratory disease or significant gross lesions in the respiratory tract (air sacs or trachea), and was poorly transmissible to in-contact birds. We also showed that it was efficacious when administered to 3-week-old turkeys, inducing protective immunity against challenge with the M.gallisepticum wild-type strain Ap3AS. MG ts-304 is therefore a promising live attenuated vaccine candidate for use in turkeys. Copyright © 2018. Published by Elsevier Ltd.

Flu myths: dispelling the myths associated with live attenuated influenza vaccine.

PubMed

Tosh, Pritish K; Boyce, Thomas G; Poland, Gregory A

2008-01-01

Live attenuated influenza vaccine (LAIV), commercially available since 2003, has not gained widespread acceptance among prescribers. This underuse can be traced to several misperceptions and fears regarding LAIV. This review examines both the facts (safety, immunogenicity, and effectiveness) and the most pervasive myths about LAIV. Live attenuated influenza vaccine is a safe, highly immunogenic, and effective vaccine. It is well tolerated; only mild and transient upper respiratory infection symptoms occur with LAIV vs placebo, even in higher-risk patients with asthma or the early stages of human immunodeficiency virus. It is immunogenic, especially in induction of mucosal immunity. In certain populations, LAIV is as effective as, and in some cases more effective than, inactivated influenza in preventing influenza infection. It appears to be more effective in preventing influenza infection than trivalent inactivated influenza vaccine when the vaccine virus strain does not closely match that of the circulating wild-type virus. Many myths and misperceptions about the vaccine exist, foremost among them the myth of genetic reversion. Independent mutation in 4 gene segments would be required for reversion of the vaccine strain of influenza virus to a wild type, an unlikely and as yet unobserved event. Although shedding of vaccine virus is common, transmission of vaccine virus has been documented only in a single person, who remained asymptomatic. In the age groups for which it is indicated, LAIV is a safe and effective vaccine to prevent influenza infection.

Reverse Genetics Approaches for the Development of Influenza Vaccines

PubMed Central

Nogales, Aitor; Martínez-Sobrido, Luis

2016-01-01

Influenza viruses cause annual seasonal epidemics and occasional pandemics of human respiratory disease. Influenza virus infections represent a serious public health and economic problem, which are most effectively prevented through vaccination. However, influenza viruses undergo continual antigenic variation, which requires either the annual reformulation of seasonal influenza vaccines or the rapid generation of vaccines against potential pandemic virus strains. The segmented nature of influenza virus allows for the reassortment between two or more viruses within a co-infected cell, and this characteristic has also been harnessed in the laboratory to generate reassortant viruses for their use as either inactivated or live-attenuated influenza vaccines. With the implementation of plasmid-based reverse genetics techniques, it is now possible to engineer recombinant influenza viruses entirely from full-length complementary DNA copies of the viral genome by transfection of susceptible cells. These reverse genetics systems have provided investigators with novel and powerful approaches to answer important questions about the biology of influenza viruses, including the function of viral proteins, their interaction with cellular host factors and the mechanisms of influenza virus transmission and pathogenesis. In addition, reverse genetics techniques have allowed the generation of recombinant influenza viruses, providing a powerful technology to develop both inactivated and live-attenuated influenza vaccines. In this review, we will summarize the current knowledge of state-of-the-art, plasmid-based, influenza reverse genetics approaches and their implementation to provide rapid, convenient, safe and more effective influenza inactivated or live-attenuated vaccines. PMID:28025504

Quantitative mutant analysis of viral quasispecies by chip-based matrix-assisted laser desorption/ ionization time-of-flight mass spectrometry

PubMed Central

Amexis, Georgios; Oeth, Paul; Abel, Kenneth; Ivshina, Anna; Pelloquin, Francois; Cantor, Charles R.; Braun, Andreas; Chumakov, Konstantin

2001-01-01

RNA viruses exist as quasispecies, heterogeneous and dynamic mixtures of mutants having one or more consensus sequences. An adequate description of the genomic structure of such viral populations must include the consensus sequence(s) plus a quantitative assessment of sequence heterogeneities. For example, in quality control of live attenuated viral vaccines, the presence of even small quantities of mutants or revertants may indicate incomplete or unstable attenuation that may influence vaccine safety. Previously, we demonstrated the monitoring of oral poliovirus vaccine with the use of mutant analysis by PCR and restriction enzyme cleavage (MAPREC). In this report, we investigate genetic variation in live attenuated mumps virus vaccine by using both MAPREC and a platform (DNA MassArray) based on matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. Mumps vaccines prepared from the Jeryl Lynn strain typically contain at least two distinct viral substrains, JL1 and JL2, which have been characterized by full length sequencing. We report the development of assays for characterizing sequence variants in these substrains and demonstrate their use in quantitative analysis of substrains and sequence variations in mixed virus cultures and mumps vaccines. The results obtained from both the MAPREC and MALDI-TOF methods showed excellent correlation. This suggests the potential utility of MALDI-TOF for routine quality control of live viral vaccines and for assessment of genetic stability and quantitative monitoring of genetic changes in other RNA viruses of clinical interest. PMID:11593021

Antigen-Specific lgA B Memory Cell Responses to Shigella Antigens Elicited in Volunteers Immunized with Live Attenuated Shigella flexneri 2a Oral Vaccine Candidates

DTIC Science & Technology

2011-01-01

parenterally (e.g. small· pox vaccine [33]) and orally (e.g., rotavirus vaccines [34]) and parenteral conjugate vaccines consisting of bacterial polysacchar...Angel, Evaluation of circulating intestinally committed memory B cells in children vaccinated with attenuated human rotavirus vaccine, Viral lmmunol...Soler, E. C. Butcher, D. Bass, J. Angel, M.A. Franco, H.B. Greenberg, Maturation and trafficking markers on rotavirus -specific B cells during

Investigation of a dual modal method for bone pathologies using quantitative ultrasound and photoacoustics

NASA Astrophysics Data System (ADS)

Steinberg, Idan; Gannot, Israel; Eyal, Avishay

2015-03-01

Osteoporosis is a widespread disease that has a catastrophic impact on patient's lives and overwhelming related healthcare costs. In recent works, we have developed a multi-spectral, frequency domain photoacoustic method for the evaluation of bone pathologies. This method has great advantages over pure ultrasonic or optical methods as it provides both molecular information from the bone absorption spectrum and bone mechanical status from the characteristics of the ultrasound propagation. These characteristics include both the Speed of Sound (SOS) and Broadband Ultrasonic Attenuation (BUA). To test the method's quantitative predictions, we have constructed a combined ultrasound and photoacoustic setup. Here, we experimentally present a dual modality system, and compares between the methods on bone samples in-vitro. The differences between the two modalities are shown to provide valuable insight into the bone structure and functional status.

Targeting the Transient Receptor Potential Vanilloid Type 1 (TRPV1) Assembly Domain Attenuates Inflammation-induced Hypersensitivity*

PubMed Central

Flynn, Robyn; Chapman, Kevin; Iftinca, Mircea; Aboushousha, Reem; Varela, Diego; Altier, Christophe

2014-01-01

The transient receptor potential channel vanilloid type 1 (TRPV1) is a non-selective cation channel expressed in sensory neurons of the dorsal root and trigeminal ganglia. TRPV1 is a polymodal channel activated by noxious heat, capsaicin, and protons. As a sensor for noxious stimuli, TRPV1 channel has been described as a key contributor to pain signaling. To form a functional channel, TRPV1 subunits must assemble into tetramers, and several studies have identified the TRPV1 C terminus as an essential element in subunit association. Here we combined biochemical assays with electrophysiology and imaging-based bimolecular fluorescence complementation (BiFC) and bioluminescence resonance energy transfer (BRET) in live cells to identify a short motif in the C-terminal tail of the TRPV1 subunit that governs channel assembly. Removing this region through early truncation or targeted deletion results in loss of subunit association and channel function. Importantly, we found that interfering with TRPV1 subunit association using a plasma membrane-tethered peptide attenuated mechanical and thermal hypersensitivity in two mouse models of inflammatory hyperalgesia. This represents a novel mechanism to disrupt TRPV1 subunit assembly and hence may offer a new analgesic tool for pain relief. PMID:24808184

Targeting the transient receptor potential vanilloid type 1 (TRPV1) assembly domain attenuates inflammation-induced hypersensitivity.

PubMed

Flynn, Robyn; Chapman, Kevin; Iftinca, Mircea; Aboushousha, Reem; Varela, Diego; Altier, Christophe

2014-06-13

The transient receptor potential channel vanilloid type 1 (TRPV1) is a non-selective cation channel expressed in sensory neurons of the dorsal root and trigeminal ganglia. TRPV1 is a polymodal channel activated by noxious heat, capsaicin, and protons. As a sensor for noxious stimuli, TRPV1 channel has been described as a key contributor to pain signaling. To form a functional channel, TRPV1 subunits must assemble into tetramers, and several studies have identified the TRPV1 C terminus as an essential element in subunit association. Here we combined biochemical assays with electrophysiology and imaging-based bimolecular fluorescence complementation (BiFC) and bioluminescence resonance energy transfer (BRET) in live cells to identify a short motif in the C-terminal tail of the TRPV1 subunit that governs channel assembly. Removing this region through early truncation or targeted deletion results in loss of subunit association and channel function. Importantly, we found that interfering with TRPV1 subunit association using a plasma membrane-tethered peptide attenuated mechanical and thermal hypersensitivity in two mouse models of inflammatory hyperalgesia. This represents a novel mechanism to disrupt TRPV1 subunit assembly and hence may offer a new analgesic tool for pain relief. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Chimeric human parainfluenza virus bearing the Ebola virus glycoprotein as the sole surface protein is immunogenic and highly protective against Ebola virus challenge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bukreyev, Alexander; Marzi, Andrea; Feldmann, Friederike

2009-01-20

We generated a new live-attenuated vaccine against Ebola virus (EBOV) based on a chimeric virus HPIV3/{delta}F-HN/EboGP that contains the EBOV glycoprotein (GP) as the sole transmembrane envelope protein combined with the internal proteins of human parainfluenza virus type 3 (HPIV3). Electron microscopy analysis of the virus particles showed that they have an envelope and surface spikes resembling those of EBOV and a particle size and shape resembling those of HPIV3. When HPIV3/{delta}F-HN/EboGP was inoculated via apical surface of an in vitro model of human ciliated airway epithelium, the virus was released from the apical surface; when applied to basolateral surface,more » the virus infected basolateral cells but did not spread through the tissue. Following intranasal (IN) inoculation of guinea pigs, scattered infected cells were detected in the lungs by immunohistochemistry, but infectious HPIV3/{delta}F-HN/EboGP could not be recovered from the lungs, blood, or other tissues. Despite the attenuation, the virus was highly immunogenic, and a single IN dose completely protected the animals against a highly lethal intraperitoneal challenge of guinea pig-adapted EBOV.« less

Immunizations in solid organ and hematopoeitic stem cell transplant patients: A comprehensive review

PubMed Central

L'Huillier, Arnaud G; Kumar, Deepali

2015-01-01

The Solid Organ Transplantation (SOT) and Haematopoietic Stem Cell Transplantation (HSCT) population is continuously increasing as a result of broader indications for transplant and improved survival. Infectious diseases, including vaccine-preventable diseases, are a significant threat for this population, primarily after but also prior to transplantation. As a consequence, clinicians must ensure that patients are optimally immunized before transplantation, to provide the best protection during the early post-transplantation period, when immunosuppression is the strongest and vaccine responses are poor. After 3–6 months, inactivated vaccines immunization can be resumed. By contrast, live-attenuated vaccines are lifelong contraindicated in SOT patients, but can be considered in HSCT patients at least 2 years after transplantation, if there is no immunosuppression or graft-versus-host-disease. However, because of the advantages of live-attenuated over inactivated vaccines - and also sometimes the absence of an inactivated alternative - an increasing number of prospective studies on live vaccine immunization after transplantation are performed and give new insights about safety and immunogenicity in this population. PMID:26291740

An Introduction to Poliovirus: Pathogenesis, Vaccination, and the Endgame for Global Eradication.

PubMed

Minor, Philip D

2016-01-01

Poliomyelitis is caused by poliovirus, which is a positive strand non-enveloped virus that occurs in three distinct serotypes (1, 2, and 3). Infection is mainly by the fecal-oral route and can be confined to the gut by antibodies induced either by vaccine, previous infection or maternally acquired. Vaccines include the live attenuated strains developed by Sabin and the inactivated vaccines developed by Salk; the live attenuated vaccine (Oral Polio Vaccine or OPV) has been the main tool in the Global Program of Polio eradication of the World Health Organisation. Wild type 2 virus has not caused a case since 1999 and type 3 since 2012 and eradication seems near. However most infections are entirely silent so that sophisticated environmental surveillance may be needed to ensure that the virus has been eradicated, and the live vaccine can sometimes revert to virulent circulating forms under conditions that are not wholly understood. Cessation of vaccination is therefore an increasingly important issue and inactivated polio vaccine (IPV) is playing a larger part in the end game.

Next-generation dengue vaccines: novel strategies currently under development.

PubMed

Durbin, Anna P; Whitehead, Stephen S

2011-10-01

Dengue has become the most important arboviral infection worldwide with more than 30 million cases of dengue fever estimated to occur each year. The need for a dengue vaccine is great and several live attenuated dengue candidate vaccines are proceeding through clinical evaluation. The need to induce a balanced immune response against all four DENV serotypes with a single vaccine has been a challenge for dengue vaccine developers. A live attenuated DENV chimeric vaccine produced by Sanofi Pasteur has recently entered Phase III evaluation in numerous dengue-endemic regions of the world. Viral interference between serotypes contained in live vaccines has required up to three doses of the vaccine be given over a 12-month period of time. For this reason, novel DENV candidate vaccines are being developed with the goal of achieving a protective immune response with an immunization schedule that can be given over the course of a few months. These next-generation candidates include DNA vaccines, recombinant adenovirus vectored vaccines, alphavirus replicons, and sub-unit protein vaccines. Several of these novel candidates will be discussed.

Live attenuated vaccines: Historical successes and current challenges

DOE Office of Scientific and Technical Information (OSTI.GOV)

Minor, Philip D., E-mail: Philip.Minor@nibsc.org

Live attenuated vaccines against human viral diseases have been amongst the most successful cost effective interventions in medical history. Smallpox was declared eradicated in 1980; poliomyelitis is nearing global eradication and measles has been controlled in most parts of the world. Vaccines function well for acute diseases such as these but chronic infections such as HIV are more challenging for reasons of both likely safety and probable efficacy. The derivation of the vaccines used has in general not been purely rational except in the sense that it has involved careful clinical trials of candidates and subsequent careful follow up inmore » clinical use; the identification of the candidates is reviewed. - Highlights: • Live vaccines against human diseases caused by viruses have been very successful. • They have been developed by empirical clinical studies and problems identified in later use. • It can be difficult to balance ability to cause disease and ability to immunise for a strain. • There is currently no reliable basis for predicting success from pure virological studies. • Vaccinia, which eradicated smallpox, is the paradigm for all successes and issues.« less

A Phase II, Randomized, Safety and Immunogenicity Trial of a Re-Derived, Live-Attenuated Dengue Virus Vaccine in Healthy Children and Adults Living in Puerto Rico.

PubMed

Bauer, Kristen; Esquilin, Ines O; Cornier, Alberto Santiago; Thomas, Stephen J; Quintero Del Rio, Ana I; Bertran-Pasarell, Jorge; Morales Ramirez, Javier O; Diaz, Clemente; Carlo, Simon; Eckels, Kenneth H; Tournay, Elodie; Toussaint, Jean-Francois; De La Barrera, Rafael; Fernandez, Stefan; Lyons, Arthur; Sun, Wellington; Innis, Bruce L

2015-09-01

This was a double-blind, randomized, controlled, phase II clinical trial, two dose study of re-derived, live-attenuated, tetravalent dengue virus (TDEN) vaccine (two formulations) or placebo in subjects 1-50 years of age. Among the 636 subjects enrolled, 331 (52%) were primed, that is, baseline seropositive to at least one dengue virus (DENV) type. Baseline seropositivity prevalence increased with age (10% [< 2 years], 26% [2-4 years], 60% [5-20 years], and 93% [21-50 years]). Safety profiles of TDEN vaccines were similar to placebo regardless of priming status. No vaccine-related serious adverse events (SAEs) were reported. Among unprimed subjects, immunogenicity (geometric mean antibody titers [GMT] and seropositivity rates) for each DENV increased substantially in both TDEN vaccine groups with at least 74.6% seropositive for four DENV types. The TDEN vaccine candidate showed an acceptable safety and immunogenicity profile in children and adults ranging from 1 to 50 years of age, regardless of priming status. ClinicalTrials.gov: NCT00468858. © The American Society of Tropical Medicine and Hygiene.

TLR7 agonist in combination with Salmonella as an effective antimelanoma immunotherapy.

PubMed

Vola, Magdalena; Mónaco, Amy; Bascuas, Thais; Rimsky, Geraldine; Agorio, Caroline Isabel; Chabalgoity, José Alejandro; Moreno, María

2018-03-22

We evaluated a novel approach combining the use of attenuated Salmonella immunotherapy with a Toll-like receptor agonist, imiquimod, in B16F1 melanoma-bearing mice. B16F1 melanoma-bearing mice were daily treated with topical imiquimod in combination with one intratumoral injection of attenuated Salmonella enterica serovar Typhimurium LVR01. The combined therapy resulted in retarded tumor growth and prolonged survival. Combination treatment led to an enhancement in the expression of pro-inflammatory cytokines and chemokines in the tumor microenvironment, with a Th1-skewed profile, resulting in a broad antitumor response. The induced immunity was effective in controlling the occurrence of metastasis. Salmonella LVR01 immunotherapy in combination with imiquimod is a novel approach that could be considered as an effective antimelanoma therapy.

Automatic correction of dental artifacts in PET/MRI

PubMed Central

Ladefoged, Claes N.; Andersen, Flemming L.; Keller, Sune. H.; Beyer, Thomas; Law, Ian; Højgaard, Liselotte; Darkner, Sune; Lauze, Francois

2015-01-01

Abstract. A challenge when using current magnetic resonance (MR)-based attenuation correction in positron emission tomography/MR imaging (PET/MRI) is that the MRIs can have a signal void around the dental fillings that is segmented as artificial air-regions in the attenuation map. For artifacts connected to the background, we propose an extension to an existing active contour algorithm to delineate the outer contour using the nonattenuation corrected PET image and the original attenuation map. We propose a combination of two different methods for differentiating the artifacts within the body from the anatomical air-regions by first using a template of artifact regions, and second, representing the artifact regions with a combination of active shape models and k-nearest-neighbors. The accuracy of the combined method has been evaluated using 25 F18-fluorodeoxyglucose PET/MR patients. Results showed that the approach was able to correct an average of 97±3% of the artifact areas. PMID:26158104

Interferon-alpha/beta deficiency greatly exacerbates arthritogenic disease in mice infected with wild-type chikungunya virus but not with the cell culture-adapted live-attenuated 181/25 vaccine candidate

PubMed Central

Gardner, Christina L.; Burke, Crystal W.; Higgs, Stephen T.; Klimstra, William B.; Ryman, Kate D.

2012-01-01

In humans, chikungunya virus (CHIKV) infection causes fever, rash, and acute and persisting polyarthalgia/arthritis associated with joint swelling. We report a new CHIKV disease model in adult mice that distinguishes the wild-type CHIKV-LR strain from the live-attenuated vaccine strain (CHIKV-181/25). Although eight-week old normal mice inoculated in the hind footpad developed no hind limb swelling with either virus, CHIKV-LR replicated in musculoskeletal tissues and caused detectable inflammation. In mice deficient in STAT1-dependent interferon (IFN) responses, CHIKV-LR caused significant swelling of the inoculated and contralateral limbs and dramatic inflammatory lesions, while CHIKV-181/25 vaccine and another arthritogenic alphavirus, Sindbis, failed to induce swelling. IFN responses suppressed CHIKV-LR and CHIKV-181/25 replication equally in dendritic cells in vitro whereas macrophages were refractory to infection independently of STAT1-mediated IFN responses. Glycosaminoglycan (GAG) binding may be a CHIKV vaccine attenuation mechanism as CHIKV-LR infectivity was not dependent upon GAG, while CHIKV-181/25 was highly dependent. PMID:22305131

In Vivo Visualization of Bacterial Colonization, Antigen Expression, and Specific T-Cell Induction following Oral Administration of Live Recombinant Salmonella enterica Serovar Typhimurium

PubMed Central

Bumann, Dirk

2001-01-01

Live attenuated Salmonella strains that express a foreign antigen are promising oral vaccine candidates. Numerous genetic modifications have been empirically tested, but their effects on immunogenicity are difficult to interpret since important in vivo properties of recombinant Salmonella strains such as antigen expression and localization are incompletely characterized and the crucial early inductive events of an immune response to the foreign antigen are not fully understood. Here, methods were developed to directly localize and quantitate the in situ expression of an ovalbumin model antigen in recombinant Salmonella enterica serovar Typhimurium using two-color flow cytometry and confocal microscopy. In parallel, the in vivo activation, blast formation, and division of ovalbumin-specific CD4+ T cells were followed using a well-characterized transgenic T-cell receptor mouse model. This combined approach revealed a biphasic induction of ovalbumin-specific T cells in the Peyer's patches that followed the local ovalbumin expression of orally administered recombinant Salmonella cells in a dose- and time-dependent manner. Interestingly, intact Salmonella cells and cognate T cells seemed to remain in separate tissue compartments throughout induction, suggesting a transport of killed Salmonella cells from the colonized subepithelial dome area to the interfollicular inductive sites. The findings of this study will help to rationally optimize recombinant Salmonella strains as efficacious live antigen carriers for oral vaccination. PMID:11402006

Remediation by Natural Attenuation Treatability Study for Operable Unit 5

DTIC Science & Technology

1997-12-01

remaining as a result of all attenuation processes is equivalent to the fraction of contaminant remaining as a result of non - destructive attenuation...Alternative 1-- RNA Combined with LTM, Institutional Controls , Air Sparging Along Main Street, and Groundwater Extraction and Treatment Near Well Pair MW137...MW138 .............................. 6-4 6.3.2 Alternative 2 -- RNA, LTM, Institutional Controls , Air Sparging along Main Street, Groundwater

Virulent strain of African swine fever virus eclipses its attenuated derivative after challenge.

PubMed

Titov, Ilya; Burmakina, Galina; Morgunov, Yuriy; Morgunov, Sergey; Koltsov, Andrey; Malogolovkin, Alexander; Kolbasov, Denis

2017-10-01

African swine fever (ASF) is one of the most devastating diseases affecting the swine industry worldwide. No effective vaccine is currently available for disease prevention and control. Although live attenuated vaccines (LAV) have demonstrated great potential for immunizing against homologous strains of African swine fever virus (ASFV), adverse reactions from LAV remain a concern. Here, by using a homologous ASFV Congo strain system, we show passage-attenuated Congo LAV to induce an efficient protective immune response against challenge with the virulent parental Congo strain. Notably, only the parental challenge Congo strain was identified in blood and organs of recovered pigs through B602L gene PCR, long-range PCR, nucleotide sequencing and virus isolation. Thus, despite the great protective potential of homologous attenuated ASFV strain, the challenge Congo strain can persist for weeks in recovered pigs and a recrudescence of virulent virus at late time post-challenge may occur.

Block the Buzzing, Bites, and Bumps: Preventing Mosquito-Borne Illnesses

MedlinePlus

... Ten Mosquito Facts West Nile Virus Dengue Fever Malaria Zika Virus Infection Zika Virus Information and Resources References The live attenuated dengue vaccine TV003 elicits complete protection against dengue in a ...

Contaminant Attenuation Processes at Mining Sites

EPA Science Inventory

Monitored natural attenuation is sometimes used in combination with active treatment technologies to achieve site-specific remediation objectives. The global imprint of acid drainage problems at mining sites, however, is a clear reminder that in most cases natural processes are ...

Systems Biology of Immune Response to Live and Inactivated Dengue Virus Vaccines

DTIC Science & Technology

2017-09-01

transcriptomics; innate immunity; adaptive immunity; correlates of immunity; live-attenuated; purified inactivated; biomarkers; T- cell; B-cell; epitope. 5...original copies of journal articles, reprints of manuscripts and abstracts, a curriculum vitae, patent applications, study questionnaires, and surveys ...of DENV and capable of secreting IgG were detected in all arms at 6 moths post-vaccination. Of note is that little correlation with contemporaneous

Brucella lipopolysaccharide reinforced Salmonella delivering Brucella immunogens protects mice against virulent challenge.

PubMed

Lalsiamthara, Jonathan; Lee, John Hwa

2017-06-01

Intracellular pathogen Salmonella exhibits natural infection broadly analogous to Brucella, this phenomenon makes Salmonella a pragmatic choice for an anti-Brucella vaccine delivery platform. In this study we developed and formulated a combination of four attenuated Salmonella Typhimurium live vector strains delivering heterologous Brucella antigens (rBs), namely lumazine synthase, proline racemase subunit A, lipoprotein outer membrane protein-19, and Cu-Zn superoxide dismutase. With an aim to develop a cross-protecting vaccine, Brucella pan-species conserved rBs were selected. The present study compared the efficacy of smooth and rough variants of Salmonella delivery vector and also evaluated the inclusion of purified Brucella lipopolysaccharide (LPS) in the formulation. Immunization of SPF-BALB/c mice with the vaccine combinations significantly (P≤0.05) reduced splenic wild-type Brucella abortus 544 colonization as compared to non-immunized mice as well as Salmonella only immunized mice. Increased induction of Brucella specific-IgG, sIgA production, and antigen-specific splenocyte proliferative responses were observed in the mice immunized with the formulations as compared to naïve or vector only immunized mice. Modulatory effects of rB and LPS on production of interleukin (IL)-4, IL-12, and interferon-γ were detected in splenocytes of mice immunized with the formulation. Rough Salmonella variant in combination with LPS could further enhance the efficacy of the delivery when applied intraperitoneally. Taken together, it is compelling that Brucella LPS-augmented Salmonella vector delivering immunogenic Brucella proteins may be more suitable than the current non-ideal live Brucella abortus vaccine. The vaccine system also provides a basis for the development of cross-protecting vaccine capable of preventing multispecies brucellosis. Copyright © 2017 Elsevier B.V. All rights reserved.

Combined subchronic fluoride-lead intoxication and its attenuation with the help of a complex of bioprotectors.

PubMed

Katsnelson, B A; Privalova, L I; Kireyeva, Y P; Yeremenko, O S; Sutunkova, M P; Valamina, I E; Varaksin, A N; Panov, V G; Kazmer, J I

2012-01-01

Combined toxicity of lead and fluoride has been studied insufficiently, and there is no known information about attempts to inhibit it with any bioprotectors. Lead acetate and sodium fluoride, administered separately or in combination, were injected i.p. to rats at isoeffective sublethal doses 3 times a week for 6 weeks. Some of the rats were exposed to the same combination against the background of oral administration of a bioprotector complex (BPC) comprising pectin, glutamate, and multivitamin/multimineral preparations. Following exposure, functional and biochemical indices and histopathological examinations of the femur of exposed and control rats were evaluated for signs of toxicity. We have shown that with regard to a number of effects on the organism level the combined toxicity of lead and fluoride may be evaluated as additive or even superadditive, but lead reduces fluoride accumulation in the bone, and pathological changes in the bone tissue proved to be less marked for combined exposure compared with separate exposures. The BPC has been demonstrated to attenuate a range of the combined harmful effects of lead and fluoride, including those on the bone tissue. In spite of the fact that fluoride and lead may reciprocally attenuate their harmful effects on the bone tissue in case of combined exposure, they prove to be more toxic for soft tissues just in combination than when administered separately. The development of combined intoxication may be substantially inhibited by means of the tested set of innocuous biologically active agents.

A Live-Attenuated Chimeric Porcine Circovirus Type 2 (PCV2) Vaccine Is Transmitted to Contact Pigs but Is Not Upregulated by Concurrent Infection with Porcine Parvovirus (PPV) and Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) and Is Efficacious in a PCV2b-PRRSV-PPV Challenge Model▿

PubMed Central

Opriessnig, T.; Shen, H. G.; Pal, N.; Ramamoorthy, S.; Huang, Y. W.; Lager, K. M.; Beach, N. M.; Halbur, P. G.; Meng, X. J.

2011-01-01

The live chimeric porcine circovirus type 2 (PCV2) vaccine with the capsid gene of the emerging subtype 2b cloned in the genomic backbone of the nonpathogenic PCV1 is attenuated in vivo and induces protective immunity against PCV2. To further determine the safety and efficacy of this experimental vaccine, we tested for evidence of pig-to-pig transmission by commingling nonvaccinated and vaccinated pigs, determined potential upregulation by simultaneous vaccination and infection with porcine parvovirus (PPV) and porcine reproductive and respiratory syndrome virus (PRRSV), and determined vaccine efficacy by challenging pigs 4 weeks after vaccination with PCV2b, PRRSV, and PPV. Forty-six 21-day-old, PCV2-naïve pigs were randomly assigned to one of six groups. Twenty-nine of 46 pigs were challenged with PCV2b, PRRSV, and PPV at day 28, 8/46 remained nonvaccinated and nonchallenged and served as negative controls, and 9/46 remained nonchallenged and served as vaccination controls. All animals were necropsied at day 49. PCV1-PCV2 viremia was detected in nonvaccinated contact pigs commingled with vaccinated pigs, indicating pig-to-pig transmission; however, PCV1-PCV2 DNA levels remained low in all vaccinated and contact pigs regardless of concurrent infection. Finally, vaccination 28 days before challenge resulted in significantly (P < 0.05) decreased amounts of PCV2 in tissues and sera and significantly (P < 0.05) reduced macroscopic and microscopic lesions. The results of this study indicate that the experimental live-attenuated chimeric PCV2 vaccine, although transmissible to contact pigs, remains attenuated in pigs concurrently infected with PRRSV and PPV and induces protective immunity against PCV2b when it is administered 28 days before PCV2 exposure. PMID:21653745

A live-attenuated chimeric porcine circovirus type 2 (PCV2) vaccine is transmitted to contact pigs but is not upregulated by concurrent infection with porcine parvovirus (PPV) and porcine reproductive and respiratory syndrome virus (PRRSV) and is efficacious in a PCV2b-PRRSV-PPV challenge model.

PubMed

Opriessnig, T; Shen, H G; Pal, N; Ramamoorthy, S; Huang, Y W; Lager, K M; Beach, N M; Halbur, P G; Meng, X J

2011-08-01

The live chimeric porcine circovirus type 2 (PCV2) vaccine with the capsid gene of the emerging subtype 2b cloned in the genomic backbone of the nonpathogenic PCV1 is attenuated in vivo and induces protective immunity against PCV2. To further determine the safety and efficacy of this experimental vaccine, we tested for evidence of pig-to-pig transmission by commingling nonvaccinated and vaccinated pigs, determined potential upregulation by simultaneous vaccination and infection with porcine parvovirus (PPV) and porcine reproductive and respiratory syndrome virus (PRRSV), and determined vaccine efficacy by challenging pigs 4 weeks after vaccination with PCV2b, PRRSV, and PPV. Forty-six 21-day-old, PCV2-naïve pigs were randomly assigned to one of six groups. Twenty-nine of 46 pigs were challenged with PCV2b, PRRSV, and PPV at day 28, 8/46 remained nonvaccinated and nonchallenged and served as negative controls, and 9/46 remained nonchallenged and served as vaccination controls. All animals were necropsied at day 49. PCV1-PCV2 viremia was detected in nonvaccinated contact pigs commingled with vaccinated pigs, indicating pig-to-pig transmission; however, PCV1-PCV2 DNA levels remained low in all vaccinated and contact pigs regardless of concurrent infection. Finally, vaccination 28 days before challenge resulted in significantly (P < 0.05) decreased amounts of PCV2 in tissues and sera and significantly (P < 0.05) reduced macroscopic and microscopic lesions. The results of this study indicate that the experimental live-attenuated chimeric PCV2 vaccine, although transmissible to contact pigs, remains attenuated in pigs concurrently infected with PRRSV and PPV and induces protective immunity against PCV2b when it is administered 28 days before PCV2 exposure.

Variable photonic crystal fiber optical attenuator combining air hole reduction induced radiation and bending loss

NASA Astrophysics Data System (ADS)

Yokota, Hirohisa; Sano, Tomohiko; Imai, Yoh

2018-06-01

Recently, an optical attenuator has been important in fiber optic communication systems, because a transmission power in fiber has become higher due to a channel increment in wavelength division multiplexing transmission. A photonic crystal fiber (PCF) optical attenuator is fabricated by air hole diameter reduction in a part of PCF in which radiations are caused in the air hole diameter reduced part of PCF. A PCF optical attenuator has a high power resistance feature due to its radiation-induced operation of optical attenuation. In this paper, we proposed a variable PCF optical attenuator in which a bend was applied to the air hole diameter reduced part in PCF optical attenuator that was fabricated by CO2 laser irradiation. In PCF optical attenuator fabrication, the attenuation was adjusted by the reduced air hole diameter with laser irradiation time control. It was demonstrated that 10.6-13.5 dB of variable attenuation was obtained at 1550 nm-wavelength with 0°-90° bending angle applied to the air hole diameter reduced part in PCF optical attenuator.

Variable photonic crystal fiber optical attenuator combining air hole reduction induced radiation and bending loss

NASA Astrophysics Data System (ADS)

Yokota, Hirohisa; Sano, Tomohiko; Imai, Yoh

2018-02-01

Recently, an optical attenuator has been important in fiber optic communication systems, because a transmission power in fiber has become higher due to a channel increment in wavelength division multiplexing transmission. A photonic crystal fiber (PCF) optical attenuator is fabricated by air hole diameter reduction in a part of PCF in which radiations are caused in the air hole diameter reduced part of PCF. A PCF optical attenuator has a high power resistance feature due to its radiation-induced operation of optical attenuation. In this paper, we proposed a variable PCF optical attenuator in which a bend was applied to the air hole diameter reduced part in PCF optical attenuator that was fabricated by CO2 laser irradiation. In PCF optical attenuator fabrication, the attenuation was adjusted by the reduced air hole diameter with laser irradiation time control. It was demonstrated that 10.6-13.5 dB of variable attenuation was obtained at 1550 nm-wavelength with 0°-90° bending angle applied to the air hole diameter reduced part in PCF optical attenuator.

The perceived impact of cancer on quality of life for post-treatment survivors of childhood cancer.

PubMed

Zebrack, Brad J; Landier, Wendy

2011-12-01

To examine whether childhood cancer survivors' perceptions of the impact of cancer are related to quality of life (QOL) and psychological distress. 621 survivors (aged 18-39 years) completed a mailed survey assessing distress and QOL. Hierarchical linear regression models analyzed the independent effects of perceived impacts of cancer on distress and QOL and the extent to which positive and negative perceptions attenuated the effects of covariates on outcomes. After accounting for perceptions of cancer's impact on their lives, employment/occupation status, marital/relationship status, and health problems were observed to be significant predictors of QOL and distress. Psychological distress and the mental health component of QOL appeared to be less influenced by sociodemographic status and health problems and more a function of how survivors perceive cancer as impacting their lives. Results suggest that distress and QOL are partially a function of survivors' perceptions of how cancer has affected them and continues to affect them in both positive and negative ways. Future research is needed to examine combinations of pharmacological, psychological and/or social interventions that are likely to result in better outcomes in this population.

Does neighborhood social capital buffer the effects of maternal depression on adolescent behavior problems?

PubMed

Delany-Brumsey, Ayesha; Mays, Vickie M; Cochran, Susan D

2014-06-01

Neighborhood characteristics have been shown to impact child well-being. However, it remains unclear how these factors combine with family characteristics to influence child development. The current study helps develop that understanding by investigating how neighborhoods directly impact child and adolescent behavior problems as well as moderate the influence of family characteristics on behavior. Using multilevel linear models, we examined the relationship among neighborhood conditions (poverty and social capital) and maternal depression on child and adolescent behavior problems. The sample included 741 children, age 5–11, and 564 adolescents, age 12–17. Outcomes were internalizing (e.g. anxious/depressed) and externalizing (e.g. aggressive/hyperactive) behavior problems. Neighborhood poverty and maternal depression were both positively associated with behavior problems for children and adolescents. However, while neighborhood social capital was not directly associated with behavior problems, the interaction of social capital and maternal depression was significantly related to behavior problems for adolescents. This interaction showed that living in neighborhoods with higher levels of social capital attenuated the relationship between maternal depression and adolescent behavior problems and confirmed the expectation that raising healthy well-adjusted children depends not only on the family, but also the context in which the family lives.

Physiology, pathogenicity and immunogenicity of live, attenuated Salmonella enterica serovar Enteritidis mutants in chicks.

PubMed

Si, Wei; Wang, Xiumei; Liu, Huifang; Yu, Shenye; Li, Zhaoli; Chen, Liping; Zhang, Wanjiang; Liu, Siguo

2015-01-01

To construct a novel live, attenuated Salmonella vaccine, the lon, cpxR and cpdB genes were deleted from a wild-type Salmonella enterica serovar Enteritidis-6 (SM-6) strain using the phage λ Red homologous recombination system, resulting in SM-△CpxR, SM-△C/Lon and SM-△C/L/CpdB. The growth curves of strain SM-△C/Lon grew more rapidly than the other strains and had OD 600 values higher than the other strains starting at the 4 h time point. The growth curves of strain SM-△C/L/CpdB were relatively flat. The colonization time of SM-△C/L/CpdB is about 8-10 days. Deleting the lon/cpxR/cpdB (SM-6) genes resulted in an approximate 10(3)-fold attenuation in virulence assessed by the analysis of the LD50 of specific pathogen-free (SPF) chicks. This result indicated that the deletion of the lon, cpxR and cpdB genes induced significant virulence attenuation. The protective effects of SM-△C/L/CpdB vaccination in SPF chicks against 5 × 10(9) colony forming units (CFU) of S. Enteritidis were resulted from the induction of an effective immune response. These findings demonstrate the potential of mutant SM-△C/L/CpdB to be used as an effective vaccine. Copyright © 2015 Elsevier Ltd. All rights reserved.

The yellow fever 17D virus as a platform for new live attenuated vaccines.

PubMed

Bonaldo, Myrna C; Sequeira, Patrícia C; Galler, Ricardo

2014-01-01

The live-attenuated yellow fever 17D virus is one of the most outstanding human vaccines ever developed. It induces efficacious immune responses at a low production cost with a well-established manufacture process. These advantages make the YF17D virus attractive as a vector for the development of new vaccines. At the beginning of vector development studies, YF17D was genetically manipulated to express other flavivirus prM and E proteins, components of the viral envelope. While these 17D recombinants are based on the substitution of equivalent YF17D genes, other antigens from unrelated pathogens have also been successfully expressed and delivered by recombinant YF17D viruses employing alternative strategies for genetic manipulation of the YF17D genome. Herein, we discuss these strategies in terms of possibilities of single epitope or larger sequence expression and the main properties of these replication-competent viral platforms.

Identification and development of a promising novel mumps vaccine candidate strain.

PubMed

Liang, Yan; Ma, Shaohui; Liu, Longding; Zhao, Hongling; Wang, Lichun; Jiang, Li; Xie, Zhongping; Dong, Chenghong; Li, Qihan

2010-12-01

Mumps epidemics are usually caused by airborne transmission of mumps virus (MuV) and have high morbidity in non-immunized children. Epidemiological studies in many regions of China show that the genotype F viral strain is the most prevalent. However, the genotype A strain is currently used to prepare vaccines. Regional epidemiological MuV data suggest a significant application for the development of live attenuated mumps vaccines targeting specific genotypes. This article reports the isolation and culture of a genotype F MuV candidate strain that could be used to prepare a live attenuated mumps vaccine. This strain is shown to have good immunological efficacy and stability in neurovirulence evaluations. This work should facilitate the implementation of mumps vaccination in mainland China by targeting the most prevalent MuV genotype, genotype F. Copyright © 2010 Institut Pasteur. Published by Elsevier SAS. All rights reserved.

Vaccines against invasive Salmonella disease

PubMed Central

MacLennan, Calman A; Martin, Laura B; Micoli, Francesca

2014-01-01

Though primarily enteric pathogens, Salmonellae are responsible for a considerable yet under-appreciated global burden of invasive disease. In South and South-East Asia, this manifests as enteric fever caused by serovars Typhi and Paratyphi A. In sub-Saharan Africa, a similar disease burden results from invasive nontyphoidal Salmonellae, principally serovars Typhimurium and Enteritidis. The existing Ty21a live-attenuated and Vi capsular polysaccharide vaccines target S. Typhi and are not effective in young children where the burden of invasive Salmonella disease is highest. After years of lack of investment in new Salmonella vaccines, recent times have seen increased interest in the area led by emerging-market manufacturers, global health vaccine institutes and academic partners. New glycoconjugate vaccines against S. Typhi are becoming available with similar vaccines against other invasive serovars in development. With other new vaccines under investigation, including live-attenuated, protein-based and GMMA vaccines, now is an exciting time for the Salmonella vaccine field. PMID:24804797

African swine fever virus (ASFV) protection mediated by NH/P68 and NH/P68 recombinant live-attenuated viruses.

PubMed

Gallardo, Carmina; Sánchez, Elena G; Pérez-Núñez, Daniel; Nogal, Marisa; de León, Patricia; Carrascosa, Ángel L; Nieto, Raquel; Soler, Alejandro; Arias, María Luisa; Revilla, Yolanda

2018-05-03

The risk of spread of African swine fever virus (ASFV) from Russia and Caucasian areas to several EU countries has recently emerged, making it imperative to improve our knowledge and defensive tools against this important pathogen. The ASFV genome encodes many genes which are not essential for virus replication but are known to control host immune evasion, such as NFκB and the NFAT regulator A238L, the apoptosis inhibitor A224L, the MHC-I antigen presenting modulator EP153R, and the A276R gene, involved in modulating type I IFN. These genes are hypothesized to be involved in virulence of the genotype I parental ASFV NH/P68. We here describe the generation of putative live attenuated vaccines (LAV) prototypes by constructing recombinant NH/P68 viruses lacking these specific genes and containing specific markers. Copyright © 2018 Elsevier Ltd. All rights reserved.

Live Attenuated Yellow Fever 17D Vaccine: A Legacy Vaccine Still Controlling Outbreaks In Modern Day.

PubMed

Collins, Natalie D; Barrett, Alan D T

2017-03-01

Live attenuated 17D vaccine is considered one of the safest and efficacious vaccines developed to date. This review highlights what is known and the gaps in knowledge of vaccine-induced protective immunity. Recently, the World Health Organization modifying its guidance from 10-year booster doses to one dose gives lifelong protection in most populations. Nonetheless, there are some data suggesting immunity, though protective, may wane over time in certain populations and more research is needed to address this question. Despite having an effective vaccine to control yellow fever, vaccine shortages were identified during outbreaks in 2016, eventuating the use of a fractional-dosing campaign in the Democratic Republic of the Congo. Limited studies hinder identification of the underlying mechanism(s) of vaccine longevity; however, concurrent outbreaks during 2016 provide an opportunity to evaluate vaccine immunity following fractional dosing and insights into vaccine longevity in populations where there is limited information.

Live, attenuated Salmonella typhimurium vectoring Campylobacter antigens.

PubMed

Sizemore, Donata R; Warner, Beth; Lawrence, Julie; Jones, Amy; Killeen, Kevin P

2006-05-01

We describe the evaluation of three live, attenuated deltaphoP/Q Salmonella enteric serovar Typhimurium strains expressing PEB1 minus its signal sequence (PEB1-ss) from three different plasmids: a pBR-based asd plasmid, an arabinose-based runaway plasmid, which each expressed PEB1-ss in the bacterial cytosol, and a PEB1::HlyA fusion plasmid that directs secretion of PEB1-ss into the extracellular milieu. Serum IgG responses specific for PEB1-ss were induced by pBR-derived and runaway plasmids, with 100 and 90% seroconversion, respectively, at a 1:500 dilution of anti-sera as measured by Western blot analysis, while the PEB1-ss::HlyA fusion plasmid induced serum IgG in only 20% of the mice. Although significant levels of anti-PEB serum IgG were induced, no protection against oral Campylobacter jejuni challenge was observed.

Histo-blood group antigens as receptors for rotavirus, new understanding on rotavirus epidemiology and vaccine strategy

PubMed Central

Jiang, Xi; Liu, Yang; Tan, Ming

2017-01-01

The success of the two rotavirus (RV) vaccines (Rotarix and RotaTeq) in many countries endorses a live attenuated vaccine approach against RVs. However, the lower efficacies of both vaccines in many low- and middle-income countries indicate a need to improve the current RV vaccines. The recent discovery that RVs recognize histo-blood group antigens (HBGAs) as potential receptors has significantly advanced our understanding of RV diversity, evolution and epidemiology, providing important new insights into the performances of current RV vaccines in different populations and emphasizing a P-type-based vaccine approach. New understanding of RV diversity and evolution also raises a fundamental question about the ‘Jennerian' approach, which needs to be addressed for future development of live attenuated RV vaccines. Alternative approaches to develop safer and more cost-effective subunit vaccines against RVs are also discussed. PMID:28400594

Safety and immunogenicity of a live attenuated Japanese encephalitis chimeric virus vaccine (IMOJEV®) in children.

PubMed

Chokephaibulkit, K; Houillon, G; Feroldi, E; Bouckenooghe, A

2016-01-01

JE-CV (IMOJEV®, Sanofi Pasteur, France) is a live attenuated virus vaccine constructed by inserting coding sequences of the prM and E structural proteins of the Japanese encephalitis SA14-14-2 virus into the genome of yellow fever 17D virus. Primary immunization with JE-CV requires a single dose of the vaccine. This article reviews clinical trials of JE-CV in children aged up to 6 years conducted in countries across South-East Asia. Strong and persistent antibody responses were observed after single primary and booster doses, with 97% of children seroprotected up to five years after booster vaccination. Models of long-term antibody persistence predict a median duration of protection of approximately 30 years after a booster dose. The safety and reactogenicity profiles of JE-CV primary and booster doses are comparable to other widely used childhood vaccines.

The yellow fever 17D virus as a platform for new live attenuated vaccines

PubMed Central

Bonaldo, Myrna C; Sequeira, Patrícia C; Galler, Ricardo

2014-01-01

The live-attenuated yellow fever 17D virus is one of the most outstanding human vaccines ever developed. It induces efficacious immune responses at a low production cost with a well-established manufacture process. These advantages make the YF17D virus attractive as a vector for the development of new vaccines. At the beginning of vector development studies, YF17D was genetically manipulated to express other flavivirus prM and E proteins, components of the viral envelope. While these 17D recombinants are based on the substitution of equivalent YF17D genes, other antigens from unrelated pathogens have also been successfully expressed and delivered by recombinant YF17D viruses employing alternative strategies for genetic manipulation of the YF17D genome. Herein, we discuss these strategies in terms of possibilities of single epitope or larger sequence expression and the main properties of these replication-competent viral platforms. PMID:24553128

The Association Between Higher Social Support and Lower Depressive Symptoms Among Aging Services Clients is Attenuated at Higher Levels of Functional Impairment

PubMed Central

Van Orden, Kimberly A.; Yan, Li; Podgorski, Carol A.; Conwell, Yeates

2015-01-01

Objective Adults seeking services from the Aging Services Provider Network (ASPN) are at risk for depression. ASPN clients also have high prevalence of both functional impairments and social morbidities. Study of the relationships between these factors may inform the development of interventions for depression in this service setting. Methods We interviewed 373 older adults accessing ASPN services and assessed depression symptom severity, functional impairment (instrumental activities of daily living and activities of daily living), and social support. Results Lower social support and greater functional impairment were associated with greater depressive symptoms. At a high level of functional impairment, the inverse associations between indices of social support and depressive symptoms were attenuated. Conclusions Results suggest that older adults with more severe functional impairment may benefit somewhat less from increased social support with respect to depression symptom severity. PMID:25663607

African Horse Sickness Caused by Genome Reassortment and Reversion to Virulence of Live, Attenuated Vaccine Viruses, South Africa, 2004–2014

PubMed Central

Weyer, Camilla T.; Grewar, John D.; Burger, Phillippa; Rossouw, Esthea; Lourens, Carina; Joone, Christopher; le Grange, Misha; Coetzee, Peter; Venter, Estelle; Martin, Darren P.; MacLachlan, N. James

2016-01-01

African horse sickness (AHS) is a hemorrhagic viral fever of horses. It is the only equine disease for which the World Organization for Animal Health has introduced specific guidelines for member countries seeking official recognition of disease-free status. Since 1997, South Africa has maintained an AHS controlled area; however, sporadic outbreaks of AHS have occurred in this area. We compared the whole genome sequences of 39 AHS viruses (AHSVs) from field AHS cases to determine the source of 3 such outbreaks. Our analysis confirmed that individual outbreaks were caused by virulent revertants of AHSV type 1 live, attenuated vaccine (LAV) and reassortants with genome segments derived from AHSV types 1, 3, and 4 from a LAV used in South Africa. These findings show that despite effective protection of vaccinated horses, polyvalent LAV may, paradoxically, place susceptible horses at risk for AHS. PMID:27442883

Deficient Binocular Combination Reveals Mechanisms of Anisometropic Amblyopia: Signal Attenuation and Interocular Inhibition

PubMed Central

Huang, Chang-Bing; Zhou, Jiawei; Lu, Zhong-Lin; Zhou, Yifeng

2012-01-01

Amblyopia is a developmental disorder that results in deficits of monocular and binocular vision. It's presently unclear whether these deficits result from attenuation of signals in the amblyopic eye, inhibition by signals in the fellow eye, or both. In this study, we characterize the mechanisms underlying anisometropic amblyopia using a binocular phase and contrast combination paradigm and a contrast-gain control model. Subjects dichoptically viewed two slightly different images and reported the perceived contrast and phase of the resulting cyclopean percept. We found that the properties of binocular combination were abnormal in many aspects, which is explained by a combination of (1) attenuated monocular signal in the amblyopic eye, (2) stronger interocular contrast-gain control from the fellow eye to the signal in amblyopic eye (direct interocular inhibition), and (3) stronger interocular contrast-gain control from the fellow eye to the contrast gain control signal from the amblyopic eye (indirect interocular inhibition). We conclude that anisometropic amblyopia led to both monocular and interocular deficits. A complete understanding of the mechanisms underlying amblyopia requires studies of both monocular deficits and binocular interactions. PMID:21546609

Enhanced Thermal Ablation by Combining Ultrasound Contrast Agents with a Miniature Flat Transducer

NASA Astrophysics Data System (ADS)

Murillo, A.; Goldendstedt, C.; Lafon, C.; Cathignol, D.; Chapelon, J.-Y.

2007-05-01

Miniature transducers can be used for performing interstitial thermal ablation. Increasing the frequency of non-focused transducers enhances energy deposition but limits the therapeutic range. In order to treat extended tumors, new therapeutic strategies must be explored. This work aimed to combine ultrasound contrast agents (UCA) with flat transducers for increasing the treatment depth. The idea consists in increasing attenuation away from the transducer to favor remote heat deposition. Thermal ablation is induced in three steps. 1- Attenuation raises by injecting UCA; 2- Destruction of bubbles next to the transducer by pulsed high intensity bursts, results in a gradient of attenuation; 3- Continuous ultrasound are applied for generating a localized thermal lesion. In vitro tests were performed on temperature-sensitive tissue phantoms in which the UCA BR14 (Bracco) was injected during the liquid phase. The feasibility of the idea was demonstrated in three stages. 1- The coefficient of attenuation was measured with the force balance as a function of the concentration of BR14. For 0.8 and 4.8% attenuation at 10MHz was found to be 0.35 and 1.33 Np/cm respectively. 2- Pulsed ultrasound was applied on phantoms to destroy UCA. Based on the echogenicity decay evidenced on ultrasound images, a 1MPa-pressure was required at 10MHz. 3- Heating beams were applied on phantoms presenting a gradient in attenuation. Lesions were 1.5 times larger than in phantoms with constant attenuation. This study demonstrates that UCA can be selectively destroyed in order to generate a gradient of attenuation and extended thermal lesions.

Black carbon cookstove emissions: A field assessment of 19 stove/fuel combinations

NASA Astrophysics Data System (ADS)

Garland, Charity; Delapena, Samantha; Prasad, Rajendra; L'Orange, Christian; Alexander, Donee; Johnson, Michael

2017-11-01

Black carbon (BC) emissions from household cookstoves consuming solid fuel produce approximately 25 percent of total anthropogenic BC emissions. The short atmospheric lifetime of BC means that reducing BC emissions would result in a faster climate response than mitigating CO2 and other long-lived greenhouse gases. This study presents the results of optical BC measurements of two new cookstove emissions field assessments and 17 archived cookstove datasets. BC was determined from attenuation of 880 nm light, which is strongly absorbed by BC, and linearly related between 1 and 125 attenuation units. A relationship was experimentally determined correlating BC mass deposition on quartz filters determined via thermal optical analysis (TOA) and on PTFE and quartz filters using transmissometry, yielding an attenuation cross-section (σATN) for both filter media types. σATN relates TOA measurements to optical measurements on PTFE and quartz (σATN(PTFE) = 13.7 cm-2 μg, R2 = 0.87, σATN(Quartz) = 15.6 cm-2 μg, R2 = 0.87). These filter-specific σATN, optical measurements of archived filters were used to determine BC emission factors and the fraction of particulate matter (PM) in the form of black carbon (BC/PM). The 19 stoves measured fell into five stove classes; simple wood, rocket, advanced biomass, simple charcoal, and advanced charcoal. Advanced biomass stoves include forced- and natural-draft gasifiers which use wood or biomass pellets as fuel. Of these classes, the simple wood and rocket stoves demonstrated the highest median BC emission factors, ranging from 0.051 to 0.14 g MJ-1. The lowest BC emission factors were seen in charcoal stoves, which corresponds to the generally low PM emission factors observed during charcoal combustion, ranging from 0.0084 to 0.014 g MJ-1. The advanced biomass stoves generally showed an improvement in BC emissions factors compared to simple wood and rocket stoves, ranging from 0.0031 to 0.071 g MJ-1. BC/PM ratios were highest for the advanced and rocket stoves. Potential relative climate impacts were estimated by converting aerosol emissions to CO2-equivalent, and suggest that some advanced stove/fuel combinations could provide substantial climate benefits.

Attenuation correction for flexible magnetic resonance coils in combined magnetic resonance/positron emission tomography imaging.

PubMed

Eldib, Mootaz; Bini, Jason; Calcagno, Claudia; Robson, Philip M; Mani, Venkatesh; Fayad, Zahi A

2014-02-01

Attenuation correction for magnetic resonance (MR) coils is a new challenge that came about with the development of combined MR and positron emission tomography (PET) imaging. This task is difficult because such coils are not directly visible on either PET or MR acquisitions with current combined scanners and are therefore not easily localized in the field of view. This issue becomes more evident when trying to localize flexible MR coils (eg, cardiac or body matrix coil) that change position and shape from patient to patient and from one imaging session to another. In this study, we proposed a novel method to localize and correct for the attenuation and scatter of a flexible MR cardiac coil, using MR fiducial markers placed on the surface of the coil to allow for accurate registration of a template computed tomography (CT)-based attenuation map. To quantify the attenuation properties of the cardiac coil, a uniform cylindrical water phantom injected with 18F-fluorodeoxyglucose (18F-FDG) was imaged on a sequential MR/PET system with and without the flexible cardiac coil. After establishing the need to correct for the attenuation of the coil, we tested the feasibility of several methods to register a precomputed attenuation map to correct for the attenuation. To accomplish this, MR and CT visible markers were placed on the surface of the cardiac flexible coil. Using only the markers as a driver for registration, the CT image was registered to the reference image through a combination of rigid and deformable registration. The accuracy of several methods was compared for the deformable registration, including B-spline, thin-plate spline, elastic body spline, and volume spline. Finally, we validated our novel approach both in phantom and patient studies. The findings from the phantom experiments indicated that the presence of the coil resulted in a 10% reduction in measured 18F-FDG activity when compared with the phantom-only scan. Local underestimation reached 22% in regions of interest close to the coil. Various registration methods were tested, and the volume spline was deemed to be the most accurate, as measured by the Dice similarity metric. The results of our phantom experiments showed that the bias in the 18F-FDG quantification introduced by the presence of the coil could be reduced by using our registration method. An overestimation of only 1.9% of the overall activity for the phantom scan with the coil attenuation map was measured when compared with the baseline phantom scan without coil. A local overestimation of less than 3% was observed in the ROI analysis when using the proposed method to correct for the attenuation of the flexible cardiac coil. Quantitative results from the patient study agreed well with the phantom findings. We presented and validated an accurate method to localize and register a CT-based attenuation map to correct for the attenuation and scatter of flexible MR coils. This method may be translated to clinical use to produce quantitatively accurate measurements with the use of flexible MR coils during MR/PET imaging.

Foot-and-mouth disease virus type O specific mutations determine RNA-dependent RNA polymerase fidelity and virus attenuation.

PubMed

Li, Chen; Wang, Haiwei; Yuan, Tiangang; Woodman, Andrew; Yang, Decheng; Zhou, Guohui; Cameron, Craig E; Yu, Li

2018-05-01

Previous studies have shown that the FMDV Asia1/YS/CHA/05 high-fidelity mutagen-resistant variants are attenuated (Zeng et al., 2014). Here, we introduced the same single or multiple-amino-acid substitutions responsible for increased 3D pol fidelity of type Asia1 FMDV into the type O FMDV O/YS/CHA/05 infectious clone. The rescued viruses O-DA and O-DAMM are lower replication fidelity mutants and showed an attenuated phenotype. These results demonstrated that the same amino acid substitution of 3D pol in different serotypes of FMDV strains had different effects on viral fidelity. In addition, nucleoside analogues were used to select high-fidelity mutagen-resistant type O FMDV variants. The rescued mutagen-resistant type O FMDV high-fidelity variants exhibited significantly attenuated fitness and a reduced virulence phenotype. These results have important implications for understanding the molecular mechanism of FMDV evolution and pathogenicity, especially in developing a safer modified live-attenuated vaccine against FMDV. Copyright © 2018 Elsevier Inc. All rights reserved.

Memory T-cell immune response in healthy young adults vaccinated with live attenuated influenza A (H5N2) vaccine.

PubMed

Chirkova, T V; Naykhin, A N; Petukhova, G D; Korenkov, D A; Donina, S A; Mironov, A N; Rudenko, L G

2011-10-01

Cellular immune responses of both CD4 and CD8 memory/effector T cells were evaluated in healthy young adults who received two doses of live attenuated influenza A (H5N2) vaccine. The vaccine was developed by reassortment of nonpathogenic avian A/Duck/Potsdam/1402-6/68 (H5N2) and cold-adapted A/Leningrad/134/17/57 (H2N2) viruses. T-cell responses were measured by standard methods of intracellular cytokine staining of gamma interferon (IFN-γ)-producing cells and a novel T-cell recognition of antigen-presenting cells by protein capture (TRAP) assay based on the trogocytosis phenomenon, namely, plasma membrane exchange between interacting immune cells. TRAP enables the detection of activated trogocytosis-positive T cells after virus stimulation. We showed that two doses of live attenuated influenza A (H5N2) vaccine promoted both CD4 and CD8 T-memory-cell responses in peripheral blood of healthy young subjects in the clinical study. Significant differences in geometric mean titers (GMTs) of influenza A (H5N2)-specific IFN-γ(+) cells were observed at day 42 following the second vaccination, while peak levels of trogocytosis(+) T cells were detected earlier, on the 21st day after the second vaccination. The inverse correlation of baseline levels compared to postvaccine fold changes in GMTs of influenza-specific CD4 and CD8 T cells demonstrated that baseline levels of these specific cells could be considered a predictive factor of vaccine immunogenicity.

Modified polarized geometrical attenuation model for bidirectional reflection distribution function based on random surface microfacet theory.

PubMed

Liu, Hong; Zhu, Jingping; Wang, Kai

2015-08-24

The geometrical attenuation model given by Blinn was widely used in the geometrical optics bidirectional reflectance distribution function (BRDF) models. Blinn's geometrical attenuation model based on symmetrical V-groove assumption and ray scalar theory causes obvious inaccuracies in BRDF curves and negatives the effects of polarization. Aiming at these questions, a modified polarized geometrical attenuation model based on random surface microfacet theory is presented by combining of masking and shadowing effects and polarized effect. The p-polarized, s-polarized and unpolarized geometrical attenuation functions are given in their separate expressions and are validated with experimental data of two samples. It shows that the modified polarized geometrical attenuation function reaches better physical rationality, improves the precision of BRDF model, and widens the applications for different polarization.

Powerful vascular protection by combining cilnidipine with valsartan in stroke-prone, spontaneously hypertensive rats

PubMed Central

Takai, Shinji; Jin, Denan; Aritomi, Shizuka; Niinuma, Kazumi; Miyazaki, Mizuo

2013-01-01

Cilnidipine is an L- and N-type calcium channel blocker (CCB), and amlodipine is an L-type CCB. Valsartan (10 mg kg−1), valsartan (10 mg kg−1) and amlodipine (1 mg kg−1), and valsartan (10 mg kg−1) and cilnidipine (1 mg kg−1) were administered once daily for 2 weeks to stroke-prone, spontaneously hypertensive rats (SHR-SPs). Blood pressure was significantly reduced by valsartan, and it was further reduced by the combination therapies. Vascular endothelial dysfunction was significantly attenuated in all therapeutic groups, and further significant attenuation was observed in the valsartan+cilnidipine-treated group, but not in the valsartan+amlodipine-treated group. Vascular nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunit NOX1 gene expression was significantly attenuated in all therapeutic groups, and significantly greater attenuation was observed in the valsartan+cilnidipine-treated group than in the valsartan-treated group. Compared with the valsartan-treated group, the positive areas for 4-hydroxy-2-nonenal were significantly lower only in the valsartan+cilnidipine-treated group. Plasma renin activity was significantly augmented in the valsartan-treated group, and it was significantly attenuated in the valsartan+cilnidipine-treated group. A significant increase in the ratio of plasma angiotensin-(1-7) to angiotensin II was observed only in the valsartan+cilnidipine-treated group. Vascular angiotensin-converting enzyme (ACE) gene expression was significantly attenuated only in the valsartan+cilnidipine-treated group, but ACE2 gene expression was significantly higher in all of the therapeutic groups. Thus, valsartan and cilnidipine combination therapy might have a powerful protective effect in the vascular tissues via increases in the angiotensin-(1-7)/angiotensin II ratio in plasma. PMID:23190689

Attenuation and scattering tomography of the deep plumbing system of Mount St. Helens

USGS Publications Warehouse

De Siena, Luca; Thomas, Christine; Waite, Greg P.; Moran, Seth C.; Klemme, Stefan

2014-01-01

We present a combined 3-D P wave attenuation, 2-D S coda attenuation, and 3-D S coda scattering tomography model of fluid pathways, feeding systems, and sediments below Mount St. Helens (MSH) volcano between depths of 0 and 18 km. High-scattering and high-attenuation shallow anomalies are indicative of magma and fluid-rich zones within and below the volcanic edifice down to 6 km depth, where a high-scattering body outlines the top of deeper aseismic velocity anomalies. Both the volcanic edifice and these structures induce a combination of strong scattering and attenuation on any seismic wavefield, particularly those recorded on the northern and eastern flanks of the volcanic cone. North of the cone between depths of 0 and 10 km, a low-velocity, high-scattering, and high-attenuation north-south trending trough is attributed to thick piles of Tertiary marine sediments within the St. Helens Seismic Zone. A laterally extended 3-D scattering contrast at depths of 10 to 14 km is related to the boundary between upper and lower crust and caused in our interpretation by the large-scale interaction of the Siletz terrane with the Cascade arc crust. This contrast presents a low-scattering, 4–6 km2 “hole” under the northeastern flank of the volcano. We infer that this section represents the main path of magma ascent from depths greater than 6 km at MSH, with a small north-east shift in the lower plumbing system of the volcano. We conclude that combinations of different nonstandard tomographic methods, leading toward full-waveform tomography, represent the future of seismic volcano imaging.

Hypocortisolism as a potential marker of allostatic load in children: Associations with family risk and internalizing disorders

PubMed Central

Watamura, Sarah Enos; Hankin, Benjamin L.

2014-01-01

Although the majority of research attention to the HPA-axis in stress-related disorders and as a marker of allostatic load has focused on over-activation of this stress system, theory and data clearly indicate that under-activation is also an important type of dysregulation. In the current study, we focused on low cortisol, exploring a constellation of risk factors comprised of stress exposure, maternal depression, and attenuated basal and stress reactive cortisol in two samples of children. The first sample is 110 preschoolers living in high stress environments. Cortisol was assessed across the day at home and at child care as well as across two stress paradigms. These data were used to classify whether children’s HPA-axis activity was attenuated. Serious family financial strain, maternal depression, and attenuated cortisol all made unique contributions in models predicting current clinical levels of internalizing symptoms as rated by mothers and teachers. The second sample was 166 3rd, 6th, and 9th graders studied 5 times across a 1-year period. Maternal and child depression were determined through structured clinical interviews, and stress exposure was assessed via checklist and interview techniques with the child and the parent. Cortisol was assessed multiple times across a lab visit at time 1, and these data were combined into a single continuous measure. Cortisol concentrations across the lab visit interacted with stress exposure across the year such that children with lower average cortisol at time 1, maternal depressive symptoms, and increased stress across the 12 months showed increasing levels of internalizing symptoms. Based on these and related data we propose that prior to puberty, low cortisol may be an important marker of allostatic load, particularly for risk of depression and anxiety. PMID:21756439

Chimeric recombinant human metapneumoviruses with the nucleoprotein or phosphoprotein open reading frame replaced by that of avian metapneumovirus exhibit improved growth in vitro and attenuation in vivo.

PubMed

Pham, Quynh N; Biacchesi, Stéphane; Skiadopoulos, Mario H; Murphy, Brian R; Collins, Peter L; Buchholz, Ursula J

2005-12-01

Chimeric versions of recombinant human metapneumovirus (HMPV) were generated by replacing the nucleoprotein (N) or phosphoprotein (P) open reading frame with its counterpart from the closely related avian metapneumovirus (AMPV) subgroup C. In Vero cells, AMPV replicated to an approximately 100-fold-higher titer than HMPV. Surprisingly, the N and P chimeric viruses replicated to a peak titer that was 11- and 25-fold higher, respectively, than that of parental HMPV. The basis for this effect is not known but was not due to obvious changes in the efficiency of gene expression. AMPV and the N and P chimeras were evaluated for replication, immunogenicity, and protective efficacy in hamsters. AMPV was attenuated compared to HMPV in this mammalian host on day 5 postinfection, but not on day 3, and only in the nasal turbinates. In contrast, the N and P chimeras were reduced approximately 100-fold in both the upper and lower respiratory tract on day 3 postinfection, although there was little difference by day 5. The N and P chimeras induced a high level of neutralizing serum antibodies and protective efficacy against HMPV; AMPV was only weakly immunogenic and protective against HMPV challenge, reflecting antigenic differences. In African green monkeys immunized intranasally and intratracheally, the mean peak titer of the P chimera was reduced 100- and 1,000-fold in the upper and lower respiratory tracts, whereas the N chimera was reduced only 10-fold in the lower respiratory tract. Both chimeras were comparable to wild-type HMPV in immunogenicity and protective efficacy. Thus, the P chimera is a promising live HMPV vaccine candidate that paradoxically combines improved growth in vitro with attenuation in vivo.

Vaccine instability in the cold chain: mechanisms, analysis and formulation strategies.

PubMed

Kumru, Ozan S; Joshi, Sangeeta B; Smith, Dawn E; Middaugh, C Russell; Prusik, Ted; Volkin, David B

2014-09-01

Instability of vaccines often emerges as a key challenge during clinical development (lab to clinic) as well as commercial distribution (factory to patient). To yield stable, efficacious vaccine dosage forms for human use, successful formulation strategies must address a combination of interrelated topics including stabilization of antigens, selection of appropriate adjuvants, and development of stability-indicating analytical methods. This review covers key concepts in understanding the causes and mechanisms of vaccine instability including (1) the complex and delicate nature of antigen structures (e.g., viruses, proteins, carbohydrates, protein-carbohydrate conjugates, etc.), (2) use of adjuvants to further enhance immune responses, (3) development of physicochemical and biological assays to assess vaccine integrity and potency, and (4) stabilization strategies to protect vaccine antigens and adjuvants (and their interactions) during storage. Despite these challenges, vaccines can usually be sufficiently stabilized for use as medicines through a combination of formulation approaches combined with maintenance of an efficient cold chain (manufacturing, distribution, storage and administration). Several illustrative case studies are described regarding mechanisms of vaccine instability along with formulation approaches for stabilization within the vaccine cold chain. These include live, attenuated (measles, polio) and inactivated (influenza, polio) viral vaccines as well as recombinant protein (hepatitis B) vaccines. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Analysis of the dose-sparing effect of adjuvanted Sabin-inactivated poliovirus vaccine (sIPV).

PubMed

Li, Zhuofan; Ding, Wenting; Guo, Qi; Liu, Ze; Zhu, Zhe; Song, Shaohui; Li, Weidong; Liao, Guoyang

2018-03-30

Sabin-based inactivated poliovirus vaccine(sIPV) is gradually replacing live-attenuated oral polio vaccine(OPV). Sabin-inactivated poliovirus vaccine(sIPV) has played a vital role in reducing economic burden of poliomyelitis and maintaining appropriate antibody levels in the population. However, due to its high cost and limited manufacturing capacity, sIPV cannot reach its full potential for global poliovirus eradication in developing countries. Therefore, to address this situation, we designed this study to evaluate the dose-sparing effects of AS03, CpG oligodeoxynucleotides (CpG-ODN) and polyinosinic:polycytidylic acid (PolyI:C) admixed with sIPV in rats. Our results showed that a combination of 1/4-dose sIPV adjuvanted with AS03 or AS03 with BW006 provides a seroconversion rate similar to that of full-dose sIPV without adjuvant and that, this rate is 5-fold higher than that of 1/4-dose sIPV without adjuvant after the first immunization. The combination of AS03 or AS03 with BW006 as an adjuvant effectively reduced sIPV dose by at least 4-fold and induced both humoral and cellular immune responses. Therefore, our study revealed that the combination of AS03 or AS03 with BW006 is a promising adjuvant for sIPV development.

Heat Shock Protein 70 Enhances Mucosal Immunity against Human Norovirus When Coexpressed from a Vesicular Stomatitis Virus Vector

PubMed Central

Ma, Yuanmei; Duan, Yue; Wei, Yongwei; Liang, Xueya; Niewiesk, Stefan; Oglesbee, Michael

2014-01-01

ABSTRACT Human norovirus (NoV) accounts for 95% of nonbacterial gastroenteritis worldwide. Currently, there is no vaccine available to combat human NoV as it is not cultivable and lacks a small-animal model. Recently, we demonstrated that recombinant vesicular stomatitis virus (rVSV) expressing human NoV capsid protein (rVSV-VP1) induced strong immunities in mice (Y. Ma and J. Li, J. Virol. 85:2942–2952, 2011). To further improve the safety and efficacy of the vaccine candidate, heat shock protein 70 (HSP70) was inserted into the rVSV-VP1 backbone vector. A second construct was generated in which the firefly luciferase (Luc) gene was inserted in place of HSP70 as a control for the double insertion. The resultant recombinant viruses (rVSV-HSP70-VP1 and rVSV-Luc-VP1) were significantly more attenuated in cell culture and viral spread in mice than rVSV-VP1. At the inoculation dose of 1.0 × 106 PFU, rVSV-HSP70-VP1 triggered significantly higher vaginal IgA than rVSV-VP1 and significantly higher fecal and vaginal IgA responses than rVSV-Luc-VP1, although serum IgG and T cell responses were similar. At the inoculation dose of 5.0 × 106 PFU, rVSV-HSP70-VP1 stimulated significantly higher T cell, fecal, and vaginal IgA responses than rVSV-VP1. Fecal and vaginal IgA responses were also significantly increased when combined vaccination of rVSV-VP1 and rVSV-HSP70 was used. Collectively, these data indicate that (i) insertion of an additional gene (HSP70 or Luc) into the rVSV-VP1 backbone further attenuates the VSV-based vaccine in vitro and in vivo, thus improving the safety of the vaccine candidate, and (ii) HSP70 enhances the human NoV-specific mucosal and T cell immunities triggered by a VSV-based human NoV vaccine. IMPORTANCE Human norovirus (NoV) is responsible for more than 95% of acute nonbacterial gastroenteritis worldwide. Currently, there is no vaccine for this virus. Development of a live attenuated vaccine for human NoV has not been possible because it is uncultivable. Thus, a live vector-based vaccine may provide an alternative vaccine strategy. In this study, we developed a vesicular stomatitis virus (VSV)-based human NoV vaccine candidate. We constructed rVSV-HSP70-VP1, coexpressing heat shock protein (HSP70) and capsid (VP1) genes of human NoV, and rVSV-Luc-VP1, coexpressing firefly luciferase (Luc) and VP1 genes. We found that VSVs with a double gene insertion were significantly more attenuated than VSV with a single VP1 insertion (rVSV-VP1). Furthermore, we found that coexpression or coadministration of HSP70 from VSV vector significantly enhanced human NoV-specific mucosal immunity. Collectively, we developed an improved live vectored vaccine candidate for human NoV which will be useful for future clinical studies. PMID:24574391

Canine parvovirus type 2 vaccine protects against virulent challenge with type 2c virus.

PubMed

Spibey, N; Greenwood, N M; Sutton, D; Chalmers, W S K; Tarpey, I

2008-04-01

The ability of dogs vaccinated with a live attenuated CPV type 2 (Nobivac Intervet) vaccine to resist challenge with a current CPV2c isolate was investigated. Six SPF beagle dogs were given the minimum recommended course of vaccination, comprising a single inoculation of vaccine (Nobivac Lepto+Nobivac Pi) at 8-10 weeks of age followed 3 weeks later with a parvovirus vaccine in combination with distemper, adenovirus and parainfluenza virus (Nobivac DHPPi) and a repeat leptospirosis vaccine. Six control dogs were kept unvaccinated. All animals were challenged orally with a type 2c isolate of CPV and monitored for clinical signs, virus shedding, white blood cell fluctuations and serological responses. All vaccinated dogs were fully protected; showing no clinical signs nor shedding challenge virus in the faeces, in contrast to control animals, which displayed all the typical signs of infection with pathogenic CPV and shed challenge virus in the faeces.

Diverse coral communities in mangrove habitats suggest a novel refuge from climate change

USGS Publications Warehouse

Yates, Kimberly K.; Rogers, Caroline S.; Herlan, James J.; Brooks, Gregg R.; Smiley, Nathan A.; Larson, Rebekka A.

2014-01-01

Over 30 species of scleractinian corals were growing in association with mangroves. Corals were thriving in low-light (more than 70% attenuation of incident PAR) from mangrove shading and at higher temperatures than nearby reef tract corals. A higher percentage of C. natans colonies were living shaded by mangroves, and no shaded colonies were bleached. Fewer D. labyrinthiformis colonies were shaded by mangroves, however more unshaded colonies were bleached. A combination of substrate and habitat heterogeneity, proximity of different habitat types, hydrographic conditions, and biological influences on seawater chemistry generate chemical conditions that buffer against ocean acidification. This previously undocumented refuge for corals provides evidence for adaptation of coastal organisms and ecosystem transition due to recent climate change. Identifying and protecting other natural, non-reef coral refuges is critical for sustaining corals and other reef species into the future.

Toward RNA nanoparticle vaccines: synergizing RNA and inorganic nanoparticles to achieve immunopotentiation.

PubMed

DeLong, Robert K; Curtis, Chandler B

2017-03-01

Traditionally, vaccines have been composed of live attenuated or killed microorganisms. Alternatively, individual protein subunits or other molecular components of the microorganism can serve as the antigen and trigger an antibody response by the immune system. The immune system is a coordinated molecular and cellular response that works in concert to check the spread of infection. In the past decade, there has been much progress on DNA vaccines. DNA vaccination includes using the coding segments of a viral or bacterial genome to generate an immune response. However, the potential advantage of combining an RNA molecule with inorganic nanoparticle delivery should be considered, with the goal to achieve immuno-synergy between the two and to overcome some of the current limitations of DNA vaccines and traditional vaccines. WIREs Nanomed Nanobiotechnol 2017, 9:e1415. doi: 10.1002/wnan.1415 For further resources related to this article, please visit the WIREs website. © 2016 Wiley Periodicals, Inc.

CpG oligodeoxynucleotides are a potent adjuvant for an inactivated polio vaccine produced from Sabin strains of poliovirus.

PubMed

Yang, Chunting; Shi, Huiying; Zhou, Jun; Liang, Yanwen; Xu, Honglin

2009-11-05

Poliovirus transmission is controlled globally through world-wide use of a live attenuated oral polio vaccine (OPV). However, the imminence of global poliovirus eradication calls for a switch to the inactivated polio vaccine (IPV). Given the limited manufacturing capacity and high cost of IPV, this switch is unlikely in most developing and undeveloped countries. Adjuvantation is an effective strategy for antigen sparing. In this study, we evaluated the adjuvanticity of CpG oligodeoxynucleotides (CpG-ODN) for an experimental IPV produced from Sabin strains of poliovirus. Our results showed that CpG-ODN, alone or in combination with alum, can significantly enhance both the humoral and cellular immune responses to IPV in mice, and, consequently, the antigen dose could be reduced substantially. Therefore, our study suggests that the global use of IPV could be facilitated by using CpG-ODN or other feasible adjuvants.

New approaches in oral rotavirus vaccines.

PubMed

Kuate Defo, Zenas; Lee, Byong

2016-05-01

Rotavirus is the leading cause of severe dehydrating diarrhea worldwide, and affects primarily developing nations, in large part because of the inaccessibility of vaccines and high rates of mortality present therein. At present, there exist two oral rotaviral vaccines, Rotarix™ and RotaTeq™. These vaccines are generally effective in their actions: however, associated costs often stymie their effectiveness, and they continue to be associated with a slight risk of intussusception. While different programs are being implemented worldwide to enhance vaccine distribution and monitor vaccine administration for possible intussusception in light of recent WHO recommendation, another major problem persists: that of the reduced efficacy of the existing rotaviral vaccines in developing countries over time. The development of new oral rotavirus vaccine classes - live-attenuated vaccines, virus-like particles, lactic acid bacteria-containing vaccines, combination therapy with immunoglobulins, and biodegradable polymer-encapsulated vaccines - could potentially circumvent these problems.

Forward-masking based gain control in odontocete biosonar: an evoked-potential study.

PubMed

Supin, Alexander Ya; Nachtigall, Paul E; Breese, Marlee

2009-04-01

Auditory evoked potentials (AEPs) were recorded during echolocation in a false killer whale Pseudorca crassidens. An electronically synthesized and played-back ("phantom") echo was used. Each electronic echo was triggered by an emitted biosonar pulse. The echo had a spectrum similar to that of the emitted biosonar clicks, and its intensity was proportional to that of the emitted click. The attenuation of the echo relative to the emitted click and its delay was controlled by the experimenter. Four combinations of echo attenuation and delay were tested (-31 dB, 2 ms), (-40 dB, 4 ms), (-49 dB, 8 ms), and (-58 dB, 16 ms); thus, attenuation and delay were associated with a rate of 9 dB of increased attenuation per delay doubling. AEPs related to emitted clicks displayed a regular amplitude dependence on the click level. Echo-related AEPs did not feature amplitude dependence on echo attenuation or emitted click levels, except in a few combinations of the lowest values of these two variables. The results are explained by a hypothesis that partial forward masking of the echoes by the preceding emitted sonar pulses serves as a kind of automatic gain control in the auditory system of echolocating odontocetes.

Effectiveness and safety of immunization with live-attenuated and inactivated vaccines for pediatric liver transplantation recipients.

PubMed

Kawano, Yoshihiko; Suzuki, Michio; Kawada, Jun-ichi; Kimura, Hiroshi; Kamei, Hideya; Ohnishi, Yasuharu; Ono, Yasuyuki; Uchida, Hiroo; Ogura, Yasuhiro; Ito, Yoshinori

2015-03-17

Liver transplantation recipients are at high risk for severe complications due to infections because of being treated with immunosuppressive drugs that affect the immune system. Vaccination for liver transplantation candidates is generally recommended before surgery, but the opportunities for vaccination prior to transplantation in pediatric candidates are often limited by severe disease conditions. The participants in this study comprised 39 pediatric recipients of living donor liver transplantation performed between 2005 and 2013. Criteria for administering live-attenuated (measles, rubella, mumps, and varicella) and inactivated (hepatitis B, pertussis, and Japanese encephalitis) vaccines were as follows: (1) >1 year after transplantation; (2) no use of systemic steroids to treat acute rejection within the last 6 months; (3) serum trough concentration of tacrolimus <5 ng/mL; (4) no severe immunosuppression according to blood examinations; and (5) provision of written informed consent. Median age at transplantation was 17 months, and median period from transplantation to the beginning of immunization was 18 months. Seroprotection rates for measles, rubella, mumps, varicella, hepatitis B, pertussis, and Japanese encephalitis after post-transplant immunization were 44% (11/25), 70% (19/27), 48% (12/25), 32% (6/19), 83% (19/23), 87% (13/15), and 88% (7/8), respectively. Seroprotection rates for measles, rubella, mumps, and varicella after second vaccination for recipients with primary vaccine failure after first vaccination were 100% (8/8), 50% (1/2), 71% (5/7), and 50% (5/10), respectively. While four recipients contracted mumps and eight contracted varicella before immunization, one recipient developed varicella after immunization. No serious systemic adverse events were observed in vaccinated recipients. Seroprotection rates for measles, mumps, and varicella appeared low in children after the first post-transplantation vaccination. Immunizations with four live-attenuated and three inactivated vaccines were safe and effective for pediatric liver transplantation recipients who were not severely immunosuppressed. Copyright © 2015. Published by Elsevier Ltd.

Newcastle Disease Virus (NDV) Recombinants Expressing Infectious Laryngotracheitis Virus (ILTV) Glycoproteins gB and gD Protect Chickens against ILTV and NDV Challenges

PubMed Central

Zhao, Wei; Spatz, Stephen; Zhang, Zhenyu; Wen, Guoyuan; Garcia, Maricarmen; Zsak, Laszlo

2014-01-01

ABSTRACT Infectious laryngotracheitis (ILT) is a highly contagious acute respiratory disease of chickens caused by infectious laryngotracheitis virus (ILTV). The disease is controlled mainly through biosecurity and vaccination with live attenuated strains of ILTV and vectored vaccines based on turkey herpesvirus (HVT) and fowlpox virus (FPV). The current live attenuated vaccines (chicken embryo origin [CEO] and tissue culture origin [TCO]), although effective, can regain virulence, whereas HVT- and FPV-vectored ILTV vaccines are less efficacious than live attenuated vaccines. Therefore, there is a pressing need to develop safer and more efficacious ILTV vaccines. In the present study, we generated Newcastle disease virus (NDV) recombinants, based on the LaSota vaccine strain, expressing glycoproteins B (gB) and D (gD) of ILTV using reverse genetics technology. These recombinant viruses, rLS/ILTV-gB and rLS/ILTV-gD, were slightly attenuated in vivo yet retained growth dynamics, stability, and virus titers in vitro that were similar to those of the parental LaSota virus. Expression of ILTV gB and gD proteins in the recombinant virus-infected cells was detected by immunofluorescence assay. Vaccination of specific-pathogen-free chickens with these recombinant viruses conferred significant protection against virulent ILTV and velogenic NDV challenges. Immunization of commercial broilers with rLS/ILTV-gB provided a level of protection against clinical disease similar to that provided by the live attenuated commercial vaccines, with no decrease in body weight gains. The results of the study suggested that the rLS/ILTV-gB and -gD viruses are safe, stable, and effective bivalent vaccines that can be mass administered via aerosol or drinking water to large chicken populations. IMPORTANCE This paper describes the development and evaluation of novel bivalent vaccines against chicken infectious laryngotracheitis (ILT) and Newcastle disease (ND), two of the most economically important infectious diseases of poultry. The current commercial ILT vaccines are either not safe or less effective. Therefore, there is a pressing need to develop safer and more efficacious ILT vaccines. In the present study, we generated Newcastle disease virus (NDV) recombinants expressing glycoproteins B (gB) and D (gD) of infectious laryngotracheitis virus (ILTV) using reverse genetics technology. These recombinant viruses were safe, stable, and immunogenic and replicated efficiently in birds. Vaccination of chickens with these recombinant viruses conferred complete protection against ILTV and NDV challenge. These novel bivalent vaccines can be mass administered via aerosol or drinking water to large chicken populations at low cost, which will have a direct impact on poultry health, fitness, and performance. PMID:24829337

Promoting ADL independence in vulnerable, community-dwelling older adults: a pilot RCT comparing 3-Step Workout for Life versus resistance exercise

PubMed Central

Liu, Chiung-ju; Xu, Huiping; Keith, NiCole R; Clark, Daniel O

2017-01-01

Background Resistance exercise is effective to increase muscle strength for older adults; however, its effect on the outcome of activities of daily living is often limited. The purpose of this study was to examine whether 3-Step Workout for Life (which combines resistance exercise, functional exercise, and activities of daily living exercise) would be more beneficial than resistance exercise alone. Methods A single-blind randomized controlled trial was conducted. Fifty-two inactive, community-dwelling older adults (mean age =73 years) with muscle weakness and difficulty in activities of daily living were randomized to receive 3-Step Workout for Life or resistance exercise only. Participants in the 3-Step Workout for Life Group performed functional movements and selected activities of daily living at home in addition to resistance exercise. Participants in the Resistance Exercise Only Group performed resistance exercise only. Both groups were comparable in exercise intensity (moderate), duration (50–60 minutes each time for 10 weeks), and frequency (three times a week). Assessment of Motor and Process Skills, a standard performance test on activities of daily living, was administered at baseline, postintervention, and 6 months after intervention completion. Results At postintervention, the 3-Step Workout for Life Group showed improvement on the outcome measure (mean change from baseline =0.29, P=0.02), but the improvement was not greater than the Resistance Exercise Only Group (group mean difference =0.24, P=0.13). However, the Resistance Exercise Only Group showed a significant decline (mean change from baseline =−0.25, P=0.01) 6 months after the intervention completion. Meanwhile, the superior effect of 3-Step Workout for Life was observed (group mean difference =0.37, P<0.01). Conclusion Compared to resistance exercise alone, 3-Step Workout for Life improves the performance of activities of daily living and attenuates the disablement process in older adults. PMID:28769559

Co-administration of live measles and yellow fever vaccines and inactivated pentavalent vaccines is associated with increased mortality compared with measles and yellow fever vaccines only. An observational study from Guinea-Bissau.

PubMed

Fisker, Ane Bærent; Ravn, Henrik; Rodrigues, Amabelia; Østergaard, Marie Drivsholm; Bale, Carlito; Benn, Christine Stabell; Aaby, Peter

2014-01-23

Studies from low-income countries indicate that co-administration of inactivated diphtheria-tetanus-pertussis (DTP) vaccine and live attenuated measles vaccine (MV) is associated with increased mortality compared with receiving MV only. Pentavalent (DTP-H. Influenza type B-Hepatitis B) vaccine is replacing DTP in many low-income countries and yellow fever vaccine (YF) has been introduced to be given together with MV. Pentavalent and YF vaccines were introduced in Guinea-Bissau in 2008. We investigated whether co-administration of pentavalent vaccine with MV and yellow fever vaccine has similar negative effects. In 2007-2011, we conducted a randomised placebo-controlled trial of vitamin A at routine vaccination contacts among children aged 6-23 months in urban and rural Guinea-Bissau. In the present study, we included 2331 children randomised to placebo who received live vaccines only (MV or MV+YF) or a combination of live and inactivated vaccines (MV+DTP or MV+YF+pentavalent). Mortality was compared in Cox proportional hazards models stratified for urban/rural enrolment adjusted for age and unevenly distributed baseline factors. While DTP was still used 685 children received MV only and 358 MV+DTP; following the change in programme, 940 received MV+YF only and 348 MV+YF+pentavalent. During 6 months of follow-up, the adjusted mortality rate ratio (MRR) for co-administered live and inactivated vaccines compared with live vaccines only was 3.24 (1.20-8.73). For MV+YF+pentavalent compared with MV+YF only, the adjusted MRR was 7.73 (1.79-33.4). In line with previous studies of DTP, the present results indicate that pentavalent vaccine co-administered with MV and YF is associated with increased mortality. Copyright © 2013 Elsevier Ltd. All rights reserved.

Safety and immunogenecity of a live attenuated Rift Valley fever vaccine (CL13T) in camels.

PubMed

Daouam, S; Ghzal, F; Naouli, Y; Tadlaoui, K O; Ennaji, M M; Oura, C; El Harrak, M

2016-07-26

Rift Valley fever is an emerging zoonotic viral disease, enzootic and endemic in Africa and the Arabian Peninsula, which poses a significant threat to both human and animal health. The disease is most severe in ruminants causing abortions in pregnant animals, especially sheep animals and high mortality in young populations. High mortality rates and severe clinical manifestation have also been reported among camel populations in Africa, to attend however none of the currently available live vaccines against RVF have been tested for safety and efficacy in this species. In this study, the safety and efficacy (through a neutralizing antibody response) of the thermostable live attenuated RVF CL13T vaccine were evaluated in camels in two different preliminary experiments involving 16 camels, (that 12 camels and 4 pregnant camels). The study revealed that the CL13T vaccine was safe to use in camels and no abortions or teratogenic effects were observed. The single dose of the vaccine stimulated a strong and long-lasting neutralizing antibody response for up to 12 months. The presence of neutralization antibodies is likely to correlate with protection; however protection would need to be confirmed by challenge experiments using the virulent RVF virus.

Improving work zone safety for freight vehicles : effective design patterns for vehicle mounted attenuators.

DOT National Transportation Integrated Search

2010-12-01

This report presents a study of driver perceptions using a driving simulator carried out on the effectiveness of : four markings which vary in striping patterns and color combinations used at the rear of vehicle mounted : attenuators (VMAs) in work z...

Enhancement of the safety of live influenza vaccine by attenuating mutations from cold-adapted hemagglutinin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Yoon Jae; Laboratory of Molecular Medicine, Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul; Vaccine Translational Research Center, Yonsei University, Seoul

In our previous study, X-31ca-based H5N1 LAIVs, in particular, became more virulent in mice than the X-31ca MDV, possibly by the introduction of the surface antigens of highly pathogenic H5N1 influenza virus, implying that additional attenuation is needed in this cases to increase the safety level of the vaccine. In this report we suggest an approach to further increase the safety of LAIV through additional cold-adapted mutations in the hemagglutinin. The cold-adaptation of X-31 virus resulted in four amino acid mutations in the HA. We generated a panel of 7:1 reassortant viruses each carrying the hemagglutinins with individual single aminomore » acid mutations. We examined their phenotypes and found a major attenuating mutation, N81K. This attenuation marker conferred additional temperature-sensitive and attenuation phenotype to the LAIV. Our data indicate that the cold-adapted mutation in the HA confers additional attenuation to the LAIV strain, without compromising its productivity and immune response. - Highlights: • Cold-adaptation process induced four amino acid mutations in the HA of X-31 virus. • The four mutations in the HA also contributed to attenuation of the X-31ca virus • N81K mutation was the most significant marker for the attenuation of X-31ca virus. • Introduction of N81K mutation into H3N2 LAIV further attenuated the vaccine. • This approach provides a useful guideline for enhancing the safety of the LAIVs.« less

Rift Valley Fever vaccines: An overview of the safety and efficacy of the live-attenuated MP-12 vaccine candidate

PubMed Central

Ikegami, Tetsuro

2017-01-01

Introduction Rift Valley fever (RVF) is a mosquito-borne zoonotic viral disease endemic to Africa and the Arabian Peninsula. High rates of abortion among infected ruminants and hemorrhagic fever in infected humans are major public health concerns. Commercially available veterinary RVF vaccines are important for preventing the spread of the Rift Valley fever virus (RVFV) in endemic countries; however, RVFV outbreaks continue to occur frequently in endemic countries in the 21st century. In the U.S., the live-attenuated MP-12 vaccine has been developed for both animal and human vaccination. This vaccine strain is well attenuated, and a single dose induces neutralizing antibodies in both ruminants and humans. Areas covered This review describes scientific evidences of MP-12 vaccine efficacy and safety, as well as MP-12 variants recently developed by reverse genetics, in comparison with other RVF vaccines. Expert commentary The containment of active RVF outbreaks and long-term protection from RVF exposure to infected mosquitoes are important goals for RVF vaccination. MP-12 vaccine will allow immediate vaccination of susceptible animals in case of an unexpected RVF outbreak in the U.S., whereas MP-12 vaccine may be also useful for the RVF control in endemic regions. PMID:28425834

Allogeneic lymphocytes persist and traffic in feral MHC-matched mauritian cynomolgus macaques.

PubMed

Greene, Justin M; Burwitz, Benjamin J; Blasky, Alex J; Mattila, Teresa L; Hong, Jung Joo; Rakasz, Eva G; Wiseman, Roger W; Hasenkrug, Kim J; Skinner, Pamela J; O'Connor, Shelby L; O'Connor, David H

2008-06-11

Thus far, live attenuated SIV has been the most successful method for vaccinating macaques against pathogenic SIV challenge; however, it is not clear what mechanisms are responsible for this protection. Adoptive transfer studies in mice have been integral to understanding live attenuated vaccine protection in models like Friend virus. Previous adoptive transfers in primates have failed as transferred cells are typically cleared within hours after transfer. Here we describe adoptive transfer studies in Mauritian origin cynomolgus macaques (MCM), a non-human primate model with limited MHC diversity. Cells transferred between unrelated MHC-matched macaques persist for at least fourteen days but are rejected within 36 hours in MHC-mismatched macaques. Cells trafficked from the blood to peripheral lymphoid tissues within 12 hours of transfer. MHC-matched MCM provide the first viable primate model for adoptive transfer studies. Because macaques infected with SIV are the best model for HIV/AIDS pathogenesis, we can now directly study the correlates of protective immune responses to AIDS viruses. For example, plasma viral loads following pathogenic SIV challenge are reduced by several orders of magnitude in macaques previously immunized with attenuated SIV. Adoptive transfer of lymphocyte subpopulations from vaccinated donors into SIV-naïve animals may define the immune mechanisms responsible for protection and guide future vaccine development.

Breeding status affects the hormonal and metabolic response to acute stress in a long-lived seabird, the king penguin.

PubMed

Viblanc, Vincent A; Gineste, Benoit; Robin, Jean-Patrice; Groscolas, René

2016-09-15

Stress responses are suggested to physiologically underlie parental decisions promoting the redirection of behaviour away from offspring care when survival is jeopardized (e.g., when facing a predator). Besides this classical view, the "brood-value hypothesis" suggests that parents' stress responses may be adaptively attenuated to increase fitness, ensuring continued breeding when the relative value of the brood is high. Here, we test the brood-value hypothesis in breeding king penguins (Aptenodytes patagonicus), long-lived seabirds for which the energy commitment to reproduction is high. We subjected birds at different breeding stages (courtship, incubation and chick brooding) to an acute 30-min capture stress and measured their hormonal (corticosterone, CORT) and metabolic (non-esterified fatty acid, NEFA) responses to stress. We found that CORT responses were markedly attenuated in chick-brooding birds when compared to earlier stages of breeding (courtship and incubation). In addition, NEFA responses appeared to be rapidly attenuated in incubating and brooding birds, but a progressive increase in NEFA plasma levels in courting birds suggested energy mobilization to deal with the threat. Our results support the idea that stress responses may constitute an important life-history mechanism mediating parental reproductive decisions in relation to their expected fitness outcome. Copyright © 2016 Elsevier Inc. All rights reserved.

Rift Valley fever vaccines: an overview of the safety and efficacy of the live-attenuated MP-12 vaccine candidate.

PubMed

Ikegami, Tetsuro

2017-06-01

Rift Valley fever (RVF) is a mosquito-borne zoonotic viral disease endemic to Africa and the Arabian Peninsula. High rates of abortion among infected ruminants and hemorrhagic fever in infected humans are major public health concerns. Commercially available veterinary RVF vaccines are important for preventing the spread of the Rift Valley fever virus (RVFV) in endemic countries; however, RVFV outbreaks continue to occur frequently in endemic countries in the 21st century. In the U.S., the live-attenuated MP-12 vaccine has been developed for both animal and human vaccination. This vaccine strain is well attenuated, and a single dose induces neutralizing antibodies in both ruminants and humans. Areas covered: This review describes scientific evidences of MP-12 vaccine efficacy and safety, as well as MP-12 variants recently developed by reverse genetics, in comparison with other RVF vaccines. Expert commentary: The containment of active RVF outbreaks and long-term protection from RVF exposure to infected mosquitoes are important goals for RVF vaccination. MP-12 vaccine will allow immediate vaccination of susceptible animals in case of an unexpected RVF outbreak in the U.S., whereas MP-12 vaccine may be also useful for the RVF control in endemic regions.

Theoretical and Experimental Investigation of Mufflers with Comments on Engine-Exhaust Muffler Design

NASA Technical Reports Server (NTRS)

Davis, Don D , Jr; Stokes, George M; Moore, Dewey; Stevens, George L , Jr

1954-01-01

Equations are presented for the attenuation characteristics of single-chamber and multiple-chamber mufflers of both the expansion-chamber and resonator types, for tuned side-branch tubes, and for the combination of an expansion chamber with a resonator. Experimental curves of attenuation plotted against frequency are presented for 77 different mufflers with a reflection-free tailpipe termination. The experiments were made at room temperature without flow; the sound source was a loud-speaker. A method is given for including the tailpipe reflections in the calculations. Experimental attenuation curves are presented for four different muffler-tailpipe combinations, and the results are compared with the theory. The application of the theory to the design of engine-exhaust mufflers is discussed, and charts are included for the assistance of the designer.

75 FR 39667 - Availability for Non-Exclusive or Partially Exclusive Licensing of a U.S. Patent Application

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-12

... Serial No. 11/132,199, entitled ``Construction of Live Attenuated Shigella Vaccine Strains that Express... proteins in Shigella spp. without affecting the ability of the Shigella strain to invade cells of the...

Long-Term Safety and Immunogenicity of a Tetravalent Live-Attenuated Dengue Vaccine and Evaluation of a Booster Dose Administered to Healthy Thai Children

PubMed Central

Watanaveeradej, Veerachai; Simasathien, Sriluck; Mammen, Mammen P.; Nisalak, Ananda; Tournay, Elodie; Kerdpanich, Phirangkul; Samakoses, Rudiwilai; Putnak, Robert J.; Gibbons, Robert V.; Yoon, In-Kyu; Jarman, Richard G.; De La Barrera, Rafael; Moris, Philippe; Eckels, Kenneth H.; Thomas, Stephen J.; Innis, Bruce L.

2016-01-01

We evaluated the safety and immunogenicity of two doses of a live-attenuated, tetravalent dengue virus vaccine (F17/Pre formulation) and a booster dose in a dengue endemic setting in two studies. Seven children (7- to 8-year-olds) were followed for 1 year after dose 2 and then given a booster dose (F17/Pre formulation), and followed for four more years (Child study). In the Infant study, 49 2-year-olds, vaccinated as infants, were followed for approximately 3.5 years after dose 2 and then given a booster dose (F17) and followed for one additional year. Two clinically notable events were observed, both in dengue vaccine recipients in the Infant study: 1 case of dengue approximately 2.7 years after dose 2 and 1 case of suspected dengue after booster vaccinations. The booster vaccinations had a favorable safety profile in terms of reactogenicity and adverse events reported during the 1-month follow-up periods. No vaccine-related serious adverse events were reported during the studies. Neutralizing antibodies against dengue viruses 1–4 waned during the 1–3 years before boosting, which elicited a short-lived booster response but did not provide a long-lived, multivalent antibody response in most subjects. Overall, this candidate vaccine did not elicit a durable humoral immune response. PMID:27022153

Development of a human live attenuated West Nile infectious DNA vaccine: Identification of a minimal mutation set conferring the attenuation level acceptable for a human vaccine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamshchikov, Vladimir, E-mail: yaximik@gmail.com

ABSTRACT: For the development of a human West Nile (WN) infectious DNA (iDNA) vaccine, we created highly attenuated chimeric virus W1806 with the serological identity of highly virulent WN-NY99. Earlier, we attempted to utilize mutations found in the E protein of the SA14-14-2 vaccine to bring safety of W1806 to the level acceptable for human use (). Here, we analyzed effects of the SA14-14-2 changes on growth properties and neurovirulence of W1806. A set including the E138K, K279M, K439R and G447D changes was identified as the perspective subset for satisfying the target safety profile without compromising immunogenicity of the vaccinemore » candidate. The genetic stability of the attenuated phenotype was found to be unsatisfactory being dependent on a subset of attenuating changes incorporated in W1806. Elucidation of underlying mechanisms influencing selection of pathways for restoration of the envelope protein functionality will facilitate resolution of the emerged genetic stability issue. - Highlights: •Effect of mutations in E on properties of WN1806 is determined. •A subset of attenuating mutations suitable for a human vaccine is defined. •Mechanism of attenuation is proposed and illustrated. •Underlying mechanisms of neurovirulence reversion are suggested.« less

Combining operando synchrotron X-ray tomographic microscopy and scanning X-ray diffraction to study lithium ion batteries

PubMed Central

Pietsch, Patrick; Hess, Michael; Ludwig, Wolfgang; Eller, Jens; Wood, Vanessa

2016-01-01

We present an operando study of a lithium ion battery combining scanning X-ray diffraction (SXRD) and synchrotron radiation X-ray tomographic microscopy (SRXTM) simultaneously for the first time. This combination of techniques facilitates the investigation of dynamic processes in lithium ion batteries containing amorphous and/or weakly attenuating active materials. While amorphous materials pose a challenge for diffraction techniques, weakly attenuating material systems pose a challenge for attenuation-contrast tomography. Furthermore, combining SXRD and SRXTM can be used to correlate processes occurring at the atomic level in the crystal lattices of the active materials with those at the scale of electrode microstructure. To demonstrate the benefits of this approach, we investigate a silicon powder electrode in lithium metal half-cell configuration. Combining SXRD and SRXTM, we are able to (i) quantify the dissolution of the metallic lithium electrode and the expansion of the silicon electrode, (ii) better understand the formation of the Li15Si4 phase, and (iii) non-invasively probe kinetic limitations within the silicon electrode. A simple model based on the 1D diffusion equation allows us to qualitatively understand the observed kinetics and demonstrates why high-capacity electrodes are more prone to inhomogeneous lithiation reactions. PMID:27324109

Combining operando synchrotron X-ray tomographic microscopy and scanning X-ray diffraction to study lithium ion batteries

NASA Astrophysics Data System (ADS)

Pietsch, Patrick; Hess, Michael; Ludwig, Wolfgang; Eller, Jens; Wood, Vanessa

2016-06-01

We present an operando study of a lithium ion battery combining scanning X-ray diffraction (SXRD) and synchrotron radiation X-ray tomographic microscopy (SRXTM) simultaneously for the first time. This combination of techniques facilitates the investigation of dynamic processes in lithium ion batteries containing amorphous and/or weakly attenuating active materials. While amorphous materials pose a challenge for diffraction techniques, weakly attenuating material systems pose a challenge for attenuation-contrast tomography. Furthermore, combining SXRD and SRXTM can be used to correlate processes occurring at the atomic level in the crystal lattices of the active materials with those at the scale of electrode microstructure. To demonstrate the benefits of this approach, we investigate a silicon powder electrode in lithium metal half-cell configuration. Combining SXRD and SRXTM, we are able to (i) quantify the dissolution of the metallic lithium electrode and the expansion of the silicon electrode, (ii) better understand the formation of the Li15Si4 phase, and (iii) non-invasively probe kinetic limitations within the silicon electrode. A simple model based on the 1D diffusion equation allows us to qualitatively understand the observed kinetics and demonstrates why high-capacity electrodes are more prone to inhomogeneous lithiation reactions.

A driving simulator study : evaluation of vehicle mounted attenuator markings in work zones during different times of the day.

DOT National Transportation Integrated Search

2010-09-01

This report presents a study of driver perceptions using a driving simulator carried out on the : effectiveness of four markings which vary in striping patterns and color combinations used at the : rear of vehicle mounted attenuators (VMAs) in work z...

The temperature-sensitive and attenuation phenotypes conferred by mutations in the influenza virus PB2, PB1, and NP genes are influenced by the species of origin of the PB2 gene in reassortant viruses derived from influenza A/California/07/2009 and A/WSN/33 viruses.

PubMed

Broadbent, Andrew J; Santos, Celia P; Godbout, Rachel A; Subbarao, Kanta

2014-11-01

Live attenuated influenza vaccines in the United States are derived from a human virus that is temperature sensitive (ts), characterized by restricted (≥ 100-fold) replication at 39 °C. The ts genetic signature (ts sig) has been mapped to 5 loci in 3 genes: PB1 (391 E, 581 G, and 661 T), PB2 (265 S), and NP (34 G). However, when transferred into avian and swine influenza viruses, only partial ts and attenuation phenotypes occur. To investigate the reason for this, we introduced the ts sig into the human origin virus A/WSN/33 (WSN), the avian-origin virus A/Vietnam/1203/04 (VN04), and the swine origin triple-reassortant 2009 pandemic H1N1 virus A/California/07/2009 (CA07), which contains gene segments from human, avian, and swine viruses. The VN04(ts sig) and CA07(ts sig) viruses replicated efficiently in Madin-Darby canine kidney (MDCK) cells at 39 °C, but the replication of WSN(ts sig) was restricted ≥ 100-fold compared to that at 33 °C. Reassortant CA07(ts sig) viruses were generated with individual polymerase gene segments from WSN, and vice versa. Only ts sig viruses with a PB2 gene segment derived from WSN were restricted in replication ≥ 100-fold at 39 °C. In ferrets, the CA07(ts sig) virus replicated in the upper and lower respiratory tract, but the replication of a reassortant CA07(ts sig) virus with a WSN PB2 gene was severely restricted in the lungs. Taken together, these data suggest that the origin of the PB2 gene segment influences the ts phenotype in vitro and attenuation in vivo. This could have implications for the design of novel live vaccines against animal origin influenza viruses. Live attenuated influenza vaccines (LAIVs) on temperature-sensitive (ts) backbones derived from animal origin influenza viruses are being sought for use in the poultry and swine industries and to protect people against animal origin influenza. However, inserting the ts genetic signature from a licensed LAIV backbone fails to fully attenuate these viruses. Our data indicate this is associated with the presence of a PB2 gene segment derived from an avian influenza virus. We show that a reassortant 2009 pandemic H1N1 virus with the ts signature from a licensed LAIV donor virus is ts in vitro and attenuated in vivo when the PB2 gene is derived from a human origin virus but not from an avian virus. Our study provides information that could benefit the rational design of alternative LAIV backbones against animal origin influenza viruses. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

The Temperature-Sensitive and Attenuation Phenotypes Conferred by Mutations in the Influenza Virus PB2, PB1, and NP Genes Are Influenced by the Species of Origin of the PB2 Gene in Reassortant Viruses Derived from Influenza A/California/07/2009 and A/WSN/33 Viruses

PubMed Central

Broadbent, Andrew J.; Santos, Celia P.; Godbout, Rachel A.

2014-01-01

ABSTRACT Live attenuated influenza vaccines in the United States are derived from a human virus that is temperature sensitive (ts), characterized by restricted (≥100-fold) replication at 39°C. The ts genetic signature (ts sig) has been mapped to 5 loci in 3 genes: PB1 (391E, 581G, and 661T), PB2 (265S), and NP (34G). However, when transferred into avian and swine influenza viruses, only partial ts and attenuation phenotypes occur. To investigate the reason for this, we introduced the ts sig into the human origin virus A/WSN/33 (WSN), the avian-origin virus A/Vietnam/1203/04 (VN04), and the swine origin triple-reassortant 2009 pandemic H1N1 virus A/California/07/2009 (CA07), which contains gene segments from human, avian, and swine viruses. The VN04ts sig and CA07ts sig viruses replicated efficiently in Madin-Darby canine kidney (MDCK) cells at 39°C, but the replication of WSNts sig was restricted ≥100-fold compared to that at 33°C. Reassortant CA07ts sig viruses were generated with individual polymerase gene segments from WSN, and vice versa. Only ts sig viruses with a PB2 gene segment derived from WSN were restricted in replication ≥100-fold at 39°C. In ferrets, the CA07ts sig virus replicated in the upper and lower respiratory tract, but the replication of a reassortant CA07ts sig virus with a WSN PB2 gene was severely restricted in the lungs. Taken together, these data suggest that the origin of the PB2 gene segment influences the ts phenotype in vitro and attenuation in vivo. This could have implications for the design of novel live vaccines against animal origin influenza viruses. IMPORTANCE Live attenuated influenza vaccines (LAIVs) on temperature-sensitive (ts) backbones derived from animal origin influenza viruses are being sought for use in the poultry and swine industries and to protect people against animal origin influenza. However, inserting the ts genetic signature from a licensed LAIV backbone fails to fully attenuate these viruses. Our data indicate this is associated with the presence of a PB2 gene segment derived from an avian influenza virus. We show that a reassortant 2009 pandemic H1N1 virus with the ts signature from a licensed LAIV donor virus is ts in vitro and attenuated in vivo when the PB2 gene is derived from a human origin virus but not from an avian virus. Our study provides information that could benefit the rational design of alternative LAIV backbones against animal origin influenza viruses. PMID:25122786

[Immune Response of Recombinant Pseudorabies Virus rPRV-VP2 Expressing VP2 Gene of Porcine Parvovirus in Mice].

PubMed

Fu, Pengfei; Pan, Xinlong; Han, Qiao; Yang, Xingwu; Zhu, Qianlei; Guo, Xiaoqing; Zhang, Yu; Chen, Hongying

2016-03-01

In order to develop a combined live vaccine that will be used to prevent against porcine parvovirus (PPV) and Pseudorabies virus (PRV) infection, the VP2 gene of PPV was inserted into the transfer vector plasmid pG to produce the recombinant plasmid pGVP2. The plasmid pGVP2 and the genome of PRV HB98 attenuated vaccine were transfected by using lipofectamine into swine testis cells for the homologous recombination. The recombinant virus rPRV-VP2 was purified by selection of green fluorescence plaques for five cycles. 6-week-old female Kunming mice were immunized intramuscularly with attenuated PRV parent HB98 strain, commercial inactivated vaccine against PPV, recombinant virus, DMEM culture solution. The injections were repeated with an equivalent dose after 2 weeks in all of the groups, and then challenged with the virulent PRV NY strain at 7 weeks after the first immunization. The recombinant virus rPRV-VP2 was successfully generated, and the recombinant virus could effectively elicite anti-PPV and PRV antibody and significant cellular immune response as indicated by anti-PPV ELISA and HI, PRV-neutralizing assay and flow cytometry. The challenge assay indicated that recombinant virus could protect the mice against the virulent PRV challenge. These results demonstrated that the recombinant virus can be a candidate recombinant vaccine strain for the prevention of PRV and PPV.

Quantitative Determination of Lethal Toxin Proteins in Culture Supernatant of Human Live Anthrax Vaccine Bacillus anthracis A16R.

PubMed

Zai, Xiaodong; Zhang, Jun; Liu, Ju; Liu, Jie; Li, Liangliang; Yin, Ying; Fu, Ling; Xu, Junjie; Chen, Wei

2016-02-25

Bacillus anthracis (B. anthracis) is the etiological agent of anthrax affecting both humans and animals. Anthrax toxin (AT) plays a major role in pathogenesis. It includes lethal toxin (LT) and edema toxin (ET), which are formed by the combination of protective antigen (PA) and lethal factor (LF) or edema factor (EF), respectively. The currently used human anthrax vaccine in China utilizes live-attenuated B. anthracis spores (A16R; pXO1+, pXO2-) that produce anthrax toxin but cannot produce the capsule. Anthrax toxins, especially LT, have key effects on both the immunogenicity and toxicity of human anthrax vaccines. Thus, determining quantities and biological activities of LT proteins expressed by the A16R strain is meaningful. Here, we explored LT expression patterns of the A16R strain in culture conditions using another vaccine strain Sterne as a control. We developed a sandwich ELISA and cytotoxicity-based method for quantitative detection of PA and LF. Expression and degradation of LT proteins were observed in culture supernatants over time. Additionally, LT proteins expressed by the A16R and Sterne strains were found to be monomeric and showed cytotoxic activity, which may be the main reason for side effects of live anthrax vaccines. Our work facilitates the characterization of anthrax vaccines components and establishment of a quality control standard for vaccine production which may ultimately help to ensure the efficacy and safety of the human anthrax vaccine A16R.

Intranasal Inactivated Influenza Vaccines: a Reasonable Approach to Improve the Efficacy of Influenza Vaccine?

PubMed

Tamura, Shin-Ichi; Ainai, Akira; Suzuki, Tadaki; Kurata, Takeshi; Hasegawa, Hideki

2016-01-01

Influenza is a contagious, acute respiratory disease caused by the influenza virus. The mucosal lining in the host respiratory tract is not only the site of virus infection, but also the site of defense; it is at this site that the host immune response targets the virus and protects against reinfection. One of the most effective methods to prevent influenza is to induce specific antibody (Ab) responses in the respiratory tract by vaccination. Two types of influenza vaccines, intranasal live attenuated influenza virus (LAIV) vaccines and parenteral (injectable) inactivated vaccines, are currently used worldwide. These vaccines are approved by the European Medicines Agency (EMA) and the US Food and Drug Administration. Live attenuated vaccines induce both secretory IgA (S-IgA) and serum IgG antibodies (Abs), whereas parenteral vaccines induce only serum IgG Abs. However, intranasal administration of inactivated vaccines together with an appropriate adjuvant induces both S-IgA and IgG Abs. Several preclinical studies on adjuvant-combined, nasal-inactivated vaccines revealed that nasal S-IgA Abs, a major immune component in the upper respiratory tract, reacted with homologous virus hemagglutinin (HA) and were highly cross-reactive with viral HA variants, resulting in protection and cross-protection against infection by both homologous and variant viruses, respectively. Serum-derived IgG Abs, which are present mainly in the lower respiratory tract, are less cross-reactive and cross-protective. In addition, our own clinical trials have shown that nasal-inactivated whole virus vaccines, including a built-in adjuvant (single-stranded RNA), induced serum hemagglutination inhibition (HI) Ab titers that fulfilled the EMA criteria for vaccine efficacy. The nasal-inactivated whole virus vaccines also induced high levels of nasal HI and neutralizing Ab titers, although we have not yet evaluated the nasal HI titers due to the lack of official criteria to establish efficacy based on this parameter. Data suggest that adjuvant-combined nasal-inactivated vaccines have advantages over the current injectable vaccine because the former induce both S-IgA and serum IgG Abs. In addition, nasal-inactivated vaccines seem to be superior to the LAIV vaccines, because non-infectious preparations could be used in high-risk groups. Thus, the development of intranasal inactivated vaccines is recommended, because such vaccines are expected to improve the efficacy of influenza vaccines.

The High Degree of Sequence Plasticity of the Arenavirus Noncoding Intergenic Region (IGR) Enables the Use of a Nonviral Universal Synthetic IGR To Attenuate Arenaviruses

PubMed Central

Iwasaki, Masaharu; Cubitt, Beatrice; Sullivan, Brian M.

2016-01-01

ABSTRACT Hemorrhagic fever arenaviruses (HFAs) pose important public health problems in regions where they are endemic. Concerns about human-pathogenic arenaviruses are exacerbated because of the lack of FDA-licensed arenavirus vaccines and because current antiarenaviral therapy is limited to an off-label use of ribavirin that is only partially effective. We have recently shown that the noncoding intergenic region (IGR) present in each arenavirus genome segment, the S and L segments (S-IGR and L-IGR, respectively), plays important roles in the control of virus protein expression and that this knowledge could be harnessed for the development of live-attenuated vaccine strains to combat HFAs. In this study, we further investigated the sequence plasticity of the arenavirus IGR. We demonstrate that recombinants of the prototypic arenavirus lymphocytic choriomeningitis virus (rLCMVs), whose S-IGRs were replaced by the S-IGR of Lassa virus (LASV) or an entirely nonviral S-IGR-like sequence (Ssyn), are viable, indicating that the function of S-IGR tolerates a high degree of sequence plasticity. In addition, rLCMVs whose L-IGRs were replaced by Ssyn or S-IGRs of the very distantly related reptarenavirus Golden Gate virus (GGV) were viable and severely attenuated in vivo but able to elicit protective immunity against a lethal challenge with wild-type LCMV. Our findings indicate that replacement of L-IGR by a nonviral Ssyn could serve as a universal molecular determinant of arenavirus attenuation. IMPORTANCE Hemorrhagic fever arenaviruses (HFAs) cause high rates of morbidity and mortality and pose important public health problems in regions where they are endemic. Implementation of live-attenuated vaccines (LAVs) will represent a major step to combat HFAs. Here we document that the arenavirus noncoding intergenic region (IGR) has a high degree of plasticity compatible with virus viability. This observation led us to generate recombinant LCMVs containing nonviral synthetic IGRs. These rLCMVs were severely attenuated in vivo but able to elicit protective immunity against a lethal challenge with wild-type LCMV. These nonviral synthetic IGRs can be used as universal molecular determinants of arenavirus attenuation for the rapid development of safe and effective, as well as stable, LAVs to combat HFA. PMID:26739049

Effects of environmental tobacco smoke on nasal responses to live attenuated influenza virus

EPA Science Inventory

Background: Published and preliminary data in our laboratory suggest that airborne pollutants including tobacco smoke increase susceptibility of respiratory epithelium to infection with influenza A. However, no studies have specifically looked at the interaction between tobacco s...

Developing live bacterial vaccines by selecting resistance to antibacterials

USDA-ARS?s Scientific Manuscript database

Four chemicals were used in this study to modify bacterial isolates through chemical-resistance strategy. All bacteria were able to develop high resistance to gossypol. However, none of the gossypol-resistant isolate was attenuated. Although majority of the proflavine hemisulfate-resistant isolates ...

Lifetime measurements of high-lying short lived states in {sup 69}As

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matejska-Minda, M.; Bednarczyk, P.; Fornal, B.

2012-10-20

Lifetimes of high-spin states in {sup 69}As have been measured using Doppler shift attenuation technique with the GASP and RFD setup. The determined transition probabilities indicate large deformation associated with some rotational bands in this nucleus.

Recent Developments in Livestock and Wildlife Brucellosis Vaccination

USDA-ARS?s Scientific Manuscript database

Live attenuated brucellosis vaccines have been available for protecting domestic livestock against B. melitensis or B. abortus for more than 60 years. Current vaccines are effective in preventing abortion and transmission of brucellosis, but poor at preventing infection or seroconversion. In addit...

High-Throughput, Signature-Tagged Mutagenic Approach To Identify Novel Virulence Factors of Yersinia pestis CO92 in a Mouse Model of Infection

PubMed Central

Ponnusamy, Duraisamy; Fitts, Eric C.; Erova, Tatiana E.; Kozlova, Elena V.; Kirtley, Michelle L.; Tiner, Bethany L.; Andersson, Jourdan A.

2015-01-01

The identification of new virulence factors in Yersinia pestis and understanding their molecular mechanisms during an infection process are necessary in designing a better vaccine or to formulate an appropriate therapeutic intervention. By using a high-throughput, signature-tagged mutagenic approach, we created 5,088 mutants of Y. pestis strain CO92 and screened them in a mouse model of pneumonic plague at a dose equivalent to 5 50% lethal doses (LD50) of wild-type (WT) CO92. From this screen, we obtained 118 clones showing impairment in disseminating to the spleen, based on hybridization of input versus output DNA from mutant pools with 53 unique signature tags. In the subsequent screen, 20/118 mutants exhibited attenuation at 8 LD50 when tested in a mouse model of bubonic plague, with infection by 10/20 of the aforementioned mutants resulting in 40% or higher survival rates at an infectious dose of 40 LD50. Upon sequencing, six of the attenuated mutants were found to carry interruptions in genes encoding hypothetical proteins or proteins with putative functions. Mutants with in-frame deletion mutations of two of the genes identified from the screen, namely, rbsA, which codes for a putative sugar transport system ATP-binding protein, and vasK, a component of the type VI secretion system, were also found to exhibit some attenuation at 11 or 12 LD50 in a mouse model of pneumonic plague. Likewise, among the remaining 18 signature-tagged mutants, 9 were also attenuated (40 to 100%) at 12 LD50 in a pneumonic plague mouse model. Previously, we found that deleting genes encoding Braun lipoprotein (Lpp) and acyltransferase (MsbB), the latter of which modifies lipopolysaccharide function, reduced the virulence of Y. pestis CO92 in mouse models of bubonic and pneumonic plague. Deletion of rbsA and vasK genes from either the Δlpp single or the Δlpp ΔmsbB double mutant augmented the attenuation to provide 90 to 100% survivability to mice in a pneumonic plague model at 20 to 50 LD50. The mice infected with the Δlpp ΔmsbB ΔrbsA triple mutant at 50 LD50 were 90% protected upon subsequent challenge with 12 LD50 of WT CO92, suggesting that this mutant or others carrying combinational deletions of genes identified through our screen could potentially be further tested and developed into a live attenuated plague vaccine(s). PMID:25754198

High-throughput, signature-tagged mutagenic approach to identify novel virulence factors of Yersinia pestis CO92 in a mouse model of infection.

PubMed

Ponnusamy, Duraisamy; Fitts, Eric C; Sha, Jian; Erova, Tatiana E; Kozlova, Elena V; Kirtley, Michelle L; Tiner, Bethany L; Andersson, Jourdan A; Chopra, Ashok K

2015-05-01

The identification of new virulence factors in Yersinia pestis and understanding their molecular mechanisms during an infection process are necessary in designing a better vaccine or to formulate an appropriate therapeutic intervention. By using a high-throughput, signature-tagged mutagenic approach, we created 5,088 mutants of Y. pestis strain CO92 and screened them in a mouse model of pneumonic plague at a dose equivalent to 5 50% lethal doses (LD50) of wild-type (WT) CO92. From this screen, we obtained 118 clones showing impairment in disseminating to the spleen, based on hybridization of input versus output DNA from mutant pools with 53 unique signature tags. In the subsequent screen, 20/118 mutants exhibited attenuation at 8 LD50 when tested in a mouse model of bubonic plague, with infection by 10/20 of the aforementioned mutants resulting in 40% or higher survival rates at an infectious dose of 40 LD50. Upon sequencing, six of the attenuated mutants were found to carry interruptions in genes encoding hypothetical proteins or proteins with putative functions. Mutants with in-frame deletion mutations of two of the genes identified from the screen, namely, rbsA, which codes for a putative sugar transport system ATP-binding protein, and vasK, a component of the type VI secretion system, were also found to exhibit some attenuation at 11 or 12 LD50 in a mouse model of pneumonic plague. Likewise, among the remaining 18 signature-tagged mutants, 9 were also attenuated (40 to 100%) at 12 LD50 in a pneumonic plague mouse model. Previously, we found that deleting genes encoding Braun lipoprotein (Lpp) and acyltransferase (MsbB), the latter of which modifies lipopolysaccharide function, reduced the virulence of Y. pestis CO92 in mouse models of bubonic and pneumonic plague. Deletion of rbsA and vasK genes from either the Δlpp single or the Δlpp ΔmsbB double mutant augmented the attenuation to provide 90 to 100% survivability to mice in a pneumonic plague model at 20 to 50 LD50. The mice infected with the Δlpp ΔmsbB ΔrbsA triple mutant at 50 LD50 were 90% protected upon subsequent challenge with 12 LD50 of WT CO92, suggesting that this mutant or others carrying combinational deletions of genes identified through our screen could potentially be further tested and developed into a live attenuated plague vaccine(s). Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Progress Toward Cleanup of Operable Unit 1 Groundwater at the US DOE Mound, Ohio, Site: Success of a Phase-Combined Remedy – 15310

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hooten, Gwendolyn; Cato, Rebecca; Looney, Brian

2015-03-01

Operable Unit 1 (OU-1) soil and groundwater have been affected by volatile organic compounds (VOC) Present groundwater remedy is collection, treatment, and disposal (pump and treat [P&T]) Several combinations of technologies were used to address soil and groundwater contamination Monitored natural attenuation (MNA) is a viable alternative Majority of source term has been excavated VOC concentrations in groundwater have decreased Attenuation mechanisms have been observed in the subsurface at OU-1

The effect of intrinsic attenuation correction methods on the stationarity of the 3-D modulation transfer function of SPECT.

PubMed

Glick, S J; Hawkins, W G; King, M A; Penney, B C; Soares, E J; Byrne, C L

1992-01-01

The application of stationary restoration techniques to SPECT images assumes that the modulation transfer function (MTF) of the imaging system is shift invariant. It was hypothesized that using intrinsic attenuation correction (i.e., methods which explicitly invert the exponential radon transform) would yield a three-dimensional (3-D) MTF which varies less with position within the transverse slices than the combined conjugate view two-dimensional (2-D) MTF varies with depth. Thus the assumption of shift invariance would become less of an approximation for 3-D post- than for 2-D pre-reconstruction restoration filtering. SPECT acquisitions were obtained from point sources located at various positions in three differently shaped, water-filled phantoms. The data were reconstructed with intrinsic attenuation correction, and 3-D MTFs were calculated. Four different intrinsic attenuation correction methods were compared: (1) exponentially weighted backprojection, (2) a modified exponentially weighted backprojection as described by Tanaka et al. [Phys. Med. Biol. 29, 1489-1500 (1984)], (3) a Fourier domain technique as described by Bellini et al. [IEEE Trans. ASSP 27, 213-218 (1979)], and (4) the circular harmonic transform (CHT) method as described by Hawkins et al. [IEEE Trans. Med. Imag. 7, 135-148 (1988)]. The dependence of the 3-D MTF obtained with these methods, on point source location within an attenuator, and on shape of the attenuator, was studied. These 3-D MTFs were compared to: (1) those MTFs obtained with no attenuation correction, and (2) the depth dependence of the arithmetic mean combined conjugate view 2-D MTFs.(ABSTRACT TRUNCATED AT 250 WORDS)

Oral administration of live- or heat-killed Candida albicans worsened cecal ligation and puncture sepsis in a murine model possibly due to an increased serum (1→3)-β-D-glucan.

PubMed

Panpetch, Wimonrat; Somboonna, Naraporn; Bulan, Dewi Embong; Issara-Amphorn, Jiraphorn; Finkelman, Malcolm; Worasilchai, Navaporn; Chindamporn, Ariya; Palaga, Tanapat; Tumwasorn, Somying; Leelahavanichkul, Asada

2017-01-01

Candida albicans is the most common fungus in the human intestinal microbiota but not in mice. To make a murine sepsis model more closely resemble human sepsis and to explore the role of intestinal C. albicans, in the absence of candidemia, in bacterial sepsis, live- or heat-killed C. albicans was orally administered to mice at 3h prior to cecal ligation and puncture (CLP). A higher mortality rate of CLP was demonstrated with Candida-administration (live- or heat-killed) prior to CLP. Fecal Candida presented only in experiments with live-Candida administration. Despite the absence of candidemia, serum (1→3)-β-D-glucan (BG) was higher in CLP with Candida-administration than CLP-controls (normal saline administration) at 6h and/or 18h post-CLP. Interestingly, fluconazole attenuated the fecal Candida burden and improved survival in mice with live-Candida administration, but not CLP-control. Microbiota analysis revealed increased Bacteroides spp. and reduced Lactobacillus spp. in feces after Candida administration. Additionally, synergy in the elicitation of cytokine production from bone marrow-derived macrophages, in vitro, was demonstrated by co-exposure to heat-killed E. coli and BG. In conclusion, intestinal abundance of fungi and/or fungal-molecules was associated with increased bacterial sepsis-severity, perhaps through enhanced cytokine elicitation induced by synergistic responses to molecules from gut-derived bacteria and fungi. Conversely, reducing intestinal fungal burdens decreased serum BG and attenuated sepsis in our model.

[PERSPECTIVES OF DEVELOPMENT OF LIVE RECOMBINANT ANTHRAX VACCINES BASED ON OPPORTUNISTIC AND APATHOGENIC MICROORGANISMS].

PubMed

Popova, P Yu; Mikshis, N I

2016-01-01

Live genetic engineering anthrax vaccines on the platform of avirulent and probiotic micro-organisms are a safe and adequate alternative to preparations based on attenuated Bacillus anthracis strains. Mucosal application results in a direct contact of the vaccine preparations with mucous membranes in those organs arid tissues of the macro-organisms, that are exposed to the pathogen in the first place, resulting in a development of local and systemic immune response. Live recombinant anthrax vaccines could be used both separately as well as in a prime-boost immunization scheme. The review focuses on immunogenic and protective properties of experimental live genetic engineering prearations, created based on members of geni of Salmonella, Lactobacillus and adenoviruses.

Wavelength tunable and broadband variable fiber-optic attenuators using liquid crystals

NASA Astrophysics Data System (ADS)

Khan, Sajjad A.; Riza, Nabeel A.

2005-05-01

Fiber-Optic Variable Optical Attenuators (VOAs) are demonstrated using Liquid Crystals (LC) for broadband as well as wavelength tunable applications. Attenuation is achieved by using a beam spoiling approach implemented via electrically reconfigurable non-pixelated no moving parts Nematic LC deflectors. The VOAs feature in-line architecture and polarization insensitive design without the use of bulky polarization splitting and combining optics. The proof-of-concept VOAs in the 1550 nm band demonstrate >30 dB attenuation ranges, low polarization dependent losses and low power consumption. Applications for these VOAs include agile wavelength tunable secure data communications networks and RF sensor systems.

Vaccine and Wild-Type Strains of Yellow Fever Virus Engage Distinct Entry Mechanisms and Differentially Stimulate Antiviral Immune Responses.

PubMed

Fernandez-Garcia, Maria Dolores; Meertens, Laurent; Chazal, Maxime; Hafirassou, Mohamed Lamine; Dejarnac, Ophélie; Zamborlini, Alessia; Despres, Philippe; Sauvonnet, Nathalie; Arenzana-Seisdedos, Fernando; Jouvenet, Nolwenn; Amara, Ali

2016-02-09

The live attenuated yellow fever virus (YFV) vaccine 17D stands as a "gold standard" for a successful vaccine. 17D was developed empirically by passaging the wild-type Asibi strain in mouse and chicken embryo tissues. Despite its immense success, the molecular determinants for virulence attenuation and immunogenicity of the 17D vaccine are poorly understood. 17D evolved several mutations in its genome, most of which lie within the envelope (E) protein. Given the major role played by the YFV E protein during virus entry, it has been hypothesized that the residues that diverge between the Asibi and 17D E proteins may be key determinants of attenuation. In this study, we define the process of YFV entry into target cells and investigate its implication in the activation of the antiviral cytokine response. We found that Asibi infects host cells exclusively via the classical clathrin-mediated endocytosis, while 17D exploits a clathrin-independent pathway for infectious entry. We demonstrate that the mutations in the 17D E protein acquired during the attenuation process are sufficient to explain the differential entry of Asibi versus 17D. Interestingly, we show that 17D binds to and infects host cells more efficiently than Asibi, which culminates in increased delivery of viral RNA into the cytosol and robust activation of the cytokine-mediated antiviral response. Overall, our study reveals that 17D vaccine and Asibi enter target cells through distinct mechanisms and highlights a link between 17D attenuation, virus entry, and immune activation. The yellow fever virus (YFV) vaccine 17D is one of the safest and most effective live virus vaccines ever developed. The molecular determinants for virulence attenuation and immunogenicity of 17D are poorly understood. 17D was generated by serially passaging the virulent Asibi strain in vertebrate tissues. Here we examined the entry mechanisms engaged by YFV Asibi and the 17D vaccine. We found the two viruses use different entry pathways. We show that the mutations differentiating the Asibi envelope (E) protein from the 17D E protein, which arose during attenuation, are key determinants for the use of these distinct entry routes. Finally, we demonstrate that 17D binds and enters host cells more efficiently than Asibi. This results in a higher uptake of viral RNA into the cytoplasm and consequently a greater cytokine-mediated antiviral response. Overall, our data provide new insights into the biology of YFV infection and the mechanisms of viral attenuation. Copyright © 2016 Fernandez-Garcia et al.

Attenuation and Restoration of Severe Acute Respiratory Syndrome Coronavirus Mutant Lacking 2′-O-Methyltransferase Activity

PubMed Central

Menachery, Vineet D.; Yount, Boyd L.; Josset, Laurence; Gralinski, Lisa E.; Scobey, Trevor; Agnihothram, Sudhakar; Katze, Michael G.

2014-01-01

ABSTRACT The sudden emergence of severe acute respiratory syndrome coronavirus (SARS-CoV) in 2002 and, more recently, Middle Eastern respiratory syndrome CoV (MERS-CoV) underscores the importance of understanding critical aspects of CoV infection and pathogenesis. Despite significant insights into CoV cross-species transmission, replication, and virus-host interactions, successful therapeutic options for CoVs do not yet exist. Recent identification of SARS-CoV NSP16 as a viral 2′-O-methyltransferase (2′-O-MTase) led to the possibility of utilizing this pathway to both attenuate SARS-CoV infection and develop novel therapeutic treatment options. Mutations were introduced into SARS-CoV NSP16 within the conserved KDKE motif and effectively attenuated the resulting SARS-CoV mutant viruses both in vitro and in vivo. While viruses lacking 2′-O-MTase activity had enhanced sensitivity to type I interferon (IFN), they were not completely restored in their absence in vivo. However, the absence of either MDA5 or IFIT1, IFN-responsive genes that recognize unmethylated 2′-O RNA, resulted in restored replication and virulence of the dNSP16 mutant virus. Finally, using the mutant as a live-attenuated vaccine showed significant promise for possible therapeutic development against SARS-CoV. Together, the data underscore the necessity of 2′-O-MTase activity for SARS-CoV pathogenesis and identify host immune pathways that mediate this attenuation. In addition, we describe novel treatment avenues that exploit this pathway and could potentially be used against a diverse range of viral pathogens that utilize 2′-O-MTase activity to subvert the immune system. IMPORTANCE Preventing recognition by the host immune response represents a critical aspect necessary for successful viral infection. Several viruses, including SARS-CoV, utilize virally encoded 2′-O-MTases to camouflage and obscure their viral RNA from host cell sensing machinery, thus preventing recognition and activation of cell intrinsic defense pathways. For SARS-CoV, the absence of this 2′-O-MTase activity results in significant attenuation characterized by decreased viral replication, reduced weight loss, and limited breathing dysfunction in mice. The results indicate that both MDA5, a recognition molecule, and the IFIT family play an important role in mediating this attenuation with restored virulence observed in their absence. Understanding this virus-host interaction provided an opportunity to design a successful live-attenuated vaccine for SARS-CoV and opens avenues for treatment and prevention of emerging CoVs and other RNA virus infections. PMID:24478444

Japanese encephalitis vaccines: current vaccines and future prospects.

PubMed

Monath, T P

2002-01-01

Vaccination against JE ideally should be practiced in all areas of Asia where the virus is responsible for human disease. The WHO has placed a high priority on the development of a new vaccine for prevention of JE. Some countries in Asia (Japan, South Korea, North Korea, Taiwan, Vietnam, Thailand, and the PRC) manufacture JE vaccines and practice childhood immunization, while other countries suffering endemic or epidemic disease (India, Nepal, Laos, Cambodia, Bangladesh, Myanmar, Malaysia, Indonesia and the Philippines) have no JE vaccine manufacturing or policy for use. With the exception of the PRC, all countries practicing JE vaccination use formalin inactivated mouse brain vaccines, which are relatively expensive and are associated with rare but clinically significant allergic and neurological adverse events. New inactivated JE vaccines manufactured in Vero cells are in advanced preclinical or early clinical development in Japan, South Korea, Taiwan, and the PRC. An empirically derived, live attenuated vaccine (SA14-14-2) is widely used in the PRC. Trials in the PRC have shown SA14-14-2 to be safe and effective when administered in a two-dose regimen, but regulatory concerns over manufacturing and control have restricted international distribution. The genetic basis of attenuation of SA14-14-2 has been partially defined. A new live attenuated vaccine (ChimeriVax-JE) that uses a reliable flavivirus vaccine--yellow fever 17D--as a live vector for the envelope genes of SA14-14-2 virus is in early clinical trials and appears to be well tolerated and immunogenic after a single dose. Vaccinia and avipox vectored vaccines have also been tested clinically, but are no longer being pursued due to restricted effectiveness mediated by anti-vector immunity. Other approaches to JE vaccines--including naked DNA, oral vaccination, and recombinant subunit vaccines--have been reviewed.

Concomitant or sequential administration of live attenuated Japanese encephalitis chimeric virus vaccine and yellow fever 17D vaccine: randomized double-blind phase II evaluation of safety and immunogenicity.

PubMed

Nasveld, Peter E; Marjason, Joanne; Bennett, Sonya; Aaskov, John; Elliott, Suzanne; McCarthy, Karen; Kanesa-Thasan, Niranjan; Feroldi, Emmanuel; Reid, Mark

2010-11-01

A randomized, double-blind, study was conducted to evaluate the safety, tolerability and immunogenicity of a live attenuated Japanese encephalitis chimeric virus vaccine (JE-CV) co-administered with live attenuated yellow fever vaccine (YF-17D strain; Stamaril®, Sanofi Pasteur) or administered successively. Participants (n = 108) were randomized to receive: YF followed by JE-CV 30 days later, JE followed by YF 30 days later, or the co-administration of JE and YF followed or preceded by placebo 30 days later or earlier. Placebo was used in a double-dummy fashion to ensure masking. Neutralizing antibody titers against JE-CV, YF-17D and selected wild-type JE strains was determined using a 50% serum-dilution plaque reduction neutralization test. Seroconversion was defined as the appearance of a neutralizing antibody titer above the assay cut-off post-immunization when not present pre-injection at day 0, or a least a four-fold rise in neutralizing antibody titer measured before the pre-injection day 0 and later post vaccination samples. There were no serious adverse events. Most adverse events (AEs) after JE vaccination were mild to moderate in intensity, and similar to those reported following YF vaccination. Seroconversion to JE-CV was 100% and 91% in the JE/YF and YF/JE sequential vaccination groups, respectively, compared with 96% in the co-administration group. All participants seroconverted to YF vaccine and retained neutralizing titers above the assay cut-off at month six. Neutralizing antibodies against JE vaccine were detected in 82-100% of participants at month six. These results suggest that both vaccines may be successfully co-administered simultaneously or 30 days apart.

O-Serotype Conversion in Salmonella Typhimurium Induces Protective Immune Responses against Invasive Non-Typhoidal Salmonella Infections.

PubMed

Li, Pei; Liu, Qing; Luo, Hongyan; Liang, Kang; Yi, Jie; Luo, Ying; Hu, Yunlong; Han, Yue; Kong, Qingke

2017-01-01

Salmonella infections remain a big problem worldwide, causing enteric fever by Salmonella Typhi (or Paratyphi) or self-limiting gastroenteritis by non-typhoidal Salmonella (NTS) in healthy individuals. NTS may become invasive and cause septicemia in elderly or immuno-compromised individuals, leading to high mortality and morbidity. No vaccines are currently available for preventing NTS infection in human. As these invasive NTS are restricted to several O-antigen serogroups including B1, D1, C1, and C2, O-antigen polysaccharide is believed to be a good target for vaccine development. In this study, a strategy of O-serotype conversion was investigated to develop live attenuated S . Typhimurium vaccines against the major serovars of NTS infections. The immunodominant O4 serotype of S . Typhimurium was converted into O9, O7, and O8 serotypes through unmarked chromosomal deletion-insertion mutations. O-serotype conversion was confirmed by LPS silver staining and western blotting. All O-serotype conversion mutations were successfully introduced into the live attenuated S . Typhimurium vaccine S738 (Δ crp Δ cya ) to evaluate their immunogenicity in mice model. The vaccine candidates induced high amounts of heterologous O-polysaccharide-specific functional IgG responses. Vaccinated mice survived a challenge of 100 times the 50% lethality dose (LD 50 ) of wild-type S . Typhimurium. Protective efficacy against heterologous virulent Salmonella challenges was highly O-serotype related. Furthermore, broad-spectrum protection against S . Typhimurium, S . Enteritidis, and S . Choleraesuis was observed by co-vaccination of O9 and O7 O-serotype-converted vaccine candidates. This study highlights the strategy of expressing heterologous O-polysaccharides via genetic engineering in developing live attenuated S . Typhimurium vaccines against NTS infections.

Concomitant or sequential administration of live attenuated japanese encephalitis chimeric virus vaccine and yellow fever 17D vaccine

PubMed Central

Nasveld, Peter E; Marjason, Joanne; Bennett, Sonya; Aaskov, John; Elliott, Suzanne; McCarthy, Karen; Kanesa-thasan, Niranjan; Feroldi, Emmanuel

2010-01-01

A randomized, double-blind, study was conducted to evaluate the safety, tolerability and immunogenicity of a live attenuated Japanese encephalitis chimeric virus vaccine (JE-CV) co-administered with live attenuated yellow fever (YF) vaccine (YF-17D strain; Stamaril®, Sanofi Pasteur) or administered sequentially. Participants (n = 108) were randomized to receive: YF followed by JE-CV 30 days later, JE followed by YF 30 days later, or the co-administration of JE and YF followed or preceded by placebo 30 days later or earlier. Placebo was used in a double-dummy fashion to ensure masking. Neutralizing antibody titers against JE-CV, YF-17D and selected wild-type JE virus strains was determined using a 50% serum-dilution plaque reduction neutralization test (PRNT50). Seroconversion was defined as the appearance of a neutralizing antibody titer above the assay cut-off post-immunization when not present pre-injection at day 0, or a least a four-fold rise in neutralizing antibody titer measured before the pre-injection day 0 and later post vaccination samples. There were no serious adverse events. Most adverse events (AEs) after JE vaccination were mild to moderate in intensity, and similar to those reported following YF vaccination. Seroconversion to JE-CV was 100% and 91% in the JE/YF and YF/JE sequential vaccination groups, respectively, compared with 96% in the co-administration group. All participants seroconverted to YF vaccine and retained neutralizing titers above the assay cut-off at month six. Neutralizing antibodies against JE vaccine were detected in 82–100% of participants at month six. These results suggest that both vaccines may be successfully co-administered simultaneously or 30 days apart. PMID:20864814

Immunogenicity and protective efficacy of a Salmonella Enteritidis sptP mutant as a live attenuated vaccine candidate.

PubMed

Lin, Zhijie; Tang, Peipei; Jiao, Yang; Kang, Xilong; Li, Qiuchun; Xu, Xiulong; Sun, Jun; Pan, Zhiming; Jiao, Xinan

2017-06-24

Salmonella enterica serovar Enteritidis (S. Enteritidis) is a highly adaptive pathogen in both humans and animals. As a Salmonella Type III secretion system (T3SS) effector, Salmonella protein tyrosine phosphatase (SptP) is critical for virulence in this genus. To investigate the feasibility of using C50336ΔsptP as a live attenuated oral vaccine in mice, we generated the sptP gene deletion mutant C50336ΔsptP in S. Enteritidis strain C50336 by λ-Red mediated recombination and evaluated the protective ability of the S. Enteritidis sptP mutant strain C50336ΔsptP against mice salmonellosis. We found that C50336ΔsptP was a highly immunogenic, effective, and safe vaccine in mice. Compared to wild-type C50336, C50336ΔsptP showed reduced virulence as confirmed by the 50% lethal dose (LD 50 ) in orally infected mice. C50336ΔsptP also showed decreased bacterial colonization both in vivo and in vitro. Immunization with C50336ΔsptP had no significant effect on body weight and did not result in obvious clinical symptoms relative to control animals treated with phosphate-buffered saline (PBS), but induced humoral and cellular immune responses at 12 and 26 days post inoculation. Immunization with 1 × 10 8 colony-forming units (CFU) C50336ΔsptP per mouse provided 100% protection against subsequent challenge with the wild-type C50336 strain, and immunized mice showed mild and temporary clinical symptoms as compared to those of control group. These results demonstrate that C50336ΔsptP can be a live attenuated oral vaccine for salmonellosis.

Single-cycle replicable Rift Valley fever virus mutants as safe vaccine candidates

PubMed Central

Terasaki, Kaori; Tercero, Breanna R.; Makino, Shinji

2015-01-01

Rift Valley fever virus (RVFV) is an arbovirus circulating between ruminants and mosquitoes to maintain its enzootic cycle. Humans are infected with RVFV through mosquito bites or direct contact with materials of infected animals. The virus causes Rift Valley fever, which was first recognized in the Great Rift Valley of Kenya in 1931. RVFV is characterized by a febrile illness resulting in a high rate of abortions in ruminants and an acute febrile illness, followed by fatal hemorrhagic fever and encephalitis in humans. Initially, the virus was restricted to the eastern region of Africa, but the disease has now spread to southern and western Africa, as well as outside of the African continent, e.g., Madagascar, Saudi Arabia and Yemen. There is a serious concern that the virus may spread to other areas, such as North America and Europe. As vaccination is an effective tool to control RVFV epidemics, formalin-inactivated vaccines and live-attenuated RVFV vaccines have been used in endemic areas. The formalin-inactivated vaccines require boosters for effective protection, whereas the live-attenuated vaccines enable the induction of protective immunity by a single vaccination. However, the use of live-attenuated RVFV vaccines for large human populations having a varied health status is of concern, because of these vaccines’ residual neuro-invasiveness and neurovirulence. Recently, novel vaccine candidates have been developed using replication-defective RVFV that can undergo only a single round of replication in infected cells. The single-cycle replicable RVFV does not cause systemic infection in immunized hosts, but enables the conferring of protective immunity. This review summarizes the properties of various RVFV vaccines and recent progress on the development of the single-cycle replicable RVFV vaccines. PMID:26022573

Single-cycle replicable Rift Valley fever virus mutants as safe vaccine candidates.

PubMed

Terasaki, Kaori; Tercero, Breanna R; Makino, Shinji

2016-05-02

Rift Valley fever virus (RVFV) is an arbovirus circulating between ruminants and mosquitoes to maintain its enzootic cycle. Humans are infected with RVFV through mosquito bites or direct contact with materials of infected animals. The virus causes Rift Valley fever (RVF), which was first recognized in the Great Rift Valley of Kenya in 1931. RVF is characterized by a febrile illness resulting in a high rate of abortions in ruminants and an acute febrile illness, followed by fatal hemorrhagic fever and encephalitis in humans. Initially, the virus was restricted to the eastern region of Africa, but the disease has now spread to southern and western Africa, as well as outside of the African continent, e.g., Madagascar, Saudi Arabia and Yemen. There is a serious concern that the virus may spread to other areas, such as North America and Europe. As vaccination is an effective tool to control RVFV epidemics, formalin-inactivated vaccines and live-attenuated RVFV vaccines have been used in endemic areas. The formalin-inactivated vaccines require boosters for effective protection, whereas the live-attenuated vaccines enable the induction of protective immunity by a single vaccination. However, the use of live-attenuated RVFV vaccines for large human populations having a varied health status is of concern, because of these vaccines' residual neuro-invasiveness and neurovirulence. Recently, novel vaccine candidates have been developed using replication-defective RVFV that can undergo only a single round of replication in infected cells. The single-cycle replicable RVFV does not cause systemic infection in immunized hosts, but enables the conferring of protective immunity. This review summarizes the properties of various RVFV vaccines and recent progress on the development of the single-cycle replicable RVFV vaccines. Copyright © 2015 Elsevier B.V. All rights reserved.

TTSS2-deficient hha mutant of Salmonella Typhimurium exhibits significant systemic attenuation in immunocompromised hosts

PubMed Central

Vishwakarma, Vikalp; Pati, Niladri Bhusan; Ray, Shilpa; Das, Susmita; Suar, Mrutyunjay

2014-01-01

Non-typhoidal Salmonella (NTS) infections are emerging as leading problem worldwide and the variations in host immune status append to the concern of NTS. Salmonella enterica serovar Typhimurium is one of the causative agents of NTS infections and has been extensively studied. The inactivation of Salmonella pathogenicity island 2 (SPI2) encoded type-III secretion system 2 (TTSS2) has been reported rendering the strain incapable for systemic dissemination to host sites and has also been proposed as live-attenuated vaccine. However, infections from TTSS2-deficient Salmonella have also been reported. In this study, mutant strain MT15 was developed by inactivation of the hemolysin expression modulating protein (hha) in TTSS2-deficient S. Typhimurium background. The MT15 strain showed significant level of attenuation in immune-deprived murine colitis model when tested in iNos−/−, IL10−/−, and CD40L−/− mice groups in C57BL/6 background. Further, the mutation in hha does not implicate any defect in bacterial colonization to the host gut. The long-term infection of developed mutant strain conferred protective immune responses to suitably immunized streptomycin pre-treated C57BL/6 mice. The immunization enhanced the CD4+ and CD8+ cell types involved in bacterial clearance. The serum IgG and luminal secretory IgA (sIgA) was also found to be elevated after the due course of infection. Additionally, the immunized C57BL/6 mice were protected from the subsequent lethal infection of Salmonella Typhimurium. Collectively, these findings implicate the involvement of hemolysin expression modulating protein (Hha) in establishment of bacterial infection. In light of the observed attenuation of the developed mutant strain, this study proposes the possible significance of SPI2-deficient hha mutant as an alternative live-attenuated vaccine strain for use against lethal Salmonella infections. PMID:24401482

Numerical simulation of several impact attenuator design for a formula student car

NASA Astrophysics Data System (ADS)

Sinaga, Farlian Rizky; Ubaidillah, Kurniawan, Krishna Eka; Fadhil, Muhamad Ivan; Cahyono, Sukmaji Indro; Idris, Muhamad Hafiz

2018-02-01

In the Formula Society of Automotive Engineer (SAE), safety is a vigorous factor. One of the safety components in the Formula SAE car is the impact attenuator. The purpose of this study is to get the impact attenuator design with the best ability to absorb kinetic energy from several existing designs, through numerical approaches, for estimating conditions against dynamic impacts. Material of impact attenuator use combination of aluminum and Zirconium G350. The simulation was caried out by crashing the impact with the rigid wall, to find the deformation that occurs and the energies are absorbed. The impact attenuator design to be simulated should be optimized to meet some parameters in the SAE Formula. The result of impact attenuator simulation should be able to absorb energy of 7350 joules at move 7 m/s and deformation at bulkhead less than 25.4 mm.

Theory and preliminary experimental verification of quantitative edge illumination x-ray phase contrast tomography.

PubMed

Hagen, C K; Diemoz, P C; Endrizzi, M; Rigon, L; Dreossi, D; Arfelli, F; Lopez, F C M; Longo, R; Olivo, A

2014-04-07

X-ray phase contrast imaging (XPCi) methods are sensitive to phase in addition to attenuation effects and, therefore, can achieve improved image contrast for weakly attenuating materials, such as often encountered in biomedical applications. Several XPCi methods exist, most of which have already been implemented in computed tomographic (CT) modality, thus allowing volumetric imaging. The Edge Illumination (EI) XPCi method had, until now, not been implemented as a CT modality. This article provides indications that quantitative 3D maps of an object's phase and attenuation can be reconstructed from EI XPCi measurements. Moreover, a theory for the reconstruction of combined phase and attenuation maps is presented. Both reconstruction strategies find applications in tissue characterisation and the identification of faint, weakly attenuating details. Experimental results for wires of known materials and for a biological object validate the theory and confirm the superiority of the phase over conventional, attenuation-based image contrast.

Two-dimensional frequency-domain acoustic full-waveform inversion with rugged topography

NASA Astrophysics Data System (ADS)

Zhang, Qian-Jiang; Dai, Shi-Kun; Chen, Long-Wei; Li, Kun; Zhao, Dong-Dong; Huang, Xing-Xing

2015-09-01

We studied finite-element-method-based two-dimensional frequency-domain acoustic FWI under rugged topography conditions. The exponential attenuation boundary condition suitable for rugged topography is proposed to solve the cutoff boundary problem as well as to consider the requirement of using the same subdivision grid in joint multifrequency inversion. The proposed method introduces the attenuation factor, and by adjusting it, acoustic waves are sufficiently attenuated in the attenuation layer to minimize the cutoff boundary effect. Based on the law of exponential attenuation, expressions for computing the attenuation factor and the thickness of attenuation layers are derived for different frequencies. In multifrequency-domain FWI, the conjugate gradient method is used to solve equations in the Gauss-Newton algorithm and thus minimize the computation cost in calculating the Hessian matrix. In addition, the effect of initial model selection and frequency combination on FWI is analyzed. Examples using numerical simulations and FWI calculations are used to verify the efficiency of the proposed method.

Public health impact and cost-effectiveness of intranasal live attenuated influenza vaccination of children in Germany.

PubMed

Damm, Oliver; Eichner, Martin; Rose, Markus Andreas; Knuf, Markus; Wutzler, Peter; Liese, Johannes Günter; Krüger, Hagen; Greiner, Wolfgang

2015-06-01

In 2011, intranasally administered live attenuated influenza vaccine (LAIV) was approved in the EU for prophylaxis of seasonal influenza in 2-17-year-old children. Our objective was to estimate the potential epidemiological impact and cost-effectiveness of an LAIV-based extension of the influenza vaccination programme to healthy children in Germany. An age-structured dynamic model of influenza transmission was developed and combined with a decision-tree to evaluate different vaccination strategies in the German health care system. Model inputs were based on published literature or were derived by expert consulting using the Delphi technique. Unit costs were drawn from German sources. Under base-case assumptions, annual routine vaccination of children aged 2-17 years with LAIV assuming an uptake of 50% would prevent, across all ages, 16 million cases of symptomatic influenza, over 600,000 cases of acute otitis media, nearly 130,000 cases of community-acquired pneumonia, nearly 1.7 million prescriptions of antibiotics and over 165,000 hospitalisations over 10 years. The discounted incremental cost-effectiveness ratio was 1,228 per quality-adjusted life year gained from a broad third-party payer perspective (including reimbursed direct costs and specific transfer payments), when compared with the current strategy of vaccinating primarily risk groups with the conventional trivalent inactivated vaccine. Inclusion of patient co-payments and indirect costs in terms of productivity losses resulted in discounted 10-year cost savings of 3.4 billion. In conclusion, adopting universal influenza immunisation of healthy children and adolescents would lead to a substantial reduction in influenza-associated disease at a reasonable cost to the German statutory health insurance system. On the basis of the epidemiological and health economic simulation results, a recommendation of introducing annual routine influenza vaccination of children 2-17 years of age might be taken into consideration.

Inactivated Recombinant Rabies Viruses Displaying Canine Distemper Virus Glycoproteins Induce Protective Immunity against Both Pathogens

PubMed Central

da Fontoura Budaszewski, Renata; Hudacek, Andrew; Sawatsky, Bevan; Krämer, Beate; Yin, Xiangping

2017-01-01

ABSTRACT The development of multivalent vaccines is an attractive methodology for the simultaneous prevention of several infectious diseases in vulnerable populations. Both canine distemper virus (CDV) and rabies virus (RABV) cause lethal disease in wild and domestic carnivores. While RABV vaccines are inactivated, the live-attenuated CDV vaccines retain residual virulence for highly susceptible wildlife species. In this study, we developed recombinant bivalent vaccine candidates based on recombinant vaccine strain rabies virus particles, which concurrently display the protective CDV and RABV glycoprotein antigens. The recombinant viruses replicated to near-wild-type titers, and the heterologous glycoproteins were efficiently expressed and incorporated in the viral particles. Immunization of ferrets with beta-propiolactone-inactivated recombinant virus particles elicited protective RABV antibody titers, and animals immunized with a combination of CDV attachment protein- and fusion protein-expressing recombinant viruses were protected from lethal CDV challenge. However, animals that were immunized with only a RABV expressing the attachment protein of CDV vaccine strain Onderstepoort succumbed to infection with a more recent wild-type strain, indicating that immune responses to the more conserved fusion protein contribute to protection against heterologous CDV strains. IMPORTANCE Rabies virus and canine distemper virus (CDV) cause high mortality rates and death in many carnivores. While rabies vaccines are inactivated and thus have an excellent safety profile and high stability, live-attenuated CDV vaccines can retain residual virulence in highly susceptible species. Here we generated recombinant inactivated rabies viruses that carry one of the CDV glycoproteins on their surface. Ferrets immunized twice with a mix of recombinant rabies viruses carrying the CDV fusion and attachment glycoproteins were protected from lethal CDV challenge, whereas all animals that received recombinant rabies viruses carrying only the CDV attachment protein according to the same immunization scheme died. Irrespective of the CDV antigens used, all animals developed protective titers against rabies virus, illustrating that a bivalent rabies virus-based vaccine against CDV induces protective immune responses against both pathogens. PMID:28148801

Recombinants of influenza virus type B as potential live vaccine candidates: RNA characterization and evaluation in man.

PubMed Central

Lobmann, M.; Delem, A.; Jovanovic, D.; Peetermans, J.

1981-01-01

Two recombinants (R22 and R75) of the attenuated B/USSR/69 strain Bright and the virulent B/Hong Kong/5/72 and one recombinant (R5) of Bright and the virulent B/Hong Kong /8/73 were selected for genotypic and phenotypic caracterization. All three recombinants had the growth property of the attenuated parent Brigit. Analysis of their RNA's by polyacrylamide gel electrophoresis revealed that, the strains R22 and R75 had derived all their genes from Brigit, those coding for haemagglutinin excepted. These recombinants were clinically evaluated and found to be attenuated and immunogenic. The recombinant R5 which derived, besides the bene coding for the haemagglutinin, several other genes from B/Hong Kong/8/73 was only partly attenuated since it induced influenza-like symptoms in one out of three volunteers. It is concluded that the strain Brigit can be used as a donor of genes for the attenuation of the B/Hong Kong/5/72 virus and that recombinants of influenza type B can be identified, like influenza type A recombinants, by their RNA pattern. Images Plate 1 PMID:7019320

Comparison of egg and high yielding MDCK cell-derived live attenuated influenza virus for commercial production of trivalent influenza vaccine: in vitro cell susceptibility and influenza virus replication kinetics in permissive and semi-permissive cells.

PubMed

Hussain, Althaf I; Cordeiro, Melissa; Sevilla, Elizabeth; Liu, Jonathan

2010-05-14

Currently MedImmune manufactures cold-adapted (ca) live, attenuated influenza vaccine (LAIV) from specific-pathogen free (SPF) chicken eggs. Difficulties in production scale-up and potential exposure of chicken flocks to avian influenza viruses especially in the event of a pandemic influenza outbreak have prompted evaluation and development of alternative non-egg based influenza vaccine manufacturing technologies. As part of MedImmune's effort to develop the live attenuated influenza vaccine (LAIV) using cell culture production technologies we have investigated the use of high yielding, cloned MDCK cells as a substrate for vaccine production by assessing host range and virus replication of influenza virus produced from both SPF egg and MDCK cell production technologies. In addition to cloned MDCK cells the indicator cell lines used to evaluate the impact of producing LAIV in cells on host range and replication included two human cell lines: human lung carcinoma (A549) cells and human muco-epidermoid bronchiolar carcinoma (NCI H292) cells. The influenza viruses used to infect the indicators cell lines represented both the egg and cell culture manufacturing processes and included virus strains that composed the 2006-2007 influenza seasonal trivalent vaccine (A/New Caledonia/20/99 (H1N1), A/Wisconsin/67/05 (H3N2) and B/Malaysia/2506/04). Results from this study demonstrate remarkable similarity between influenza viruses representing the current commercial egg produced and developmental MDCK cell produced vaccine production platforms. MedImmune's high yielding cloned MDCK cells used for the cell culture based vaccine production were highly permissive to both egg and cell produced ca attenuated influenza viruses. Both the A549 and NCI H292 cells regardless of production system were less permissive to influenza A and B viruses than the MDCK cells. Irrespective of the indicator cell line used the replication properties were similar between egg and the cell produced influenza viruses. Based on these study results we conclude that the MDCK cell produced and egg produced vaccine strains are highly comparable. Copyright 2010 Elsevier Ltd. All rights reserved.

Streptococcus iniae M-Like Protein Contributes to Virulence in Fish and Is a Target for Live Attenuated Vaccine Development

PubMed Central

Locke, Jeffrey B.; Aziz, Ramy K.; Vicknair, Mike R.; Nizet, Victor; Buchanan, John T.

2008-01-01

Background Streptococcus iniae is a significant pathogen in finfish aquaculture, though knowledge of virulence determinants is lacking. Through pyrosequencing of the S. iniae genome we have identified two gene homologues to classical surface-anchored streptococcal virulence factors: M-like protein (simA) and C5a peptidase (scpI). Methodology/Principal Findings S. iniae possesses a Mga-like locus containing simA and a divergently transcribed putative mga-like regulatory gene, mgx. In contrast to the Mga locus of group A Streptococcus (GAS, S. pyogenes), scpI is located distally in the chromosome. Comparative sequence analysis of the Mgx locus revealed only one significant variant, a strain with an insertion frameshift mutation in simA and a deletion mutation in a region downstream of mgx, generating an ORF which may encode a second putative mga-like gene, mgx2. Allelic exchange mutagenesis of simA and scpI was employed to investigate the potential role of these genes in S. iniae virulence. Our hybrid striped bass (HSB) and zebrafish models of infection revealed that M-like protein contributes significantly to S. iniae pathogenesis whereas C5a peptidase-like protein does not. Further, in vitro cell-based analyses indicate that SiMA, like other M family proteins, contributes to cellular adherence and invasion and provides resistance to phagocytic killing. Attenuation in our virulence models was also observed in the S. iniae isolate possessing a natural simA mutation. Vaccination of HSB with the ΔsimA mutant provided 100% protection against subsequent challenge with a lethal dose of wild-type (WT) S. iniae after 1,400 degree days, and shows promise as a target for live attenuated vaccine development. Conclusions/Significance Analysis of M-like protein and C5a peptidase through allelic replacement revealed that M-like protein plays a significant role in S. iniae virulence, and the Mga-like locus, which may regulate expression of this gene, has an unusual arrangement. The M-like protein mutant created in this research holds promise as live-attenuated vaccine. PMID:18665241

Mucosal Vaccine Development Based on Liposome Technology

PubMed Central

Norling, Karin; Bally, Marta; Höök, Fredrik

2016-01-01

Immune protection against infectious diseases is most effective if located at the portal of entry of the pathogen. Hence, there is an increasing demand for vaccine formulations that can induce strong protective immunity following oral, respiratory, or genital tract administration. At present, only few mucosal vaccines are found on the market, but recent technological advancements and a better understanding of the principles that govern priming of mucosal immune responses have contributed to a more optimistic view on the future of mucosal vaccines. Compared to live attenuated vaccines, subcomponent vaccines, most often protein-based, are considered safer, more stable, and less complicated to manufacture, but they require the addition of nontoxic and clinically safe adjuvants to be effective. In addition, another limiting factor is the large antigen dose that usually is required for mucosal vaccines. Therefore, the combination of mucosal adjuvants with the recent progress in nanoparticle technology provides an attractive solution to these problems. In particular, the liposome technology is ideal for combining protein antigen and adjuvant into an effective mucosal vaccine. Here, we describe and discuss recent progress in nanoparticle formulations using various types of liposomes that convey strong promise for the successful development of the next generation of mucosal vaccines. PMID:28127567

Clinical development of a novel inactivated poliomyelitis vaccine based on attenuated Sabin poliovirus strains.

PubMed

Verdijk, Pauline; Rots, Nynke Y; Bakker, Wilfried A M

2011-05-01

Following achievement of polio eradication, the routine use of all live-attenuated oral poliovirus vaccines should be discontinued. However, the costs per vaccine dose for the alternative inactivated poliovirus vaccine (IPV) are significantly higher and the current production capacity is not sufficient for worldwide distribution of the vaccine. In order to achieve cost-prize reduction and improve affordability, IPV production processes and dose-sparing strategies should be developed to facilitate local manufacture at a relatively lower cost. The use of attenuated Sabin instead of wild-type polio strains will provide additional safety during vaccine production and permits production in low-cost settings. Sabin-IPV is under development by several manufacturers. This article gives an overview of results from clinical trials with Sabin-IPV and discusses the requirements and challenges in the clinical development of this novel IPV.

Live Attenuated Bacterial Vaccines in Aquaculture

USDA-ARS?s Scientific Manuscript database

Aquaculture has emerged as an important economical agribusiness, worldwide. Among the top barrier to growth of aquaculture is infectious disease that is causing severe economic losses. Bacterial species of more than 20 genera have been reported as causes of diseases. The risk of disease is often ...

Tobacco Smoke Exposure and Altered Nasal Responses to Live Attenuated Influenza Virus

EPA Science Inventory

Background: Epidemiologic evidence links tobacco smoke and increased risk for influenza in humans, but the specific host defense pathways involved are unclear. Objective. Develop a model to examine influenza-induced innate immune responses in humans and test the hypothesis that ...

Submission of nucleotide sequence eimeria acervulina profilin to genbank database

USDA-ARS?s Scientific Manuscript database

Poultry coccidiosis, caused by intestinal protozoa Eimeria, is a severe problem for the poultry industry, leading to a substantial economic burden of over three billion dollars worldwide. Conventional vaccines including live vaccines and attenuated vaccines could cause mild to severe reactions Numer...

Vaccine Mediated Protection Against Zika Virus-Induced Congenital Disease.

PubMed

Richner, Justin M; Jagger, Brett W; Shan, Chao; Fontes, Camila R; Dowd, Kimberly A; Cao, Bin; Himansu, Sunny; Caine, Elizabeth A; Nunes, Bruno T D; Medeiros, Daniele B A; Muruato, Antonio E; Foreman, Bryant M; Luo, Huanle; Wang, Tian; Barrett, Alan D; Weaver, Scott C; Vasconcelos, Pedro F C; Rossi, Shannan L; Ciaramella, Giuseppe; Mysorekar, Indira U; Pierson, Theodore C; Shi, Pei-Yong; Diamond, Michael S

2017-07-13

The emergence of Zika virus (ZIKV) and its association with congenital malformations has prompted the rapid development of vaccines. Although efficacy with multiple viral vaccine platforms has been established in animals, no study has addressed protection during pregnancy. We tested in mice two vaccine platforms, a lipid nanoparticle-encapsulated modified mRNA vaccine encoding ZIKV prM and E genes and a live-attenuated ZIKV strain encoding an NS1 protein without glycosylation, for their ability to protect against transmission to the fetus. Vaccinated dams challenged with a heterologous ZIKV strain at embryo day 6 (E6) and evaluated at E13 showed markedly diminished levels of viral RNA in maternal, placental, and fetal tissues, which resulted in protection against placental damage and fetal demise. As modified mRNA and live-attenuated vaccine platforms can restrict in utero transmission of ZIKV in mice, their further development in humans to prevent congenital ZIKV syndrome is warranted. Copyright © 2017 Elsevier Inc. All rights reserved.

Live Attenuated Pertussis Vaccine BPZE1 Protects Baboons Against Bordetella pertussis Disease and Infection

PubMed Central

Papin, James F.; Lecher, Sophie; Debrie, Anne-Sophie; Thalen, Marcel; Solovay, Ken; Rubin, Keith; Mielcarek, Nathalie

2017-01-01

Abstract Evidence suggests that the resurgence of pertussis in many industrialized countries may result from the failure of current vaccines to prevent nasopharyngeal colonization by Bordetella pertussis, the principal causative agent of whooping cough. Here, we used a baboon model to test the protective potential of the novel, live attenuated pertussis vaccine candidate BPZE1. A single intranasal/intratracheal inoculation of juvenile baboons with BPZE1 resulted in transient nasopharyngeal colonization and induction of immunoglobulin G and immunoglobulin A to all antigens tested, while causing no adverse symptoms or leukocytosis. When BPZE1-vaccinated baboons were challenged with a high dose of a highly virulent B. pertussis isolate, they were fully protected against disease, whereas naive baboons developed illness (with 1 death) and leukocytosis. Total postchallenge nasopharyngeal virulent bacterial burden of vaccinated animals was substantially reduced (0.002%) compared to naive controls, providing promising evidence in nonhuman primates that BPZE1 protects against both pertussis disease and B. pertussis infection. PMID:28535276

Oral vaccination with different antigens from Yersinia pestis KIM delivered by live attenuated Salmonella typhimurium elicits a protective immune response against plague.

PubMed

Branger, Christine G; Fetherston, Jacqueline D; Perry, Robert D; Curtiss, Roy

2007-01-01

The use of live recombinant Salmonella attenuated vaccine (RASV) encoding Yersinia proteins is a promising new approach for the vaccination against Yersinia pestis. We have tested the efficacy of 2 proteins, Psn and a portion of LcrV in protecting mice against virulent Yersinia pestis challenge. To remove the immunosuppressive properties of LcrV protein, the lcrV gene, without the TLR2 receptor sequence, was cloned into a beta-lactamase secretion vector. Immunizations were performed with RSAV expressing LcrV or Psn. Challenge with a virulent Y. pestis strain was performed 4 weeks after the last immunization. Our results show that the truncated LcrV protein delivered by RASV is sufficient to afford a full protective immune response in a mouse model of bubonic plague and the Psn protein afforded partial protection in a non-optimized system. This finding should facilitate the design and development of a new generation of vaccines against Y. pestis.

Multiple antigens of Yersinia pestis delivered by live recombinant attenuated Salmonella vaccine strains elicit protective immunity against plague.

PubMed

Sanapala, Shilpa; Rahav, Hannah; Patel, Hetal; Sun, Wei; Curtiss, Roy

2016-05-05

Based on our improved novel Salmonella vaccine delivery platform, we optimized the recombinant attenuated Salmonella typhimurium vaccine (RASV) χ12094 to deliver multiple Yersinia pestis antigens. These included LcrV196 (amino acids, 131-326), Psn encoded on pYA5383 and F1 encoded in the chromosome, their synthesis did not cause adverse effects on bacterial growth. Oral immunization with χ12094(pYA5383) simultaneously stimulated high antibody titers to LcrV, Psn and F1 in mice and presented complete protection against both subcutaneous (s.c.) and intranasal (i.n.) challenges with high lethal doses of Y. pestis CO92. Moreover, no deaths or other disease symptoms were observed in SCID mice orally immunized with χ12094(pYA5383) over a 60-day period. Therefore, the trivalent S. typhimurium-based live vaccine shows promise for a next-generation plague vaccine. Copyright © 2016 Elsevier Ltd. All rights reserved.

A live attenuated strain of Yersinia pestis ΔyscB provides protection against bubonic and pneumonic plagues in mouse model.

PubMed

Zhang, Xuecan; Qi, Zhizhen; Du, Zongmin; Bi, Yujing; Zhang, Qingwen; Tan, Yafang; Yang, Huiying; Xin, Youquan; Yang, Ruifu; Wang, Xiaoyi

2013-05-24

To develop a safe and effective live plague vaccine, the ΔyscB mutant was constructed based on Yersinia pestis biovar Microtus strain 201 that is avirulent to humans, but virulent to mice. The virulence, immunogenicity and protective efficacy of the ΔyscB mutant were evaluated in this study. The results showed that the ΔyscB mutant was severely attenuated, elicited a higher F1-specific antibody titer and provided protective efficacy against bubonic and pneumonic plague in mouse model. The ΔyscB mutant could induce the secretion of both Th1-associated cytokines (IFN-γ, IL-2 and TNF-α) and Th2-associated cytokines (IL-4 and IL-10). Taken together, the ΔyscB mutant represented a potential vaccine candidate based on its ability to generate strong humoral and cell-mediated immune responses and to provide good protection against both subcutaneous and intranasal Y. pestis challenge. Copyright © 2013 Elsevier Ltd. All rights reserved.

Vaccinating high-risk children with the intranasal live-attenuated influenza vaccine: the Quebec experience.

PubMed

Quach, Caroline

2014-12-01

Given the burden of illness associated with influenza, vaccination is recommended for individuals at high risk of complications. The live-attenuated influenza vaccine (LAIV) is administered by intranasal spray, thus directly stimulating mucosal immunity. In this review, we aimed to provide evidence for its efficacy and safety in different paediatric populations. We also share the Quebec experience of LAIV use through a publicly funded vaccination program for children with chronic, high-risk conditions. from randomized controlled trials in healthy children and in asthmatics have demonstrated superior efficacy of LAIV over the injectable vaccine (IIV). LAIV is well tolerated: its administration is associated with runny nose and nasal congestion, but not with asthma exacerbations and is well tolerated in children with cystic fibrosis, when compared to IIV. The vaccine is well accepted by children and parents and can easily be part of vaccination clinics in paediatric tertiary care centres targeting children with chronic, high-risk conditions, not leading to immunosuppression. Copyright © 2014 Elsevier Ltd. All rights reserved.

Poxvirus-vectored vaccines for rabies--a review.

PubMed

Weyer, Jacqueline; Rupprecht, Charles E; Nel, Louis H

2009-11-27

Oral rabies vaccination of target reservoir species has proved to be one of the pillars of successful rabies elimination programs. The use of live attenuated rabies virus vaccines has been extensive but several limitations hamper its future use. A recombinant vaccinia-rabies vaccine has also been successfully used for the oral vaccination of several species. Nevertheless, its lack of efficacy in certain important rabies reservoirs and concerns on the use of this potent live virus as vaccine carrier (vector) impair the expansion of its use for new target species and new areas. Several attenuated and host-restricted poxvirus alternatives, which supposedly offer enhanced safety, have been investigated. Once again, efficacy in certain target species and innocuity through the oral route remain major limitations of these vaccines. Alternative recombinant vaccines using adenovirus as an antigen delivery vector have been extensively investigated and may provide an important addition to the currently available oral rabies vaccine repertoire, but are not the primary subject of this review.

Aerogenic vaccination with a Burkholderia mallei auxotroph protects against aerosol-initiated glanders in mice.

PubMed

Ulrich, Ricky L; Amemiya, Kei; Waag, David M; Roy, Chad J; DeShazer, David

2005-03-14

Burkholderia mallei is an obligate mammalian pathogen that causes the zoonotic disease glanders. Two live attenuated B. mallei strains, a capsule mutant and a branched-chain amino acid auxotroph, were evaluated for use as vaccines against aerosol-initiated glanders in mice. Animals were aerogenically vaccinated and serum samples were obtained before aerosol challenge with a high-dose (>300 times the LD50) of B. mallei ATCC 23344. Mice vaccinated with the capsule mutant developed a Th2-like Ig subclass antibody response and none survived beyond 5 days. In comparison, the auxotrophic mutant elicited a Th1-like Ig subclass antibody response and 25% of the animals survived for 1 month postchallenge. After a low-dose (5 times the LD50) aerosol challenge, the survival rates of auxotroph-vaccinated and unvaccinated animals were 50 and 0%, respectively. Thus, live attenuated strains that promote a Th1-like Ig response may serve as promising vaccine candidates against aerosol infection with B. mallei.

A Live Attenuated Chimeric West Nile Virus Vaccine, rWN/DEN4Δ30, Is Well Tolerated and Immunogenic in Flavivirus-Naive Older Adult Volunteers.

PubMed

Pierce, Kristen K; Whitehead, Stephen S; Kirkpatrick, Beth D; Grier, Palmtama L; Jarvis, Adrienne; Kenney, Heather; Carmolli, Marya P; Reynolds, Cynthia; Tibery, Cecilia M; Lovchik, Janece; Janiak, Anna; Luke, Catherine J; Durbin, Anna P; Pletnev, Alexander G

2017-01-01

West Nile virus (WNV) is a major cause of mosquito-borne illness in the United States. Human disease ranges from mild febrile illness to severe fatal neurologic infection. Adults aged >60 years are more susceptible to neuroinvasive disease accompanied by a high mortality rate or long-lasting neurologic sequelae. A chimeric live attenuated West Nile virus vaccine, rWN/DEN4Δ30, was shown to be safe and immunogenic in healthy adults aged 18-50 years. This study evaluated rWN/DEN4Δ30 in flavivirus-naive adults aged 50-65 years and found it to be safe and immunogenic. Outbreaks of WNV infection tend to be unpredictable, and a safe and effective vaccine will be an important public health tool. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Successful respiratory immunization with dry powder live-attenuated measles virus vaccine in rhesus macaques

PubMed Central

Lin, Wen-Hsuan; Griffin, Diane E.; Rota, Paul A.; Papania, Mark; Cape, Stephen P.; Bennett, David; Quinn, Brian; Sievers, Robert E.; Shermer, Charles; Powell, Kenneth; Adams, Robert J.; Godin, Steven; Winston, Scott

2011-01-01

Measles remains an important cause of childhood mortality worldwide. Sustained high vaccination coverage is the key to preventing measles deaths. Because measles vaccine is delivered by injection, hurdles to high coverage include the need for trained medical personnel and a cold chain, waste of vaccine in multidose vials and risks associated with needle use and disposal. Respiratory vaccine delivery could lower these barriers and facilitate sustained high coverage. We developed a novel single unit dose, dry powder live-attenuated measles vaccine (MVDP) for respiratory delivery without reconstitution. We tested the immunogenicity and protective efficacy in rhesus macaques of one dose of MVDP delivered either with a mask or directly intranasal with two dry powder inhalers, PuffHaler and BD Solovent. MVDP induced robust measles virus (MeV)-specific humoral and T-cell responses, without adverse effects, which completely protected the macaques from infection with wild-type MeV more than one year later. Respiratory delivery of MVDP was safe and effective and could aid in measles control. PMID:21282608

Successful respiratory immunization with dry powder live-attenuated measles virus vaccine in rhesus macaques.

PubMed

Lin, Wen-Hsuan; Griffin, Diane E; Rota, Paul A; Papania, Mark; Cape, Stephen P; Bennett, David; Quinn, Brian; Sievers, Robert E; Shermer, Charles; Powell, Kenneth; Adams, Robert J; Godin, Steven; Winston, Scott

2011-02-15

Measles remains an important cause of childhood mortality worldwide. Sustained high vaccination coverage is the key to preventing measles deaths. Because measles vaccine is delivered by injection, hurdles to high coverage include the need for trained medical personnel and a cold chain, waste of vaccine in multidose vials and risks associated with needle use and disposal. Respiratory vaccine delivery could lower these barriers and facilitate sustained high coverage. We developed a novel single unit dose, dry powder live-attenuated measles vaccine (MVDP) for respiratory delivery without reconstitution. We tested the immunogenicity and protective efficacy in rhesus macaques of one dose of MVDP delivered either with a mask or directly intranasal with two dry powder inhalers, PuffHaler and BD Solovent. MVDP induced robust measles virus (MeV)-specific humoral and T-cell responses, without adverse effects, which completely protected the macaques from infection with wild-type MeV more than one year later. Respiratory delivery of MVDP was safe and effective and could aid in measles control.

Does Neighborhood Social Capital Buffer the Effects of Maternal Depression on Adolescent Behavior Problems?

PubMed Central

Mays, Vickie M.; Cochran, Susan D.

2014-01-01

Neighborhood characteristics have been shown to impact child well-being. However, it remains unclear how these factors combine with family characteristics to influence child development. The current study helps develop that understanding by investigating how neighborhoods directly impact child and adolescent behavior problems as well as moderate the influence of family characteristics on behavior. Using multilevel linear models, we examined the relationship among neighborhood conditions (poverty and social capital) and maternal depression on child and adolescent behavior problems. The sample included 741 children, age 5–11, and 564 adolescents, age 12–17. Outcomes were internalizing (e.g. anxious/depressed) and externalizing (e.g. aggressive/hyperactive) behavior problems. Neighborhood poverty and maternal depression were both positively associated with behavior problems for children and adolescents. However, while neighborhood social capital was not directly associated with behavior problems, the interaction of social capital and maternal depression was significantly related to behavior problems for adolescents. This interaction showed that living in neighborhoods with higher levels of social capital attenuated the relationship between maternal depression and adolescent behavior problems and confirmed the expectation that raising healthy well-adjusted children depends not only on the family, but also the context in which the family lives. PMID:24659390

The extradomain a of fibronectin enhances the efficacy of lipopolysaccharide defective Salmonella bacterins as vaccines in mice

PubMed Central

2012-01-01

The Extradomain A from fibronectin (EDA) has an immunomodulatory role as fusion protein with viral and tumor antigens, but its effect when administered with bacteria has not been assessed. Here, we investigated the adjuvant effect of EDA in mice immunizations against Salmonella enterica subspecies enterica serovar Enteritidis (Salmonella Enteritidis). Since lipopolysaccharide (LPS) is a major virulence factor and the LPS O-polysaccharide (O-PS) is the immunodominant antigen in serological diagnostic tests, Salmonella mutants lacking O-PS (rough mutants) represent an interesting approach for developing new vaccines and diagnostic tests to differentiate infected and vaccinated animals (DIVA tests). Here, antigenic preparations (hot-saline extracts and formalin-inactivated bacterins) from two Salmonella Enteritidis rough mutants, carrying either intact (SEΔwaaL) or deep-defective (SEΔgal) LPS-Core, were used in combination with EDA. Biotinylated bacterins, in particular SEΔwaaL bacterin, decorated with EDAvidin (EDA and streptavidin fusion protein) improved the protection conferred by hot-saline or bacterins alone and prevented significantly the virulent infection at least to the levels of live attenuated rough mutants. These findings demonstrate the adjuvant effect of EDAvidin when administered with biotinylated bacterins from Salmonella Enteritidis lacking O-PS and the usefulness of BEDA-SEΔwaaL as non-live vaccine in the mouse model. PMID:22515195

Immunogenicity and protective efficacy of Semliki forest virus replicon-based DNA vaccines encoding goatpox virus structural proteins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng Min; Guangxi Center for Animal Disease Control and Prevention, Nanning 530001; College of Animal Science and Veterinary Medicine, Jilin University, Changchun 130062

Goatpox, caused by goatpox virus (GTPV), is an acute feverish and contagious disease in goats often associated with high morbidity and high mortality. To resolve potential safety risks and vaccination side effects of existing live attenuated goatpox vaccine (AV41), two Semliki forest virus (SFV) replicon-based bicistronic expression DNA vaccines (pCSm-AAL and pCSm-BAA) which encode GTPV structural proteins corresponding to the Vaccinia virus proteins A27, L1, A33, and B5, respectively, were constructed. Then, theirs ability to induce humoral and cellular response in mice and goats, and protect goats against virulent virus challenge were evaluated. The results showed that, vaccination with pCSm-AALmore » and pCSm-BAA in combination could elicit strong humoral and cellular responses in mice and goats, provide partial protection against viral challenge in goats, and reduce disease symptoms. Additionally, priming vaccination with the above-mentioned DNA vaccines could significantly reduce the goats' side reactions from boosting vaccinations with current live vaccine (AV41), which include skin lesions at the inoculation site and fevers. Data obtained in this study could not only facilitate improvement of the current goatpox vaccination strategy, but also provide valuable guidance to suitable candidates for evaluation and development of orthopoxvirus vaccines.« less

The effect of metal artefact reduction on CT-based attenuation correction for PET imaging in the vicinity of metallic hip implants: a phantom study.

PubMed

Harnish, Roy; Prevrhal, Sven; Alavi, Abass; Zaidi, Habib; Lang, Thomas F

2014-07-01

To determine if metal artefact reduction (MAR) combined with a priori knowledge of prosthesis material composition can be applied to obtain CT-based attenuation maps with sufficient accuracy for quantitative assessment of (18)F-fluorodeoxyglucose uptake in lesions near metallic prostheses. A custom hip prosthesis phantom with a lesion-sized cavity filled with 0.2 ml (18)F-FDG solution having an activity of 3.367 MBq adjacent to a prosthesis bore was imaged twice with a chrome-cobalt steel hip prosthesis and a plastic replica, respectively. Scanning was performed on a clinical hybrid PET/CT system equipped with an additional external (137)Cs transmission source. PET emission images were reconstructed from both phantom configurations with CT-based attenuation correction (CTAC) and with CT-based attenuation correction using MAR (MARCTAC). To compare results with the attenuation-correction method extant prior to the advent of PET/CT, we also carried out attenuation correction with (137)Cs transmission-based attenuation correction (TXAC). CTAC and MARCTAC images were scaled to attenuation coefficients at 511 keV using a trilinear function that mapped the highest CT values to the prosthesis alloy attenuation coefficient. Accuracy and spatial distribution of the lesion activity was compared between the three reconstruction schemes. Compared to the reference activity of 3.37 MBq, the estimated activity quantified from the PET image corrected by TXAC was 3.41 MBq. The activity estimated from PET images corrected by MARCTAC was similar in accuracy at 3.32 MBq. CTAC corrected PET images resulted in nearly 40 % overestimation of lesion activity at 4.70 MBq. Comparison of PET images obtained with the plastic and metal prostheses in place showed that CTAC resulted in a marked distortion of the (18)F-FDG distribution within the lesion, whereas application of MARCTAC and TXAC resulted in lesion distributions similar to those observed with the plastic replica. MAR combined with a trilinear CT number mapping for PET attenuation correction resulted in estimates of lesion activity comparable in accuracy to that obtained with (137)Cs transmission-based attenuation correction, and far superior to estimates made without attenuation correction or with a standard CT attenuation map. The ability to use CT images for attenuation correction is a potentially important development because it obviates the need for a (137)Cs transmission source, which entails extra scan time, logistical complexity and expense.

Long-Term Safety and Immunogenicity of a Tetravalent Live-Attenuated Dengue Vaccine and Evaluation of a Booster Dose Administered to Healthy Thai Children.

PubMed

Watanaveeradej, Veerachai; Simasathien, Sriluck; Mammen, Mammen P; Nisalak, Ananda; Tournay, Elodie; Kerdpanich, Phirangkul; Samakoses, Rudiwilai; Putnak, Robert J; Gibbons, Robert V; Yoon, In-Kyu; Jarman, Richard G; De La Barrera, Rafael; Moris, Philippe; Eckels, Kenneth H; Thomas, Stephen J; Innis, Bruce L

2016-06-01

We evaluated the safety and immunogenicity of two doses of a live-attenuated, tetravalent dengue virus vaccine (F17/Pre formulation) and a booster dose in a dengue endemic setting in two studies. Seven children (7- to 8-year-olds) were followed for 1 year after dose 2 and then given a booster dose (F17/Pre formulation), and followed for four more years (Child study). In the Infant study, 49 2-year-olds, vaccinated as infants, were followed for approximately 3.5 years after dose 2 and then given a booster dose (F17) and followed for one additional year. Two clinically notable events were observed, both in dengue vaccine recipients in the Infant study: 1 case of dengue approximately 2.7 years after dose 2 and 1 case of suspected dengue after booster vaccinations. The booster vaccinations had a favorable safety profile in terms of reactogenicity and adverse events reported during the 1-month follow-up periods. No vaccine-related serious adverse events were reported during the studies. Neutralizing antibodies against dengue viruses 1-4 waned during the 1-3 years before boosting, which elicited a short-lived booster response but did not provide a long-lived, multivalent antibody response in most subjects. Overall, this candidate vaccine did not elicit a durable humoral immune response. © The American Society of Tropical Medicine and Hygiene.

Targeted surface expression of an exogenous antigen in stably transfected babesia bovis

USDA-ARS?s Scientific Manuscript database

Babesia bovis is a tick-borne intraerythocytic protozoan responsible for acute disease in cattle which can be controlled by vaccination with attenuated B. bovis strains. Emerging B. bovis transfection technologies may increase the usefulness of these live vaccines. Here we propose using transfected ...

Controlling Johne's disease: Vaccination is the way forward

USDA-ARS?s Scientific Manuscript database

In this article, we summarize current research on the state of vaccination against Johne’s disease. We promote the use of live attenuated vaccine candidates over subunit approaches, but don’t wholly discount other strategies. We conclude by suggesting new research directions that may make the highes...

Infectious laryngotracheitis genomics: What’s circulating in the backyard flocks from the United States?

USDA-ARS?s Scientific Manuscript database

Phylogenetic and comparative genomic studies of infectious laryngotracheitis virus (ILTV) has mainly focused on the differences among live attenuated vaccines, vicinal revertants and natural recombinant strains from Australia, the United States, and China. This analysis suggests that most strains fr...

African Green Monkeys Recapitulate the Clinical Experience with Replication of Live Attenuated Pandemic Influenza Virus Vaccine Candidates

PubMed Central

Matsuoka, Yumiko; Suguitan, Amorsolo; Orandle, Marlene; Paskel, Myeisha; Boonnak, Kobporn; Gardner, Donald J.; Feldmann, Friederike; Feldmann, Heinz; Marino, Michael; Jin, Hong; Kemble, George

2014-01-01

ABSTRACT Live attenuated cold-adapted (ca) H5N1, H7N3, H6N1, and H9N2 influenza vaccine viruses replicated in the respiratory tract of mice and ferrets, and 2 doses of vaccines were immunogenic and protected these animals from challenge infection with homologous and heterologous wild-type (wt) viruses of the corresponding subtypes. However, when these vaccine candidates were evaluated in phase I clinical trials, there were inconsistencies between the observations in animal models and in humans. The vaccine viruses did not replicate well and immune responses were variable in humans, even though the study subjects were seronegative with respect to the vaccine viruses before vaccination. Therefore, we sought a model that would better reflect the findings in humans and evaluated African green monkeys (AGMs) as a nonhuman primate model. The distribution of sialic acid (SA) receptors in the respiratory tract of AGMs was similar to that in humans. We evaluated the replication of wt and ca viruses of avian influenza (AI) virus subtypes H5N1, H6N1, H7N3, and H9N2 in the respiratory tract of AGMs. All of the wt viruses replicated efficiently, while replication of the ca vaccine viruses was restricted to the upper respiratory tract. Interestingly, the patterns and sites of virus replication differed among the different subtypes. We also evaluated the immunogenicity and protective efficacy of H5N1, H6N1, H7N3, and H9N2 ca vaccines. Protection from wt virus challenge correlated well with the level of serum neutralizing antibodies. Immune responses were slightly better when vaccine was delivered by both intranasal and intratracheal delivery than when it was delivered intranasally by sprayer. We conclude that live attenuated pandemic influenza virus vaccines replicate similarly in AGMs and human subjects and that AGMs may be a useful model to evaluate the replication of ca vaccine candidates. IMPORTANCE Ferrets and mice are commonly used for preclinical evaluation of influenza vaccines. However, we observed significant inconsistencies between observations in humans and in these animal models. We used African green monkeys (AGMs) as a nonhuman primate (NHP) model for a comprehensive and comparative evaluation of pairs of wild-type and pandemic live attenuated influenza virus vaccines (pLAIV) representing four subtypes of avian influenza viruses and found that pLAIVs replicate similarly in AGMs and humans and that AGMs can be useful for evaluation of the protective efficacy of pLAIV. PMID:24807726

Development of a live, attenuated, potential vaccine strain of R. equi expressing vapA and the virR operon, and virulence assessment in the mouse.

PubMed

Whitehead, Ashley E; Parreira, Valeria R; Hewson, Joanne; Watson, Johanna L; Prescott, John F

2012-01-15

Pneumonia caused by Rhodococcus equi remains a significant problem in foals. The objective of this study was to develop a safe and efficacious attenuated strain of R. equi for eventual use in oral immunization of foals. The approach involved expression of vapA in a live, virulence plasmid-negative, strain of R. equi (strain 103-). PCR-amplified fragments of the vapA gene, with and without the upstream genes virR, orf5, vapH, orf7 and orf8 (orf4-8), were cloned into a shuttle vector pNBV1. These plasmids, named pAW48A and pAWVapA respectively, were electroporated into strain 103-. The presence of the recombinant vectors in the attenuated strain (103-) and the integrity of the inserted genes were confirmed, and both constructs expressed VapA. The virulence of the two strains was compared to that of wild type R. equi 103+ and negative controls by their intravenous inoculation into mice, followed by examination of liver clearance 4 days later. Mice inoculated with R. equi 103-, 103-/pAWVapA and 103-/pNBV1 completely cleared infection, whereas strain 103-/pAW48A persisted in 47% of mice. Copyright © 2011 Elsevier B.V. All rights reserved.

Attenuation and protection efficacy of ORF C gene-deleted recombinant of infectious laryngotracheitis virus.

PubMed

Garcia, Maricarmen; Spatz, S J; Cheng, Y; Riblet, S M; Volkening, J D; Schneiders, G H

2016-09-01

Infectious laryngotracheitis (ILT) is a highly contagious respiratory disease of chickens caused by infectious laryngotracheitis virus (ILTV). The disease is controlled by the use of live-attenuated vaccines. Previously we reported the complete nucleotide sequence of the ILTV vaccine strain (TCO) and identified a nonsense mutation in the gene encoding the ORF C protein. This suggested that the ORF C protein might be associated with viral virulence. To investigate this, an ILTV recombinant with a deletion in the gene encoding ORF C was constructed using the genome of the virulent United States Department of Agriculture (USDA) challenge strain (USDAch). Compared to the parental virus, the ΔORF C recombinant replicated in chicken kidney (CK) cells with similar kinetics and generated similar titres. This demonstrated that the ORF C deletion had no deleterious effects on replication efficacy in vitro. In chickens, the recombinant induced only minor microscopic tracheal lesions when inoculated via the intra-tracheal/ocular route, while the parental strain induced moderate to severe microscopic tracheal lesions, even though virus load in the tracheas were comparable. Groups of chickens vaccinated via eye-drop with the ∆ORFC-ILTV were protected to levels comparable to those elicited by TCO vaccination. To our knowledge, this is the first report that demonstrates the suitability of ∆ORFC as a live-attenuated vaccine to prevent the losses caused by ILTV.

Yersinia pestis biovar Microtus strain 201, an avirulent strain to humans, provides protection against bubonic plague in rhesus macaques.

PubMed

Zhang, Qingwen; Wang, Qiong; Tian, Guang; Qi, Zhizhen; Zhang, Xuecan; Wu, Xiaohong; Qiu, Yefeng; Bi, Yujing; Yang, Xiaoyan; Xin, Youquan; He, Jian; Zhou, Jiyuan; Zeng, Lin; Yang, Ruifu; Wang, Xiaoyi

2014-01-01

Yersinia pestis biovar Microtus is considered to be a virulent to larger mammals, including guinea pigs, rabbits and humans. It may be used as live attenuated plague vaccine candidates in terms of its low virulence. However, the Microtus strain's protection against plague has yet to be demonstrated in larger mammals. In this study, we evaluated the protective efficacy of the Microtus strain 201 as a live attenuated plague vaccine candidate. Our results show that this strain is highly attenuated by subcutaneous route, elicits an F1-specific antibody titer similar to the EV and provides a protective efficacy similar to the EV against bubonic plague in Chinese-origin rhesus macaques. The Microtus strain 201 could induce elevated secretion of both Th1-associated cytokines (IFN-γ, IL-2 and TNF-α) and Th2-associated cytokines (IL-4, IL-5, and IL-6), as well as chemokines MCP-1 and IL-8. However, the protected animals developed skin ulcer at challenge site with different severity in most of the immunized and some of the EV-immunized monkeys. Generally, the Microtus strain 201 represented a good plague vaccine candidate based on its ability to generate strong humoral and cell-mediated immune responses as well as its good protection against high dose of subcutaneous virulent Y. pestis challenge.

Yersinia pestis biovar Microtus strain 201, an avirulent strain to humans, provides protection against bubonic plague in rhesus macaques

PubMed Central

Zhang, Qingwen; Wang, Qiong; Tian, Guang; Qi, Zhizhen; Zhang, Xuecan; Wu, Xiaohong; Qiu, Yefeng; Bi, Yujing; Yang, Xiaoyan; Xin, Youquan; He, Jian; Zhou, Jiyuan; Zeng, Lin; Yang, Ruifu; Wang, Xiaoyi

2014-01-01

Yersinia pestis biovar Microtus is considered to be a virulent to larger mammals, including guinea pigs, rabbits and humans. It may be used as live attenuated plague vaccine candidates in terms of its low virulence. However, the Microtus strain’s protection against plague has yet to be demonstrated in larger mammals. In this study, we evaluated the protective efficacy of the Microtus strain 201 as a live attenuated plague vaccine candidate. Our results show that this strain is highly attenuated by subcutaneous route, elicits an F1-specific antibody titer similar to the EV and provides a protective efficacy similar to the EV against bubonic plague in Chinese-origin rhesus macaques. The Microtus strain 201 could induce elevated secretion of both Th1-associated cytokines (IFN-γ, IL-2 and TNF-α) and Th2-associated cytokines (IL-4, IL-5, and IL-6), as well as chemokines MCP-1 and IL-8. However, the protected animals developed skin ulcer at challenge site with different severity in most of the immunized and some of the EV-immunized monkeys. Generally, the Microtus strain 201 represented a good plague vaccine candidate based on its ability to generate strong humoral and cell-mediated immune responses as well as its good protection against high dose of subcutaneous virulent Y. pestis challenge. PMID:24225642

Maraba MG1 Virus Enhances Natural Killer Cell Function via Conventional Dendritic Cells to Reduce Postoperative Metastatic Disease

PubMed Central

Zhang, Jiqing; Tai, Lee-Hwa; Ilkow, Carolina S; Alkayyal, Almohanad A; Ananth, Abhirami A; de Souza, Christiano Tanese; Wang, Jiahu; Sahi, Shalini; Ly, Lundi; Lefebvre, Charles; Falls, Theresa J; Stephenson, Kyle B; Mahmoud, Ahmad B; Makrigiannis, Andrew P; Lichty, Brian D; Bell, John C; Stojdl, David F; Auer, Rebecca C

2014-01-01

This study characterizes the ability of novel oncolytic rhabdoviruses (Maraba MG1) to boost natural killer (NK) cell activity. Our results demonstrate that MG1 activates NK cells via direct infection and maturation of conventional dendritic cells. Using NK depletion and conventional dendritic cells ablation studies in vivo, we established that both are required for MG1 efficacy. We further explored the efficacy of attenuated MG1 (nonreplicating MG1-UV2min and single-cycle replicating MG1-Gless) and demonstrated that these viruses activate conventional dendritic cells, although to a lesser extent than live MG1. This translates to equivalent abilities to remove tumor metastases only at the highest viral doses of attenuated MG1. In tandem, we characterized the antitumor ability of NK cells following preoperative administration of live and attenuated MG1. Our results demonstrates that a similar level of NK activation and reduction in postoperative tumor metastases was achieved with equivalent high viral doses concluding that viral replication is important, but not necessary for NK activation. Biochemical characterization of a panel of UV-inactivated MG1 (2–120 minutes) revealed that intact viral particle and target cell recognition are essential for NK cell–mediated antitumor responses. These findings provide mechanistic insight and preclinical rationale for safe perioperative virotherapy to effectively reduce metastatic disease following cancer surgery. PMID:24695102

Contamination of infectious RD-114 virus in vaccines produced using non-feline cell lines.

PubMed

Yoshikawa, Rokusuke; Sato, Eiji; Miyazawa, Takayuki

2011-01-01

All domestic cats have a replication-competent endogenous retrovirus, termed RD-114 virus, in their genome and several feline cell lines produce RD-114 viruses. Recently, we found that a portion of live attenuated feline and canine vaccines produced using feline cell lines was contaminated with infectious RD-114 viruses. In this study, we expanded our survey and examined canine vaccines produced using 'non-feline' cell lines. Consequently, we found two vaccines containing RD-114 viral RNA by reverse transcriptase (RT)-polymerase chain reaction (PCR) and real-time RT-PCR. We also confirmed the presence of infectious RD-114 virus in the vaccines by the LacZ marker rescue assay and PCR to detect proviral DNA in TE671 cells (human rhabdomyosarcoma cells) inoculated with the vaccines. It is impossible to investigate the definitive cause of contamination with RD-114 virus; however, we suspect that a seed canine parvovirus type 2 was contaminated with RD-114 virus, because many canine parvoviruses have been isolated and attenuated using feline cell lines. To exclude RD-114 virus from live attenuated vaccines, we must pay attention to the contamination of seed viruses with RD-114 virus in addition to avoiding feline cell lines producing RD-114 virus when manufacturing vaccines. Copyright © 2010 The International Association for Biologicals. Published by Elsevier Ltd. All rights reserved.

Genetically modified organisms and visceral leishmaniasis.

PubMed

Chhajer, Rudra; Ali, Nahid

2014-01-01

Vaccination is the most effective method of preventing infectious diseases. Since the eradication of small pox in 1976, many other potentially life compromising if not threatening diseases have been dealt with subsequently. This event was a major leap not only in the scientific world already burdened with many diseases but also in the mindset of the common man who became more receptive to novel treatment options. Among the many protozoan diseases, the leishmaniases have emerged as one of the largest parasite killers of the world, second only to malaria. There are three types of leishmaniasis namely cutaneous (CL), mucocutaneous (ML), and visceral (VL), caused by a group of more than 20 species of Leishmania parasites. Visceral leishmaniasis, also known as kala-azar is the most severe form and almost fatal if untreated. Since the first attempts at leishmanization, we have killed parasite vaccines, subunit protein, or DNA vaccines, and now we have live recombinant carrier vaccines and live attenuated parasite vaccines under various stages of development. Although some research has shown promising results, many more potential genes need to be evaluated as live attenuated vaccine candidates. This mini-review attempts to summarize the success and failures of genetically modified organisms used in vaccination against some of major parasitic diseases for their application in leishmaniasis.

Probabilistic atlas-based segmentation of combined T1-weighted and DUTE MRI for calculation of head attenuation maps in integrated PET/MRI scanners.

PubMed

Poynton, Clare B; Chen, Kevin T; Chonde, Daniel B; Izquierdo-Garcia, David; Gollub, Randy L; Gerstner, Elizabeth R; Batchelor, Tracy T; Catana, Ciprian

2014-01-01

We present a new MRI-based attenuation correction (AC) approach for integrated PET/MRI systems that combines both segmentation- and atlas-based methods by incorporating dual-echo ultra-short echo-time (DUTE) and T1-weighted (T1w) MRI data and a probabilistic atlas. Segmented atlases were constructed from CT training data using a leave-one-out framework and combined with T1w, DUTE, and CT data to train a classifier that computes the probability of air/soft tissue/bone at each voxel. This classifier was applied to segment the MRI of the subject of interest and attenuation maps (μ-maps) were generated by assigning specific linear attenuation coefficients (LACs) to each tissue class. The μ-maps generated with this "Atlas-T1w-DUTE" approach were compared to those obtained from DUTE data using a previously proposed method. For validation of the segmentation results, segmented CT μ-maps were considered to the "silver standard"; the segmentation accuracy was assessed qualitatively and quantitatively through calculation of the Dice similarity coefficient (DSC). Relative change (RC) maps between the CT and MRI-based attenuation corrected PET volumes were also calculated for a global voxel-wise assessment of the reconstruction results. The μ-maps obtained using the Atlas-T1w-DUTE classifier agreed well with those derived from CT; the mean DSCs for the Atlas-T1w-DUTE-based μ-maps across all subjects were higher than those for DUTE-based μ-maps; the atlas-based μ-maps also showed a lower percentage of misclassified voxels across all subjects. RC maps from the atlas-based technique also demonstrated improvement in the PET data compared to the DUTE method, both globally as well as regionally.

Omega-3 polyunsaturated fatty acid and ursodeoxycholic acid have an additive effect in attenuating diet-induced nonalcoholic steatohepatitis in mice

PubMed Central

Kim, Ja Kyung; Lee, Kwan Sik; Lee, Dong Ki; Lee, Su Yeon; Chang, Hye Young; Choi, Junjeong; Lee, Jung Il

2014-01-01

Nonalcoholic steatohepatitis (NASH) can progress into liver cirrhosis; however, no definite treatment is available. Omega-3 polyunsaturated fatty acid (omega-3) has been reported to alleviate experimental NASH, although its beneficial effect was not evident when tested clinically. Thus, this study aimed to investigate the additive effect of omega-3 and ursodeoxycholic acid (UDCA) on diet-induced NASH in mice. C57BL/6 mice were given a high-fat diet (HFD) for 24 weeks, at which point the mice were divided into three groups and fed HFD alone, HFD with omega-3 or HFD with omega-3 in combination with UDCA for another 24 weeks. Feeding mice an HFD and administering omega-3 improved histologically assessed liver fibrosis, and UDCA in combination with omega-3 further attenuated this disease. The assessment of collagen α1(I) expression agreed with the histological evaluation. Omega-3 in combination with UDCA resulted in a significant attenuation of inflammation whereas administering omega-3 alone failed to improve histologically assessed liver inflammation. Quantitative analysis of tumor necrosis factor α showed an additive effect of omega-3 and UDCA on liver inflammation. HFD-induced hepatic triglyceride accumulation was attenuated by omega-3 and adding UDCA accentuated this effect. In accordance with this result, the expression of sterol regulatory binding protein-1c decreased after omega-3 administration and adding UDCA further diminished SREBP-1c expression. The expression of inducible nitric oxide synthase (iNOS), which may reflect oxidative stress-induced tissue damage, was suppressed by omega-3 administration and adding UDCA further attenuated iNOS expression. These results demonstrated an additive effect of omega-3 and UDCA for alleviating fibrosis, inflammation and steatosis in diet-induced NASH. PMID:25523099

Omega-3 polyunsaturated fatty acid and ursodeoxycholic acid have an additive effect in attenuating diet-induced nonalcoholic steatohepatitis in mice.

PubMed

Kim, Ja Kyung; Lee, Kwan Sik; Lee, Dong Ki; Lee, Su Yeon; Chang, Hye Young; Choi, Junjeong; Lee, Jung Il

2014-12-19

Nonalcoholic steatohepatitis (NASH) can progress into liver cirrhosis; however, no definite treatment is available. Omega-3 polyunsaturated fatty acid (omega-3) has been reported to alleviate experimental NASH, although its beneficial effect was not evident when tested clinically. Thus, this study aimed to investigate the additive effect of omega-3 and ursodeoxycholic acid (UDCA) on diet-induced NASH in mice. C57BL/6 mice were given a high-fat diet (HFD) for 24 weeks, at which point the mice were divided into three groups and fed HFD alone, HFD with omega-3 or HFD with omega-3 in combination with UDCA for another 24 weeks. Feeding mice an HFD and administering omega-3 improved histologically assessed liver fibrosis, and UDCA in combination with omega-3 further attenuated this disease. The assessment of collagen α1(I) expression agreed with the histological evaluation. Omega-3 in combination with UDCA resulted in a significant attenuation of inflammation whereas administering omega-3 alone failed to improve histologically assessed liver inflammation. Quantitative analysis of tumor necrosis factor α showed an additive effect of omega-3 and UDCA on liver inflammation. HFD-induced hepatic triglyceride accumulation was attenuated by omega-3 and adding UDCA accentuated this effect. In accordance with this result, the expression of sterol regulatory binding protein-1c decreased after omega-3 administration and adding UDCA further diminished SREBP-1c expression. The expression of inducible nitric oxide synthase (iNOS), which may reflect oxidative stress-induced tissue damage, was suppressed by omega-3 administration and adding UDCA further attenuated iNOS expression. These results demonstrated an additive effect of omega-3 and UDCA for alleviating fibrosis, inflammation and steatosis in diet-induced NASH.

Protection induced by a glycoprotein E-deleted bovine herpesvirus type 1 marker strain used either as an inactivated or live attenuated vaccine in cattle.

PubMed

Romera, Sonia Alejandra; Puntel, Mariana; Quattrocchi, Valeria; Del Médico Zajac, Paula; Zamorano, Patricia; Blanco Viera, Javier; Carrillo, Consuelo; Chowdhury, Shafiqul; Borca, Manuel V; Sadir, Ana M

2014-01-08

Bovine herpesvirus type 1 (BoHV-1) is the causative agent of respiratory and genital tract infections; causing a high economic loss in all continents. Use of marker vaccines in IBR eradication programs is widely accepted since it allows for protection of the animals against the disease while adding the possibility of differentiating vaccinated from infected animals.The aim of the present study was the development and evaluation of safety and efficacy of a glycoprotein E-deleted (gE-) BoHV-1 marker vaccine strain (BoHV-1ΔgEβgal) generated by homologous recombination, replacing the viral gE gene with the β-galactosidase (βgal) gene. In vitro growth kinetics of the BoHV-1ΔgEβgal virus was similar to BoHV-1 LA. The immune response triggered by the new recombinant strain in cattle was characterized both as live attenuated vaccine (LAV) and as an inactivated vaccine. BoHV-1ΔgEβgal was highly immunogenic in both formulations, inducing specific humoral and cellular immune responses. Antibody titers found in animals vaccinated with the inactivated vaccine based on BoHV-1ΔgEβgal was similar to the titers found for the control vaccine (BoHV-1 LA). In the same way, titers of inactivated vaccine groups were significantly higher than any of the LAV immunized groups, independently of the inoculation route (p < 0.001). Levels of IFN-γ were significantly higher (p < 0.001) in those animals that received the LAV compared to those that received the inactivated vaccine. BoHV-1ΔgEβgal exhibited an evident attenuation when administered as a LAV; no virus was detected in nasal secretions of vaccinated or sentinel animals during the post-vaccination period. BoHV-1ΔgEβgal, when used in either formulation, elicited an efficient immune response that protected animals against challenge with virulent wild-type BoHV-1. Also, the deletion of the gE gene served as an immunological marker to differentiate vaccinated animals from infected animals. All animals vaccinated with the BoHV-1ΔgE βgal strain were protected against disease after challenge and shed significantly less virus than control calves, regardless of the route and formulation they were inoculated. Based on its attenuation, immunogenicity and protective effect after challenge, BoHV-1ΔgEβgal virus is an efficient and safe vaccine candidate when used either as inactivated or as live attenuated forms.

Morphology supporting function: attenuation correction for SPECT/CT, PET/CT, and PET/MR imaging

PubMed Central

Lee, Tzu C.; Alessio, Adam M.; Miyaoka, Robert M.; Kinahan, Paul E.

2017-01-01

Both SPECT, and in particular PET, are unique in medical imaging for their high sensitivity and direct link to a physical quantity, i.e. radiotracer concentration. This gives PET and SPECT imaging unique capabilities for accurately monitoring disease activity for the purposes of clinical management or therapy development. However, to achieve a direct quantitative connection between the underlying radiotracer concentration and the reconstructed image values several confounding physical effects have to be estimated, notably photon attenuation and scatter. With the advent of dual-modality SPECT/CT, PET/CT, and PET/MR scanners, the complementary CT or MR image data can enable these corrections, although there are unique challenges for each combination. This review covers the basic physics underlying photon attenuation and scatter and summarizes technical considerations for multimodal imaging with regard to PET and SPECT quantification and methods to address the challenges for each multimodal combination. PMID:26576737

Live Attenuated Tularemia Vaccines for Protection Against Respiratory Challenge With Virulent F. tularensis subsp. tularensis

PubMed Central

Jia, Qingmei; Horwitz, Marcus A.

2018-01-01

Francisella tularensis is the causative agent of tularemia and a Tier I bioterrorism agent. In the 1900s, several vaccines were developed against tularemia including the killed “Foshay” vaccine, subunit vaccines comprising F. tularensis protein(s) or lipoproteins(s) in an adjuvant formulation, and the F. tularensis Live Vaccine Strain (LVS); none were licensed in the U.S.A. or European Union. The LVS vaccine retains toxicity in humans and animals—especially mice—but has demonstrated efficacy in humans, and thus serves as the current gold standard for vaccine efficacy studies. The U.S.A. 2001 anthrax bioterrorism attack spawned renewed interest in vaccines against potential biowarfare agents including F. tularensis. Since live attenuated—but not killed or subunit—vaccines have shown promising efficacy and since vaccine efficacy against respiratory challenge with less virulent subspecies holarctica or F. novicida, or against non-respiratory challenge with virulent subsp. tularensis (Type A) does not reliably predict vaccine efficacy against respiratory challenge with virulent subsp. tularensis, the route of transmission and species of greatest concern in a bioterrorist attack, in this review, we focus on live attenuated tularemia vaccine candidates tested against respiratory challenge with virulent Type A strains, including homologous vaccines derived from mutants of subsp. holarctica, F. novicida, and subsp. tularensis, and heterologous vaccines developed using viral or bacterial vectors to express F. tularensis immunoprotective antigens. We compare the virulence and efficacy of these vaccine candidates with that of LVS and discuss factors that can significantly impact the development and evaluation of live attenuated tularemia vaccines. Several vaccines meet what we would consider the minimum criteria for vaccines to go forward into clinical development—safety greater than LVS and efficacy at least as great as LVS, and of these, several meet the higher standard of having efficacy ≥LVS in the demanding mouse model of tularemia. These latter include LVS with deletions in purMCD, sodBFt, capB or wzy; LVS ΔcapB that also overexpresses Type VI Secretion System (T6SS) proteins; FSC200 with a deletion in clpB; the single deletional purMCD mutant of F. tularensis SCHU S4, and a heterologous prime-boost vaccine comprising LVS ΔcapB and Listeria monocytogenes expressing T6SS proteins. PMID:29868510

Fourier-transform infrared spectroscopy for rapid screening and live-cell monitoring: application to nanotoxicology.

PubMed

Sundaram, S K; Sacksteder, Colette A; Weber, Thomas J; Riley, Brian J; Addleman, R Shane; Harrer, Bruce J; Peterman, John W

2013-01-01

A significant challenge to realize the full potential of nanotechnology for therapeutic and diagnostic applications is to understand and evaluate how live cells interact with an external stimulus, such as a nanosized particle, and the toxicity and broad risk associated with these stimuli. It is difficult to capture the complexity and dynamics of these interactions by following omics-based approaches exclusively, which can be expensive and time-consuming. Attenuated total reflectance-Fourier transform infrared spectroscopy is well suited to provide noninvasive live-cell monitoring of cellular responses to potentially toxic nanosized particles or other stimuli. This alternative approach provides the ability to carry out rapid toxicity screenings and nondisruptive monitoring of live-cell cultures. We review the technical basis of the approach, the instrument configuration and interface with the biological media, the various effects that impact the data, subsequent data analysis and toxicity, and present some preliminary results on live-cell monitoring.

Label-free monitoring of cell death induced by oxidative stress in living human cells using terahertz ATR spectroscopy

PubMed Central

Zou, Yi; Liu, Qiao; Yang, Xia; Huang, Hua-Chuan; Li, Jiang; Du, Liang-Hui; Li, Ze-Ren; Zhao, Jian-Heng; Zhu, Li-Guo

2017-01-01

We demonstrated that attenuated total reflectance terahertz time-domain spectroscopy (ATR THz-TDS) is able to monitor oxidative stress response of living human cells, which is proven in this work that it is an efficient non-invasive, label-free, real-time and in situ monitoring of cell death. Furthermore, the dielectric constant and dielectric loss of cultured living human breast epithelial cells, and along with their evolution under oxidative stress response induced by high concentration of H2O2, were quantitatively determined in the work. Our observation and results were finally confirmed using standard fluorescence-labeled flow cytometry measurements and visible fluorescence imaging. PMID:29359084

Prospecting genomic regions associated with Columnaris disease in two commercially important rainbow trout breeding populations

USDA-ARS?s Scientific Manuscript database

Flavbacterium Columnare, the causative agent of Columnaris disease (CD), is distributed around the world in fresh water sources, infecting freshwater finfish species. Recently it has been identified as an emerging problem for the rainbow trout aquaculture industry in the US. Two live-attenuated va...

Rational design of avian metapneumovirus live attenuated vaccines by inhibiting viral messenger RNA cap methyltransferase

USDA-ARS?s Scientific Manuscript database

Avian metapneumovirus (aMPV), also known as avian pneumovirus or turkey rhinotracheitis, is a non-segmented negative-sense RNA virus belonging to the family of Paramyxoviridae, the subfamily Pneumovirinae, and the genus Metapneumovirus. aMPV is the causative agent of respiratory tract infection and ...

Factors affecting induction of peripheral IFN-gamma recall response to influenza A virus vaccination in pigs

USDA-ARS?s Scientific Manuscript database

While T cell contribution to IAV immunity is appreciated, data comparing methods to evaluate IFN-gamma production by IAV-specific T cells elicited following vaccination is limited. To understand the differential immunogenicity between live-attenuated influenza virus (LAIV) and whole-inactivated viru...

Oral vaccination of channel catfish against enteric septicemia of catfish using a live attenuated Edwardsiella ictaluri isolate

USDA-ARS?s Scientific Manuscript database

Enteric septicemia of catfish (ESC), caused by Edwardsiella ictaluri, is the most problematic bacterial disease affecting catfish aquaculture in the southeastern United States. Efforts to develop an effective ESC vaccine have had limited industrial success. In commercial settings, ESC vaccines are...

Nasal lavage natural killer cell function is suppressed in smokers after live attenuated influenza virus

EPA Science Inventory

Background Modified function of immune cells in nasal secretions may playa role in the enhanced susceptibility to resp iratory viruses that is seen in smokers. Innate immune cells in nasal secretions have largely been characterized by cellular differentials using morphologic c...

Towards the intelligent design of a vaccine against Edwardsiella ictaluri

USDA-ARS?s Scientific Manuscript database

Edwardsiella ictaluri is the leading cause of disease loss in the catfish industry in the United States, accounting for an estimated 20.2 % loss in 2009. Previous work to establish live-attenuated vaccines for E. ictaluri demonstrated a relatively weak channel catfish immune response, with better im...

Laboratory measurements of wave attenuation through model and live vegetation

USDA-ARS?s Scientific Manuscript database

Surge and waves generated by hurricanes and tropical storms often cause severe damage and loss of life in coastal areas. It is widely recognized that wetlands along coastal fringes reduce storm surge and waves. Yet, the potential role and primary mechanisms of wave mitigation by wetland vegetation a...

Experimental investigation of wave attenuation through model and live vegetation

USDA-ARS?s Scientific Manuscript database

Hurricanes and tropical storms often cause severe damage and loss of life in coastal areas. It is widely recognized that wetlands along coastal fringes reduce storm surge and waves. Yet, the potential role and primary mechanisms of wave mitigation by wetland vegetation are not fully understood. K...

Sequence Stability of PRRSV Chimeras After Passage in Swine

USDA-ARS?s Scientific Manuscript database

Recombinant chimeric porcine reproductive and respiratory syndrome virus (PRRSV), generated from parental strains MN184 and a licensed modified live vaccine (Ingelvac® PRRS MLV), and a MN184 nsp2 deletion mutant were used to elucidate the mechanisms of attenuation and/or protective immunity to heter...

Earth-Space Link Attenuation Estimation via Ground Radar Kdp

NASA Technical Reports Server (NTRS)

Bolen, Steven M.; Benjamin, Andrew L.; Chandrasekar, V.

2003-01-01

A method of predicting attenuation on microwave Earth/spacecraft communication links, over wide areas and under various atmospheric conditions, has been developed. In the area around the ground station locations, a nearly horizontally aimed polarimetric S-band ground radar measures the specific differential phase (Kdp) along the Earth-space path. The specific attenuation along a path of interest is then computed by use of a theoretical model of the relationship between the measured S-band specific differential phase and the specific attenuation at the frequency to be used on the communication link. The model includes effects of rain, wet ice, and other forms of precipitation. The attenuation on the path of interest is then computed by integrating the specific attenuation over the length of the path. This method can be used to determine statistics of signal degradation on Earth/spacecraft communication links. It can also be used to obtain real-time estimates of attenuation along multiple Earth/spacecraft links that are parts of a communication network operating within the radar coverage area, thereby enabling better management of the network through appropriate dynamic routing along the best combination of links.

Preparation of live attenuated leishmania parasites by using laser technology

NASA Astrophysics Data System (ADS)

Hussain, Nabiha; Alkhouri, Hassan; Haddad, Shaden

2018-05-01

Leishmaniasis is a parasitic disease of humans, affecting the skin, mucosal and/or internal organs, caused by flagellate protozoa Leishmania of the Trypanosomatidae family. Leishmania would be one for which a vaccine could be developed with relative ease. Many studies mount an effective response that resolves the infection and confers solid immunity to reinfection and suggesting that infection may be a prerequisite for immunological memory. Genetically altered live attenuated parasites with controlled infectivity could achieve such immunological memory. Recent concepts include use of genetically modified live-attenuated Leishmania parasites, and proteomics approach for the search of a cross-protective leishmanial vaccine that would ideally protect against both cutaneous and visceral forms of the disease. No licensed vaccine is available till date against any form of leishmaniasis. The present study evaluated role of laser technology in development of a safe live Leishmania vaccine, a vaccine is a biological preparation that improves immunity to a particular disease, and is often made from weakened or killed forms of LPs. The parasite culture was expanded in RPMI 1640 medium with 10% fetal calf serum (FCS) and grown until stationary phase for experiments. 80 samples of leishmania promastigotes (Culture media of LPs) were exposed to Nd:YAG laser (wavelength 1064 nm, single spot or double) with different outputs powers (7w, 100 Hz, 99.03w/cm2, 0.99 J/cm2 and 8 w, 100 Hz, 113.18w/cm2 1.13J/cm2)) for suitable exposer times. The effect of semiconductor laser (wavelength 810 nm, 7w, 2000 Hz, 99.03w/cm2, 0.05 J/cm2) or (7 w, 500 Hz, 99.03 w/cm2, 0.2J/cm2) single spot or double with long exposure times. The viability of Leishmania parasites was measured using XTT method; viable parasites were decreased with long exposure times. XTT test referred both these wavelengths were effective in killing percentage of Leishmania promastigotes, the remaining were devoid flagellum that may lost their ability to cause infection and could be used as vaccine.

Attenuation of an original US porcine epidemic diarrhea virus strain PC22A via serial cell culture passage.

PubMed

Lin, Chun-Ming; Hou, Yixuan; Marthaler, Douglas G; Gao, Xiang; Liu, Xinsheng; Zheng, Lanlan; Saif, Linda J; Wang, Qiuhong

2017-03-01

Although porcine epidemic diarrhea (PED) has caused huge economic losses in the pork industry worldwide, an effective live, attenuated vaccine is lacking. In this study, an original US, highly virulent PED virus (PEDV) strain PC22A was serially passaged in Vero CCL81 and Vero BI cells. The virus growth kinetics in cell culture, virulence in neonatal pigs and the whole genomic sequences of selected passages were examined. Increased virus titers and sizes of syncytia were observed at the 65th passage level (P65) and P120, respectively. Based on the severity of clinical signs, histopathological lesions and the distribution of PEDV antigens in the gut, the virulence of P100 and above, but not P95C13 (CCL81), was markedly reduced in 4-day-old, caesarian-derived, colostrum-deprived piglets. Subsequently, the attenuation of P120 and P160 was confirmed in 4-day-old, conventional suckling piglets. Compared with P120, P160 replicated less efficiently in the intestine of pigs and induced a lower rate of protection after challenge. Sequence analysis revealed that the virulent viruses [P3 and P95C13 (CCL81)] had one, one, sixteen (including an early termination of nine amino acids) and two amino acid differences in non-structure protein 1 (nsp1), nsp4, spike and membrane proteins, respectively, from the fully attenuated P160. However, the overall pattern of attenuation-related genetic changes in PC22A differed from those of the other four pairs of PEDV wild type strains and their attenuated derivatives. These results suggest that PEDV attenuation can occur through multiple molecular mechanisms. The knowledge provides insights into potential molecular mechanisms of PEDV attenuation. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparison of RNFL thickness and RPE-normalized RNFL attenuation coefficient for glaucoma diagnosis

NASA Astrophysics Data System (ADS)

Vermeer, K. A.; van der Schoot, J.; Lemij, H. G.; de Boer, J. F.

2013-03-01

Recently, a method to determine the retinal nerve fiber layer (RNFL) attenuation coefficient, based on normalization on the retinal pigment epithelium, was introduced. In contrast to conventional RNFL thickness measures, this novel measure represents a scattering property of the RNFL tissue. In this paper, we compare the RNFL thickness and the RNFL attenuation coefficient on 10 normal and 8 glaucomatous eyes by analyzing the correlation coefficient and the receiver operator curves (ROCs). The thickness and attenuation coefficient showed moderate correlation (r=0.82). Smaller correlation coefficients were found within normal (r=0.55) and glaucomatous (r=0.48) eyes. The full separation between normal and glaucomatous eyes based on the RNFL attenuation coefficient yielded an area under the ROC (AROC) of 1.0. The AROC for the RNFL thickness was 0.9875. No statistically significant difference between the two measures was found by comparing the AROC. RNFL attenuation coefficients may thus replace current RNFL thickness measurements or be combined with it to improve glaucoma diagnosis.

Attenuated live cholera vaccine strain CVD 103-HgR elicits significantly higher serum vibriocidal antibody titers in persons of blood group O.

PubMed Central

Lagos, R; Avendaño, A; Prado, V; Horwitz, I; Wasserman, S; Losonsky, G; Cryz, S; Kaper, J B; Levine, M M

1995-01-01

Persons of blood group O are at increased risk of developing cholera gravis. In a randomized, placebo-controlled, double-blind safety-immunogenicity trial of live oral cholera vaccine CVD 103-HgR in 5- to 9-year-old Chilean children, vibriocidal antibody seroconversion (74% overall) did not differ by blood group. However, the reciprocal geometric mean titer (GMT) in blood group O vaccines (GMT = 486) was higher than that in non-O vaccines (GMT = 179) (P < 0.02). PMID:7822046

Safety of live vaccines on immunosuppressive or immunomodulatory therapy-a retrospective study in three Swiss Travel Clinics.

PubMed

Huber, Fabienne; Ehrensperger, Benoît; Hatz, Christoph; Chappuis, François; Bühler, Silja; Eperon, Gilles

2018-01-01

Patients increasingly benefit from immunosuppressive/immunomodulatory medications for a range of conditions allowing them a lifestyle similar to healthy individuals, including travel. However, the administration of live vaccines to immunodeficient patients bears the risk of replication of the attenuated vaccine microorganism. Therefore, live vaccines are generally contraindicated on immunosuppression. Data on live vaccinations on immunosuppressive/immunomodulatory medication are scarce. We identified all travellers seeking pre-travel advice in three Swiss travel clinics with a live vaccine during immunosuppressive/immunomodulatory therapy to ascertain experienced side effects. A retrospective and multi-centre study design was chosen to increase the sample size. This study was conducted in the travel clinics of the University of Zurich; the Swiss TPH, Basel; and Geneva University Hospitals. Travellers on immunosuppressive/immunomodulatory therapy who received live vaccines [yellow fever vaccination (YFV), measles/mumps/rubella (MMR), varicella and/ or oral typhoid vaccination (OTV)] between 2008 and 2015 were identified and interviewed. A total of 60 age- and sex-matched controls (matched to Basel/Zurich travel clinics travellers) were included. Overall, 197 patients were identified. And 116 patients (59%) and 60 controls were interviewed. YFV was administered 92 times, MMR 21 times, varicella 4 times and OTV 6 times to patients on immunosuppressive/immunomodulatory therapy. Most common medications were corticosteroids (n = 45), mesalazine (n = 28) and methotrexate (n = 19). Live vaccines were also administered on biological treatment, e.g. TNF-alpha inhibitors (n = 8). Systemic reactions were observed in 12.2% of the immunosuppressed vs 13.3% of controls; local reactions in 7.8% of the immunosuppressed vs 11.7% of controls. In controls, all reactions were mild/moderate. In the immunosuppressed, 2/21 severe reactions occurred: severe local pain on interferon-beta and severe muscle/joint pain on sulfasalazine. Safety of live vaccines given to immunosuppressed patients cannot be concluded. However, it is re-assuring that in the examined patient groups no serious side effects or infections by the attenuated vaccine strain occurred. © International Society of Travel Medicine, 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

Time‐lapse imaging of saline‐tracer transport in fractured rock using difference‐attenuation radar tomography

USGS Publications Warehouse

Day-Lewis, Frederick D.; Lane, John W.; Harris, Jerry M.; Gorelick, Steven M.

2003-01-01

Accurate characterization of fractured‐rock aquifer heterogeneity remains one of the most challenging and important problems in groundwater hydrology. We demonstrate a promising strategy to identify preferential flow paths in fractured rock using a combination of geophysical monitoring and conventional hydrogeologic tests. Cross‐well difference‐attenuation ground‐penetrating radar was used to monitor saline‐tracer migration in an experiment at the U.S. Geological Survey Fractured Rock Hydrology Research Site in Grafton County, New Hampshire. Radar data sets were collected every 10 min in three adjoining planes for 5 hours during each of 12 tracer tests. An innovative inversion method accounts for data acquisition times and temporal changes in attenuation during data collection. The inverse algorithm minimizes a combination of two functions. The first is the sum of weighted squared data residuals. Second is a measure of solution complexity based on an a priori space‐time covariance function, subject to constraints that limit radar‐attenuation changes to regions of the tomograms traversed by high difference‐attenuation ray paths. The time series of tomograms indicate relative tracer concentrations and tracer arrival times in the image planes; from these we infer the presence and location of a preferential flow path within a previously identified zone of transmissive fractures. These results provide new insights into solute channeling and the nature of aquifer heterogeneity at the site.

New Technologies in Using Recombinant Attenuated Salmonella Vaccine Vectors

PubMed Central

Curtiss, Roy; Xin, Wei; Li, Yuhua; Kong, Wei; Wanda, Soo-Young; Gunn, Bronwyn; Wang, Shifeng

2014-01-01

Recombinant attenuated Salmonella vaccines (RASVs) have been constructed to deliver antigens from other pathogens to induce immunity to those pathogens in vaccinated hosts. The attenuation means should ensure that the vaccine survives following vaccination to colonize lymphoid tissues without causing disease symptoms. This necessitates that attenuation and synthesis of recombinant gene encoded protective antigens do not diminish the ability of orally administered vaccines to survive stresses encountered in the gastrointestinal tract. We have eliminated these problems by using RASVs with regulated delayed expression of attenuation and regulated delayed synthesis of recombinant antigens. These changes result in RASVs that colonize effector lymphoid tissues efficiently to serve as “factories” to synthesize protective antigens that induce higher protective immune responses than achieved when using previously constructed RASVs. We have devised a biological containment system with regulated delayed lysis to preclude RASV persistence in vivo and survival if excreted. Attributes were added to reduce the mild diarrhea sometimes experienced with oral live RASVs and to ensure complete safety in newborns. These collective technologies have been used to develop a novel, low-cost, RASV-synthesizing, multiple-protective Streptococcus pneumoniae antigens that will be safe for newborns/infants and will induce protective immunity to diverse S. pneumoniae serotypes after oral immunization. PMID:20370633

Quantitative Determination of Lethal Toxin Proteins in Culture Supernatant of Human Live Anthrax Vaccine Bacillus anthracis A16R

PubMed Central

Zai, Xiaodong; Zhang, Jun; Liu, Ju; Liu, Jie; Li, Liangliang; Yin, Ying; Fu, Ling; Xu, Junjie; Chen, Wei

2016-01-01

Bacillus anthracis (B. anthracis) is the etiological agent of anthrax affecting both humans and animals. Anthrax toxin (AT) plays a major role in pathogenesis. It includes lethal toxin (LT) and edema toxin (ET), which are formed by the combination of protective antigen (PA) and lethal factor (LF) or edema factor (EF), respectively. The currently used human anthrax vaccine in China utilizes live-attenuated B. anthracis spores (A16R; pXO1+, pXO2−) that produce anthrax toxin but cannot produce the capsule. Anthrax toxins, especially LT, have key effects on both the immunogenicity and toxicity of human anthrax vaccines. Thus, determining quantities and biological activities of LT proteins expressed by the A16R strain is meaningful. Here, we explored LT expression patterns of the A16R strain in culture conditions using another vaccine strain Sterne as a control. We developed a sandwich ELISA and cytotoxicity-based method for quantitative detection of PA and LF. Expression and degradation of LT proteins were observed in culture supernatants over time. Additionally, LT proteins expressed by the A16R and Sterne strains were found to be monomeric and showed cytotoxic activity, which may be the main reason for side effects of live anthrax vaccines. Our work facilitates the characterization of anthrax vaccines components and establishment of a quality control standard for vaccine production which may ultimately help to ensure the efficacy and safety of the human anthrax vaccine A16R. PMID:26927174

Detector power linearity requirements and verification techniques for TMI direct detection receivers

NASA Technical Reports Server (NTRS)

Reinhardt, Victor S. (Inventor); Shih, Yi-Chi (Inventor); Toth, Paul A. (Inventor); Reynolds, Samuel C. (Inventor)

1997-01-01

A system (36, 98) for determining the linearity of an RF detector (46, 106). A first technique involves combining two RF signals from two stable local oscillators (38, 40) to form a modulated RF signal having a beat frequency, and applying the modulated RF signal to a detector (46) being tested. The output of the detector (46) is applied to a low frequency spectrum analyzer (48) such that a relationship between the power levels of the first and second harmonics generated by the detector (46) of the beat frequency of the modulated RF signal are measured by the spectrum analyzer (48) to determine the linearity of the detector (46). In a second technique, an RF signal from a local oscillator (100) is applied to a detector (106) being tested through a first attenuator (102) and a second attenuator (104). The output voltage of the detector (106) is measured when the first attenuator (102) is set to a particular attenuation value and the second attenuator (104) is switched between first and second attenuation values. Further, the output voltage of the detector (106) is measured when the first attenuator (102) is set to another attenuation value, and the second attenuator (104) is again switched between the first and second attenuation values. A relationship between the voltage outputs determines the linearity of the detector (106).

Detection of attenuated plaque in stable angina with 64-multidetector computed tomography: a comparison with intravascular ultrasound.

PubMed

Jinzaki, Masahiro; Okabe, Teruo; Endo, Ayaka; Kawamura, Akio; Koga, Seiko; Yamada, Minoru; Fukuda, Keiichi; Kuribayashi, Sachio

2012-01-01

To clarify multidetector computed tomography (MDCT) findings of attenuated plaque detected by intravascular ultrasound (IVUS). One hundred and fifty-four patients with stable angina underwent MDCT before IVUS. The attenuated plaque was identified in the targeted artery with IVUS, and the same artery was analyzed with MDCT for the presence of a high density area (HDA) >130 Hounsfield units (HU), and a low density area (LDA) <30 HU. A HDA in attenuated plaque was compared with that in calcified plaque. Ten attenuated plaques and 15 calcified plaques were identified in 9 of 154 patients (males=9, 66.2 ± 9.5 years). Eight of the 10 attenuated plaques and all 15 calcified plaques were accompanied with a HDA on MDCT. The HDA ranged from 174 to 667 HU (mean 389.0 ± 148.3 HU) in the 8 attenuated plaques, and from 545 to 1,205 HU (mean 920.9 ± 215.9 HU) in 15 calcified plaques. There was a significant difference in CT density of the HDA between the attenuated and calcified plaque (P<0.001). All attenuated plaques contained LDA <30 HU in the portions without HDA. MDCT has the ability to demonstrate attenuated plaque as the combination of HDA (approximately 400 HU on average) and LDA <30 HU. The HDA can be differentiated from calcified plaque by its lower CT density value.

Vibration attenuations induced by periodic arrays of piezoelectric patches connected by enhanced resonant shunting circuits

NASA Astrophysics Data System (ADS)

Wang, Gang; Wang, Jianwei; Chen, Shengbing; Wen, Jihong

2011-12-01

Periodic arrays of piezoelectric patches connected by enhanced resonant shunting circuits are attached to a slender beam to control the propagation of vibration. Numerical models based on the transfer matrix methodology are constructed to predict the band structure, attenuation factors and the transmission of vibration in the proposed smart structure. The vibration attenuations of the proposed smart structure and that with the passive resonant shunting circuits are compared in order to verify the efficiency of the enhanced resonant shunting circuits. Vibration experiments are conducted in order to validate the theoretical predictions. The specimen with a combination of different types of resonant shunting circuits is also studied in order to gain wider attenuation frequency ranges.

Micro-attenuated total reflection spectral imaging in archaeology: application to Maya paint and plaster wall decorations.

PubMed

Goodall, Rosemary A; Hall, Jay; Sharer, Robert J; Traxler, Loa; Rintoul, Llew; Fredericks, Peter M

2008-01-01

Fourier transform infrared (FT-IR) attenuated total reflection (ATR) imaging has been successfully used to identify individual mineral components of ancient Maya paint. The high spatial resolution of a micro FT-IR-ATR system in combination with a focal plane array detector has allowed individual particles in the paint to be resolved and identified from their spectra. This system has been used in combination with micro-Raman spectroscopy to characterize the paint, which was found to be a mixture of hematite and silicate particles with minor amounts of calcite, carbon, and magnetite particles in a sub-micrometer hematite and calcite matrix. The underlying stucco was also investigated and found to be a combination of calcite with fine carbon particles, making a dark sub-ground for the paint.

An adaptive tensor voting algorithm combined with texture spectrum

NASA Astrophysics Data System (ADS)

Wang, Gang; Su, Qing-tang; Lü, Gao-huan; Zhang, Xiao-feng; Liu, Yu-huan; He, An-zhi

2015-01-01

An adaptive tensor voting algorithm combined with texture spectrum is proposed. The image texture spectrum is used to get the adaptive scale parameter of voting field. Then the texture information modifies both the attenuation coefficient and the attenuation field so that we can use this algorithm to create more significant and correct structures in the original image according to the human visual perception. At the same time, the proposed method can improve the edge extraction quality, which includes decreasing the flocculent region efficiently and making image clear. In the experiment for extracting pavement cracks, the original pavement image is processed by the proposed method which is combined with the significant curve feature threshold procedure, and the resulted image displays the faint crack signals submerged in the complicated background efficiently and clearly.

Ground potential rise monitor

DOEpatents

Allen, Zachery Warren; Zevenbergen, Gary Allen

2012-07-17

A device and method for detecting ground potential rise (GPR) comprising a first electrode, a second electrode, and a voltage attenuator. The first electrode and the second electrode are both electrically connected to the voltage attenuator. A means for determining the presence of a dangerous ground potential is connected to the voltage attenuator. The device and method further comprises a means for enabling one or more alarms upon the detection of the dangerous ground potential. Preferably, a first transmitter/receiver is connected to the means for enabling one or more alarms. Preferably, a second transmitter/receiver, comprising a button, is electromagnetically connected to the first transmitter/receiver. Preferably, the means for determining the presence of a dangerous ground potential comprises a means for determining the true RMS voltage at the output of the voltage attenuator, a transient detector connected to the output of the voltage attenuator, or a combination thereof.

Calculated mammographic spectra confirmed with attenuation curves for molybdenum, rhodium, and tungsten targets.

PubMed

Blough, M M; Waggener, R G; Payne, W H; Terry, J A

1998-09-01

A model for calculating mammographic spectra independent of measured data and fitting parameters is presented. This model is based on first principles. Spectra were calculated using various target and filter combinations such as molybdenum/molybdenum, molybdenum/rhodium, rhodium/rhodium, and tungsten/aluminum. Once the spectra were calculated, attenuation curves were calculated and compared to measured attenuation curves. The attenuation curves were calculated and measured using aluminum alloy 1100 or high purity aluminum filtration. Percent differences were computed between the measured and calculated attenuation curves resulting in an average of 5.21% difference for tungsten/aluminum, 2.26% for molybdenum/molybdenum, 3.35% for rhodium/rhodium, and 3.18% for molybdenum/rhodium. Calculated spectra were also compared to measured spectra from the Food and Drug Administration [Fewell and Shuping, Handbook of Mammographic X-ray Spectra (U.S. Government Printing Office, Washington, D.C., 1979)] and a comparison will also be presented.

Zika Virus Attenuation by Codon Pair Deoptimization Induces Sterilizing Immunity in Mouse Models.

PubMed

Li, Penghui; Ke, Xianliang; Wang, Ting; Tan, Zhongyuan; Luo, Dan; Miao, Yuanjiu; Sun, Jianhong; Zhang, Yuan; Liu, Yan; Hu, Qinxue; Xu, Fuqiang; Wang, Hanzhong; Zheng, Zhenhua

2018-06-20

Zika virus (ZIKV) infection during the large epidemics in the Americas is related to congenital abnormities or fetal demise. To date, there is no vaccine, antiviral drug, or other modality available to prevent or treat Zika virus infection. Here we designed novel live attenuated ZIKV vaccine candidates using a codon pair deoptimization strategy. Three codon pair-deoptimized ZIKVs (Min E, Min NS1, and Min E+NS1) were de novo synthesized, and recovered by reverse genetics, containing large amounts of underrepresented codon pairs in E gene and/or NS1 gene. Amino acid sequence was 100% unchanged. The codon pair-deoptimized variants had decreased replication fitness in Vero cells (Min NS1 ≫ Min E > Min E+NS1), replicated more efficiently in insect cells than in mammalian cells, and demonstrated diminished virulence in a mouse model. In particular, Min E+NS1, the most restrictive variant, induced sterilizing immunity with a robust neutralizing antibody titer, and a single immunization achieved complete protection against lethal challenge and vertical ZIKV transmission during pregnancy. More importantly, due to the numerous synonymous substitutions in the codon pair-deoptimized strains, reversion to wild-type virulence through gradual nucleotide sequence mutations is unlikely. Our results collectively demonstrate that ZIKV can be effectively attenuated by codon pair deoptimization, highlighting the potential of Min E+NS1 as a safe vaccine candidate to prevent ZIKV infections. IMPORTANCE Due to unprecedented epidemics of Zika virus (ZIKV) across the Americas and the unexpected clinical symptoms including Guillain-Barré syndrome, microcephaly and other birth defects in human, there is an urgent need for ZIKV vaccine development. Here, we provided the first attenuated versions of ZIKV with two important genes (E and/or NS1) that were subjected to codon pair deoptimization. Compared to parental ZIKV, the codon pair-deoptimized ZIKVs were mammalian-attenuated, and preferred insect to mammalian Cells. Min E+NS1, the most restrictive variant, induced sterilizing immunity with a robust neutralizing antibody titer, and achieved complete protection against lethal challenge and vertical virus transmission during pregnancy. More importantly, the massive synonymous mutational approach made it impossible to revert to wild-type virulence. Our results have proven the feasibility of codon pair deoptimization as a strategy to develop live-attenuated vaccine candidates against flavivirues like ZIKV, Japanese encephalitis virus and West Nile virus. Copyright © 2018 American Society for Microbiology.

Prodromal disease: Immune responses of the host macrophage system to humoral factors

NASA Technical Reports Server (NTRS)

Criswell, B. S.; Knight, V.

1973-01-01

A composite is presented of nine studies, each yielding information contributing toward an understanding of methods designed to detect disease during the prodromal stages. The data further point to new areas of study that might be useful in early diagnoses. Five of the none experiments were done in mice. Four of these involved acute infectious disease states and one involved a chronic autoimmune type disease. Of the numerous perimeters studied of the acute diseases, the uptake of H3- thymidine by peripheral blood lymphocytes appeared to yield the earliest indication of disease. This test was not useful in studying the chronic disease state. Four of the nine studies involved application of diagnostic technics to human disease. A normal baseline for H3-thymidine incorporation by human lymphocytes was determined. A subject with severe combined immunodeficiency disease was studied. A human volunteer study was done using Influenza A live attenuated vaccine. Finally, a human volunteer study of subjects infected with Influenza A was done.

Kif18A and chromokinesins confine centromere movements via microtubule growth suppression and spatial control of kinetochore tension

PubMed Central

Stumpff, Jason; Wagenbach, Michael; Franck, Andrew; Asbury, Charles L.; Wordeman, Linda

2012-01-01

Summary Alignment of chromosomes at the metaphase plate is a signature of cell division in metazoan cells, yet the mechanisms controlling this process remain ambiguous. Here we use a combination of quantitative live cell imaging and reconstituted dynamic microtubule assays to investigate the molecular control of mitotic centromere movements. We establish that Kif18A (kinesin-8) attenuates centromere movement by directly promoting microtubule pausing in a concentration-dependent manner. This activity provides the dominant mechanism for restricting centromere movement to the spindle midzone. Furthermore, polar ejection forces spatially confine chromosomes via position-dependent regulation of kinetochore tension and centromere switch rates. We demonstrate that polar ejection forces are antagonistically modulated by chromokinesins. These pushing forces depend on Kid (kinesin-10) activity and are antagonized by Kif4A (kinesin-4), which functions to directly suppress microtubule growth. These data support a model in which Kif18A and polar ejection forces synergistically promote centromere alignment via spatial control of kinetochore-microtubule dynamics. PMID:22595673

A Role for the Juxtamembrane Cytoplasm in the Molecular Dynamics of Focal Adhesions

PubMed Central

Wolfenson, Haguy; Lubelski, Ariel; Regev, Tamar; Klafter, Joseph; Henis, Yoav I.; Geiger, Benjamin

2009-01-01

Focal adhesions (FAs) are specialized membrane-associated multi-protein complexes that link the cell to the extracellular matrix and play crucial roles in cell-matrix sensing. Considerable information is available on the complex molecular composition of these sites, yet the regulation of FA dynamics is largely unknown. Based on a combination of FRAP studies in live cells, with in silico simulations and mathematical modeling, we show that the FA plaque proteins paxillin and vinculin exist in four dynamic states: an immobile FA-bound fraction, an FA-associated fraction undergoing exchange, a juxtamembrane fraction experiencing attenuated diffusion, and a fast-diffusing cytoplasmic pool. The juxtamembrane region surrounding FAs displays a gradient of FA plaque proteins with respect to both concentration and dynamics. Based on these findings, we propose a new model for the regulation of FA dynamics in which this juxtamembrane domain acts as an intermediary layer, enabling an efficient regulation of FA formation and reorganization. PMID:19172999

Clinical and serological response of wild dogs (Lycaon pictus) to vaccination against canine distemper, canine parvovirus infection and rabies.

PubMed

van Heerden, J; Bingham, J; van Vuuren, M; Burroughs, R E J; Stylianides, E

2002-03-01

Wild dogs Lycaon pictuis (n = 8) were vaccinated 4 times against canine distemper (n = 8) (initially with inactivated and subsequently with live attenuated strains of canine distemper) and canine parvovirus infection (n = 8) over a period of 360 days. Four of the wild dogs were also vaccinated 3 times against rabies using a live oral vaccine and 4 with an inactivated parenteral vaccine. Commercially-available canine distemper, canine parvovirus and parenteral rabies vaccines, intended for use in domestic dogs, were used. None of the vaccinated dogs showed any untoward clinical signs. The inactivated canine distemper vaccine did not result in seroconversion whereas the attenuated live vaccine resulted in seroconversion in all wild dogs. Presumably protective concentrations of antibodies to canine distemper virus were present in all wild dogs for at least 451 days. Canine parvovirus haemagglutination inhibition titres were present in all wild dogs prior to the administration of vaccine and protective concentrations persisted for at least 451 days. Vaccination against parvovirus infection resulted in a temporary increase in canine parvovirus haemagglutination inhibition titres in most dogs. Administration of both inactivated parenteral and live oral rabies vaccine initially resulted in seroconversion in 7 of 8 dogs. These titres, however, dropped to very low concentrations within 100 days. Booster administrations resulted in increased antibody concentrations in all dogs. It was concluded that the vaccines were safe to use in healthy subadult wild dogs and that a vaccination protocol in free-ranging wild dogs should at least incorporate booster vaccinations against rabies 3-6 months after the first inoculation.

Vaccine-induced canine distemper in a lesser panda.

PubMed

Bush, M; Montali, R J; Brownstein, D; James, A E; Appel, M J

1976-11-01

A fatal disease occurred in a lesser panda (Ailurus fulgens) 2 weeks after vaccination with modified live distemper vaccine. The disease clinically resembled canine distemper. Pathologically there was giant cell pneumonia, with canine distemper viral inclusion bodies in pulmonary and digestive tract epithelium. Viral isolates were indicative of an attenuated strain rather than virulent types.

Oral vaccination of channel catfish against enteric septicemia of catfish (ESC) using a live attenuated Edwardsiella ictaluri isolate

USDA-ARS?s Scientific Manuscript database

Enteric septicemia of catfish (ESC), caused by Edwardsiella ictaluri, is the most problematic bacterial disease affecting catfish aquaculture in the southeastern United States. Efforts to develop an effective ESC vaccine have had limited industrial success. In commercial settings, ESC vaccines are t...

An overview of live attenuated recombinant pseudorabies viruses for use as novel vaccines

USDA-ARS?s Scientific Manuscript database

Pseudorabies virus (PRV) is a double-stranded, DNA-based swine virus with a genome approximating 150 kb in size. In cell culture, PRV has many non-essential genes which can be replaced with genes encoding heterologous antigens but without deleterious effects on virus propagation. Recombinant PRVs ex...

Evaluation of the infection and transmission of wild type and recombinant strains of Newcastle disease virus in Japanese Quail

USDA-ARS?s Scientific Manuscript database

Newcastle disease virus (NDV) causes a range of clinical disease ranging from asymptomatic infection to severe disease with high mortality. Vaccination for NDV is practiced almost worldwide in commercial chickens. Attenuated live vaccines are most commonly used, with recombinant vaccines becoming ...

Inactivated and subunit vaccines against porcine reproductive and respiratory syndrome: current status and future direction

USDA-ARS?s Scientific Manuscript database

Within a few years of its emergence in the late 1980's, the PRRS virus had spread globally to become the foremost infectious disease concern for the pork industry. Since 1994, modified live-attenuated vaccines against porcine reproductive and respiratory syndrome virus (PRRSV-MLV) have been widely u...

Engineered newcastle disease virus expressing the F and G protein of AMPV-C confers protection against challenges in turkeys.

USDA-ARS?s Scientific Manuscript database

Avian metapneumovirus (aMPV) infects the respiratory and reproductive tracts of domestic poultry, which may develop into secondary infections that can result in substantial economic losses for producers. Live attenuated vaccines appear to be the most effective in countries where the disease is prev...

Random codon re-encoding induces stable reduction of replicative fitness of Chikungunya virus in primate and mosquito cells.

PubMed

Nougairede, Antoine; De Fabritus, Lauriane; Aubry, Fabien; Gould, Ernest A; Holmes, Edward C; de Lamballerie, Xavier

2013-02-01

Large-scale codon re-encoding represents a powerful method of attenuating viruses to generate safe and cost-effective vaccines. In contrast to specific approaches of codon re-encoding which modify genome-scale properties, we evaluated the effects of random codon re-encoding on the re-emerging human pathogen Chikungunya virus (CHIKV), and assessed the stability of the resultant viruses during serial in cellulo passage. Using different combinations of three 1.4 kb randomly re-encoded regions located throughout the CHIKV genome six codon re-encoded viruses were obtained. Introducing a large number of slightly deleterious synonymous mutations reduced the replicative fitness of CHIKV in both primate and arthropod cells, demonstrating the impact of synonymous mutations on fitness. Decrease of replicative fitness correlated with the extent of re-encoding, an observation that may assist in the modulation of viral attenuation. The wild-type and two re-encoded viruses were passaged 50 times either in primate or insect cells, or in each cell line alternately. These viruses were analyzed using detailed fitness assays, complete genome sequences and the analysis of intra-population genetic diversity. The response to codon re-encoding and adaptation to culture conditions occurred simultaneously, resulting in significant replicative fitness increases for both re-encoded and wild type viruses. Importantly, however, the most re-encoded virus failed to recover its replicative fitness. Evolution of these viruses in response to codon re-encoding was largely characterized by the emergence of both synonymous and non-synonymous mutations, sometimes located in genomic regions other than those involving re-encoding, and multiple convergent and compensatory mutations. However, there was a striking absence of codon reversion (<0.4%). Finally, multiple mutations were rapidly fixed in primate cells, whereas mosquito cells acted as a brake on evolution. In conclusion, random codon re-encoding provides important information on the evolution and genetic stability of CHIKV viruses and could be exploited to develop a safe, live attenuated CHIKV vaccine.

Genetic stability of Rift Valley fever virus MP-12 vaccine during serial passages in culture cells.

PubMed

Lokugamage, Nandadeva; Ikegami, Tetsuro

2017-01-01

Rift Valley fever (RVF) is a mosquito-borne zoonotic disease endemic to Africa which affects both ruminants and humans. RVF causes serious damage to the livestock industry and is also a threat to public health. The Rift Valley fever virus has a segmented negative-stranded RNA genome consisting of Large (L)-, Medium (M)-, and Small (S)-segments. The live-attenuated MP-12 vaccine is immunogenic in livestock and humans, and is conditionally licensed for veterinary use in the U.S. The MP-12 strain encodes 23 mutations (nine amino acid substitutions) and is attenuated through a combination of mutations in the L-, M-, and S-segments. Among them, the M-U795C, M-A3564G, and L-G3104A mutations contribute to viral attenuation through the L- and M-segments. The M-U795C, M-A3564G, L-U533C, and L-G3750A mutations are also independently responsible for temperature-sensitive (ts) phenotype. We hypothesized that a serial passage of the MP-12 vaccine in culture cells causes reversions of the MP-12 genome. The MP-12 vaccine and recombinant rMP12-ΔNSs16/198 were serially passaged 25 times. Droplet digital PCR analysis revealed that the reversion occurred at L-G3750A during passages of MP-12 in Vero or MRC-5 cells. The reversion also occurred at M-A3564G and L-U533C of rMP12-ΔNSs16/198 in Vero cells. Reversion mutations were not found in MP-12 or the variant, rMP12-TOSNSs, in the brains of mice with encephalitis. This study characterized genetic stability of the MP-12 vaccine and the potential risk of reversion mutation at the L-G3750A ts mutation after excessive viral passages in culture cells.

Foot-and-mouth disease virus 5'-terminal S fragment is required for replication and modulation of the innate immune response in host cells.

PubMed

Kloc, Anna; Diaz-San Segundo, Fayna; Schafer, Elizabeth A; Rai, Devendra K; Kenney, Mary; de Los Santos, Teresa; Rieder, Elizabeth

2017-12-01

The S fragment of the FMDV 5' UTR is predicted to fold into a long stem-loop structure and it has been implicated in virus-host protein interactions. In this study, we report the minimal S fragment sequence required for virus viability and show a direct correlation between the extent of the S fragment deletion mutations and attenuated phenotypes. Furthermore, we provide novel insight into the role of the S fragment in modulating the host innate immune response. Importantly, in an FMDV mouse model system, all animals survive the inoculation with the live A 24 FMDV-S 4 mutant, containing a 164 nucleotide deletion in the upper S fragment loop, at a dose 1000 higher than the one causing lethality by parental A 24 FMDV, indicating that the A 24 FMDV-S 4 virus is highly attenuated in vivo. Additionally, mice exposed to high doses of live A 24 FMDV-S 4 virus are fully protected when challenged with parental A 24 FMDV virus. Published by Elsevier Inc.

Advances & challenges in leptospiral vaccine development.

PubMed

Bashiru, Garba; Bahaman, Abdul Rani

2018-01-01

Considerable progress has been made in the field of leptospiral vaccines development since its first use as a killed vaccine in guinea pigs. Despite the fact that the immunity conferred is restricted to serovars with closely related lipopolysaccharide antigen, certain vaccines have remained useful, especially in endemic regions, for the protection of high-risk individuals. Other conventional vaccines such as the live-attenuated vaccine and lipopolysaccharide (LPS) vaccine have not gained popularity due to the reactive response that follows their administration and the lack of understanding of the pathogenesis of leptospirosis. With the recent breakthrough and availability of complete genome sequences of Leptospira, development of novel vaccine including recombinant protein vaccine using reverse vaccinology approaches has yielded encouraging results. However, factors hindering the development of effective leptospiral vaccines include variation in serovar distribution from region to region, establishment of renal carrier status following vaccination and determination of the dose and endpoint titres acceptable as definitive indicators of protective immunity. In this review, advancements and progress made in LPS-based vaccines, killed- and live-attenuated vaccines, recombinant peptide vaccines and DNA vaccines against leptospirosis are highlighted.

Japanese encephalitis virus/yellow fever virus chimera is safe and confers full protection against yellow fever virus in intracerebrally challenged mice.

PubMed

Yang, Huiqiang; Yang, Huan; Li, Zhushi; Liu, Lina; Wang, Wei; He, Ting; Fan, Fengming; Sun, Yan; Liu, Jie; Li, Yuhua; Zeng, Xianwu

2018-04-25

Yellow fever (YF) is an acute viral haemorrhagic disease caused by the yellow fever virus (YFV), which remains a potential threat to public health. The live-attenuated YF vaccine (17D strain) is a safe and highly effective measure against YF. However, increasing adverse events have been associated with YF vaccinations in recent years; thus, safer, alternative vaccines are needed. In this study, using the Japanese encephalitis live vaccine strain SA14-14-2 as a backbone, a novel chimeric virus was constructed by replacing the pre-membrane (prM) and envelope (E) genes with their YFV 17D counterparts.The chimeric virus exhibited a reduced growth rate and a much smaller plaque morphology than did either parental virus. Furthermore, the chimera was much less neurovirulent than was YF17D and protected mice that were challenged with a lethal dose of the YF virus. These results suggest that this chimera has potential as a novel attenuated YF vaccine. Copyright © 2018 Elsevier Ltd. All rights reserved.

Antigenic characterization of a formalin-inactivated poliovirus vaccine derived from live-attenuated Sabin strains.

PubMed

Tano, Yoshio; Shimizu, Hiroyuki; Martin, Javier; Nishimura, Yorihiro; Simizu, Bunsiti; Miyamura, Tatsuo

2007-10-10

A candidate inactivated poliovirus vaccine derived from live-attenuated Sabin strains (sIPV), which are used in the oral poliovirus vaccine (OPV), was prepared in a large-production scale. The modification of viral antigenic epitopes during the formalin inactivation process was investigated by capture ELISA assays using type-specific and antigenic site-specific monoclonal antibodies (MoAbs). The major antigenic site 1 was modified during the formalin inactivation of Sabin 1. Antigenic sites 1-3 were slightly modified during the formalin inactivation of Sabin 2 strain. Sites 1 and 3 were altered on inactivated Sabin 3 virus. These alterations were different to those shown by wild-type Saukett strain, used in conventional IPV (cIPV). It has been previously reported that type 1 sIPV showed higher immunogenicity to type 1 cIPV whereas types 2 and 3 sIPV induced lower level of immunogenicity than their cIPV counterparts. Our results suggest that the differences in epitope structure after formalin inactivation may account, at least in part, for the observed differences in immunogenicity between Sabin and wild-type inactivated poliovaccines.

Comparison of monovalent and trivalent live attenuated influenza vaccines in young children.

PubMed

Gruber, W C; Kirschner, K; Tollefson, S; Thompson, J; Reed, G; Edwards, K M; Wright, P F

1993-07-01

Fifty children, 6 months to 2 years of age, were vaccinated intranasally with a trivalent preparation containing 10(6) TCID50 each of H1N1 and H3N2 and 10(4) (n = 14) or 10(6) (n = 36) TCID50 of B live, attenuated, cold-adapted (ca) influenza strains. The same doses were administered as monovalent vaccines to 69 comparably aged children. Forty-five controls were given placebo. No clinically significant adverse reactions to vaccines were observed. Of children seronegative to H1N1 or H3N2, > or = 90% were infected by these vaccine strains. Trivalent vaccine containing 10(4) TCID50 of B infected only 27% of children seronegative to B (3/11), which was markedly reduced from the 88% infection rate (7/8) following monovalent B vaccine of the same dose (P = .02); increasing the B dose to 10(6) TCID50 increased the infection rate to 81% (21/26). Replication of ca influenza viruses in tissue culture matched vaccine responses. Trivalent ca influenza vaccines can be formulated that are safe and immunogenic in young children.

Broadly protective anti-hemagglutinin stalk antibodies induced by live attenuated influenza vaccine expressing chimeric hemagglutinin.

PubMed

Isakova-Sivak, Irina; Korenkov, Daniil; Smolonogina, Tatiana; Kotomina, Tatiana; Donina, Svetlana; Matyushenko, Victoria; Mezhenskaya, Daria; Krammer, Florian; Rudenko, Larisa

2018-05-01

The development of influenza vaccines that can provide broad protection against all drifted seasonal virus variants, zoonotic infections and emerging pandemic strains, has been a priority for two decades. Here we propose a strategy of inducing broadly-reactive anti-stalk antibody by sequential immunizations with live attenuated influenza vaccines (LAIVs) expressing chimeric HAs (cHAs). These vaccines are designed to contain identical hemagglutinin stalk domains from H1N1 virus but antigenically unrelated globular head domains from avian influenza virus subtypes H5, H8 and H9. Mouse experiments demonstrated enhanced cross-protection of cHA-containing LAIVs compared to the relevant vaccine viruses expressing natural HAs, and this enhanced protection was driven by stalk-HA-reactive IgG antibodies. The establishment of fully functional cross-protective immunity after two doses of cHA LAIV vaccination in naïve animals suggests that a similar effect might be expected after a single cHA LAIV dose in primed individuals, or after two to three doses in naïve children. Copyright © 2018 Elsevier Inc. All rights reserved.

Antigen-specific IgA B memory cell responses to Shigella antigens elicited in volunteers immunized with live attenuated Shigella flexneri 2a oral vaccine candidates

PubMed Central

Simon, J. K.; Maciel, M.; Weld, E.D.; Wahid, R.; Pasetti, M.F.; Picking, W.L.; Kotloff, K. L.; Levine, M. M.; Sztein, M. B.

2011-01-01

We studied the induction of antigen-specific IgA memory B cells (BM) in volunteers who received live attenuated Shigella flexneri 2a vaccines. Subjects ingested a single oral dose of 107, 108 or 109 CFU of S. flexneri 2a with deletions in guaBA (CVD 1204) or in guaBA, set and sen (CVD 1208). Antigen-specific serum and stool antibody responses to LPS and Ipa B were measured on days 0, 7, 14, 28 and 42. IgA BM cells specific to LPS, Ipa B and total IgA were assessed on days 0 and 28. We show the induction of significant LPS-specific IgA BM cells in anti-LPS IgA seroresponders. Positive correlations were found between anti-LPS IgA BM cells and anti-LPS IgA in serum and stool; IgA BM cell responses to IpaB were also observed. These BM cell responses are likely play an important role in modulating the magnitude and longevity of the humoral response. PMID:21388888