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Sample records for combination live attenuated

  1. Novel vaccine against Venezuelan equine encephalitis combines advantages of DNA immunization and a live attenuated vaccine.

    PubMed

    Tretyakova, Irina; Lukashevich, Igor S; Glass, Pamela; Wang, Eryu; Weaver, Scott; Pushko, Peter

    2013-02-04

    DNA vaccines combine remarkable genetic and chemical stability with proven safety and efficacy in animal models, while remaining less immunogenic in humans. In contrast, live-attenuated vaccines have the advantage of inducing rapid, robust, long-term immunity after a single-dose vaccination. Here we describe novel iDNA vaccine technology that is based on an infectious DNA platform and combines advantages of DNA and live attenuated vaccines. We applied this technology for vaccination against infection with Venezuelan equine encephalitis virus (VEEV), an alphavirus from the Togaviridae family. The iDNA vaccine is based on transcription of the full-length genomic RNA of the TC-83 live-attenuated virus from plasmid DNA in vivo. The in vivo-generated viral RNA initiates limited replication of the vaccine virus, which in turn leads to efficient immunization. This technology allows the plasmid DNA to launch a live-attenuated vaccine in vitro or in vivo. Less than 10 ng of pTC83 iDNA encoding the full-length genomic RNA of the TC-83 vaccine strain initiated replication of the vaccine virus in vitro. In order to evaluate this approach in vivo, BALB/c mice were vaccinated with a single dose of pTC83 iDNA. After vaccination, all mice seroconverted with no adverse reactions. Four weeks after immunization, animals were challenged with the lethal epidemic strain of VEEV. All iDNA-vaccinated mice were protected from fatal disease, while all unvaccinated controls succumbed to infection and died. To our knowledge, this is the first example of launching a clinical live-attenuated vaccine from recombinant plasmid DNA in vivo.

  2. [Economic evaluation on different two-dose-vaccination-strategies related to Measles, Mumps and Rubella Combined Attenuated Live Vaccine].

    PubMed

    He, H Q; Zhang, B; Yan, R; Li, Q; Fu, J; Tang, X W; Zhou, Y; Deng, X; Xie, S Y

    2016-08-10

    To evaluate the economic effect of Measles, Mumps and Rubella Combined Attenuated Live Vaccine (MMR) under different two-dose vaccination programs. A hypothetical birth cohort of 750 000 infants over their lifetime, was followed up from birth through death in Zhejiang province. The current MMR vaccination strategie would include three different ones: 1) Childlern were vaccinated with Measles-Rubella Combined Attenuated Live Vaccine and MMR, respectively at the age of 8 months and 18 months. 2) Children receive MMR at 8 months and 18 months, 3) Strategy 1 plus an additional vaccination of MMR at 4 years of age. Incremental cost-effectiveness ratio (ICER), incremental cost-benefit ratio (ICBR) and incremental net benefit (INB) were applied to calculate the health economic difference for Strategy 2 and Strategy 3 as compared to Strategy 1. Univariate sensitivity analysis was used to assess the robustness of results with main parameters, including the rate of immunization coverage, effectiveness of the vaccines, incidence and burdens of the related diseases, cost of vaccines and the vaccination program itself. ICER, ICBR and INB for Strategy 2 and Strategy 3 appeared as 2 012.51∶1 RMB Yuan per case and 4 238.72∶1 RMB Yuan per case, 1∶3.14 and 1∶1.58, 21 277 800 RMB Yuan and 9 276 500 RMB Yuan, respectively. Only slight changes (<20%) were found under the univariate sensitivity analysis, with varied values on main parameters. Based on the current national immunization program, infants vaccinated with MMR at 8 months of age, generated more health economic effects than the Strategy 3.

  3. Combined semi-empirical screening and design of experiments (DOE) approach to identify candidate formulations of a lyophilized live attenuated tetravalent viral vaccine candidate.

    PubMed

    Patel, Ashaben; Erb, Steven M; Strange, Linda; Shukla, Ravi S; Kumru, Ozan S; Smith, Lee; Nelson, Paul; Joshi, Sangeeta B; Livengood, Jill A; Volkin, David B

    2017-05-12

    A combination experimental approach, utilizing semi-empirical excipient screening followed by statistical modeling using design of experiments (DOE), was undertaken to identify stabilizing candidate formulations for a lyophilized live attenuated Flavivirus vaccine candidate. Various potential pharmaceutical compounds used in either marketed or investigative live attenuated viral vaccine formulations were first identified. The ability of additives from different categories of excipients, either alone or in combination, were then evaluated for their ability to stabilize virus against freeze-thaw, freeze-drying, and accelerated storage (25°C) stresses by measuring infectious virus titer. An exploratory data analysis and predictive DOE modeling approach was subsequently undertaken to gain a better understanding of the interplay between the key excipients and stability of virus as well as to determine which combinations were interacting to improve virus stability. The lead excipient combinations were identified and tested for stabilizing effects using a tetravalent mixture of viruses in accelerated and real time (2-8°C) stability studies. This work demonstrates the utility of combining semi-empirical excipient screening and DOE experimental design strategies in the formulation development of lyophilized live attenuated viral vaccine candidates. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Brucellosis: the case for live, attenuated vaccines.

    PubMed

    Ficht, Thomas A; Kahl-McDonagh, Melissa M; Arenas-Gamboa, Angela M; Rice-Ficht, Allison C

    2009-11-05

    The successful control of animal brucellosis and associated reduction in human exposure has limited the development of human brucellosis vaccines. However, the potential use of Brucella in bioterrorism or biowarfare suggests that direct intervention strategies are warranted. Although the dominant approach has explored the use of live attenuated vaccines, side effects associated with their use has prevented widespread use in humans. Development of live, attenuated Brucella vaccines that are safe for use in humans has focused on the deletion of important genes required for survival. However, the enhanced safety of deletion mutants is most often associated with reduced efficacy. For this reason recent efforts have sought to combine the optimal features of a attenuated live vaccine that is safe, free of side effects and efficacious in humans with enhanced immune stimulation through microencapsulation. The competitive advantages and innovations of this approach are: (1) use of highly attenuated, safe, gene knockout, live Brucella mutants; (2) manufacturing with unique disposable closed system technologies, and (3) oral/intranasal delivery in a novel microencapsulation-mediated controlled release formula to optimally provide the long term mucosal immunostimulation required for protective immunity. Based upon preliminary data, it is postulated that such vaccine delivery systems can be storage stable, administered orally or intranasally, and generally applicable to a number of agents.

  5. Live attenuated vaccines against pertussis.

    PubMed

    Locht, Camille; Mielcarek, Nathalie

    2014-09-01

    The intensive use of pertussis vaccines has dramatically reduced the incidence of whooping cough during the 20th century. However, recent outbreaks in countries with high vaccination coverage illustrate the shortcomings of current vaccination regimens, and immunity induced by the most recent, acellular vaccines wanes much faster than anticipated. As an alternative, live attenuated vaccine candidates have recently been developed in order to mimic natural infection, which induces long-lasting immunity. One of them has successfully completed a Phase I trial in humans and is now undergoing further product and clinical developments. This article describes the development of such vaccines, discusses their advantages over existing vaccines and their interesting bystander properties as powerful anti-inflammatory agents, which widens their potential use far beyond that for protection against whooping cough.

  6. DNA-launched live-attenuated vaccines for biodefense applications.

    PubMed

    Pushko, Peter; Lukashevich, Igor S; Weaver, Scott C; Tretyakova, Irina

    2016-09-01

    A novel vaccine platform uses DNA immunization to launch live-attenuated virus vaccines in vivo. This technology has been applied for vaccine development against positive-strand RNA viruses with global public health impact including alphaviruses and flaviviruses. The DNA-launched vaccine represents the recombinant plasmid that encodes the full-length genomic RNA of live-attenuated virus downstream from a eukaryotic promoter. When administered in vivo, the genomic RNA of live-attenuated virus is transcribed. The RNA initiates limited replication of a genetically defined, live-attenuated vaccine virus in the tissues of the vaccine recipient, thereby inducing a protective immune response. This platform combines the strengths of reverse genetics, DNA immunization and the advantages of live-attenuated vaccines, resulting in a reduced chance of genetic reversions, increased safety, and improved immunization. With this vaccine technology, the field of DNA vaccines is expanded from those that express subunit antigens to include a novel type of DNA vaccines that launch live-attenuated viruses.

  7. DNA-launched live-attenuated vaccines for biodefense applications

    PubMed Central

    Pushko, Peter; Lukashevich, Igor S.; Weaver, Scott C.; Tretyakova, Irina

    2016-01-01

    Summary A novel vaccine platform uses DNA immunization to launch live-attenuated virus vaccines in vivo. This technology has been applied for vaccine development against positive-strand RNA viruses with global public health impact including alphaviruses and flaviviruses. The DNA-launched vaccine represents the recombinant plasmid that encodes the full-length genomic RNA of live-attenuated virus downstream from a eukaryotic promoter. When administered in vivo, the genomic RNA of live-attenuated virus is transcribed. The RNA initiates limited replication of a genetically defined, live-attenuated vaccine virus in the tissues of the vaccine recipient, thereby inducing a protective immune response. This platform combines the strengths of reverse genetics, DNA immunization and the advantages of live-attenuated vaccines, resulting in a reduced chance of genetic reversions, increased safety, and improved immunization. With this vaccine technology, the field of DNA vaccines is expanded from those that express subunit antigens to include a novel type of DNA vaccines that launch live-attenuated viruses. PMID:27055100

  8. Live attenuated vaccines for invasive Salmonella infections.

    PubMed

    Tennant, Sharon M; Levine, Myron M

    2015-06-19

    Salmonella enterica serovar Typhi produces significant morbidity and mortality worldwide despite the fact that there are licensed Salmonella Typhi vaccines available. This is primarily due to the fact that these vaccines are not used in the countries that most need them. There is growing recognition that an effective invasive Salmonella vaccine formulation must also prevent infection due to other Salmonella serovars. We anticipate that a multivalent vaccine that targets the following serovars will be needed to control invasive Salmonella infections worldwide: Salmonella Typhi, Salmonella Paratyphi A, Salmonella Paratyphi B (currently uncommon but may become dominant again), Salmonella Typhimurium, Salmonella Enteritidis and Salmonella Choleraesuis (as well as other Group C Salmonella). Live attenuated vaccines are an attractive vaccine formulation for use in developing as well as developed countries. Here, we describe the methods of attenuation that have been used to date to create live attenuated Salmonella vaccines and provide an update on the progress that has been made on these vaccines.

  9. Live attenuated vaccines for invasive Salmonella infections

    PubMed Central

    Tennant, Sharon M.; Levine, Myron M.

    2015-01-01

    Salmonella enterica serovar Typhi produces significant morbidity and mortality worldwide despite the fact that there are licensed S. Typhi vaccines available. This is primarily due to the fact that these vaccines are not used in the countries that most need them. There is growing recognition that an effective invasive Salmonella vaccine formulation must also prevent infection due to other Salmonella serovars. We anticipate that a multivalent vaccine that targets the following serovars will be needed to control invasive Salmonella infections worldwide: S. Typhi, S. Paratyphi A, S. Paratyphi B (currently uncommon but may become dominant again), S. Typhimurium, S. Enteritidis and S. Choleraesuis (as well as other Group C Salmonella). Live attenuated vaccines are an attractive vaccine formulation for use in developing as well as developed countries. Here, we describe the methods of attenuation that have been used to date to create live attenuated Salmonella vaccines and provide an update on the progress that has been made on these vaccines. PMID:25902362

  10. Mycoplasma gallisepticum: Control by live attenuated 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...

  11. [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

  12. Immune responses after live attenuated influenza vaccination.

    PubMed

    Mohn, Kristin G-I; Smith, Ingrid; Sjursen, Haakon; Cox, Rebecca

    2017-09-21

    Since 2003 (US) and 2012 (Europe) the live attenuated influenza vaccine (LAIV) has been used as an alternative to the traditional inactivated influenza vaccines (IIV). The immune responses elicted by LAIV mimic natural infection and have been found to provide broader clinical protection in children compared to the IIVs. However, our knowledge of the detailed immunological mechanisims induced by LAIV remain to be fully elucidated, and despite 14 years on the global market, there exists no correlate of protection. Recently, matters are further complicated by differing efficacy data from the US and Europe which are not understood. Better understanding of the immune responses after LAIV may aid in achieving the ultimate goal of a future "universal influenza vaccine". In this review we aim to cover the current understanding of the immune responses induced after LAIV.

  13. A new generation of modified live-attenuated avian influenza viruses using a two-strategy combination as potential vaccine candidates.

    PubMed

    Song, Haichen; Nieto, Gloria Ramirez; Perez, Daniel R

    2007-09-01

    In light of the recurrent outbreaks of low pathogenic avian influenza (LPAI) and highly pathogenic avian influenza (HPAI), there is a pressing need for the development of vaccines that allow rapid mass vaccination. In this study, we introduced by reverse genetics temperature-sensitive mutations in the PB1 and PB2 genes of an avian influenza virus, A/Guinea Fowl/Hong Kong/WF10/99 (H9N2) (WF10). Further genetic modifications were introduced into the PB1 gene to enhance the attenuated (att) phenotype of the virus in vivo. Using the att WF10 as a backbone, we substituted neuraminidase (NA) for hemagglutinin (HA) for vaccine purposes. In chickens, a vaccination scheme consisting of a single dose of an att H7N2 vaccine virus at 2 weeks of age and subsequent challenge with the wild-type H7N2 LPAI virus resulted in complete protection. We further extended our vaccination strategy against the HPAI H5N1. In this case, we reconstituted an att H5N1 vaccine virus, whose HA and NA genes were derived from an Asian H5N1 virus. A single-dose immunization in ovo with the att H5N1 vaccine virus in 18-day-old chicken embryos resulted in more than 60% protection for 4-week-old chickens and 100% protection for 9- to 12-week-old chickens. Boosting at 2 weeks posthatching provided 100% protection against challenge with the HPAI H5N1 virus for chickens as young as 4 weeks old, with undetectable virus shedding postchallenge. Our results highlight the potential of live att avian influenza vaccines for mass vaccination in poultry.

  14. Molecular basis of live-attenuated influenza virus.

    PubMed

    He, Wen; Wang, Wei; Han, Huamin; Wang, Lei; Zhang, Ge; Gao, Bin

    2013-01-01

    Human influenza is a seasonal disease associated with significant morbidity and mortality. The most effective means for controlling infection and thereby reducing morbidity and mortality is vaccination with a three inactivated influenza virus strains mixture, or by intranasal administration of a group of three different live attenuated influenza vaccine strains. Comparing to the inactivated vaccine, the attenuated live viruses allow better elicitation of a long-lasting and broader immune (humoral and cellular) response that represents a naturally occurring transient infection. The cold-adapted (ca) influenza A/AA/6/60 (H2N2) (AA ca) virus is the backbone for the live attenuated trivalent seasonal influenza vaccine licensed in the United States. Similarly, the influenza A components of live-attenuated vaccines used in Russia have been prepared as reassortants of the cold-adapted (ca) H2N2 viruses, A/Leningrad/134/17/57-ca (Len/17) and A/Leningrad/134/47/57-ca (Len/47) along with virulent epidemic strains. However, the mechanism of temperature-sensitive attenuation is largely elusive. To understand how modification at genetic level of influenza virus would result in attenuation of human influenza virus A/PR/8/34 (H1N1,A/PR8), we investigated the involvement of key mutations in the PB1 and/or PB2 genes in attenuation of influenza virus in vitro and in vivo. We have demonstrated that a few of residues in PB1 and PB2 are critical for the phenotypes of live attenuated, temperature sensitive influenza viruses by minigenome assay and real-time PCR. The information of these mutation loci could be used for elucidation of mechanism of temperature-sensitive attenuation and as a new strategy for influenza vaccine development.

  15. Urgent challenges in implementing live attenuated influenza vaccine.

    PubMed

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

    2017-08-02

    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 © 2017 Elsevier Ltd. All rights reserved.

  16. Development of a recombinant epsilon toxoid vaccine against enterotoxemia and its use as a combination vaccine with live attenuated sheep pox virus against enterotoxemia and sheep pox.

    PubMed

    Chandran, Dev; Naidu, Sureddi Satyam; Sugumar, Parthasarathy; Rani, Gudavalli Sudha; Vijayan, Shahana Pallichera; Mathur, Deepika; Garg, Lalit C; Srinivasan, Villuppanoor Alwar

    2010-06-01

    Sheep pox and enterotoxemia are important diseases of sheep, and these diseases cause severe economic losses to sheep farmers. The present study was undertaken to evaluate the potential of formaldehyde-inactivated recombinant epsilon toxin as a vaccine candidate. The potency of the recombinant epsilon toxoid with aluminum hydroxide as an adjuvant in sheep was determined. Vaccinated sheep were protected against enterotoxemia, with potency values of >5 IU being protective. Further, the use of this construct in a combination vaccine against sheep pox resulted in the sheep being protected against both sheep pox and enterotoxemia.

  17. A Novel Live-Attenuated Vaccine Candidate for Mayaro Fever

    PubMed Central

    Weise, William J.; Hermance, Meghan E.; Forrester, Naomi; Adams, A. Paige; Langsjoen, Rose; Gorchakov, Rodion; Wang, Eryu; Alcorn, Maria D. H.; Tsetsarkin, Konstantin; Weaver, Scott C.

    2014-01-01

    Mayaro virus (MAYV) is an emerging, mosquito-borne alphavirus that causes a dengue-like illness in many regions of South America, and which has the potential to urbanize. Because no specific treatment or vaccine is available for MAYV infection, we capitalized on an IRES-based approach to develop a live-attenuated MAYV vaccine candidate. Testing in infant, immunocompetent as well as interferon receptor-deficient mice demonstrated a high degree of attenuation, strong induction of neutralizing antibodies, and efficacy against lethal challenge. This vaccine strain was also unable to infect mosquito cells, a major safety feature for a live vaccine derived from a mosquito-borne virus. Further preclinical development of this vaccine candidate is warranted to protect against this important emerging disease. PMID:25101995

  18. A novel live-attenuated vaccine candidate for mayaro Fever.

    PubMed

    Weise, William J; Hermance, Meghan E; Forrester, Naomi; Adams, A Paige; Langsjoen, Rose; Gorchakov, Rodion; Wang, Eryu; Alcorn, Maria D H; Tsetsarkin, Konstantin; Weaver, Scott C

    2014-08-01

    Mayaro virus (MAYV) is an emerging, mosquito-borne alphavirus that causes a dengue-like illness in many regions of South America, and which has the potential to urbanize. Because no specific treatment or vaccine is available for MAYV infection, we capitalized on an IRES-based approach to develop a live-attenuated MAYV vaccine candidate. Testing in infant, immunocompetent as well as interferon receptor-deficient mice demonstrated a high degree of attenuation, strong induction of neutralizing antibodies, and efficacy against lethal challenge. This vaccine strain was also unable to infect mosquito cells, a major safety feature for a live vaccine derived from a mosquito-borne virus. Further preclinical development of this vaccine candidate is warranted to protect against this important emerging disease.

  19. Promises and pitfalls of live attenuated pneumococcal vaccines.

    PubMed

    Rosch, Jason W

    2014-01-01

    The pneumococcus is a remarkably adaptable pathogen whose disease manifestations range from mucosal surface infections such as acute otitis media and pneumonia to invasive infections such as sepsis and meningitis. Currently approved vaccines target the polysaccharide capsule, of which there are over 90 distinct serotypes, leading to rapid serotype replacement in vaccinated populations. Substantial progress has been made in the development of a universal pneumococcal vaccine, with efforts focused on broadly conserved and protective protein antigens. An area attracting considerable attention is the potential application of live attenuated vaccines to confer serotype-independent protection against mucosal and systemic infection. On the basis of recent work to understand the mucosal and systemic responses to nasal administration of pneumococci and to develop novel attenuation strategies, the prospect of a practical and protective live vaccine remains promising.

  20. Research progress in live attenuated Brucella vaccine development.

    PubMed

    Wang, Zhen; Wu, Qingmin

    2013-01-01

    Brucella spp. are facultative intracellular bacteria that cause brucellosis, which is a globally occurring zoonotic disease that is characterized by abortion in domestic animals and undulant fever, arthritis, endocarditis, and meningitis in humans. There are currently no licensed vaccines against brucellosis for human use, and only a few licensed live Brucella vaccines are available for use in animals. However, the available animal vaccines may cause abortion and are associated with lower protection rates in animals and higher virulence in humans. Much research has been performed recently to develop novel Brucella vaccines for the prevention and control of animal brucellosis. This article discusses the approaches and strategies for novel live attenuated vaccine development.

  1. Clinical evaluation strategies for a live attenuated tetravalent dengue vaccine.

    PubMed

    Precioso, Alexander Roberto; Palacios, Ricardo; Thomé, Beatriz; Mondini, Gabriella; Braga, Patrícia; Kalil, Jorge

    2015-12-10

    Butantan Institute is a public Brazilian biomedical research-manufacturer center affiliated to the São Paulo State Secretary of Health. Currently, Butantan is one of the main public producers of vaccines, antivenoms, and antitoxins in Latin America. The partnership between Butantan and the National Institutes of Health (NIH) of the United Sates has been one of the longest and most successful partnerships in the development and manufacturing of new vaccines. Recently, Butantan Institute has developed and manufactured a lyophilized tetravalent live attenuated dengue vaccine with the four dengue viruses attenuated and licensed from the Laboratory of Infectious Diseases at The National Institutes of Allergy and Infectious Diseases (LID/NIAID/NIH). The objective of this paper is to describe the clinical evaluation strategies of a live attenuated tetravalent dengue vaccine (Butantan-DV) developed and manufactured by Butantan Institute. These clinical strategies will be used to evaluate the Butantan-DV Phase III trial to support the Butantan-DV licensure for protection against any symptomatic dengue caused by any serotype in people aged 2 to 59 years.

  2. Safety of a live attenuated Erysipelothrix rhusiopathiae vaccine for swine.

    PubMed

    Neumann, Eric J; Grinberg, Alex; Bonistalli, Kathryn N; Mack, Hamish J; Lehrbach, Philip R; Gibson, Nicole

    2009-03-30

    Infection with Erysipelothrix rhusiopathiae has a significant economic impact on pig production systems worldwide. Both inactivated and attenuated vaccines are available to prevent development of clinical signs of swine erysipelas. The ability of a live attenuated E. rhusiopathiae strain to become persistently established in pigs after intranasal exposure and its potential to cause clinical signs consistent with swine erysipelas after being administered directly into the nasopharynx of healthy pigs was evaluated. Five, E. rhusiopathiae-negative pigs were vaccinated by deep intranasal inoculation then followed for 14 days. Nasal swabs were collected daily for 5 days and clinical observations were made daily for 14 days post-vaccination. Nasal swabs were cultured for E. rhusiopathiae with the intent of back-passaging any recovered organisms into subsequent replicates. No organism was recovered from nasal swabs in the first vaccination replicate. A second replicate including 10 pigs was initiated and followed in an identical manner to that described above. Again, no E. rhusiopathiae was recovered from any pigs. No pigs in either replicate showed any signs of clinical swine erysipelas. The live attenuated E. rhusiopathiae strain evaluated in this study did not appear to become persistently established in pigs post-vaccination, did not cause any local or systemic signs consistent with swine erysipelas, and was therefore unlikely to revert to a virulent state when used in a field setting.

  3. 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

  4. 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.

  5. Preerythrocytic, live-attenuated Plasmodium falciparum vaccine candidates by design.

    PubMed

    VanBuskirk, Kelley M; O'Neill, Matthew T; De La Vega, Patricia; Maier, Alexander G; Krzych, Urszula; Williams, Jack; Dowler, Megan G; Sacci, John B; Kangwanrangsan, Niwat; Tsuboi, Takafumi; Kneteman, Norman M; Heppner, Donald G; Murdock, Brant A; Mikolajczak, Sebastian A; Aly, Ahmed S I; Cowman, Alan F; Kappe, Stefan H I

    2009-08-04

    Falciparum malaria is initiated when Anopheles mosquitoes transmit the Plasmodium sporozoite stage during a blood meal. Irradiated sporozoites confer sterile protection against subsequent malaria infection in animal models and humans. This level of protection is unmatched by current recombinant malaria vaccines. However, the live-attenuated vaccine approach faces formidable obstacles, including development of accurate, reproducible attenuation techniques. We tested whether Plasmodium falciparum could be attenuated at the early liver stage by genetic engineering. The P. falciparum genetically attenuated parasites (GAPs) harbor individual deletions or simultaneous deletions of the sporozoite-expressed genes P52 and P36. Gene deletions were done by double-cross-over recombination to avoid genetic reversion of the knockout parasites. The gene deletions did not affect parasite replication throughout the erythrocytic cycle, gametocyte production, mosquito infections, and sporozoite production rates. However, the deletions caused parasite developmental arrest during hepatocyte infection. The double-gene deletion line exhibited a more severe intrahepatocytic growth defect compared with the single-gene deletion lines, and it did not persist. This defect was assessed in an in vitro liver-stage growth assay and in a chimeric mouse model harboring human hepatocytes. The strong phenotype of the double knockout GAP justifies its human testing as a whole-organism vaccine candidate using the established sporozoite challenge model. GAPs might provide a safe and reproducible platform to develop an efficacious whole-cell malaria vaccine that prevents infection at the preerythrocytic stage.

  6. Development of live attenuated influenza vaccines against pandemic influenza strains.

    PubMed

    Coelingh, Kathleen L; Luke, Catherine J; Jin, Hong; Talaat, Kawsar R

    2014-07-01

    Avian and animal influenza viruses can sporadically transmit to humans, causing outbreaks of varying severity. In some cases, further human-to-human virus transmission does not occur, and the outbreak in humans is limited. In other cases, sustained human-to-human transmission occurs, resulting in worldwide influenza pandemics. Preparation for future pandemics is an important global public health goal. A key objective of preparedness is to gain an understanding of how to design, test, and manufacture effective vaccines that could be stockpiled for use in a pandemic. This review summarizes results of an ongoing collaboration to produce, characterize, and clinically test a library of live attenuated influenza vaccine strains (based on Ann Arbor attenuated Type A strain) containing protective antigens from influenza viruses considered to be of high pandemic potential.

  7. A candidate live inactivatable attenuated vaccine for AIDS.

    PubMed Central

    Chakrabarti, B K; Maitra, R K; Ma, X Z; Kestler, H W

    1996-01-01

    The recent discovery of long term AIDS nonprogressors who harbor nef-attenuated HIV suggests that a naturally occurring live vaccine for AIDS may already exist. Animal models have shown that a live vaccine for AIDS, attenuated in nef, is the best candidate vaccine. There are considerable risks, real and perceived, with the use of live HIV vaccines. We have introduced a conditional lethal genetic element into HIV-1 and simian immunodeficiency virus (SIV) molecular clones deleted in nef. The antiviral strategy we employed targets both virus replication and the survival of the infected cell. The suicide gene, herpes simplex virus thymidine kinase (tk), was expressed and maintained in HIV over long periods of time. Herpes simplex virus tk confers sensitivity to the antiviral activity of acyclic nucleosides such as ganciclovir (GCV). HIV-tk and SIV-tk replication were sensitive to GCV at subtoxic concentrations, and virus-infected cells were eliminated from tumor cell lines as well as primary cell cultures. We found the HIV-tk virus to be remarkably stable even after being cultured in media containing a low concentration of GCV and then challenged with the higher dose and that while GCV resistant escape mutants did arise, a significant fraction of the virus remained sensitive to GCV. Images Fig. 1 Fig. 5 PMID:8790413

  8. Generation of a Live Attenuated Influenza Vaccine that Elicits Broad Protection in Mice and Ferrets.

    PubMed

    Wang, Lulan; Liu, Su-Yang; Chen, Hsiang-Wen; Xu, Juan; Chapon, Maxime; Zhang, Tao; Zhou, Fan; Wang, Yao E; Quanquin, Natalie; Wang, Guiqin; Tian, Xiaoli; He, Zhanlong; Liu, Longding; Yu, Wenhai; Sanchez, David Jesse; Liang, Yuying; Jiang, Taijiao; Modlin, Robert; Bloom, Barry R; Li, Qihan; Deng, Jane C; Zhou, Paul; Qin, F Xiao-Feng; Cheng, Genhong

    2017-03-08

    New influenza vaccines that provide effective and broad protection are desperately needed. Live attenuated viruses are attractive vaccine candidates because they can elicit both humoral and cellular immune responses. However, recent formulations of live attenuated influenza vaccines (LAIVs) have not been protective. We combined high-coverage transposon mutagenesis of influenza virus with a rapid high-throughput screening for attenuation to generate W7-791, a live attenuated mutant virus strain. W7-791 produced only a transient asymptomatic infection in adult and neonatal mice even at doses 100-fold higher than the LD50 of the parent strain. A single administration of W7-791 conferred full protection to mice against lethal challenge with H1N1, H3N2, and H5N1 strains, and improved viral clearance in ferrets. Adoptive transfer of T cells from W7-791-immunized mice conferred heterologous protection, indicating a role for T cell-mediated immunity. These studies present an LAIV development strategy to rapidly generate and screen entire libraries of viral clones.

  9. 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.

  10. Trials with a live attenuated rubella virus vaccine, Cendehill strain

    PubMed Central

    Grant, L.; Belle, E. A.; Provan, G.; King, S. D.; Sigel, M. M.

    1970-01-01

    This report summarizes closed, family, and open studies conducted sequentially over a 10 month period with the Cendehill rubella virus vaccine in more than 16,000 children and adolescents. This strain of rubella was attenuated by serial propagation on primary rabbit kidney cell cultures. Inoculation of the Cendehill vaccine produced seroconversion in 97% of the 3589 susceptible (seronegative) vaccinated persons. There was no spread of the virus to susceptible controls living in close contact with those vaccinated. The vaccine was well tolerated. No arthritis or arthralgia occurred in 860 female subjects 13-18 years of age who were included in the study. The Cendehill vaccine would appear to meet the requirements of an acceptable vaccine. PMID:5272349

  11. Immunity and protection by live attenuated HIV/SIV vaccines

    PubMed Central

    Wodarz, Dominik

    2008-01-01

    Live attenuated virus vaccines have shown the greatest potential to protect against simian immunodeficiency virus (SIV) infection, a model for human immunodeficiency virus (HIV). Immunity against the vaccine virus is thought to mediate protection. However, it is shown computationally that the opposite might be true. According to the model, the initial growth of the challenge strain, its peak load, and its potential to be pathogenic is higher if immunity against the vaccine virus is stronger. This is because the initial growth of the challenge strain is mainly determined by virus competition rather than immune suppression. The stronger the immunity against the vaccine strain, the weaker its competitive ability relative to the challenge strain, and the lower the level of protection. If the vaccine virus does protect the host against a challenge, it is because the competitive interactions between the viruses inhibit the initial growth of the challenge strain. According to these arguments, an inverse correlation between the level of attenuation and the level of protection is expected, and this has indeed been observed in experimental data. PMID:18586297

  12. Antibody Response to Live Attenuated Vaccines in Adults in Japan

    PubMed Central

    Uchiyama-Nakamura, Fukumi; Sugata-Tsubaki, Aiko; Yamada, Yutaka; Uno, Kenji; Kasahara, Kei; Maeda, Koichi; Konishi, Mitsuru; Mikasa, Keiichi

    2016-01-01

    Abstract The purpose of this study was to examine the efficacy rendered with a single dose of live attenuated measles, rubella, mumps, and varicella containing vaccine. We inoculated healthcare workers (HCWs) with a single dose of vaccine to a disease lacking in antibody titer for those not meeting the criteria of our hospital (measles: <16.0 (IgG enzyme immunoassay (EIA)), rubella: ≤1:32 (hemagglutination-inhibition), mumps: <4.0 (IgG EIA), and varicella: <4.0 (IgG EIA)). At 28–60 days after vaccination, the antibody titer was tested again. We included 48 HCWs. A total of 32, 15, 31, and 10 individuals were inoculated with a single dose of measles-containing, rubella-containing, mumps, or varicella vaccine, respectively, and showed significant antibody elevation (9.2 ± 12.3 to 27.6 ± 215.6, p<0.001; 8 ± 1.2 to 32 ± 65.5, p<0.001; 3.0 ± 1.0 to 13.1 ± 8.6, p<0.05; and 2.6 ± 1.3 to 11.8 ± 8.1, p<0.001, respectively). Major side effects were not observed. In a limited population, a single dose of live attenuated vaccine showed elevation of antibody titer without any severe adverse reactions. However, whether the post-vaccination response rate criteria of our university was fulfilled could not be determined owing to limited sample size. PMID:28352840

  13. Attenuation characterization of multiple combinations of imperfect polarizers.

    PubMed

    Huang, Chong; Zhao, Shuang; Chen, Haiqing; Liao, Zhaoshu

    2010-05-01

    Malus's law, when used to calculate the attenuation ratio of the combination of two imperfect polarizers (two-CIP), will introduce an error, especially near the crossed-axis orientation. In this paper, first, the Jones matrix of the imperfect polarizer is deduced and an exact algorithm of the attenuation ratio of the two-CIP is proposed as well as its monotonic attenuation interval. Experimental results confirm that our deduced expression is more accurate than Malus's law. Then based on this algorithm, an attenuation-ratio expression of the combination of three imperfect polarizers (three-CIP) is presented. In this three-CIP model, it is found that when the electric field amplitude ratio of the imperfect polarizer is epsilon, the attenuation ratio can change from 1 to epsilon(4) monotonically in a general model when P(1) and P(3) are rotated and P(2) is fixed, which is proved by experiment. Finally, it is deduced that the combination of n imperfect polarizers (n-CIP) can obtain a minimum attenuation ratio of epsilon(2(n-1)), which indicates the number of imperfect polarizers needed to achieve the required attenuation ratio.

  14. Live attenuated vaccines: Historical successes and current challenges

    SciTech Connect

    Minor, Philip D.

    2015-05-15

    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. - 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.

  15. 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.

  16. Engineering temperature sensitive live attenuated influenza vaccines from emerging viruses.

    PubMed

    Zhou, Bin; Li, Yan; Speer, Scott D; Subba, Anju; Lin, Xudong; Wentworth, David E

    2012-05-21

    The licensed live attenuated influenza A vaccine (LAIV) in the United States is created by making a reassortant containing six internal genes from a cold-adapted master donor strain (ca A/AA/6/60) and two surface glycoprotein genes from a circulating/emerging strain (e.g., A/CA/7/09 for the 2009/2010 H1N1 pandemic). Technologies to rapidly create recombinant viruses directly from patient specimens were used to engineer alternative LAIV candidates that have genomes composed entirely of vRNAs from pandemic or seasonal strains. Multiple mutations involved in the temperature-sensitive (ts) phenotype of the ca A/AA/6/60 master donor strain were introduced into a 2009 H1N1 pandemic strain rA/New York/1682/2009 (rNY1682-WT) to create rNY1682-TS1, and additional mutations identified in other ts viruses were added to rNY1682-TS1 to create rNY1682-TS2. Both rNY1682-TS1 and rNY1682-TS2 replicated efficiently at 30°C and 33°C. However, rNY1682-TS1 was partially restricted, and rNY1682-TS2 was completely restricted at 39°C. Additionally, engineering the TS1 or TS2 mutations into a distantly related human seasonal H1N1 influenza A virus also resulted pronounced restriction of replication in vitro. Clinical symptoms and virus replication in the lungs of mice showed that although rNY1682-TS2 and the licensed FluMist(®)-H1N1pdm LAIV that was used to combat the 2009/2010 pandemic were similarly attenuated, the rNY1682-TS2 was more protective upon challenge with a virulent mutant of pandemic H1N1 virus or a heterologous H1N1 (A/PR/8/1934) virus. This study demonstrates that engineering key temperature sensitive mutations (PB1-K391E, D581G, A661T; PB2-P112S, N265S, N556D, Y658H) into the genomes of influenza A viruses attenuates divergent human virus lineages and provides an alternative strategy for the generation of LAIVs. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Potential Consequences of Not Using Live Attenuated Influenza Vaccine.

    PubMed

    Smith, Kenneth J; Nowalk, Mary Patricia; Wateska, Angela; Brown, Shawn T; DePasse, Jay V; Raviotta, Jonathan M; Shim, Eunha; Zimmerman, Richard K

    2017-10-01

    Decreased live attenuated influenza vaccine (LAIV) effectiveness in the U.S. prompted the Advisory Committee on Immunization Practices in August 2016 to recommend against this vaccine's use. However, overall influenza uptake increases when LAIV is available and, unlike the U.S., LAIV has retained its effectiveness in other countries. These opposing countercurrents create a dilemma. To examine the potential consequences of the decision to not recommend LAIV, which may result in decreased influenza vaccination coverage in the U.S. population, a Markov decision analysis model was used to examine influenza vaccination options in U.S. children aged 2-8 years. Data were compiled and analyzed in 2016. Using recently observed low LAIV effectiveness values, fewer influenza cases will occur if LAIV is not used compared with having LAIV as a vaccine option. However, having the option to use LAIV may be favored if LAIV effectiveness returns to prior levels or if the absence of vaccine choice substantially decreases overall vaccine uptake. Continued surveillance of LAIV effectiveness and influenza vaccine uptake is warranted, given their importance in influenza vaccination policy decisions. Copyright © 2017 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  18. 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

    Protection against dengue virus by non-replicating and live attenuated vaccines used together in a prime boost vaccination strategy Monika Simmons a...Dengue DNA Punfied inacdvared virus Uvc artenuatcd virus Jlnmc boost A new vaccination strategy for dengue virus (DENV) was eval uated in rhesus...region (TDNA) then boosting 2 months l,ltcr with a tetravalent live aucnuated virus (TLAV) vaccine . Both vaccine combinations elicited virus

  19. Genetically modified, live attenuated dengue virus type 3 vaccine candidates.

    PubMed

    Blaney, Joseph E; Hanson, Christopher T; Firestone, Cai-Yen; Hanley, Kathryn A; Murphy, Brian R; Whitehead, Stephen S

    2004-12-01

    Three novel recombinant dengue type 3 (DEN3) virus vaccine candidates have been generated from a DEN3 virus isolated from a mild outbreak of dengue fever in the Sleman area of central Java in Indonesia in 1978. Antigenic chimeric viruses were prepared by replacing the membrane precursor and envelope (ME) proteins of recombinant DEN4 (rDEN4) virus with those from DEN3 Sleman/78 in the presence (rDEN3/4Delta30(ME)) and the absence (rDEN3/4(ME)) of the Delta30 mutation, a previously described 30-nucleotide deletion in the 3' untranslated region. In addition, a full-length infectious cDNA clone was generated from the DEN3 isolate and used to produce rDEN3 virus and the vaccine candidate rDEN3Delta30. The chimeric viruses rDEN3/4(ME) and rDEN3/4Delta30(ME) appear to be acceptable vaccine candidates since they were restricted in replication in severe combined immune deficiency mice transplanted with human hepatoma cells, in rhesus monkeys, and in Aedes and Toxorynchites mosquitoes, and each was protective in rhesus monkeys against DEN3 virus challenge. The rDEN3/4(ME) and rDEN3/4Delta30(ME) viruses were comparable in all parameters evaluated, indicating that antigenic chimerization resulted in the observed high level of attenuation. Surprisingly, rDEN3Delta30 was not attenuated in any model tested when compared with wild-type rDEN3 and therefore, is not a vaccine candidate at present. Thus, the rDEN3/4(ME) and rDEN3/4Delta30(ME) antigenic chimeric viruses can be considered for evaluation in humans and for inclusion in a tetravalent dengue vaccine.

  20. The double-edged sword: How evolution can make or break a live-attenuated virus vaccine

    PubMed Central

    Hanley, Kathryn A.

    2012-01-01

    Even students who reject evolution are often willing to consider cases in which evolutionary biology contributes to, or undermines, biomedical interventions. Moreover the intersection of evolutionary biology and biomedicine is fascinating in its own right. This review offers an overview of the ways in which evolution has impacted the design and deployment of live-attenuated virus vaccines, with subsections that may be useful as lecture material or as the basis for case studies in classes at a variety of levels. Live- attenuated virus vaccines have been modified in ways that restrain their replication in a host, so that infection (vaccination) produces immunity but not disease. Applied evolution, in the form of serial passage in novel host cells, is a “classical” method to generate live-attenuated viruses. However many live-attenuated vaccines exhibit reversion to virulence through back-mutation of attenuating mutations, compensatory mutations elsewhere in the genome, recombination or reassortment, or changes in quasispecies diversity. Additionally the combination of multiple live-attenuated strains may result in competition or facilitation between individual vaccine viruses, resulting in undesirable increases in virulence or decreases in immunogenicity. Genetic engineering informed by evolutionary thinking has led to a number of novel approaches to generate live-attenuated virus vaccines that contain substantial safeguards against reversion to virulence and that ameliorate interference among multiple vaccine strains. Finally, vaccines have the potential to shape the evolution of their wild type counterparts in counter-productive ways; at the extreme vaccine-driven eradication of a virus may create an empty niche that promotes the emergence of new viral pathogens. PMID:22468165

  1. Seasonal Effectiveness of Live Attenuated and Inactivated Influenza Vaccine

    PubMed Central

    Flannery, Brendan; Thompson, Mark G.; Gaglani, Manjusha; Jackson, Michael L.; Monto, Arnold S.; Nowalk, Mary Patricia; Talbot, H. Keipp; Treanor, John J.; Belongia, Edward A.; Murthy, Kempapura; Jackson, Lisa A.; Petrie, Joshua G.; Zimmerman, Richard K.; Griffin, Marie R.; McLean, Huong Q.; Fry, Alicia M.

    2016-01-01

    BACKGROUND: Few observational studies have evaluated the relative effectiveness of live attenuated (LAIV) and inactivated (IIV) influenza vaccines against medically attended laboratory-confirmed influenza. METHODS: We analyzed US Influenza Vaccine Effectiveness Network data from participants aged 2 to 17 years during 4 seasons (2010–2011 through 2013–2014) to compare relative effectiveness of LAIV and IIV against influenza-associated illness. Vaccine receipt was confirmed via provider/electronic medical records or immunization registry. We calculated the ratio (odds) of influenza-positive to influenza-negative participants among those age-appropriately vaccinated with either LAIV or IIV for the corresponding season. We examined relative effectiveness of LAIV and IIV by using adjusted odds ratios (ORs) and 95% confidence intervals (CIs) from logistic regression. RESULTS: Of 6819 participants aged 2 to 17 years, 2703 were age-appropriately vaccinated with LAIV (n = 637) or IIV (n = 2066). Odds of influenza were similar for LAIV and IIV recipients during 3 seasons (2010–2011 through 2012–2013). In 2013–2014, odds of influenza were significantly higher among LAIV recipients compared with IIV recipients 2 to 8 years old (OR 5.36; 95% CI, 2.37 to 12.13). Participants vaccinated with LAIV or IIV had similar odds of illness associated with influenza A/H3N2 or B. LAIV recipients had greater odds of illness due to influenza A/H1N1pdm09 in 2010–2011 and 2013–2014. CONCLUSIONS: We observed lower effectiveness of LAIV compared with IIV against influenza A/H1N1pdm09 but not A(H3N2) or B among children and adolescents, suggesting poor performance related to the LAIV A/H1N1pdm09 viral construct. PMID:26738884

  2. Live Attenuated and Inactivated Influenza Vaccines in Children

    PubMed Central

    Ilyushina, Natalia A.; Haynes, Brenda C.; Hoen, Anne G.; Khalenkov, Alexey M.; Housman, Molly L.; Brown, Eric P.; Ackerman, Margaret E.; Treanor, John J.; Luke, Catherine J.; Subbarao, Kanta; Wright, Peter F.

    2015-01-01

    Background. Live attenuated influenza vaccine (LAIV) and inactivated influenza vaccine (IIV) are available for children. Local and systemic immunity induced by LAIV followed a month later by LAIV and IIV followed by LAIV were investigated with virus recovery after LAIV doses as surrogates for protection against influenza on natural exposure. Methods. Fifteen children received IIV followed by LAIV, 13 an initial dose of LAIV, and 11 a second dose of LAIV. The studies were done during autumn 2009 and autumn 2010 with the same seasonal vaccine (A/California/07/09 [H1N1], A/Perth/16/09 [H3N2], B/Brisbane/60/08). Results. Twenty-eight of 39 possible influenza viral strains were recovered after the initial dose of LAIV. When LAIV followed IIV, 21 of 45 viral strains were identified. When compared to primary LAIV infection, the decreased frequency of shedding with the IIV-LAIV schedule was significant (P = .023). With LAIV-LAIV, the fewest viral strains were recovered (3/33)—numbers significantly lower (P < .001) than shedding after initial LAIV and after IIV-LAIV (P < .001). Serum hemagglutination inhibition antibody responses were more frequent after IIV than LAIV (P = .02). In contrast, more mucosal immunoglobulin A responses were seen with LAIV. Conclusions. LAIV priming induces greater inhibition of virus recovery on LAIV challenge than IIV priming. The correlate(s) of protection are the subject of ongoing analysis. Clinical Trials Registration. NCT01246999. PMID:25165161

  3. Live attenuated and inactivated influenza vaccines in children.

    PubMed

    Ilyushina, Natalia A; Haynes, Brenda C; Hoen, Anne G; Khalenkov, Alexey M; Housman, Molly L; Brown, Eric P; Ackerman, Margaret E; Treanor, John J; Luke, Catherine J; Subbarao, Kanta; Wright, Peter F

    2015-02-01

    Live attenuated influenza vaccine (LAIV) and inactivated influenza vaccine (IIV) are available for children. Local and systemic immunity induced by LAIV followed a month later by LAIV and IIV followed by LAIV were investigated with virus recovery after LAIV doses as surrogates for protection against influenza on natural exposure. Fifteen children received IIV followed by LAIV, 13 an initial dose of LAIV, and 11 a second dose of LAIV. The studies were done during autumn 2009 and autumn 2010 with the same seasonal vaccine (A/California/07/09 [H1N1], A/Perth/16/09 [H3N2], B/Brisbane/60/08). Twenty-eight of 39 possible influenza viral strains were recovered after the initial dose of LAIV. When LAIV followed IIV, 21 of 45 viral strains were identified. When compared to primary LAIV infection, the decreased frequency of shedding with the IIV-LAIV schedule was significant (P = .023). With LAIV-LAIV, the fewest viral strains were recovered (3/33)--numbers significantly lower (P < .001) than shedding after initial LAIV and after IIV-LAIV (P < .001). Serum hemagglutination inhibition antibody responses were more frequent after IIV than LAIV (P = .02). In contrast, more mucosal immunoglobulin A responses were seen with LAIV. LAIV priming induces greater inhibition of virus recovery on LAIV challenge than IIV priming. The correlate(s) of protection are the subject of ongoing analysis. NCT01246999. © 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.

  4. Stabilization of Live Attenuated Influenza Vaccines by Freeze Drying, Spray Drying, and Foam Drying.

    PubMed

    Lovalenti, Phillip M; Anderl, Jeff; Yee, Luisa; Nguyen, Van; Ghavami, Behnaz; Ohtake, Satoshi; Saxena, Atul; Voss, Thomas; Truong-Le, Vu

    2016-05-01

    The goal of this research is to develop stable formulations for live attenuated influenza vaccines (LAIV) by employing the drying methods freeze drying, spray drying, and foam drying. Formulated live attenuated Type-A H1N1 and B-strain influenza vaccines with a variety of excipient combinations were dried using one of the three drying methods. Process and storage stability at 4, 25 and 37°C of the LAIV in these formulations was monitored using a TCID50 potency assay. Their immunogenicity was also evaluated in a ferret model. The thermal stability of H1N1 vaccine was significantly enhanced through application of unique formulation combinations and drying processes. Foam dried formulations were as much as an order of magnitude more stable than either spray dried or freeze dried formulations, while exhibiting low process loss and full retention of immunogenicity. Based on long-term stability data, foam dried formulations exhibited a shelf life at 4, 25 and 37°C of >2, 1.5 years and 4.5 months, respectively. Foam dried LAIV Type-B manufactured using the same formulation and process parameters as H1N1 were imparted with a similar level of stability. Foam drying processing methods with appropriate selection of formulation components can produce an order of magnitude improvement in LAIV stability over other drying methods.

  5. Efficacy and effectiveness of live attenuated influenza vaccine in school-age children.

    PubMed

    Coelingh, Kathleen; Olajide, Ifedapo Rosemary; MacDonald, Peter; Yogev, Ram

    2015-01-01

    Evidence of high efficacy of live attenuated influenza vaccine (LAIV) from randomized controlled trials is strong for children 2-6 years of age, but fewer data exist for older school-age children. We reviewed the published data on efficacy and effectiveness of LAIV in children ≥5 years. QUOSA (Elsevier database) was searched for articles published from January 1990 to June 2014 that included 'FluMist', 'LAIV', 'CAIV', 'cold adapted influenza vaccine', 'live attenuated influenza vaccine', 'live attenuated cold adapted' or 'flu mist'. Studies evaluated included randomized controlled trials, effectiveness and indirect protection studies. This review demonstrates that LAIV has considerable efficacy and effectiveness in school-age children.

  6. Vaccination using radiation- or genetically attenuated live sporozoites.

    PubMed

    Vaughan, Ashley M; Kappe, Stefan H I

    2013-01-01

    The attenuation of Plasmodium parasites by either radiation or targeted gene deletion can result in viable sporozoites that invade the liver and subsequently arrest. The death of the growth-arrested liver stage parasite and the ensuing recognition by the immune system of parasite antigens promotes protective immunity in immunized mice and humans. The methods described below will enable researchers to determine the efficacy of radiation-attenuated and genetically attenuated rodent malaria sporozoite immunizations against infectious sporozoite challenge, and study protective immunity in immunized mice. In addition, by determining the time of arrest of genetically attenuated parasite liver stages and the mechanisms of clearance, researchers will be able to correlate biological features of the growth-arrested parasites with their ability to promote protective immunity.

  7. Spray application of live attenuated F Strain-derived Mycoplasma gallisepticum vaccines

    USDA-ARS?s Scientific Manuscript database

    Live attenuated vaccines (LAVs) are commonly utilized to protect commercial table egg producers from economic losses associated with challenges by the respiratory pathogen Mycoplasma gallisepticum (MG). Currently there are four MG LAVs commercially available within the United States. Consistent am...

  8. Deep Sequencing of Distinct Preparations of the Live Attenuated Varicella-Zoster Virus Vaccine Reveals a Conserved Core of Attenuating Single-Nucleotide Polymorphisms

    PubMed Central

    Yamanishi, Koichi; Gomi, Yasuyuki; Gershon, Anne A.; Breuer, Judith

    2016-01-01

    ABSTRACT The continued success of the live attenuated varicella-zoster virus vaccine in preventing varicella-zoster and herpes zoster is well documented, as are many of the mutations that contribute to the attenuation of the vOka virus for replication in skin. At least three different preparations of vOka are marketed. Here, we show using deep sequencing of seven batches of vOka vaccine (including ZostaVax, VariVax, VarilRix, and the Oka/Biken working seed) from three different manufacturers (VariVax, GSK, and Biken) that 137 single-nucleotide polymorphism (SNP) mutations are present in all vaccine batches. This includes six sites at which the vaccine allele is fixed or near fixation, which we speculate are likely to be important for attenuation. We also show that despite differences in the vaccine populations between preparations, batch-to-batch variation is minimal, as is the number and frequency of mutations unique to individual batches. This suggests that the vaccine manufacturing processes are not introducing new mutations and that, notwithstanding the mixture of variants present, VZV live vaccines are extremely stable. IMPORTANCE The continued success of vaccinations to prevent chickenpox and shingles, combined with the extremely low incidence of adverse reactions, indicates the quality of these vaccines. The vaccine itself is comprised of a heterogeneous live attenuated virus population and thus requires deep-sequencing technologies to explore the differences and similarities in the virus populations between different preparations and batches of the vaccines. Our data demonstrate minimal variation between batches, an important safety feature, and provide new insights into the extent of the mutations present in this attenuated virus. PMID:27440875

  9. Using recombinant DNA technology for the development of live-attenuated dengue vaccines.

    PubMed

    Lee, Hsiang-Chi; Butler, Michael; Wu, Suh-Chin

    2012-07-15

    Dramatic increases in dengue (DEN) incidence and disease severity have been reported, in great part due to the geographic expansion of Aedes aegypti and Aedes albopictus mosquitoes. One result is the expanded co-circulation of all dengue 1-4 serotype viruses (DENV) in urban areas worldwide, especially in South and South-East Asia, and South America. DEN disease severity ranges from asymptomatic infections to febrile dengue fevers (DF) to life-threatening dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). There is an urgent need for a safe and effective tetravalent DEN vaccine. Several live attenuated, tetravalent DEN vaccine candidates have been generated by recombinant DNA technology; these candidates are capable of providing immunity to all four DENV serotypes. In this paper we review (a) recombinant live-attenuated DEN vaccine candidates in terms of deletion, antigen chimerization, and the introduction of adaptive mutations; (b) strategies for improving tetravalent vaccine attenuation; and (c) live-attenuated DENV vaccine development.

  10. Controlling Multicycle Replication of Live-Attenuated HIV-1 Using an Unnatural Genetic Switch.

    PubMed

    Yuan, Zhe; Wang, Nanxi; Kang, Guobin; Niu, Wei; Li, Qingsheng; Guo, Jiantao

    2017-04-21

    A safe and effective human immunodeficiency virus type 1 (HIV-1) vaccine is urgently needed, but remains elusive. While HIV-1 live-attenuated vaccine can provide potent protection as demonstrated in rhesus macaque-simian immunodeficiency virus model, the potential pathogenic consequences associated with the uncontrolled virus replication preclude such vaccine from clinical applications. We investigated a novel approach to address this problem by controlling live-attenuated HIV-1 replication through an unnatural genetic switch that was based on the amber suppression strategy. Here we report the construction of all-in-one live-attenuated HIV-1 mutants that contain genomic copy of the amber suppression system. This genetic modification resulted in viruses that were capable of multicycle replication in vitro and could be switched on and off using an unnatural amino acid as the cue. This stand-alone, replication-controllable attenuated HIV-1 virus represents an important step toward the generation of a safe and efficacious live-attenuated HIV-1 vaccine. The strategy reported in this work can be adopted for the development of other live-attenuated vaccines.

  11. 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

  12. Experimental evaluation of inactivated and live attenuated vaccines against Mycoplasma mycoides subsp. mycoides.

    PubMed

    Mwirigi, Martin; Nkando, Isabel; Aye, Racheal; Soi, Reuben; Ochanda, Horace; Berberov, Emil; Potter, Andrew; Gerdts, Volker; Perez-Casal, Jose; Naessens, Jan; Wesonga, Hezron

    2016-01-01

    The current control method for contagious bovine pleuropneumonia (CBPP) in Africa is vaccination with a live, attenuated strain of Mycoplasma mycoides subsp. mycoides (Mmm). However, this method is not very efficient and often causes serious adverse reactions. Several studies have attempted to induce protection using inactivated mycoplasma, but with widely contradictory results. Therefore, we compared the protective capacity of the live T1/44 vaccine with two inactivated preparations of Mmm strain Afadé, inoculated with an adjuvant. Protection was measured after a challenge with Afadé. The protection levels were 31%, 80.8% and 74.1% for the formalin-inactivated, heat-inactivated and live attenuated preparations, respectively. These findings indicate that low doses of heat-inactivated Mmm can offer protection to a level similar to the current live attenuated (T1/44) vaccine formulation. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  13. Safety and immunogenicity of a live attenuated mumps vaccine

    PubMed Central

    Liang, Yan; Ma, Jingchen; Li, Changgui; Chen, Yuguo; Liu, Longding; Liao, Yun; Zhang, Ying; Jiang, Li; Wang, Xuan-Yi; Che, Yanchun; Deng, Wei; Li, Hong; Cui, Xiaoyu; Ma, Na; Ding, Dong; Xie, Zhongping; Cui, Pingfang; Ji, Qiuyan; Wang, Jingjing; Zhao, Yuliang; Wang, Junzhi; Li, Qihan

    2014-01-01

    Background: Mumps, a communicable, acute and previously well-controlled disease, has had recent and occasional resurgences in some areas. Methods: A randomized, double-blind, controlled and multistep phase I study of an F-genotype attenuated mumps vaccine produced in human diploid cells was conducted. A total of 300 subjects were enrolled and divided into 4 age groups: 16–60 years, 5–16 years, 2–5 years and 8–24 months. The groups were immunized with one injection per subject. Three different doses of the F-genotype attenuated mumps vaccine, A (3.5 ± 0.25 logCCID50), B (4.25 ± 0.25 logCCID50) and C (5.0 ± 0.25 logCCID50), as well as a placebo control and a positive control of a licensed A-genotype vaccine (S79 strain) were used. The safety and immunogenicity of this vaccine were compared with those of the controls. Results: The safety evaluation suggested that mild adverse reactions were observed in all groups. No serious adverse event (SAE) was reported throughout the trial. The immunogenicity test showed a similar seroconversion rate of the neutralizing and ELISA antibody in the 2- to 5-year-old and 8- to 24-month-old groups compared with the seroconversion rate in the positive control. The GMT of the neutralizing anti-F-genotype virus antibodies in the vaccine groups was slightly higher than that in the positive control group. Conclusions: The F-genotype attenuated mumps vaccine evaluated in this clinical trial was demonstrated to be safe and have effective immunogenicity vs. control. PMID:24614759

  14. DNA vaccine initiates replication of live attenuated chikungunya virus in vitro and elicits protective immune response in mice.

    PubMed

    Tretyakova, Irina; Hearn, Jason; Wang, Eryu; Weaver, Scott; Pushko, Peter

    2014-06-15

    Chikungunya virus (CHIKV) causes outbreaks of chikungunya fever worldwide and represents an emerging pandemic threat. Vaccine development against CHIKV has proved challenging. Currently there is no approved vaccine or specific therapy for the disease. To develop novel experimental CHIKV vaccine, we used novel immunization DNA (iDNA) infectious clone technology, which combines the advantages of DNA and live attenuated vaccines. Here we describe an iDNA vaccine composed of plasmid DNA that encode the full-length infectious genome of live attenuated CHIKV clone 181/25 downstream from a eukaryotic promoter. The iDNA approach was designed to initiate replication of live vaccine virus from the plasmid in vitro and in vivo. Experimental CHIKV iDNA vaccines were prepared and evaluated in cultured cells and in mice. Transfection with 10 ng of iDNA was sufficient to initiate replication of vaccine virus in vitro. Vaccination of BALB/c mice with a single 10 μg of CHIKV iDNA plasmid resulted in seroconversion, elicitation of neutralizing antibodies, and protection from experimental challenge with a neurovirulent CHIKV. Live attenuated CHIKV 181/25 vaccine can be delivered in vitro and in vivo by using DNA vaccination. The iDNA approach appears to represent a promising vaccination strategy for CHIK and other alphaviral diseases. © 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.

  15. Development of a Mouse-Adapted Live Attenuated Influenza Virus That Permits In Vivo Analysis of Enhancements to the Safety of Live Attenuated Influenza Virus Vaccine

    PubMed Central

    Cox, Andrew; Baker, Steven F.; Nogales, Aitor

    2014-01-01

    The live attenuated influenza virus vaccine (LAIV) is preferentially recommended for use in persons 2 through 49 years of age but has not been approved for children under 2 or asthmatics due to safety concerns. Therefore, increasing safety is desirable. Here we describe a murine LAIV with reduced pathogenicity that retains lethality at high doses and further demonstrate that we can enhance safety in vivo through mutations within NS1. This model may permit preliminary safety analysis of improved LAIVs. PMID:25552727

  16. Immunization of mice against Plasmodium vinckei with a combination of attenuated Salmonella typhimurium and malarial antigen.

    PubMed

    Kumar, S; Gorden, J; Flynn, J L; Berzofsky, J A; Miller, L H

    1990-10-01

    Infection with the blood stage of the malaria parasite Plasmodium vinckei is uniformly lethal in mice. We found that immunization of BALB/c mice with a combination of killed P. vinckei antigens and an attenuated (aroA) Salmonella typhimurium strain induces high levels of protection against challenge with live P. vinckei. This is especially significant because, in our previous studies, immunization of mice with killed P. vinckei antigens and adjuvants such as Bordetella pertussis, complete Freund adjuvant, and saponin failed to induce protective immunity. Immunization with attenuated S. typhimurium alone did not provide any nonspecific immunity. In vivo depletion of CD4+ T cells in the mice immunized with attenuated S. typhimurium and P. vinckei antigens caused the loss of their immunity. Expression of this immunity required the presence of a spleen. These results support our previous hypothesis that a blood stage malaria vaccine may need both induction of CD4+ T cells specific for the parasite and modification of the spleen with a vaccine vehicle. Therefore, attenuated Salmonella strains such as the one used in this study, when expressing recombinant malarial antigens, might fulfill this requirement.

  17. Serological response of foals to polyvalent and monovalent live-attenuated African horse sickness virus vaccines.

    PubMed

    Crafford, J E; Lourens, C W; Smit, T K; Gardner, I A; MacLachlan, N J; Guthrie, A J

    2014-06-17

    African horse sickness (AHS) is typically a highly fatal disease in susceptible horses and vaccination is currently used to prevent the occurrence of disease in endemic areas. Similarly, vaccination has been central to the control of incursions of African horse sickness virus (AHSV) into previously unaffected areas and will likely play a significant role in any future incursions. Horses in the AHSV-infected area in South Africa are vaccinated annually with a live-attenuated (modified-live virus [MLV]) vaccine, which includes a cocktail of serotypes 1, 3, 4 (bottle 1) and 2, 6-8 (bottle 2) delivered in two separate doses at least 21 days apart. In this study, the neutralising antibody response of foals immunized with this polyvalent MLV AHSV vaccine was evaluated and compared to the response elicited to monovalent MLV AHSV serotypes. Naïve foals were immunized with either the polyvalent MLV AHSV vaccine, or a combination of monovalent MLV vaccines containing individual AHSV serotypes 1, 4, 7 or 8. There was a marked and consistent difference in the immunogenicity of individual virus serotypes contained in the MLV vaccines. Specifically, foals most consistently seroconverted to AHSV-1 and responses to other serotypes were highly variable, and often weak or not detected. The serotype-specific responses of foals given the monovalent MLV vaccines were similar to those of foals given the polyvalent MLV preparation suggesting that there is no obvious enhanced immune response through the administration of a monovalent vaccine as opposed to the polyvalent vaccine.

  18. Long-term immunogenicity of single dose of live attenuated hepatitis A vaccine in Indian children.

    PubMed

    Bhave, Sheila; Sapru, Amita; Bavdekar, Ashish; Kapatkar, Vaibhavi; Mane, Amey

    2015-08-01

    To assess immunogenicity of a single dose of live attenuated hepatitis A vaccine in Indian children, ten years after immunization. Of 143 children vaccinated in 2004, 121 children were evaluated in 2014, clinically and for anti-HAV antibodies. 13 children were early vaccine failures who received two doses of HAV vaccine subsequently. 106 (98%) of 108 remaining children had seroprotective levels with a geometric mean titer of 100.5 mIU/mL. On analysis of all 121 children, the immunogenicity was 87.6%. Single dose of live attenuated hepatitis A vaccine provides long-term immunity in Indian children.

  19. Live Attenuated S. Typhimurium Vaccine with Improved Safety in Immuno-Compromised Mice

    PubMed Central

    Periaswamy, Balamurugan; Maier, Lisa; Vishwakarma, Vikalp; Slack, Emma; Kremer, Marcus; Andrews-Polymenis, Helene L.; McClelland, Michael; Grant, Andrew J.; Suar, Mrutyunjay; Hardt, Wolf-Dietrich

    2012-01-01

    Live attenuated vaccines are of great value for preventing infectious diseases. They represent a delicate compromise between sufficient colonization-mediated adaptive immunity and minimizing the risk for infection by the vaccine strain itself. Immune defects can predispose to vaccine strain infections. It has remained unclear whether vaccine safety could be improved via mutations attenuating a vaccine in immune-deficient individuals without compromising the vaccine's performance in the normal host. We have addressed this hypothesis using a mouse model for Salmonella diarrhea and a live attenuated Salmonella Typhimurium strain (ssaV). Vaccination with this strain elicited protective immunity in wild type mice, but a fatal systemic infection in immune-deficient cybb−/−nos2−/− animals lacking NADPH oxidase and inducible NO synthase. In cybb−/−nos2−/− mice, we analyzed the attenuation of 35 ssaV strains carrying one additional mutation each. One strain, Z234 (ssaV SL1344_3093), was >1000-fold attenuated in cybb−/−nos2−/− mice and ≈100 fold attenuated in tnfr1−/− animals. However, in wt mice, Z234 was as efficient as ssaV with respect to host colonization and the elicitation of a protective, O-antigen specific mucosal secretory IgA (sIgA) response. These data suggest that it is possible to engineer live attenuated vaccines which are specifically attenuated in immuno-compromised hosts. This might help to improve vaccine safety. PMID:23029007

  20. Mucosal correlates of cross-protection for live-attenuated influenza virus vaccines in pigs.

    USDA-ARS?s Scientific Manuscript database

    Controlling influenza A virus (IAV) in swine has become increasingly difficult with the emergence of novel reassorted strains and introduction of human seasonal IAV into pigs. In North America there are six antigenically distinct H1 subtypes currently circulating in pigs. Live-attenuated influenza v...

  1. 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...

  2. 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...

  3. 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 ...

  4. Characterization of an intracellular ATP assay for evaluating the viability of live attenuated mycobacterial vaccine preparations.

    PubMed

    Kolibab, Kristopher; Derrick, Steven C; Jacobs, William R; Morris, Sheldon L

    2012-09-01

    The viability of BCG vaccine has traditionally been monitored using a colony-forming unit (CFU) assay. Despite its widespread use, results from the CFU assay can be highly variable because of the characteristic clumping of mycobacteria, their requirement for complex growth media, and the three week incubation period needed to cultivate slow-growing mycobacteria. In this study, we evaluated whether an ATP luminescence assay (which measures intracellular ATP content) could be used to rapidly estimate the viability of lyophilized and/or frozen preparations of six different BCG vaccine preparations - Danish, Tokyo, Russia, Brazil, Tice, and Pasteur - and two live attenuated mycobacterial vaccine candidates - a ΔlysAΔpanCD M. tuberculosis strain and a ΔmmaA4 BCG vaccine mutant. For every vaccine tested, a significant correlation was observed between intracellular ATP concentrations and the number of viable attenuated bacilli. However, the extractable intracellular ATP levels detected per cell among the different live vaccines varied suggesting that validated ATP luminescence assays with specific appropriate standards must be developed for each individual live attenuated vaccine preparation. Overall, these data indicate that the ATP luminescence assay is a rapid, sensitive, and reliable alternative method for quantifying the viability of varying live attenuated mycobacterial vaccine preparations.

  5. Development of a mouse-adapted live attenuated influenza virus that permits in vivo analysis of enhancements to the safety of live attenuated influenza virus vaccine.

    PubMed

    Cox, Andrew; Baker, Steven F; Nogales, Aitor; Martínez-Sobrido, Luis; Dewhurst, Stephen

    2015-03-01

    The live attenuated influenza virus vaccine (LAIV) is preferentially recommended for use in persons 2 through 49 years of age but has not been approved for children under 2 or asthmatics due to safety concerns. Therefore, increasing safety is desirable. Here we describe a murine LAIV with reduced pathogenicity that retains lethality at high doses and further demonstrate that we can enhance safety in vivo through mutations within NS1. This model may permit preliminary safety analysis of improved LAIVs. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  6. Comparative genomics of the Mycobacterium signaling architecture and implications for a novel live attenuated Tuberculosis vaccine.

    PubMed

    Zhou, Peifu; Xie, Jianping

    2014-01-01

    Tuberculosis (TB), caused by Mycobacterium tuberculosis (M.tb), remains a major threat to global public health. A new TB vaccine affording superior immune protection to M. bovis Bacillus Calmette-Guérin (BCG) is imperative. The advantage of a live attenuated vaccine is that it can mimic the bona fide pathogen, elicit immune responses similar to natural infection, and potentially provide more protection than other vaccines. BCG, the only vaccine and a live attenuated vaccine that is the result of cumulative mutations by serial passage of M. bovis, has provided clues for the construction of novel improved vaccines. A strategy is put forward for identifying a new live attenuated TB vaccine generated by cumulative mutation based on M.tb. Given the important role of the M.tb signaling network consisting of a two-component system, eukaryotic-like Ser/Thr protein kinase system and sigma factor system based on comparisons among M.tb H37Rv, M. bovis, and BCG, we have put a premium on this signaling circuit as the starting point for the generation of an attenuated TB vaccine.

  7. 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.

  8. Envelope exchange for the generation of live-attenuated arenavirus vaccines.

    PubMed

    Bergthaler, Andreas; Gerber, Nicolas U; Merkler, Doron; Horvath, Edit; de la Torre, Juan Carlos; Pinschewer, Daniel D

    2006-06-01

    Arenaviruses such as Lassa fever virus cause significant mortality in endemic areas and represent potential bioterrorist weapons. The occurrence of arenaviral hemorrhagic fevers is largely confined to Third World countries with a limited medical infrastructure, and therefore live-attenuated vaccines have long been sought as a method of choice for prevention. Yet their rational design and engineering have been thwarted by technical limitations. In addition, viral genes had not been identified that are needed to cause disease but can be deleted or substituted to generate live-attenuated vaccine strains. Lymphocytic choriomeningitis virus, the prototype arenavirus, induces cell-mediated immunity against Lassa fever virus, but its safety for humans is unclear and untested. Using this virus model, we have developed the necessary methodology to efficiently modify arenavirus genomes and have exploited these techniques to identify an arenaviral Achilles' heel suitable for targeting in vaccine design. Reverse genetic exchange of the viral glycoprotein for foreign glycoproteins created attenuated vaccine strains that remained viable although unable to cause disease in infected mice. This phenotype remained stable even after extensive propagation in immunodeficient hosts. Nevertheless, the engineered viruses induced T cell-mediated immunity protecting against overwhelming systemic infection and severe liver disease upon wild-type virus challenge. Protection was established within 3 to 7 d after immunization and lasted for approximately 300 d. The identification of an arenaviral Achilles' heel demonstrates that the reverse genetic engineering of live-attenuated arenavirus vaccines is feasible. Moreover, our findings offer lymphocytic choriomeningitis virus or other arenaviruses expressing foreign glycoproteins as promising live-attenuated arenavirus vaccine candidates.

  9. Cross-protective Immunity Against Leptospirosis Elicited by a Live, Attenuated Lipopolysaccharide Mutant

    PubMed Central

    Srikram, Amporn; Zhang, Kunkun; Bartpho, Thanatchaporn; Lo, Miranda; Hoke, David E.; Sermswan, Rasana W.; Adler, Ben

    2011-01-01

    Background. Leptospira species cause leptospirosis, a zoonotic disease found worldwide. Current vaccines against leptospirosis provide protection only against closely related serovars. Methods. We evaluated an attenuated transposon mutant of Leptospira interrogans serovar Manilae (M1352, defective in lipopolysaccharide biosynthesis) as a live vaccine against leptospirosis. Hamsters received a single dose of vaccine and were challenged with the homologous serovar (Manilae) and a serologically unrelated heterologous serovar (Pomona). Comparisons were made with killed vaccines. Potential cross-protective antigens against leptospirosis were investigated. Results. Live M1352 vaccine induced superior protection in hamsters against homologous challenge. The live vaccine also stimulated cross-protection against heterologous challenge, with 100% survival (live M1352) versus 40% survival (killed vaccine). Hamsters receiving either vaccine responded to the dominant membrane proteins LipL32 and LipL41. Hamsters receiving the live vaccine additionally recognized LA3961/OmpL36 (unknown function), Loa22 (OmpA family protein, recognized virulence factor), LA2372 (general secretory protein G), and LA1939 (hypothetical protein). Manilae LigA was recognized by M1352 vaccinates, whereas LipL36 was detected in Pomona. Conclusion. This study demonstrated that a live, attenuated vaccine can stimulate cross-protective immunity to L. interrogans and has identified antigens that potentially confer cross-protection against leptospirosis. PMID:21220775

  10. Rift Valley Fever Virus MP-12 Vaccine Is Fully Attenuated by a Combination of Partial Attenuations in the S, M, and L Segments

    PubMed Central

    Hill, Terence E.; Smith, Jennifer K.; Zhang, Lihong; Juelich, Terry L.; Gong, Bin; Slack, Olga A. L.; Ly, Hoai J.; Lokugamage, Nandadeva; Freiberg, Alexander N.

    2015-01-01

    ABSTRACT Rift Valley fever (RVF) is a mosquito-borne zoonotic disease endemic to Africa and characterized by a high rate of abortion in ruminants and hemorrhagic fever, encephalitis, or blindness in humans. RVF is caused by Rift Valley fever virus (RVFV; family Bunyaviridae, genus Phlebovirus), which has a tripartite negative-stranded RNA genome (consisting of the S, M, and L segments). Further spread of RVF into countries where the disease is not endemic may affect the economy and public health, and vaccination is an effective approach to prevent the spread of RVFV. A live-attenuated MP-12 vaccine is one of the best-characterized RVF vaccines for safety and efficacy and is currently conditionally licensed for use for veterinary purposes in the United States. Meanwhile, as of 2015, no other RVF vaccine has been conditionally or fully licensed for use in the United States. The MP-12 strain is derived from wild-type pathogenic strain ZH548, and its genome encodes 23 mutations in the three genome segments. However, the mechanism of MP-12 attenuation remains unknown. We characterized the attenuation of wild-type pathogenic strain ZH501 carrying a mutation(s) of the MP-12 S, M, or L segment in a mouse model. Our results indicated that MP-12 is attenuated by the mutations in the S, M, and L segments, while the mutations in the M and L segments confer stronger attenuation than those in the S segment. We identified a combination of 3 amino acid changes, Y259H (Gn), R1182G (Gc), and R1029K (L), that was sufficient to attenuate ZH501. However, strain MP-12 with reversion mutations at those 3 sites was still highly attenuated. Our results indicate that MP-12 attenuation is supported by a combination of multiple partial attenuation mutations and a single reversion mutation is less likely to cause a reversion to virulence of the MP-12 vaccine. IMPORTANCE Rift Valley fever (RVF) is a mosquito-transmitted viral disease that is endemic to Africa and that has the potential to

  11. Rift Valley Fever Virus MP-12 Vaccine Is Fully Attenuated by a Combination of Partial Attenuations in the S, M, and L Segments.

    PubMed

    Ikegami, Tetsuro; Hill, Terence E; Smith, Jennifer K; Zhang, Lihong; Juelich, Terry L; Gong, Bin; Slack, Olga A L; Ly, Hoai J; Lokugamage, Nandadeva; Freiberg, Alexander N

    2015-07-01

    Rift Valley fever (RVF) is a mosquito-borne zoonotic disease endemic to Africa and characterized by a high rate of abortion in ruminants and hemorrhagic fever, encephalitis, or blindness in humans. RVF is caused by Rift Valley fever virus (RVFV; family Bunyaviridae, genus Phlebovirus), which has a tripartite negative-stranded RNA genome (consisting of the S, M, and L segments). Further spread of RVF into countries where the disease is not endemic may affect the economy and public health, and vaccination is an effective approach to prevent the spread of RVFV. A live-attenuated MP-12 vaccine is one of the best-characterized RVF vaccines for safety and efficacy and is currently conditionally licensed for use for veterinary purposes in the United States. Meanwhile, as of 2015, no other RVF vaccine has been conditionally or fully licensed for use in the United States. The MP-12 strain is derived from wild-type pathogenic strain ZH548, and its genome encodes 23 mutations in the three genome segments. However, the mechanism of MP-12 attenuation remains unknown. We characterized the attenuation of wild-type pathogenic strain ZH501 carrying a mutation(s) of the MP-12 S, M, or L segment in a mouse model. Our results indicated that MP-12 is attenuated by the mutations in the S, M, and L segments, while the mutations in the M and L segments confer stronger attenuation than those in the S segment. We identified a combination of 3 amino acid changes, Y259H (Gn), R1182G (Gc), and R1029K (L), that was sufficient to attenuate ZH501. However, strain MP-12 with reversion mutations at those 3 sites was still highly attenuated. Our results indicate that MP-12 attenuation is supported by a combination of multiple partial attenuation mutations and a single reversion mutation is less likely to cause a reversion to virulence of the MP-12 vaccine. Rift Valley fever (RVF) is a mosquito-transmitted viral disease that is endemic to Africa and that has the potential to spread into other

  12. A live-attenuated Zika virus vaccine candidate induces sterilizing immunity in mouse models.

    PubMed

    Shan, Chao; Muruato, Antonio E; Nunes, Bruno T D; Luo, Huanle; Xie, Xuping; Medeiros, Daniele B A; Wakamiya, Maki; Tesh, Robert B; Barrett, Alan D; Wang, Tian; Weaver, Scott C; Vasconcelos, Pedro F C; Rossi, Shannan L; Shi, Pei-Yong

    2017-06-01

    Zika virus (ZIKV) infection of pregnant women can cause a wide range of congenital abnormalities, including microcephaly, in the infant, a condition now collectively known as congenital ZIKV syndrome. A vaccine to prevent or significantly attenuate viremia in pregnant women who are residents of or travelers to epidemic or endemic regions is needed to avert congenital ZIKV syndrome, and might also help to suppress epidemic transmission. Here we report on a live-attenuated vaccine candidate that contains a 10-nucleotide deletion in the 3' untranslated region of the ZIKV genome (10-del ZIKV). The 10-del ZIKV is highly attenuated, immunogenic, and protective in type 1 interferon receptor-deficient A129 mice. Crucially, a single dose of 10-del ZIKV induced sterilizing immunity with a saturated neutralizing antibody titer, which no longer increased after challenge with an epidemic ZIKV, and completely prevented viremia. The immunized mice also developed a robust T cell response. Intracranial inoculation of 1-d-old immunocompetent CD-1 mice with 1 × 10(4) infectious focus units (IFU) of 10-del ZIKV caused no mortality, whereas infections with 10 IFU of wild-type ZIKV were lethal. Mechanistically, the attenuated virulence of 10-del ZIKV may be due to decreased viral RNA synthesis and increased sensitivity to type-1-interferon inhibition. The attenuated 10-del ZIKV was incapable of infecting mosquitoes after oral feeding of spiked-blood meals, representing an additional safety feature. Collectively, the safety and efficacy results suggest that further development of this promising, live-attenuated ZIKV vaccine candidate is warranted.

  13. General Molecular Strategy for Development of Arenavirus Live-Attenuated Vaccines

    PubMed Central

    Iwasaki, Masaharu; Ngo, Nhi; Cubitt, Beatrice; Teijaro, John R.

    2015-01-01

    ABSTRACT Hemorrhagic fever arenaviruses (HFA) pose important public health problems in regions where they are endemic. Thus, Lassa virus (LASV) infects several hundred thousand individuals yearly in West Africa, causing a large number of Lassa fever cases associated with high morbidity and mortality. 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. The Mopeia virus (MOPV)/LASV reassortant (ML29) is a LASV candidate live-attenuated vaccine (LAV) that has shown promising results in animal models. Nevertheless, the mechanism of ML29 attenuation remains unknown, which raises concerns about the phenotypic stability of ML29 in response to additional mutations. Development of LAVs based on well-defined molecular mechanisms of attenuation will represent a major step in combatting HFA. We used the prototypic arenavirus lymphocytic choriomeningitis virus (LCMV) to develop a general molecular strategy for arenavirus attenuation. Our approach involved replacement of the noncoding intergenic region (IGR) of the L genome segment with the IGR of the S genome segment to generate a recombinant LCMV, rLCMV(IGR/S-S), that was highly attenuated in vivo but induced protection against a lethal challenge with wild-type LCMV. Attenuation of rLCMV(IGR/S-S) was associated with a stable reorganization of the control of viral gene expression. This strategy can facilitate the rapid development of LAVs with the antigenic composition of the parental HFA and a mechanism of attenuation that minimizes concerns about increased virulence that could be caused by genetic changes in the LAV. IMPORTANCE Hemorrhagic fever arenaviruses (HFA) cause high morbidity and mortality, and pose important public health problems in the regions where they are endemic. Implementation of live-attenuated vaccines (LAV) will represent a

  14. 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.

  15. Gene-deleted live-attenuated Trypanosoma cruzi parasites as vaccines to protect against Chagas disease.

    PubMed

    Sánchez-Valdéz, Fernando J; Pérez Brandán, Cecilia; Ferreira, Arturo; Basombrío, Miguel Ángel

    2015-05-01

    Chagas disease is a neglected tropical disease caused by the protozoan parasite Trypanosoma cruzi. This illness is now becoming global, mainly due to congenital transmission, and so far, there are no prophylactic or therapeutic vaccines available to either prevent or treat Chagas disease. Therefore, different approaches aimed at identifying new protective immunogens are urgently needed. Live vaccines are likely to be more efficient in inducing protection, but safety issues linked with their use have been raised. The development of improved protozoan genetic manipulation tools and genomic and biological information has helped to increase the safety of live vaccines. These advances have generated a renewed interest in the use of genetically attenuated parasites as vaccines against Chagas disease. This review discusses the protective capacity of genetically attenuated parasite vaccines and the challenges and perspectives for the development of an effective whole-parasite Chagas disease vaccine.

  16. 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

  17. The Case for Live Attenuated Vaccines against the Neglected Zoonotic Diseases Brucellosis and Bovine Tuberculosis

    PubMed Central

    Pandey, Aseem; Cabello, Ana; Akoolo, Lavoisier; Rice-Ficht, Allison; Arenas-Gamboa, Angela; McMurray, David; Ficht, Thomas A.; de Figueiredo, Paul

    2016-01-01

    Vaccination of humans and animals with live attenuated organisms has proven to be an effective means of combatting some important infectious diseases. In fact, the 20th century witnessed tremendous improvements in human and animal health worldwide as a consequence of large-scale vaccination programs with live attenuated vaccines (LAVs). Here, we use the neglected zoonotic diseases brucellosis and bovine tuberculosis (BTb) caused by Brucella spp. and Mycobacterium bovis (M. bovis), respectively, as comparative models to outline the merits of LAV platforms with emphasis on molecular strategies that have been pursued to generate LAVs with enhanced vaccine safety and efficacy profiles. Finally, we discuss the prospects of LAV platforms in the fight against brucellosis and BTb and outline new avenues for future research towards developing effective vaccines using LAV platforms. PMID:27537413

  18. A live RSV vaccine with engineered thermostability is immunogenic in cotton rats despite high attenuation

    PubMed Central

    Stobart, Christopher C.; Rostad, Christina A.; Ke, Zunlong; Dillard, Rebecca S.; Hampton, Cheri M.; Strauss, Joshua D.; Yi, Hong; Hotard, Anne L.; Meng, Jia; Pickles, Raymond J.; Sakamoto, Kaori; Lee, Sujin; Currier, Michael G.; Moin, Syed M.; Graham, Barney S.; Boukhvalova, Marina S.; Gilbert, Brian E.; Blanco, Jorge C. G.; Piedra, Pedro A.; Wright, Elizabeth R.; Moore, Martin L.

    2016-01-01

    Respiratory syncytial virus (RSV) is a leading cause of infant hospitalization and there remains no pediatric vaccine. RSV live-attenuated vaccines (LAVs) have a history of safe testing in infants; however, achieving an effective balance of attenuation and immunogenicity has proven challenging. Here we seek to engineer an RSV LAV with enhanced immunogenicity. Genetic mapping identifies strain line 19 fusion (F) protein residues that correlate with pre-fusion antigen maintenance by ELISA and thermal stability of infectivity in live RSV. We generate a LAV candidate named OE4 which expresses line 19F and is attenuated by codon-deoptimization of non-structural (NS1 and NS2) genes, deletion of the small hydrophobic (SH) gene, codon-deoptimization of the attachment (G) gene and ablation of the secreted form of G. OE4 (RSV-A2-dNS1-dNS2-ΔSH-dGm-Gsnull-line19F) exhibits elevated pre-fusion antigen levels, thermal stability, immunogenicity, and efficacy despite heavy attenuation in the upper and lower airways of cotton rats. PMID:28000669

  19. A live RSV vaccine with engineered thermostability is immunogenic in cotton rats despite high attenuation.

    PubMed

    Stobart, Christopher C; Rostad, Christina A; Ke, Zunlong; Dillard, Rebecca S; Hampton, Cheri M; Strauss, Joshua D; Yi, Hong; Hotard, Anne L; Meng, Jia; Pickles, Raymond J; Sakamoto, Kaori; Lee, Sujin; Currier, Michael G; Moin, Syed M; Graham, Barney S; Boukhvalova, Marina S; Gilbert, Brian E; Blanco, Jorge C G; Piedra, Pedro A; Wright, Elizabeth R; Moore, Martin L

    2016-12-21

    Respiratory syncytial virus (RSV) is a leading cause of infant hospitalization and there remains no pediatric vaccine. RSV live-attenuated vaccines (LAVs) have a history of safe testing in infants; however, achieving an effective balance of attenuation and immunogenicity has proven challenging. Here we seek to engineer an RSV LAV with enhanced immunogenicity. Genetic mapping identifies strain line 19 fusion (F) protein residues that correlate with pre-fusion antigen maintenance by ELISA and thermal stability of infectivity in live RSV. We generate a LAV candidate named OE4 which expresses line 19F and is attenuated by codon-deoptimization of non-structural (NS1 and NS2) genes, deletion of the small hydrophobic (SH) gene, codon-deoptimization of the attachment (G) gene and ablation of the secreted form of G. OE4 (RSV-A2-dNS1-dNS2-ΔSH-dGm-Gsnull-line19F) exhibits elevated pre-fusion antigen levels, thermal stability, immunogenicity, and efficacy despite heavy attenuation in the upper and lower airways of cotton rats.

  20. Enhanced expression of HIV and SIV vaccine antigens in the structural gene region of live attenuated rubella viral vectors and their incorporation into virions.

    PubMed

    Virnik, Konstantin; Ni, Yisheng; Berkower, Ira

    2013-04-19

    Despite the urgent need for an HIV vaccine, its development has been hindered by virus variability, weak immunogenicity of conserved epitopes, and limited durability of the immune response. For other viruses, difficulties with immunogenicity were overcome by developing live attenuated vaccine strains. However, there is no reliable method of attenuation for HIV, and an attenuated strain would risk reversion to wild type. We have developed rubella viral vectors, based on the live attenuated vaccine strain RA27/3, which are capable of expressing important HIV and SIV vaccine antigens. The rubella vaccine strain has demonstrated safety, immunogenicity, and long lasting protection in millions of children. Rubella vectors combine the growth and immunogenicity of live rubella vaccine with the antigenicity of HIV or SIV inserts. This is the first report showing that live attenuated rubella vectors can stably express HIV and SIV vaccine antigens at an insertion site located within the structural gene region. Unlike the Not I site described previously, the new site accommodates a broader range of vaccine antigens without interfering with essential viral functions. In addition, antigens expressed at the structural site were controlled by the strong subgenomic promoter, resulting in higher levels and longer duration of antigen expression. The inserts were expressed as part of the structural polyprotein, processed to free antigen, and incorporated into rubella virions. The rubella vaccine strain readily infects rhesus macaques, and these animals will be the model of choice for testing vector growth in vivo and immunogenicity.

  1. Safety and Immunogenicity of a Live-Attenuated Junin (Argentine Hemorrhagic Fever) Vaccine in Rhesus Macaques

    DTIC Science & Technology

    1993-01-01

    virus from animals in every dose group. vetted 1-2.5 weeks after initial virus recovery. That the viruses recovered were Junin virus is certain: all...wild-type strains (LI 1.25). When vivo neutralization and virus clearance are com- we used this system to examine viruses recovered plex and multi...Fredertcktfarniand Abstract. The safety and immunogenicity of Candid #1. a live-attenuated Junin- virus vaccine, were evaluated in rhesus macaques. Candid #1 was

  2. An overview of live attenuated recombinant pseudorabies viruses for use as novel vaccines.

    PubMed

    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.

  3. Genetic analysis of attenuation markers of cold-adapted X-31 influenza live vaccine donor strain.

    PubMed

    Jang, Yo Han; Jung, Eun-Ju; Lee, Kwang-Hee; Byun, Young Ho; Yang, Seung Won; Seong, Baik Lin

    2016-03-08

    Cold-adapted live attenuated influenza vaccines (CAIVs) have been considered as a safe prophylactic measure to prevent influenza virus infections. The safety of a CAIV depends largely on genetic markers that confer specific attenuation phenotypes. Previous studies with other CAIVs reported that polymerase genes were primarily responsible for the attenuation. Here, we analyzed the genetic mutations and their phenotypic contribution in the X-31 ca strain, a recently developed alternative CAIV donor strain. During the cold-adaptation of its parental X-31 virus, various numbers of sequence changes were accumulated in all six internal genes. Phenotypic analysis with single-gene and multiple-gene reassortant viruses suggests that NP gene makes the largest contribution to the cold-adapted (ca) and temperature-sensitive (ts) characters, while the remaining other internal genes also impart attenuation characters with varying degrees. A balanced contribution of all internal genes to the attenuation suggests that X-31 ca could serve as an ideal master donor strain for CAIVs preventing influenza epidemics and pandemics. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    PubMed

    Stanfield, Brent; Kousoulas, Konstantin Gus

    2015-09-01

    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.

  5. Live-Attenuated Bacterial Vectors: Tools for Vaccine and Therapeutic Agent Delivery

    PubMed Central

    Lin, Ivan Y. C.; Van, Thi Thu Hao; Smooker, Peter M.

    2015-01-01

    Genetically attenuated microorganisms, including pathogenic and commensal bacteria, can be engineered to carry and deliver heterologous antigens to elicit host immunity against both the vector as well as the pathogen from which the donor gene is derived. These live attenuated bacterial vectors have been given much attention due to their capacity to induce a broad range of immune responses including localized mucosal, as well as systemic humoral and/or cell-mediated immunity. In addition, the unique tumor-homing characteristics of these bacterial vectors has also been exploited for alternative anti-tumor vaccines and therapies. In such approach, tumor-associated antigen, immunostimulatory molecules, anti-tumor drugs, or nucleotides (DNA or RNA) are delivered. Different potential vectors are appropriate for specific applications, depending on their pathogenic routes. In this review, we survey and summarize the main features of the different types of live bacterial vectors and discussed the clinical applications in the field of vaccinology. In addition, different approaches for using live attenuated bacterial vectors for anti-cancer therapy is discussed, and some promising pre-clinical and clinical studies in this field are outlined. PMID:26569321

  6. 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

  7. Development of live-attenuated arenavirus vaccines based on codon deoptimization.

    PubMed

    Cheng, Benson Yee Hin; Ortiz-Riaño, Emilio; Nogales, Aitor; de la Torre, Juan Carlos; Martínez-Sobrido, Luis

    2015-04-01

    Arenaviruses have a significant impact on public health and pose a credible biodefense threat, but the development of safe and effective arenavirus vaccines has remained elusive, and currently, no Food and Drug Administration (FDA)-licensed arenavirus vaccines are available. Here, we explored the use of a codon deoptimization (CD)-based approach as a novel strategy to develop live-attenuated arenavirus vaccines. We recoded the nucleoprotein (NP) of the prototypic arenavirus lymphocytic choriomeningitis virus (LCMV) with the least frequently used codons in mammalian cells, which caused lower LCMV NP expression levels in transfected cells that correlated with decreased NP activity in cell-based functional assays. We used reverse-genetics approaches to rescue a battery of recombinant LCMVs (rLCMVs) encoding CD NPs (rLCMV/NP(CD)) that showed attenuated growth kinetics in vitro. Moreover, experiments using the well-characterized mouse model of LCMV infection revealed that rLCMV/NP(CD1) and rLCMV/NP(CD2) were highly attenuated in vivo but, upon a single immunization, conferred complete protection against a subsequent lethal challenge with wild-type (WT) recombinant LCMV (rLCMV/WT). Both rLCMV/NP(CD1) and rLCMV/NP(CD2) were genetically and phenotypically stable during serial passages in FDA vaccine-approved Vero cells. These results provide proof of concept of the safety, efficacy, and stability of a CD-based approach for developing live-attenuated vaccine candidates against human-pathogenic arenaviruses. Several arenaviruses cause severe hemorrhagic fever in humans and pose a credible bioterrorism threat. Currently, no FDA-licensed vaccines are available to combat arenavirus infections, while antiarenaviral therapy is limited to the off-label use of ribavirin, which is only partially effective and is associated with side effects. Here, we describe the generation of recombinant versions of the prototypic arenavirus LCMV encoding codon-deoptimized viral nucleoproteins (r

  8. Development of Live-Attenuated Arenavirus Vaccines Based on Codon Deoptimization

    PubMed Central

    Cheng, Benson Yee Hin; Ortiz-Riaño, Emilio; Nogales, Aitor

    2015-01-01

    ABSTRACT Arenaviruses have a significant impact on public health and pose a credible biodefense threat, but the development of safe and effective arenavirus vaccines has remained elusive, and currently, no Food and Drug Administration (FDA)-licensed arenavirus vaccines are available. Here, we explored the use of a codon deoptimization (CD)-based approach as a novel strategy to develop live-attenuated arenavirus vaccines. We recoded the nucleoprotein (NP) of the prototypic arenavirus lymphocytic choriomeningitis virus (LCMV) with the least frequently used codons in mammalian cells, which caused lower LCMV NP expression levels in transfected cells that correlated with decreased NP activity in cell-based functional assays. We used reverse-genetics approaches to rescue a battery of recombinant LCMVs (rLCMVs) encoding CD NPs (rLCMV/NPCD) that showed attenuated growth kinetics in vitro. Moreover, experiments using the well-characterized mouse model of LCMV infection revealed that rLCMV/NPCD1 and rLCMV/NPCD2 were highly attenuated in vivo but, upon a single immunization, conferred complete protection against a subsequent lethal challenge with wild-type (WT) recombinant LCMV (rLCMV/WT). Both rLCMV/NPCD1 and rLCMV/NPCD2 were genetically and phenotypically stable during serial passages in FDA vaccine-approved Vero cells. These results provide proof of concept of the safety, efficacy, and stability of a CD-based approach for developing live-attenuated vaccine candidates against human-pathogenic arenaviruses. IMPORTANCE Several arenaviruses cause severe hemorrhagic fever in humans and pose a credible bioterrorism threat. Currently, no FDA-licensed vaccines are available to combat arenavirus infections, while antiarenaviral therapy is limited to the off-label use of ribavirin, which is only partially effective and is associated with side effects. Here, we describe the generation of recombinant versions of the prototypic arenavirus LCMV encoding codon-deoptimized viral

  9. Alternative live-attenuated influenza vaccines based on modifications in the polymerase genes protect against epidemic and pandemic flu.

    PubMed

    Solórzano, Alicia; Ye, Jianqiang; Pérez, Daniel R

    2010-05-01

    Human influenza is a seasonal disease associated with significant morbidity and mortality. Influenza vaccination is the most effective means for disease prevention. We have previously shown that mutations in the PB1 and PB2 genes of the live-attenuated influenza vaccine (LAIV) from the cold-adapted (ca) influenza virus A/Ann Arbor/6/60 (H2N2) could be transferred to avian influenza viruses and produce partially attenuated viruses. We also demonstrated that avian influenza viruses carrying the PB1 and PB2 mutations could be further attenuated by stably introducing a hemagglutinin (HA) epitope tag in the PB1 gene. In this work, we wanted to determine whether these modifications would also result in attenuation of a so-called triple reassortant (TR) swine influenza virus (SIV). Thus, the TR influenza A/swine/Wisconsin/14094/99 (H3N2) virus was generated by reverse genetics and subsequently mutated in the PB1 and PB2 genes. Here we show that a combination of mutations in this TR backbone results in an attenuated virus in vitro and in vivo. Furthermore, we show the potential of our TR backbone as a vaccine that provides protection against the 2009 swine-origin pandemic influenza H1N1 virus (S-OIV) when carrying the surface of a classical swine strain. We propose that the availability of alternative backbones to the conventional ca A/Ann Arbor/6/60 LAIV strain could also be useful in epidemic and pandemic influenza and should be considered for influenza vaccine development. In addition, our data provide evidence that the use of these alternative backbones could potentially circumvent the effects of original antigenic sin (OAS) in certain circumstances.

  10. 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

  11. Safety, Tolerability, and Immunogenicity of a Recombinant, Genetically Engineered, Live-Attenuated Vaccine against Canine Blastomycosis▿

    PubMed Central

    Wüthrich, Marcel; Krajaejun, Theerapong; Shearn-Bochsler, Valerie; Bass, Chris; Filutowicz, Hanna I.; Legendre, Alfred M.; Klein, Bruce S.

    2011-01-01

    Blastomycosis is a severe, commonly fatal infection caused by the dimorphic fungus Blastomyces dermatitidis in dogs that live in the United States, Canada, and parts of Africa. The cost of treating an infection can be expensive, and no vaccine against this infection is commercially available. A genetically engineered live-attenuated strain of B. dermatitidis lacking the major virulence factor BAD-1 successfully vaccinates against lethal experimental infection in mice. Here we studied the safety, toxicity, and immunogenicity of this strain as a vaccine in dogs, using 25 beagles at a teaching laboratory and 78 foxhounds in a field trial. In the beagles, escalating doses of live vaccine ranging from 2 × 104 to 2 × 107 yeast cells given subcutaneously were safe and did not disseminate to the lung or induce systemic illness, but a dose of <2 × 106 yeast cells induced less fever and local inflammation. A vaccine dose of 105 yeast cells was also well tolerated in vaccinated foxhounds who had never had blastomycosis; however, vaccinated dogs with prior infection had more local reactions at the vaccine site. The draining lymph node cells and peripheral blood lymphocytes from vaccinated dogs demonstrated gamma interferon (IFN-γ), tumor necrosis factor alpha (TNF-α), and granulocyte-macrophage colony-stimulating factor (GM-CSF) specifically in response to stimulation with Blastomyces antigens. Thus, the live-attenuated vaccine against blastomycosis studied here proved safe, well tolerated, and immunogenic in dogs and merits further studies of vaccine efficacy. PMID:21367980

  12. Immunogenicity of a Live Attenuated Chimeric Japanese Encephalitis Vaccine as a Booster Dose After Primary Vaccination With Live Attenuated SA14-14-2 Vaccine: A Phase IV Study in Thai Children.

    PubMed

    Sricharoenchai, Sirintip; Lapphra, Keswadee; Chuenkitmongkol, Sunate; Phongsamart, Wanatpreeya; Bouckenooghe, Alain; Wittawatmongkol, Orasri; Rungmaitree, Supattra; Chokephaibulkit, Kulkanya

    2017-02-01

    This single-group study investigated the immunogenicity and safety of a booster dose of the recently licensed live attenuated chimeric Japanese encephalitis vaccine in 50 healthy children (1-5 years old) who were primed with the live attenuated SA14-14-2 vaccine. A strong anamnestic response was induced 28 days postbooster: geometric mean titer, 9144 (95% confidence interval: 7365-11353); and seroprotection rate, 49 of 49 (100%) children.

  13. Reversion of Cold-Adapted Live Attenuated Influenza Vaccine into a Pathogenic Virus.

    PubMed

    Zhou, Bin; Meliopoulos, Victoria A; Wang, Wei; Lin, Xudong; Stucker, Karla M; Halpin, Rebecca A; Stockwell, Timothy B; Schultz-Cherry, Stacey; Wentworth, David E

    2016-10-01

    The only licensed live attenuated influenza A virus vaccines (LAIVs) in the United States (FluMist) are created using internal protein-coding gene segments from the cold-adapted temperature-sensitive master donor virus A/Ann Arbor/6/1960 and HA/NA gene segments from circulating viruses. During serial passage of A/Ann Arbor/6/1960 at low temperatures to select the desired attenuating phenotypes, multiple cold-adaptive mutations and temperature-sensitive mutations arose. A substantial amount of scientific and clinical evidence has proven that FluMist is safe and effective. Nevertheless, no study has been conducted specifically to determine if the attenuating temperature-sensitive phenotype can revert and, if so, the types of substitutions that will emerge (i.e., compensatory substitutions versus reversion of existing attenuating mutations). Serial passage of the monovalent FluMist 2009 H1N1 pandemic vaccine at increasing temperatures in vitro generated a variant that replicated efficiently at higher temperatures. Sequencing of the variant identified seven nonsynonymous mutations, PB1-E51K, PB1-I171V, PA-N350K, PA-L366I, NP-N125Y, NP-V186I, and NS2-G63E. None occurred at positions previously reported to affect the temperature sensitivity of influenza A viruses. Synthetic genomics technology was used to synthesize the whole genome of the virus, and the roles of individual mutations were characterized by assessing their effects on RNA polymerase activity and virus replication kinetics at various temperatures. The revertant also regained virulence and caused significant disease in mice, with severity comparable to that caused by a wild-type 2009 H1N1 pandemic virus. The live attenuated influenza vaccine FluMist has been proven safe and effective and is widely used in the United States. The phenotype and genotype of the vaccine virus are believed to be very stable, and mutants that cause disease in animals or humans have never been reported. By propagating the virus under

  14. Reversion of Cold-Adapted Live Attenuated Influenza Vaccine into a Pathogenic Virus

    PubMed Central

    Meliopoulos, Victoria A.; Wang, Wei; Lin, Xudong; Stucker, Karla M.; Halpin, Rebecca A.; Stockwell, Timothy B.; Schultz-Cherry, Stacey

    2016-01-01

    ABSTRACT The only licensed live attenuated influenza A virus vaccines (LAIVs) in the United States (FluMist) are created using internal protein-coding gene segments from the cold-adapted temperature-sensitive master donor virus A/Ann Arbor/6/1960 and HA/NA gene segments from circulating viruses. During serial passage of A/Ann Arbor/6/1960 at low temperatures to select the desired attenuating phenotypes, multiple cold-adaptive mutations and temperature-sensitive mutations arose. A substantial amount of scientific and clinical evidence has proven that FluMist is safe and effective. Nevertheless, no study has been conducted specifically to determine if the attenuating temperature-sensitive phenotype can revert and, if so, the types of substitutions that will emerge (i.e., compensatory substitutions versus reversion of existing attenuating mutations). Serial passage of the monovalent FluMist 2009 H1N1 pandemic vaccine at increasing temperatures in vitro generated a variant that replicated efficiently at higher temperatures. Sequencing of the variant identified seven nonsynonymous mutations, PB1-E51K, PB1-I171V, PA-N350K, PA-L366I, NP-N125Y, NP-V186I, and NS2-G63E. None occurred at positions previously reported to affect the temperature sensitivity of influenza A viruses. Synthetic genomics technology was used to synthesize the whole genome of the virus, and the roles of individual mutations were characterized by assessing their effects on RNA polymerase activity and virus replication kinetics at various temperatures. The revertant also regained virulence and caused significant disease in mice, with severity comparable to that caused by a wild-type 2009 H1N1 pandemic virus. IMPORTANCE The live attenuated influenza vaccine FluMist has been proven safe and effective and is widely used in the United States. The phenotype and genotype of the vaccine virus are believed to be very stable, and mutants that cause disease in animals or humans have never been reported. By

  15. Intranasal live attenuated seasonal influenza vaccine: does not challenge current practice.

    PubMed

    2013-09-01

    Influenza vaccination of children is only justified when there is a risk of serious influenza complications. In 2012, a live attenuated vaccine for intranasal administration was authorised in the European Union for influenza prevention in individuals aged from 2 to less than 18 years. This type of vaccine has been available in the United States since 2003. Clinical evaluation of this live vaccine is based on three non-inferiority trials versus an injected inactivated vaccine. There are no specific trials in children at risk of serious influenza complications. Only one of these trials was double-blinded. Two trials involved children with a history of respiratory problems. Symptomatic influenza confirmed by viral culture was less frequent in these three trials after intranasal vaccination than after injection of the conventional vaccine (about 3 to 5% and 6 to 10%, respectively). There was no difference between the vaccines in terms of clinical complications of influenza, especially asthma exacerbations. Adverse effects attributed to the intranasal vaccine mainly consisted of local reactions such as rhinorrhoea and nasal congestion, as well as flu-like syndromes. Wheezing, respiratory tract infections and hospitalisation were more frequent with the intranasal vaccine than with the injected vaccine in children aged less than 1 year and in children with a history of severe respiratory illness. The intranasal vaccine is contraindicated in these children. The intranasal vaccine contains live attenuated virus strains and is therefore contraindicated in immunocompromised patients. US pharmacovigilance data suggest that severe allergic reactions to the intranasal vaccine, Guillain-Barré syndrome, and transmission of vaccine viruses to contacts are very rare. Intranasal administration seems to be more practical, especially for children. In practice, there is no firm evidence that this live attenuated influenza vaccine has any clinical advantages over injected vaccines

  16. Duration of protective immunity after a single vaccination with a live attenuated bivalent bluetongue vaccine.

    PubMed

    Zhugunissov, Kuandyk; Yershebulov, Zakir; Barakbayev, Kainar; Bulatov, Yerbol; Taranov, Dmitriy; Amanova, Zhanat; Abduraimov, Yergali

    2015-12-01

    The prevention of bluetongue is typically achieved with mono- or polyvalent modified- live-attenuated virus (MLV) vaccines. MLV vaccines typically elicit a strong antibody response that correlates directly with their ability to replicate in the vaccinated animal. They are inexpensive, stimulate protective immunity after a single inoculation, and have been proven effective in preventing clinical bluetongue disease. In this study, we evaluated the safety, immunogenicity, and efficacy of a bluetongue vaccine against Bluetongue virus serotypes 4 and 16 in sheep. All the animals remained clinically healthy during the observation period. The vaccinated animals showed no clinical signs except fever (>40.8 °C) for 2-4 days. Rapid seroconversion was observed in the sheep, with the accumulation of high antibody titers in the vaccinated animals. No animal became ill after the challenge, indicating that effective protection was achieved. Therefore, this vaccine, prepared from attenuated bluetongue virus strains, is safe, immunogenic, and efficacious.

  17. Development of live-attenuated arenavirus vaccines based on codon deoptimization of the viral glycoprotein.

    PubMed

    Cheng, Benson Y H; Nogales, Aitor; de la Torre, Juan Carlos; Martínez-Sobrido, Luis

    2017-01-15

    Several arenaviruses, chiefly Lassa (LASV) in West Africa, cause hemorrhagic fever (HF) disease in humans and pose important public health problems in their endemic regions. To date, there are no FDA-approved arenavirus vaccines and current anti-arenaviral therapy is limited to the use of ribavirin that has very limited efficacy. In this work we document that a recombinant prototypic arenavirus lymphocytic choriomeningitis virus (LCMV) with a codon deoptimized (CD) surface glycoprotein (GP), rLCMV/CD, exhibited wild type (WT)-like growth properties in cultured cells despite barely detectable GP expression levels in rLCMV/CD-infected cells. Importantly, rLCMV/CD was highly attenuated in vivo but able to induce complete protection against a subsequent lethal challenge with rLCMV/WT. Our findings support the feasibility of implementing an arenavirus GP CD-based approach for the development of safe and effective live-attenuated vaccines (LAVs) to combat diseases caused by human pathogenic arenaviruses.

  18. Stable Salmonella live vaccine strains with two or more attenuating mutations and any desired level of attenuation.

    PubMed

    Linde, K; Beer, J; Bondarenko, V

    1990-06-01

    Mutants optimally attenuated for highly susceptible hosts and protecting after a single oral vaccination are often overattenuated for host species being less susceptible. Therefore, to select vaccine strains optimally attenuated for the particular host species it is essential that a range of mutants with graded levels of attenuation be provided so as to permit lesser susceptibility to be compensated for by a correspondingly lower level of attenuation. This, while guaranteeing the stability through two-marker or multi-marker attenuation, can be suitably accomplished by slightly to moderately virulence-reducing mutations. Aspartic acid auxotrophy and, in particular, 'metabolic drift' mutations, possibly by additionally incorporating antiepidemic markers, are adopted for the mouse model to demonstrate stepwise production of S. typhimurium and S. typhi vaccine candidate strains with graded attenuation or any level of attenuation desirable. It is emphasized that this basic approach is relevant to practice.

  19. 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.

  20. Nebulized Live-Attenuated Influenza Vaccine Provides Protection in Ferrets at a Reduced Dose

    PubMed Central

    Smith, Jennifer Humberd; Papania, Mark; Knaus, Darin; Brooks, Paula; Haas, Debra L.; Mair, Raydel; Barry, James; Tompkins, S. Mark; Tripp, Ralph A.

    2011-01-01

    Live-attenuated influenza vaccine (LAIV) is delivered to vaccine recipients using a nasal spray syringe. LAIV delivered by this method is immunogenic at current doses; however, improvements in nasal delivery might allow for significant dose reduction. We investigated LAIV vaccination in ferrets using a high efficiency nebulizer designed for nasal delivery. LAIV nasal aerosol elicited high levels of serum neutralizing antibodies and protected ferrets from homologous virus challenge at conventional (107 TCID50) and significantly reduced (103 TCID50) doses. Aerosol LAIV also provided a significant level of subtype-specific cross protection. These results demonstrate the dose-sparing potential of nebulizer-based nasal aerosol LAIV delivery. PMID:22075083

  1. 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.

  2. Live Attenuated Human Salmonella Vaccine Candidates: Tracking the Pathogen in Natural Infection and Stimulation of Host Immunity.

    PubMed

    Galen, James E; Buskirk, Amanda D; Tennant, Sharon M; Pasetti, Marcela F

    2016-11-01

    Salmonellosis, caused by members of the genus Salmonella, is responsible for considerable global morbidity and mortality in both animals and humans. In this review, we will discuss the pathogenesis of Salmonella enterica serovar Typhi and Salmonella enterica serovar Typhimurium, focusing on human Salmonella infections. We will trace the path of Salmonella through the body, including host entry sites, tissues and organs affected, and mechanisms involved in both pathogenesis and stimulation of host immunity. Careful consideration of the natural progression of disease provides an important context in which attenuated live oral vaccines can be rationally designed and developed. With this in mind, we will describe a series of attenuated live oral vaccines that have been successfully tested in clinical trials and demonstrated to be both safe and highly immunogenic. The attenuation strategies summarized in this review offer important insights into further development of attenuated vaccines against other Salmonella for which live oral candidates are currently unavailable.

  3. Live Attenuated Human Salmonella Vaccine Candidates: tracking the pathogen in natural infection and stimulation of host immunity

    PubMed Central

    Galen, James E.; Buskirk, Amanda D.; Tennant, Sharon M.; Pasetti, Marcela F.

    2016-01-01

    Salmonellosis, caused by members of the genus Salmonella, is responsible for considerable global morbidity and mortality, in both animals and humans. In this review, we will discuss the pathogenesis of S. Typhi and S. Typhimurium, focusing on human Salmonella infections. We will trace the path of Salmonella through the body, including host entry sites, tissues and organs affected, and mechanisms involved in both pathogenesis and stimulation of host immunity. Careful consideration of the natural progression of disease provides an important context in which attenuated live oral vaccines can be rationally designed and developed. With this in mind, we will describe a series of attenuated live oral vaccines that have been successfully tested in clinical trials and demonstrated to be both safe and highly immunogenic. The attenuation strategies summarized in this review offer important insights into further development of attenuated vaccines against other Salmonella for which live oral candidates are currently unavailable. PMID:27809955

  4. Safety, tolerability, and immunogenicity of a recombinant, genetically engineered, live-attenuated vaccine against canine blastomycosis.

    PubMed

    Wüthrich, Marcel; Krajaejun, Theerapong; Shearn-Bochsler, Valerie; Bass, Chris; Filutowicz, Hanna I; Legendre, Alfred M; Klein, Bruce S

    2011-05-01

    Blastomycosis is a severe, commonly fatal infection caused by the dimorphic fungus Blastomyces dermatitidis in dogs that live in the United States, Canada, and parts of Africa. The cost of treating an infection can be expensive, and no vaccine against this infection is commercially available. A genetically engineered live-attenuated strain of B. dermatitidis lacking the major virulence factor BAD-1 successfully vaccinates against lethal experimental infection in mice. Here we studied the safety, toxicity, and immunogenicity of this strain as a vaccine in dogs, using 25 beagles at a teaching laboratory and 78 foxhounds in a field trial. In the beagles, escalating doses of live vaccine ranging from 2 × 10⁴ to 2 × 10⁷ yeast cells given subcutaneously were safe and did not disseminate to the lung or induce systemic illness, but a dose of < 2 × 10⁶ yeast cells induced less fever and local inflammation. A vaccine dose of 10⁵ yeast cells was also well tolerated in vaccinated foxhounds who had never had blastomycosis; however, vaccinated dogs with prior infection had more local reactions at the vaccine site. The draining lymph node cells and peripheral blood lymphocytes from vaccinated dogs demonstrated gamma interferon (IFN-γ), tumor necrosis factor alpha (TNF-α), and granulocyte-macrophage colony-stimulating factor (GM-CSF) specifically in response to stimulation with Blastomyces antigens. Thus, the live-attenuated vaccine against blastomycosis studied here proved safe, well tolerated, and immunogenic in dogs and merits further studies of vaccine efficacy.

  5. 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.

  6. Canine influenza viruses with modified NS1 proteins for the development of live-attenuated vaccines.

    PubMed

    Nogales, Aitor; Huang, Kai; Chauché, Caroline; DeDiego, Marta L; Murcia, Pablo R; Parrish, Colin R; Martínez-Sobrido, Luis

    2017-01-01

    Canine Influenza Virus (CIV) H3N8 is the causative agent of canine influenza, a common and contagious respiratory disease of dogs. Currently, only inactivated influenza vaccines (IIVs) are available for the prevention of CIV H3N8. However, live-attenuated influenza vaccines (LAIVs) are known to provide better immunogenicity and protection efficacy than IIVs. Influenza NS1 is a virulence factor that offers an attractive target for the preparation of attenuated viruses as LAIVs. Here we generated recombinant H3N8 CIVs containing truncated or a deleted NS1 protein to test their potential as LAIVs. All recombinant viruses were attenuated in mice and showed reduced replication in cultured canine tracheal explants, but were able to confer complete protection against challenge with wild-type CIV H3N8 after a single intranasal immunization. Immunogenicity and protection efficacy was better than that observed with an IIV. This is the first description of a LAIV for the prevention of H3N8 CIV in dogs. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Characterization of Francisella tularensis Schu S4 defined mutants as live-attenuated vaccine candidates.

    PubMed

    Santiago, Araceli E; Mann, Barbara J; Qin, Aiping; Cunningham, Aimee L; Cole, Leah E; Grassel, Christen; Vogel, Stefanie N; Levine, Myron M; Barry, Eileen M

    2015-08-01

    Francisella tularensis (Ft), the etiological agent of tularemia and a Tier 1 select agent, has been previously weaponized and remains a high priority for vaccine development. Ft tularensis (type A) and Ft holarctica (type B) cause most human disease. We selected six attenuating genes from the live vaccine strain (LVS; type B), F. novicida and other intracellular bacteria: FTT0507, FTT0584, FTT0742, FTT1019c (guaA), FTT1043 (mip) and FTT1317c (guaB) and created unmarked deletion mutants of each in the highly human virulent Ft strain Schu S4 (Type A) background. FTT0507, FTT0584, FTT0742 and FTT1043 Schu S4 mutants were not attenuated for virulence in vitro or in vivo. In contrast, Schu S4 gua mutants were unable to replicate in murine macrophages and were attenuated in vivo, with an i.n. LD50 > 10(5) CFU in C57BL/6 mice. However, the gua mutants failed to protect mice against lethal challenge with WT Schu S4, despite demonstrating partial protection in rabbits in a previous study. These results contrast with the highly protective capacity of LVS gua mutants against a lethal LVS challenge in mice, and underscore differences between these strains and the animal models in which they are evaluated, and therefore have important implications for vaccine development.

  8. Cross-protection against Salmonella Typhimurium infection conferred by a live attenuated Salmonella Enteritidis vaccine

    PubMed Central

    Nandre, Rahul M.; Lee, Dajeong; Lee, John Hwa

    2015-01-01

    In this study, a genetically engineered live attenuated Salmonella Enteritidis (SE) vaccine was evaluated for its ability to protect against Salmonella Typhimurium (ST) infection in chickens. The birds were orally primed with the vaccine on the 1st day of life and given an oral booster at 5 wk of age. Control birds were orally inoculated with phosphate-buffered saline. Both groups of birds were orally challenged with a virulent ST strain at 9 wk of age. Compared with the control chickens, the vaccinated chickens had significantly higher levels of systemic IgG and mucosal IgA against specific ST antigens and a significantly greater lymphoproliferative response to ST antigens. The excretion of ST into the feces was significantly lower in the vaccinated group than in the control group on days 9 and 13 d after challenge. In addition, the vaccinated group had significantly fewer pronounced gross lesions in the liver and spleen and lower bacterial counts in the internal organs than the control group after challenge. These data indicate that genetically engineered live attenuated SE may induce humoral and cellular immune responses against ST antigens and may confer protection against virulent ST challenge. PMID:25673904

  9. 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.

  10. 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.

  11. Superior Protection from Live-Attenuated Vaccines Directed against Johne's Disease

    PubMed Central

    Shippy, Daniel C.; Lemke, Justin J.; Berry, Aubrey; Nelson, Kathryn; Hines, Murray E.

    2016-01-01

    ABSTRACT Mycobacterium avium subsp. paratuberculosis (M. paratuberculosis) is the etiological agent of Johne's disease in ruminants. Johne's disease is an important enteric infection causing large economic losses associated with infected herds. In an attempt to fight this infection, we created two novel live-attenuated vaccine candidates with mutations in sigH and lipN (pgsH and pgsN, respectively). Earlier reports in mice suggested these vaccines are promising candidates to fight Johne's disease in ruminants. In this study, we tested the performances of the two constructs as vaccine candidates using the goat model of Johne's disease. Both vaccines appeared to provide significant immunity to goats against challenge from wild-type M. paratuberculosis. The pgsH and pgsN constructs showed a significant reduction in histopathological lesions and tissue colonization compared to nonvaccinated goats and those vaccinated with an inactivated vaccine. Unlike the inactivated vaccine, the pgsN construct was able to eliminate fecal shedding from challenged animals, a feature that is highly desirable to control Johne's disease in infected herds. Furthermore, strong initial cell-mediated immune responses were elicited in goats vaccinated with pgsN that were not demonstrated in other vaccine groups. Overall, the results indicate the potential use of live-attenuated vaccines to control intracellular pathogens, including M. paratuberculosis, and warrant further testing in cattle, the main target for Johne's disease control programs. PMID:27806993

  12. 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.

  13. Correlates of Immunity to Influenza as Determined by Challenge of Children with Live, Attenuated Influenza Vaccine

    PubMed Central

    Wright, Peter F.; Hoen, Anne G.; Ilyushina, Natalia A.; Brown, Eric P.; Ackerman, Margaret E.; Wieland-Alter, Wendy; Connor, Ruth I.; Jegaskanda, Sinthujan; Rosenberg-Hasson, Yael; Haynes, Brenda C.; Luke, Catherine J.; Subbarao, Kanta; Treanor, John J.

    2016-01-01

    Background. The efficacy of live, attenuated live attenuated influenza vaccine(LAIV) and inactivated influenza vaccine(IIV) is poorly explained by either single or composite immune responses to vaccination. Protective biomarkers were therefore studied in response to LAIV or IIV followed by LAIV challenge in children. Methods. Serum and mucosal responses to LAIV or IIV were analyzed using immunologic assays to assess both quantitative and functional responses. Cytokines and chemokines were measured in nasal washes collected before vaccination, on days 2, 4, and 7 after initial LAIV, and again after LAIV challenge using a 63-multiplex Luminex panel. Results. Patterns of immunity induced by LAIV and IIV were significantly different. Serum responses induced by IIV, including hemagglutination inhibition, did not correlate with detection or quantitation of LAIV on subsequent challenge. Modalities that induced sterilizing immunity seen after LAIV challenge could not be defined by any measurements of mucosal or serum antibodies induced by the initial LAIV immunization. No single cytokine or chemokine was predictive of protection. Conclusions. The mechanism of protective immunity observed after LAIV could not be defined, and traditional measurements of immunity to IIV did not correlate with protection against an LAIV challenge. PMID:27419180

  14. Oncolytic virotherapy for human bone and soft tissue sarcomas using live attenuated poliovirus.

    PubMed

    Atsumi, Satoru; Matsumine, Akihiko; Toyoda, Hidemi; Niimi, Rui; Iino, Takahiro; Nakamura, Tomoki; Matsubara, Takao; Asanuma, Kunihiro; Komada, Yoshihiro; Uchida, Atsumasa; Sudo, Akihiro

    2012-09-01

    The poliovirus receptor CD155, is essential for poliovirus to infect and induce death in neural cells. Recently, CD155 has been shown to be selectively expressed on certain types of tumor cells originating from the neural crest, including malignant glioma and neuroblastoma. However, the expression pattern of CD155 in soft tissue sarcoma has not been examined. Therefore, we first examined CD155 expression in sarcoma cell lines, and found the expression of both CD155 mRNA and protein in 12 soft and bone tissue sarcoma cell lines. Furthermore, we examined the effect of live attenuated poliovirus (LAPV) on 6 bone and soft tissue sarcoma cell lines in vitro, and found that LAPV induced apoptosis by activating caspases 7 and 3 in all of these cell lines. Furthermore, in BALB/c nu/nu mice xenotransplanted with HT1080 fibrosarcoma cells, administration of live attenuated poliovirus caused growth suppression of the tumors. These results suggest that oncolytic therapy using a LAPV may represent a new option for the treatment of bone and soft tissue sarcomas.

  15. Reverse genetic platform for inactivated and live-attenuated influenza vaccine.

    PubMed

    Jung, Eun Ju; Lee, Kwang Hee; Seong, Baik Lin

    2010-02-28

    Influenza vaccine strains have been traditionally developed by annual reassortment between vaccine donor strain and the epidemic virulent strains. The classical method requires screening and genotyping of the vaccine strain among various reassortant viruses, which are usually laborious and time-consuming. Here we developed an efficient reverse genetic system to generate the 6:2 reassortant vaccine virus from cDNAs derived from the influenza RNAs. Thus, cDNAs of the two RNAs coding for surface antigens, haemagglutinin and neuraminidase from the epidemic virus and the 6 internal genes from the donor strain were transfected into cells and the infectious viruses of 6:2 defined RNA ratio were rescued. X-31 virus (a high- growth virus in embryonated eggs) and its cold-adapted strain X-31 ca were judiciously chosen as donor strains for the generation of inactivated vaccine and live-attenuated vaccine, respectively. The growth properties of these recombinant viruses in embryonated chicken eggs and MDCK cell were indistinguishable as compared to those generated by classical reassortment process. Based on the reverse genetic system, we generated 6+2 reassortant avian influenza vaccine strains corresponding to the A/Chicken/Korea/ MS96 (H9N2) and A/Indonesia/5/2005 (H5N1). The results would serve as technical platform for the generation of both injectable inactivated vaccine and the nasal spray live attenuated vaccine for the prevention of influenza epidemics and pandemics.

  16. Reverse genetic platform for inactivated and live-attenuated influenza vaccine

    PubMed Central

    Jung, Eun-Ju; Lee, Kwang-Hee

    2010-01-01

    Influenza vaccine strains have been traditionally developed by annual reassortment between vaccine donor strain and the epidemic virulent strains. The classical method requires screening and genotyping of the vaccine strain among various reassortant viruses, which are usually laborious and time-consuming. Here we developed an efficient reverse genetic system to generate the 6:2 reassortant vaccine virus from cDNAs derived from the influenza RNAs. Thus, cDNAs of the two RNAs coding for surface antigens, haemagglutinin and neuraminidase from the epidemic virus and the 6 internal genes from the donor strain were transfected into cells and the infectious viruses of 6:2 defined RNA ratio were rescued. X-31 virus (a high-growth virus in embryonated eggs) and its cold-adapted strain X-31 ca were judiciously chosen as donor strains for the generation of inactivated vaccine and live-attenuated vaccine, respectively. The growth properties of these recombinant viruses in embryonated chicken eggs and MDCK cell were indistinguishable as compared to those generated by classical reassortment process. Based on the reverse genetic system, we generated 6 + 2 reassortant avian influenza vaccine strains corresponding to the A/Chicken/Korea/MS96 (H9N2) and A/Indonesia/5/2005 (H5N1). The results would serve as technical platform for the generation of both injectable inactivated vaccine and the nasal spray live attenuated vaccine for the prevention of influenza epidemics and pandemics. PMID:20054235

  17. Cross-protection against Salmonella Typhimurium infection conferred by a live attenuated Salmonella Enteritidis vaccine.

    PubMed

    Nandre, Rahul M; Lee, Dajeong; Lee, John Hwa

    2015-01-01

    In this study, a genetically engineered live attenuated Salmonella Enteritidis (SE) vaccine was evaluated for its ability to protect against Salmonella Typhimurium (ST) infection in chickens. The birds were orally primed with the vaccine on the 1st day of life and given an oral booster at 5 wk of age. Control birds were orally inoculated with phosphate-buffered saline. Both groups of birds were orally challenged with a virulent ST strain at 9 wk of age. Compared with the control chickens, the vaccinated chickens had significantly higher levels of systemic IgG and mucosal IgA against specific ST antigens and a significantly greater lymphoproliferative response to ST antigens. The excretion of ST into the feces was significantly lower in the vaccinated group than in the control group on days 9 and 13 d after challenge. In addition, the vaccinated group had significantly fewer pronounced gross lesions in the liver and spleen and lower bacterial counts in the internal organs than the control group after challenge. These data indicate that genetically engineered live attenuated SE may induce humoral and cellular immune responses against ST antigens and may confer protection against virulent ST challenge.

  18. Live attenuated varicella-zoster vaccine in hematopoietic stem cell transplantation recipients.

    PubMed

    Issa, Nicolas C; Marty, Francisco M; Leblebjian, Houry; Galar, Alicia; Shea, Margaret M; Antin, Joseph H; Soiffer, Robert J; Baden, Lindsey R

    2014-02-01

    Hematopoietic stem cell transplantation (HSCT) recipients are at risk for varicella-zoster virus (VZV) reactivation. Vaccination may help restore VZV immunity; however, the available live attenuated VZV vaccine (Zostavax) is contraindicated in immunocompromised hosts. We report our experience with using a single dose of VZV vaccine in 110 adult autologous and allogeneic HSCT recipients who were about 2 years after transplantation, free of graft-versus-host disease, and not receiving immunosuppression. One hundred eight vaccine recipients (98.2%) had no clinically apparent adverse events with a median follow-up period of 9.5 months (interquartile range, 6 to 16; range, 2 to 28). Two vaccine recipients (1.8%) developed a skin rash (one zoster-like rash with associated pain, one varicella-like) within 42 days post-vaccination that resolved with antiviral therapy. We could not confirm if these rashes were due to vaccine (Oka) or wild-type VZV. No other possible cases of VZV reactivation have occurred with about 1178 months of follow-up. Live attenuated zoster vaccine appears generally safe in this population when vaccinated as noted; the overall vaccination risk needs to be weighed against the risk of wild-type VZV disease in this high-risk population.

  19. Alternative methods to compare safety of live-attenuated respiratory Newcastle disease vaccines in young chicks.

    PubMed

    Malo, Aris; de Wit, Sjaak; Swart, Wim A J M; Cook, Jane K A

    2017-09-02

    The work reported here is an initial attempt to find an alternative method by which the safety of live-attenuated Newcastle disease virus (NDV) vaccines for the respiratory tract of young chickens can be assessed. The current recommended methods involve either the subjective assessment of respiratory signs, or raise ethical concerns, as in the case of the intracerebral pathogenicity index. The two methods considered here were the use of tracheal organ cultures to assess the level of ciliostasis which the vaccines caused to the ciliated epithelium of the trachea and the incorporation of a pathogenic strain of Escherichia coli in the inoculum in order to induce colibacillosis. Both methods were successful in confirming the safety of the two vaccines. However, these results are only preliminary and more studies need to be performed to determine whether one or both methods have potential, either to replace the existing statutory tests, or provide a test which might be useful during the development stages of a new live-attenuated NDV vaccine. © British Veterinary Association (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  20. A live attenuated strain of Yersinia pestis KIM as a vaccine against plague.

    PubMed

    Sun, Wei; Six, David; Kuang, Xiaoying; Roland, Kenneth L; Raetz, Christian R H; Curtiss, Roy

    2011-04-05

    Yersinia pestis, the causative agent of plague, is a potential weapon of bioterrorism. Y. pestis evades the innate immune system by synthesizing tetra-acylated lipid A with poor Toll-like receptor 4 (TLR4)-stimulating activity at 37°C, whereas hexa-acylated lipid A, a potent TLR4 agonist, is made at lower temperatures. Synthesis of Escherichia coli LpxL, which transfers the secondary laurate chain to the 2'-position of lipid A, in Y. pestis results in production of hexa-acylated lipid A at 37°C, leading to significant attenuation of virulence. Previously, we described a Y. pestis vaccine strain in which crp expression is under the control of the arabinose-regulated araC P(BAD) promoter, resulting in a 4-5 log reduction in virulence. To reduce the virulence of the crp promoter mutant further, we introduced E. coli lpxL into the Y. pestis chromosome. The χ10030(pCD1Ap) (ΔlpxP32::P(lpxL)lpxL ΔP(crp21)::TT araC P(BAD)crp) construct likewise produced hexa-acylated lipid A at 37°C and was significantly more attenuated than strains harboring each individual mutation. The LD(50) of the mutant in mice, when administered subcutaneously or intranasally was >10(7)-times and >10(4)-times greater than wild type, respectively. Mice immunized subcutaneously with a single dose of the mutant were completely protected against a subcutaneous challenge of 3.6×10(7) wild-type Y. pestis and significantly protected (80% survival) against a pulmonary challenge of 1.2×10(4) live cells. Intranasal immunization also provided significant protection against challenges by both routes. This mutant is an immunogenic, highly attenuated live Y. pestis construct that merits further development as a vaccine candidate. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. 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

  2. Temperature-Sensitive Live-Attenuated Canine Influenza Virus H3N8 Vaccine

    PubMed Central

    Nogales, Aitor; Rodriguez, Laura; Chauché, Caroline; Huang, Kai; Reilly, Emma C.

    2016-01-01

    ABSTRACT Canine influenza is a respiratory disease of dogs caused by canine influenza virus (CIV). CIV subtypes responsible for influenza in dogs include H3N8, which originated from the transfer of H3N8 equine influenza virus to dogs; and the H3N2 CIV, which is an avian-origin virus that adapted to infect dogs. Influenza infections are most effectively prevented through vaccination to reduce transmission and future infection. Currently, only inactivated influenza vaccines (IIVs) are available for the prevention of CIV in dogs. However, the efficacy of IIVs is suboptimal, and novel approaches are necessary for the prevention of disease caused by this canine respiratory pathogen. Using reverse genetics techniques, we have developed a live-attenuated CIV vaccine (LACIV) for the prevention of H3N8 CIV. The H3N8 LACIV replicates efficiently in canine cells at 33°C but is impaired at temperatures of 37 to 39°C and was attenuated compared to wild-type H3N8 CIV in vivo and ex vivo. The LACIV was able to induce protection against H3N8 CIV challenge with a single intranasal inoculation in mice. Immunogenicity and protection efficacy were better than that observed with a commercial CIV H3N8 IIV but provided limited cross-reactive immunity and heterologous protection against H3N2 CIV. These results demonstrate the feasibility of implementing a LAIV approach for the prevention and control of H3N8 CIV in dogs and suggest the need for a new LAIV for the control of H3N2 CIV. IMPORTANCE Two influenza A virus subtypes has been reported in dogs in the last 16 years: the canine influenza viruses (CIV) H3N8 and H3N2 of equine and avian origins, respectively. To date, only inactivated influenza vaccines (IIVs) are available to prevent CIV infections. Here, we report the generation of a recombinant, temperature-sensitive H3N8 CIV as a live-attenuated influenza vaccine (LAIV), which was attenuated in mice and dog tracheal, explants compared to CIV H3N8 wild type. A single dose of H3N8

  3. 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

    2017-02-14

    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.

  4. Characterization of immune responses induced by inactivated, live attenuated and DNA vaccines against Japanese encephalitis virus in mice.

    PubMed

    Li, Jieqiong; Chen, Hui; Wu, Na; Fan, Dongying; Liang, Guodong; Gao, Na; An, Jing

    2013-08-28

    Vaccination is the most effective countermeasure for protecting individuals from Japanese encephalitis virus (JEV) infection. There are two types of JEV vaccines currently used in China: the Vero cell-derived inactivated vaccine and the live attenuated vaccine. In this study, we characterized the immune response and protective efficacy induced in mice by the inactivated vaccine, live attenuated vaccine and the DNA vaccine candidate pCAG-JME, which expresses JEV prM-E proteins. We found that the live attenuated vaccine conferred 100% protection and resulted in the generation of high levels of specific anti-JEV antibodies and cytokines. The pCAG-JME vaccine induced protective immunity as well as the live attenuated vaccine. Unexpectedly, immunization with the inactivated vaccine only induced a limited immune response and partial protection, which may be due to the decreased activity of dendritic cells and the expansion of CD4+CD25+Foxp3+ regulatory T cells observed in these mice. Altogether, our results suggest that the live attenuated vaccine is more effective in providing protection against JEV infection than the inactivated vaccine and that pCAG-JME will be a potential JEV vaccine candidate.

  5. Markless Attenuation Correction for Carotid MRI Surface Receiver Coils in Combined PET/MR Imaging

    PubMed Central

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

    2015-01-01

    Purpose To evaluate the effect of attenuation of MR coils on quantitative carotid PET/MR exams. Additionally, to develop and evaluate automated attenuation correction method for flexible carotid MR coils was developed and evaluated. Methods 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 minutes 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. Results 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. Conclusions 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. PMID:26020273

  6. 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.

  7. A Low Gastric pH Mouse Model to Evaluate Live Attenuated Bacterial Vaccines

    PubMed Central

    Brenneman, Karen E.; Willingham, Crystal; Kilbourne, Jacquelyn A.; 3rd, Roy Curtiss; Roland, Kenneth L.

    2014-01-01

    The low pH of the stomach serves as a barrier to ingested microbes and must be overcome or bypassed when delivering live bacteria for vaccine or probiotic applications. Typically, the impact of stomach acidity on bacterial survival is evaluated in vitro, as there are no small animal models to evaluate these effects in vivo. To better understand the effect of this low pH barrier to live attenuated Salmonella vaccines, which are often very sensitive to low pH, we investigated the value of the histamine mouse model for this application. A low pH gastric compartment was transiently induced in mice by the injection of histamine. This resulted in a gastric compartment of approximately pH 1.5 that was capable of distinguishing between acid-sensitive and acid-resistant microbes. Survival of enteric microbes during gastric transit in this model directly correlated with their in vitro acid resistance. Because many Salmonella enterica serotype Typhi vaccine strains are sensitive to acid, we have been investigating systems to enhance the acid resistance of these bacteria. Using the histamine mouse model, we demonstrate that the in vivo survival of S. Typhi vaccine strains increased approximately 10-fold when they carried a sugar-inducible arginine decarboxylase system. We conclude that this model will be a useful for evaluating live bacterial preparations prior to clinical trials. PMID:24489912

  8. Generation of a novel live rabies vaccine strain with a high level of safety by introducing attenuating mutations in the nucleoprotein and glycoprotein.

    PubMed

    Nakagawa, Keisuke; Nakagawa, Kento; Omatsu, Tsutomu; Katayama, Yukie; Oba, Mami; Mitake, Hiromichi; Okada, Kazuma; Yamaoka, Satoko; Takashima, Yasuhiro; Masatani, Tatsunori; Okadera, Kota; Ito, Naoto; Mizutani, Tetsuya; Sugiyama, Makoto

    2017-10-09

    The current live rabies vaccine SAG2 is attenuated by only one mutation (Arg-to-Glu) at position 333 in the glycoprotein (G333). This fact generates a potential risk of the emergence of a pathogenic revertant by a back mutation at this position during viral propagation in the body. To circumvent this risk, it is desirable to generate a live vaccine strain highly and stably attenuated by multiple mutations. However, the information on attenuating mutations other than that at G333 is very limited. We previously reported that amino acids at positions 273 and 394 in the nucleoprotein (N273/394) (Leu and His, respectively) of fixed rabies virus Ni-CE are responsible for the attenuated phenotype by enhancing interferon (IFN)/chemokine gene expressions in infected neural cells. In this study, we found that amino acid substitutions at N273/394 (Phe-to-Leu and Tyr-to-His, respectively) attenuated the pathogenicity of the oral live vaccine ERA, which has a virulent-type Arg at G333. Then we generated ERA-N273/394-G333 attenuated by the combination of the above attenuating mutations at G333 and N273/394, and checked its safety. Similar to the ERA-G333, which is attenuated by only the mutation at G333, ERA-N273/394-G333 did not cause any symptoms in adult mice after intracerebral inoculation, indicating a low level of residual pathogenicity of ERA-N273/394-G333. Further examination revealed that infection with ERA-N273/394-G333 induces IFN-β and CXCL10 mRNA expressions more strongly than ERA-G333 infection in a neuroblastoma cell line. Importantly, we found that the ERA-N273/394-G333 stain has a lower risk for emergence of a pathogenic revertant than does the ERA-G333. These results indicate that ERA-N273/394-G333 has a potential to be a promising candidate for a live rabies vaccine strain with a high level of safety. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Extended Preclinical Safety, Efficacy and Stability Testing of a Live-attenuated Chikungunya Vaccine Candidate

    PubMed Central

    Plante, Kenneth S; Rossi, Shannan L.; Bergren, Nicholas A.; Seymour, Robert L.; Weaver, Scott C.

    2015-01-01

    We recently described a new, live-attenuated vaccine candidate for chikungunya (CHIK) fever, CHIKV/IRES. This vaccine was shown to be well attenuated, immunogenic and efficacious in protecting against CHIK virus (CHIKV) challenge of mice and nonhuman primates. To further evaluate its preclinical safety, we compared CHIKV/IRES distribution and viral loads in interferon-α/β receptor-incompetent A129 mice to another CHIK vaccine candidate, 181/clone25, which proved highly immunogenic but mildly reactive in human Phase I/II clinical trials. Compared to wild-type CHIK virus, (wt-CHIKV), both vaccines generated lower viral loads in a wide variety of tissues and organs, including the brain and leg muscle, but CHIKV/IRES exhibited marked restrictions in dissemination and viral loads compared to 181/clone25, and was never found outside the blood, spleen and muscle. Unlike wt-CHIKV, which caused disrupted splenic architecture and hepatic lesions, histopathological lesions were not observed in animals infected with either vaccine strain. To examine the stability of attenuation, both vaccines were passaged 5 times intracranially in infant A129 mice, then assessed for changes in virulence by comparing parental and passaged viruses for footpad swelling, weight stability and survival after subcutaneous infection. Whereas strain 181/clone25 p5 underwent a significant increase in virulence as measured by weight loss (from <10% to >30%) and mortality (from 0 to 100%), CHIKV/IRES underwent no detectible change in any measure of virulence (no significant weight loss and no mortality). These data indicate greater nonclinical safety of the CHIKV/IRES vaccine candidate compared to 181/clone25, further supporting its eligibility for human testing. PMID:26340754

  10. Live Attenuated Influenza Vaccine contains Substantial and Unexpected Amounts of Defective Viral Genomic RNA.

    PubMed

    Gould, Philip S; Easton, Andrew J; Dimmock, Nigel J

    2017-09-21

    The live attenuated influenza vaccine FluMist(®) was withdrawn in the USA by the Centers for Disease Control and Prevention after its failure to provide adequate protective immunity during 2013-2016. The vaccine uses attenuated core type A and type B viruses, reconfigured each year to express the two major surface antigens of the currently circulating viruses. Here Fluenz™ Tetra, the European version of this vaccine, was examined directly for defective-interfering (DI) viral RNAs. DI RNAs are deleted versions of the infectious virus genome, and have powerful biological properties including attenuation of infection, reduction of infectious virus yield, and stimulation of some immune responses. Reverse transcription polymerase chain reaction followed by cloning and sequencing showed that Fluenz™ vaccine contains unexpected and substantial amounts of DI RNA arising from both its influenza A and influenza B components, with 87 different DI RNA sequences identified. Flu A DI RNAs from segment 3 replaced the majority of the genomic full-length segment 3, thus compromising its infectivity. DI RNAs arise during vaccine production and non-infectious DI virus replaces infectious virus pro rata so that fewer doses of the vaccine can be made. Instead the vaccine carries a large amount of non-infectious but biologically active DI virus. The presence of DI RNAs could significantly reduce the multiplication in the respiratory tract of the vaccine leading to reduced immunizing efficacy and could also stimulate the host antiviral responses, further depressing vaccine multiplication. The role of DI viruses in the performance of this and other vaccines requires further investigation.

  11. Innate and adaptive immune control of genetically engineered live-attenuated arenavirus vaccine prototypes.

    PubMed

    Pinschewer, Daniel D; Flatz, Lukas; Steinborn, Ralf; Horvath, Edit; Fernandez, Marylise; Lutz, Hans; Suter, Mark; Bergthaler, Andreas

    2010-09-01

    Arenaviruses such as Lassa virus (LASV) cause significant morbidity and mortality in endemic areas. Using a glycoprotein (GP) exchange strategy, we have recently developed live-attenuated arenavirus vaccine prototypes (rLCMV/VSVG) based on lymphocytic choriomeningitis virus (LCMV), a close relative of LASV. rLCMV/VSVG induced long-term CD8(+) T cell immunity against wild-type virus challenge and exhibited a stably attenuated phenotype in vivo. Here we elucidated the innate and adaptive immune requirements for the control of rLCMV/VSVG. Infection of RAG(-/-) mice resulted in persisting viral RNA in blood but not in overt viremia. The latter was only found in mice lacking both RAG and IFN type I receptor. Conversely, absence of IFN type II signaling or NK cells on an RAG-deficient background had only minor effects on vaccine virus load or none at all. rLCMV/VSVG infection of wild-type mice induced less type I IFN than did wild-type LCMV, and type I as well as type II IFNs were dispensable for the induction of virus-specific memory CD8 T cells and virus-neutralizing antibodies by rLCMV/VSVG. In conclusion, the adaptive immune systems are essential for elimination of rLCMV/VSVG, and type I but not type II IFN plays a major contributive role in lowering rLCMV/VSVG loads in vivo, attesting to the attenuation profile of the vaccine. Nevertheless, IFNs are not required for the induction of potent vaccine responses. These results provide a better understanding of the immunobiology of rLCMV/VSVG and will contribute to the further development of GP exchange vaccines for combating arenaviral hemorrhagic fevers.

  12. 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.

  13. Protective efficacy of a live attenuated vaccine against Argentine hemorrhagic fever. AHF Study Group.

    PubMed

    Maiztegui, J I; McKee, K T; Barrera Oro, J G; Harrison, L H; Gibbs, P H; Feuillade, M R; Enria, D A; Briggiler, A M; Levis, S C; Ambrosio, A M; Halsey, N A; Peters, C J

    1998-02-01

    Argentine hemorrhagic fever (AHF), caused by the arenavirus Junin, is a major public health problem among agricultural workers in Argentina. A prospective, randomized, double-blind, placebo-controlled, efficacy trial of Candid 1, a live attenuated Junin virus vaccine, was conducted over two consecutive epidemic seasons among 6500 male agricultural workers in the AHF-endemic region. Twenty-three men developed laboratory-confirmed AHF during the study; 22 received placebo and 1 received vaccine (vaccine efficacy 95%; 95% confidence interval [CI], 82%-99%). Three additional subjects in each group developed laboratory-confirmed Junin virus infection associated with mild illnesses that did not fulfill the clinical case definition for AHF, yielding a protective efficacy for prevention of any illness associated with Junin virus infection of 84% (95% CI, 60%-94%). No serious adverse events were attributed to vaccination. Candid 1, the first vaccine for the prevention of illness caused by an arenavirus, is safe and highly efficacious.

  14. 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.

  15. Is a booster dose necessary in children after immunization with live attenuated Japanese encephalitis vaccine?

    PubMed

    Choi, Ui Yoon; Lee, Soo Young; Kim, Ki Hwan; Kim, Dong Soo; Choi, Kyong Min; Cha, Sung Ho; Kang, Jin Han

    2013-10-01

    Japanese encephalitis virus is a common cause of encephalitis in Asian children; therefore, maintenance of immunity against Japanese encephalitis virus is essential. Although many countries recommend booster vaccination, some trials have concluded that administration of one or two vaccinations is sufficient. The current study was conducted to evaluate immunogenicity and safety after a booster vaccination with live attenuated vaccine. For 68 study subjects, measurement of antibody titer was performed before and at 4-6 weeks after administration of a booster dose. Adverse reactions occurring at the injection site and systemic adverse reactions were documented. The percentages of subjects with seroprotective neutralizing antibody titers was 100% before and after booster vaccination, and the geometric mean titer increased after booster vaccination. Thus, we predict that immunity will be maintained for a long time by an amnestic response. Low percentages of adverse reactions indicated the safety of the immunizations.

  16. 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.

  17. Robustness testing of live attenuated rubella vaccine potency assay using fractional factorial design of experiments.

    PubMed

    Kutle, Leonida; Pavlović, Nediljko; Dorotić, Marko; Zadro, Ivana; Kapustić, Marijana; Halassy, Beata

    2010-07-26

    The potency assay for the freeze-dried live attenuated rubella vaccine is a cell culture based biological assay. The aim of our study was to perform the robustness testing of the rubella vaccine potency assay prior to validation. Seven intra-assay operating conditions that could have an effect on the assay performance were identified and their influence on the overall assay variability investigated by fractional factorial design of experiments (DoE). The robustness testing through DoE showed that the rubella vaccine potency assay is a robust assay. Critical operating conditions can be identified using DoE, which indicates that it is a suitable approach in bioassay robustness studies. Copyright 2010 Elsevier Ltd. All rights reserved.

  18. A live-attenuated influenza vaccine for H3N2 canine influenza virus.

    PubMed

    Rodriguez, Laura; Nogales, Aitor; Reilly, Emma C; Topham, David J; Murcia, Pablo R; Parrish, Colin R; Martinez Sobrido, Luis

    2017-04-01

    Canine influenza is a contagious respiratory disease in dogs caused by two subtypes (H3N2 and H3N8) of canine influenza virus (CIV). Currently, only inactivated influenza vaccines (IIVs) are available for the prevention of CIVs. Historically, live-attenuated influenza vaccines (LAIVs) have been shown to produce better immunogenicity and protection efficacy than IIVs. Here, we have engineered a CIV H3N2 LAIV by using the internal genes of a previously described CIV H3N8 LAIV as a master donor virus (MDV) and the surface HA and NA genes of a circulating CIV H3N2 strain. Our findings show that CIV H3N2 LAIV replicates efficiently at low temperature but its replication is impaired at higher temperatures. The CIV H3N2 LAIV was attenuated in vivo but induced better protection efficacy in mice against challenge with wild-type CIV H3N2 than a commercial CIV H3N2 IIV. This is the first description of a LAIV for the prevention of CIV H3N2 in dogs.

  19. Efficacy of a live attenuated vaccine in classical swine fever virus postnatally persistently infected pigs.

    PubMed

    Muñoz-González, Sara; Perez-Simó, Marta; Muñoz, Marta; Bohorquez, José Alejandro; Rosell, Rosa; Summerfield, Artur; Domingo, Mariano; Ruggli, Nicolas; Ganges, Llilianne

    2015-07-09

    Classical swine fever (CSF) causes major losses in pig farming, with various degrees of disease severity. Efficient live attenuated vaccines against classical swine fever virus (CSFV) are used routinely in endemic countries. However, despite intensive vaccination programs in these areas for more than 20 years, CSF has not been eradicated. Molecular epidemiology studies in these regions suggests that the virus circulating in the field has evolved under the positive selection pressure exerted by the immune response to the vaccine, leading to new attenuated viral variants. Recent work by our group demonstrated that a high proportion of persistently infected piglets can be generated by early postnatal infection with low and moderately virulent CSFV strains. Here, we studied the immune response to a hog cholera lapinised virus vaccine (HCLV), C-strain, in six-week-old persistently infected pigs following post-natal infection. CSFV-negative pigs were vaccinated as controls. The humoral and interferon gamma responses as well as the CSFV RNA loads were monitored for 21 days post-vaccination. No vaccine viral RNA was detected in the serum samples and tonsils from CSFV postnatally persistently infected pigs for 21 days post-vaccination. Furthermore, no E2-specific antibody response or neutralising antibody titres were shown in CSFV persistently infected vaccinated animals. Likewise, no of IFN-gamma producing cell response against CSFV or PHA was observed. To our knowledge, this is the first report demonstrating the absence of a response to vaccination in CSFV persistently infected pigs.

  20. Live attenuated B. pertussis as a single-dose nasal vaccine against whooping cough.

    PubMed

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

    2006-07-01

    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.

  1. 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

  2. Development of live-attenuated arenavirus vaccines based on codon deoptimization of the viral glycoprotein

    PubMed Central

    Cheng, Benson Y.H.; Nogales, Aitor; de la Torre, Juan Carlos; Martínez-Sobrido, Luis

    2016-01-01

    Several arenaviruses, chiefly Lassa (LASV) in West Africa, cause hemorrhagic fever (HF) disease in humans and pose important public health problems in their endemic regions. To date, there are no FDA-approved arenavirus vaccines and current anti-arenaviral therapy is limited to the use of ribavirin that has very limited efficacy. In this work we dcument that a recombinant prototypic arenavirus lymphocytic choriomeningitis virus (LCMV) with a codon deoptimized (CD) surface glycoprotein (GP), rLCMV/CD, exhibited wild type (WT)-like growth properties in cultured cells despite barely detectable GP expression levels in rLCMV/CD-infected cells. Importantly, rLCMV/CD was highly attenuated in vivo but able to induce complete protection against a subsequent lethal challenge with rLCMV/WT. Our findings support the feasibility of implementing an arenavirus GP CD-based approach for the development of safe and effective live-attenuated vaccines (LAVs) to combat diseases caused by human pathogenic arenaviruses. PMID:27855284

  3. Superior protection elicited by live-attenuated vaccines in the murine model of paratuberculosis.

    PubMed

    Ghosh, Pallab; Shippy, Daniel C; Talaat, Adel M

    2015-12-16

    Mycobacterium avium subspecies paratuberculosis (M. paratuberculosis) causes Johne's disease, a chronic enteric infection in ruminants with severe economic impact on the dairy industry in the USA and worldwide. Currently, available vaccines have limited protective efficacy against disease progression and does not prevent spread of the infection among animals. Because of their ability to elicit wide-spectrum immune responses, we adopted a live-attenuated vaccine approach based on a sigH knock-out strain of M. paratuberculosis (ΔsigH). Earlier analysis of the ΔsigH mutant in mice indicated their inadequate ability to colonize host tissues, unlike the isogenic wild-type strain, validating the role of this sigma factor in M. paratuberculosis virulence. In the present study, we evaluated the performance of the ΔsigH mutant compared to inactivated vaccine constructs in a vaccine/challenge model of murine paratuberculosis. The presented analysis indicated that ΔsigH mutant with or without QuilA adjuvant is capable of eliciting strong immune responses (such as interferon gamma-γ, IFN-γ) suggesting their immunogenicity and ability to potentially initiate effective vaccine-induced immunity. Following a challenge with virulent strains of M. paratuberculosis, ΔsigH conferred protective immunity as indicated by the reduced bacterial burden accompanied with reduced lesions in main body organs (liver, spleen and intestine) usually infected with M. paratuberculosis. More importantly, our data indicated better ability of the ΔsigH vaccine to confer protection compared to the inactivated vaccine constructs even with the presence of oil-adjuvant. Overall, our approach provides a rational basis for using live-attenuated mutant strains to develop improved vaccines that elicit robust immunity against this chronic infection.

  4. Antibody response in seropositive multiple sclerosis patients vaccinated with attenuated live varicella zoster virus

    PubMed Central

    Ross, RT; Dawood, MR; Cheang, Mary; Nicolle, Lindsay E

    1996-01-01

    OBJECTIVE: To determine the safety and effectiveness of live attenuated varicella zoster virus (VZV) vaccine (OKA/Merck) on 50 patients with chronic progressive multiple sclerosis (MS), based on the hypothesis that VZV might be the antigen or antigen mimic of MS plus the fact that repeated high antigen doses have produced ‘antigen paralysis’ in experimental allergic encephalomyelitis mice. DESIGN: Fifty patients were randomly selected without controls. They were assessed clinically at entry and on four other occasions over 14 months. Enhanced cranial magnetic resonance imaging (MRI) was performed at entry and at six and 12 months post entry. All were vaccinated after initial assessment and again six weeks later. SETTING: All clinical and laboratory assessments were performed at the Health Sciences Centre, Winnipeg, in the out-patient department. All MRI examinations were performed at the St Boniface General Hospital, Winnipeg, Manitoba. Both are tertiary care hospitals. POPULATION STUDIED: Fifty randomly selected patients with chronic progressive MS, age 18 to 60 years, and a disability status scale of 2.0 or greater were included. Forty-five patients completed the study. INTERVENTIONS: Two vaccinations with attenuated live VZV six weeks apart. RESULTS: All patients were VZV seropositive at entry and all showed an increased antibody level following vaccination. No one was harmed by the vaccine. There may have been some changes in the MS of 15 patients. CONCLUSIONS: It may be reasonable and safe to challenge the process of MS using large doses of the immunogenic proteins of the VZV to induce ‘immune paralysis’. PMID:22514454

  5. Vaccination using live attenuated Leishmania donovani centrin deleted parasites induces protection in dogs against Leishmania infantum.

    PubMed

    Fiuza, Jacqueline Araújo; Gannavaram, Sreenivas; Santiago, Helton da Costa; Selvapandiyan, Angamuthu; Souza, Daniel Menezes; Passos, Lívia Silva Araújo; de Mendonça, Ludmila Zanandreis; Lemos-Giunchetti, Denise da Silveira; Ricci, Natasha Delaqua; Bartholomeu, Daniella Castanheira; Giunchetti, Rodolfo Cordeiro; Bueno, Lilian Lacerda; Correa-Oliveira, Rodrigo; Nakhasi, Hira L; Fujiwara, Ricardo Toshio

    2015-01-03

    Live attenuated Leishmania donovani parasites such as LdCen(-/-) have been shown elicit protective immunity against leishmanial infection in mice and hamster models. Previously, we have reported on the induction of strong immunogenicity in dogs upon vaccination with LdCen(-/-) including an increase in immunoglobulin isotypes, higher lymphoproliferative response, higher frequencies of activated CD4(+) and CD8(+) T cells, IFN-γ production by CD8(+) T cells, increased secretion of TNF-α and IL-12/IL-23p40 and, finally, decreased secretion of IL-4. To further explore the potential of LdCen(-/-) parasites as vaccine candidates, we performed a 24-month follow up of LdCen(-/-) immunized dogs after challenge with virulent Leishmania infantum, aiming determination of parasite burden by qPCR, antibody production (ELISA) and cellular responses (T cell activation and cytokine production) by flow cytometry and sandwich ELISA. Our data demonstrated that vaccination with a single dose of LdCen(-/-) (without any adjuvant) resulted in the reduction of up to 87.3% of parasite burden after 18 months of virulent challenge. These results are comparable to those obtained with commercially available vaccine in Brazil (Leishmune(®)). The protection was associated with antibody production and CD4(+) and CD8(+) proliferative responses, as well as T cell activation and significantly higher production of IFN-γ, IL-12/IL-23p40 and TNF-α, which was comparable to responses induced by immunization with Leishmune(®), with significant differences when compared to control animals (Placebo). Moreover, only animals immunized with LdCen(-/-) expressed lower levels of IL-4 when compared to animals vaccinated either with Leishmune(®) or PBS. Our results support further studies aiming to demonstrate the potential of genetically modified live attenuated L. donovani vaccine to control L. infantum transmission in endemic areas for CVL.

  6. Construction and Characterization of an Attenuated Purine Auxotroph in a Francisella tularensis Live Vaccine Strain

    PubMed Central

    Pechous, Roger; Celli, Jean; Penoske, Renee; Hayes, Stanley F.; Frank, Dara W.; Zahrt, Thomas C.

    2006-01-01

    Francisella tularensis is a facultative intracellular pathogen and is the etiological agent of tularemia. It is capable of escaping from the phagosome, replicating to high numbers in the cytosol, and inducing apoptosis in macrophages of a variety of hosts. F. tularensis has received significant attention recently due to its potential use as a bioweapon. Currently, there is no licensed vaccine against F. tularensis, although a partially protective live vaccine strain (LVS) that is attenuated in humans but remains fully virulent for mice was previously developed. An F. tularensis LVS mutant deleted in the purMCD purine biosynthetic locus was constructed and partially characterized by using an allelic exchange strategy. The F. tularensis LVS ΔpurMCD mutant was auxotrophic for purines when grown in defined medium and exhibited significant attenuation in virulence when assayed in murine macrophages in vitro or in BALB/c mice. Growth and virulence defects were complemented by the addition of the purine precursor hypoxanthine or by introduction of purMCDN in trans. The F. tularensis LVS ΔpurMCD mutant escaped from the phagosome but failed to replicate in the cytosol or induce apoptotic and cytopathic responses in infected cells. Importantly, mice vaccinated with a low dose of the F. tularensis LVS ΔpurMCD mutant were fully protected against subsequent lethal challenge with the LVS parental strain. Collectively, these results suggest that F. tularensis mutants deleted in the purMCD biosynthetic locus exhibit characteristics that may warrant further investigation of their use as potential live vaccine candidates. PMID:16861631

  7. 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

  8. Growth restriction of an experimental live attenuated human parainfluenza virus type 2 vaccine in human ciliated airway epithelium in vitro parallels attenuation in African green monkeys

    PubMed Central

    Schaap-Nutt, Anne; Scull, Margaret A.; Schmidt, Alexander C.; Murphy, Brian R.; Pickles, Raymond J.

    2010-01-01

    Human parainfluenza viruses (HPIVs) are common causes of severe pediatric respiratory viral disease. We characterized wild-type HPIV2 infection in an in vitro model of human airway epithelium (HAE) and found that the virus replicates to high titer, sheds apically, targets ciliated cells, and induces minimal cytopathology. Replication of an experimental, live attenuated HPIV2 vaccine strain, containing both temperature sensitive (ts) and non-ts attenuating mutations, was restricted >30-fold compared to rHPIV2-WT in HAE at 32°C and exhibited little productive replication at 37°C. This restriction paralleled attenuation in the upper and lower respiratory tract of African green monkeys, supporting the HAE model as an appropriate and convenient system for characterizing HPIV2 vaccine candidates. PMID:20139039

  9. Genetic stability of live attenuated vaccines against potentially pandemic influenza viruses.

    PubMed

    Kiseleva, Irina; Dubrovina, Irina; Fedorova, Ekaterina; Larionova, Natalie; Isakova-Sivak, Irina; Bazhenova, Ekaterina; Pisareva, Maria; Kuznetsova, Victoria; Flores, Jorge; Rudenko, Larisa

    2015-12-08

    Ensuring genetic stability is a prerequisite for live attenuated influenza vaccine (LAIV). This study describes the results of virus shedding and clinical isolates' testing of Phase I clinical trials of Russian LAIVs against potentially pandemic influenza viruses in healthy adults. Three live attenuated vaccines against potentially pandemic influenza viruses, H2N2 LAIV, H5N2 LAIV and H7N3 LAIV, generated by classical reassortment in eggs, were studied. For each vaccine tested, subjects were randomly distributed into two groups to receive two doses of either LAIV or placebo at a 3:1 vaccine/placebo ratio. Nasal swabs were examined for vaccine virus shedding by culturing in eggs and by PCR. Vaccine isolates were tested for temperature sensitivity and cold-adaptation (ts/ca phenotypes) and for nucleotide sequence. The majority of nasal wash positive specimens were detected on the first day following vaccination. PCR method demonstrated higher sensitivity than routine virus isolation in eggs. None of the placebo recipients had detectable vaccine virus replication. All viruses isolated from the immunized subjects retained the ts/ca phenotypic characteristics of the master donor virus (MDV) and were shown to preserve all attenuating mutations described for the MDV. These data suggest high level of vaccine virus genetic stability after replication in humans. During manufacture process, no additional mutations occurred in the genome of H2N2 LAIV. In contrast, one amino acid change in the HA of H7N3 LAIV and two additional mutations in the HA of H5N2 LAIV manufactured vaccine lot were detected, however, they did not affect their ts/ca phenotypes. Our clinical trials revealed phenotypic and genetic stability of the LAIV viruses recovered from the immunized volunteers. In addition, no vaccine virus was detected in the placebo groups indicating the lack of person-to-person transmission. LAIV TRIAL REGISTRATION at ClinicalTrials.gov: H7N3-NCT01511419; H5N2-NCT01719783; H2N2-NCT

  10. Optrodes for combined optogenetics and electrophysiology in live animals

    PubMed Central

    Dufour, Suzie; De Koninck, Yves

    2015-01-01

    Abstract. Optical tissue properties limit visible light depth penetration in tissue. Because of this, the recent development of optogenetic tools was quickly followed by the development of light delivery devices for in vivo optogenetics applications. We summarize the efforts made in the last decade to design neural probes that combine conventional electrophysiological recordings and optical channel(s) for optogenetic activation, often referred to as optodes or optrodes. Several aspects including challenges for light delivery in living brain tissue, the combination of light delivery with electrophysiological recordings, probe designs, multimodality, wireless implantable system, and practical considerations guiding the choice of configuration depending on the questions one seeks to address are presented. PMID:26158014

  11. Elucidation of the molecular basis for the attenuation of a live, attenuated influenza A H5N1 cold-adapted vaccine virus

    USDA-ARS?s Scientific Manuscript database

    A recombinant, live influenza A H5N1 vaccine candidate with the hemagglutinin (HA) and neuraminidase (NA) genes derived from A/VietNam/1203/04 (H5N1) (H5N1 2004 wt) and the internal protein genes from A/Ann Arbor/6/60 (AA) (H2N2) cold-adapted (ca) virus has been previously shown to be attenuated in ...

  12. Recurrent 6th nerve palsy in a child following different live attenuated vaccines: case report

    PubMed Central

    2012-01-01

    Background Recurrent benign 6th nerve palsy in the paediatric age group is uncommon, but has been described following viral and bacterial infections. It has also been temporally associated with immunization, but has not been previously described following two different live attenuated vaccines. Case presentation A case is presented of a 12 month old Caucasian boy with recurrent benign 6th nerve palsy following measles-mumps-rubella and varicella vaccines, given on separate occasions with complete recovery following each episode. No alternate underlying etiology was identified despite extensive investigations and review. Conclusions The majority of benign 6th nerve palsies do not have a sinister cause and have an excellent prognosis, with recovery expected in most cases. The exact pathophysiology is unknown, although hypotheses including autoimmune mechanisms and direct viral invasion could explain the pathophysiology behind immunization related nerve palsies. It is important to rule out other aetiologies with thorough history, physical examination and investigations. There is limited information in the literature regarding the safety of a repeat dose of a live vaccine in this setting. Future immunizations should be considered on a case-by-case basis. PMID:22545865

  13. African horse sickness in The Gambia: circulation of a live-attenuated vaccine-derived strain.

    PubMed

    Oura, C A L; Ivens, P A S; Bachanek-Bankowska, K; Bin-Tarif, A; Jallow, D B; Sailleau, C; Maan, S; Mertens, P C; Batten, C A

    2012-03-01

    African horse sickness virus serotype 9 (AHSV-9) has been known for some time to be circulating amongst equids in West Africa without causing any clinical disease in indigenous horse populations. Whether this is due to local breeds of horses being resistant to disease or whether the AHSV-9 strains circulating are avirulent is currently unknown. This study shows that the majority (96%) of horses and donkeys sampled across The Gambia were seropositive for AHS, despite most being unvaccinated and having no previous history of showing clinical signs of AHS. Most young horses (<3 years) were seropositive with neutralizing antibodies specific to AHSV-9. Eight young equids (<3 years) were positive for AHSV-9 by serotype-specific RT-PCR and live AHSV-9 was isolated from two of these horses. Sequence analysis revealed the presence of an AHSV-9 strain showing 100% identity to Seg-2 of the AHSV-9 reference strain, indicating that the virus circulating in The Gambia was highly likely to have been derived from a live-attenuated AHSV-9 vaccine strain.

  14. Oral immunization using live attenuated Salmonella spp. as carriers of foreign antigens.

    PubMed Central

    Cárdenas, L; Clements, J D

    1992-01-01

    A variety of techniques, including the use of live oral vaccines, have been used to deliver antigens to the gut-associated lymphoid tissues in an attempt to initiate production of specific secretory immunoglobulin A for protection against pathogens that colonize or cross mucosal surfaces to initiate infection. A number of attenuated Salmonella mutants are able to interact with the lymphoid tissues in the Peyer's patches but are not able to cause systemic disease. Some of these mutants are effective as live vaccines (i.e., able to protect against infection with the virulent Salmonella parent) and are candidates for use as carriers for virulence determinants of other mucosal pathogens. This has been shown to be an effective means of stimulating significant levels of specific mucosal secretory immunoglobulin A directed against the carrier strains and against a variety of heterologous antigens and has been shown to stimulate production of serum antibodies and cell-mediated responses as well. This review examines the history of this mechanism of vaccine delivery and summarizes the most recent applications of this evolving technology. This is a technique for vaccine delivery with significant potential for influencing the management of infectious diseases on a large scale. It can be used not only for vaccines against enteric bacterial pathogens but also for vaccines against a variety of other bacteria, viruses, and parasites. The results obtained to date are encouraging, and there is great potential for development of safe, effective, affordable vaccines. PMID:1498769

  15. 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.

  16. Safety and efficacy of a metabolic drift live attenuated Salmonella Gallinarum vaccine against fowl typhoid.

    PubMed

    Shehata, Awad Ali; Sultan, Hesham; Hafez, Hafez M; Krüger, Monika

    2013-03-01

    Fowl typhoid (FT), a systemic disease that results in septicemia in poultry, is caused by Salmonella enterica serovar Gallinarum biovar Gallinarum (SG). Mortality and morbidity rates from FT can reach up to 80%. Attenuated live Salmonella vaccine candidates have received considerable attention because they confer solid immunity, and they can produce systemic and mucosal immunity in the gut when administered orally. In the present study, five metabolic drift (MD) mutants with a single-(designated SG-Rif1, SG-Sm6) or double-attenuating marker (designated SG-Rif1-Sm4, SG-Sm6-Rif10, and SG-Rif1-Sm10) were isolated. The relative colony sizes to wild-type strain after 24 hr at 37 C incubation were 50%, 40%, 30%, 30%, and 20%, respectively. The probability of a back mutation can almost be excluded because the reduced colony sizes were stable after at least 50 passages on culture media. The safety and immunogenicity were evaluated in susceptible 1-day-old commercial layer chickens. After oral administration of 10(8) colony-forming units (CFU), all developed MD mutants proved to be safe and did not cause death of any infected birds during 15 days postvaccination, whereas chickens receiving 10(6) CFU SG wild-type strain showed a high mortality rate (40%). Vaccination of commercial layer chicks with SG-Rif1, SG-Sm6, SG-Rif1-Sm4, and SG-Sm6-Rif10 MD mutants could protect chickens against challenge by homologous wild-type strain; however, SG-Rif1-Sm10 could not protect against challenge, indicating hyperattenuation. In conclusion, vaccination with SG MD mutant vaccine appears to be safe and offers protection against FT in chickens.

  17. Temperature-Sensitive Live-Attenuated Canine Influenza Virus H3N8 Vaccine.

    PubMed

    Nogales, Aitor; Rodriguez, Laura; Chauché, Caroline; Huang, Kai; Reilly, Emma C; Topham, David J; Murcia, Pablo R; Parrish, Colin R; Martínez-Sobrido, Luis

    2017-02-15

    Canine influenza is a respiratory disease of dogs caused by canine influenza virus (CIV). CIV subtypes responsible for influenza in dogs include H3N8, which originated from the transfer of H3N8 equine influenza virus to dogs; and the H3N2 CIV, which is an avian-origin virus that adapted to infect dogs. Influenza infections are most effectively prevented through vaccination to reduce transmission and future infection. Currently, only inactivated influenza vaccines (IIVs) are available for the prevention of CIV in dogs. However, the efficacy of IIVs is suboptimal, and novel approaches are necessary for the prevention of disease caused by this canine respiratory pathogen. Using reverse genetics techniques, we have developed a live-attenuated CIV vaccine (LACIV) for the prevention of H3N8 CIV. The H3N8 LACIV replicates efficiently in canine cells at 33°C but is impaired at temperatures of 37 to 39°C and was attenuated compared to wild-type H3N8 CIV in vivo and ex vivo The LACIV was able to induce protection against H3N8 CIV challenge with a single intranasal inoculation in mice. Immunogenicity and protection efficacy were better than that observed with a commercial CIV H3N8 IIV but provided limited cross-reactive immunity and heterologous protection against H3N2 CIV. These results demonstrate the feasibility of implementing a LAIV approach for the prevention and control of H3N8 CIV in dogs and suggest the need for a new LAIV for the control of H3N2 CIV.

  18. A live attenuated vaccine prevents replication and transmission of H7N9 virus in mammals

    PubMed Central

    Kong, Huihui; Zhang, Qianyi; Gu, Chunyang; Shi, Jianzhong; Deng, Guohua; Ma, Shujie; Liu, Jinxiong; Chen, Pucheng; Guan, Yuntao; Jiang, Yongping; Chen, Hualan

    2015-01-01

    The continued spread of the newly emerged H7N9 viruses among poultry in China, together with the emergence of drug-resistant variants and the possibility of human-to-human transmission, has spurred attempts to develop an effective vaccine. An MF59-adjuvant H7N9 inactivated vaccine is reported to be well-tolerated and immunogenic in humans; however a study in ferrets indicated that while a single dose of the inactivated H7N9 vaccine reduced disease severity, it did not prevent virus replication and transmission. In this study, we used reverse genetics to produce a cold-adapted, live attenuated H7N9 vaccine (H7N9/AAca) that contains wild-type HA and NA genes from AH/1, and the backbone of the cold-adapted influenza H2N2 A/Ann Arbor/6/60 virus (AAca). H7N9/AAca was attenuated in mice and ferrets, and induced robust neutralizing antibody responses in rhesus mice, ferrets, and guinea pigs immunized once or twice intranasally. The animals immunized twice were completely protected from H7N9 virus challenge. Importantly, the animals vaccinated once were fully protected from transmission when exposed to or in contact with the H7N9 virus-inoculated animals. These results demonstrate that a cold-adapted H7N9 vaccine can prevent H7N9 virus transmission; they provide a compelling argument for further testing of this vaccine in human trials. PMID:26058711

  19. A reassortment-incompetent live attenuated influenza virus vaccine for use in protection against pandemic virus strains

    USDA-ARS?s Scientific Manuscript database

    Although live-attenuated influenza vaccines (LAIV) are safe for use in protection against seasonal influenza strains, concerns over their potential to reassort with wild-type virus strains have been voiced. LAIVs have been demonstrated to induce enhanced mucosal and cell-mediated immunity over inac...

  20. 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...

  1. 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...

  2. 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...

  3. Development of live attenuated Streptococcus agalactiae vaccine for tilapia via continuous passage in vitro.

    PubMed

    Li, L P; Wang, R; Liang, W W; Huang, T; Huang, Y; Luo, F G; Lei, A Y; Chen, M; Gan, X

    2015-08-01

    Fish Streptococcus agalactiae (S. agalactiae) seriously harms the world's aquaculture industry and causes huge economic losses. This study aimed to develop a potential live attenuated vaccine of S. agalactiae. Pre-screened vaccine candidate strain S. agalactiae HN016 was used as starting material to generate an attenuated strain S. agalactiae YM001 by continuous passage in vitro. The biological characteristics, virulence, and stability of YM001 were detected, and the protective efficacy of YM001 immunization in tilapia was also determined. Our results indicated that the growth, staining, characteristics of pulsed-field gel electrophoresis (PFGE) genotype, and virulence of YM001 were changed significantly as compared to the parental strain HN016. High doses of YM001 by intraperitoneal (IP) injection (1.0 × 10(9) CFU/fish) and oral gavage (1.0 × 10(10) CFU/fish) respectively did not cause any mortality and morbidity in tilapia. The relative percent survivals (RPSs) of fishes immunized with YM001 (1.0 × 10(8) CFU/fish, one time) via injection, immersion, and oral administration were 96.88, 67.22, and 71.81%, respectively, at 15 days, and 93.61, 60.56, and 53.16%, respectively, at 30 days. In all tests with 1-3 times of immunization in tilapia, the dosages at 1 × 10(8) and 1 × 10(9) CFU/fish displayed the similar best results, whereas the immunoprotection of the dosages at 1 × 10(6) and 1 × 10(7) CFU/fish declined significantly (P < 0.01), and 1 × 10(5) CFU/fish hardly displayed any protective effect. In addition, the efficacy of 2-3 times of immunization was significantly higher than that of single immunization (P < 0.01) while no significant difference in the efficacy between twice and thrice of immunization was seen (P > 0.05). The level of protective antibody elicited by oral immunization was significantly higher compared to that of the control group (P < 0.01), and the antibody reached their maximum levels 14-21 days after the immunization but decreased

  4. Optimization of efficacy of a live attenuated Flavobacterium psychrophilum immersion vaccine.

    PubMed

    Sudheesh, Ponnerassery S; Cain, Kenneth D

    2016-09-01

    This study was aimed at optimizing the efficacy of a recently developed live attenuated immersion vaccine (B.17-ILM) as a promising vaccine against bacterial coldwater disease (BCWD) caused by Flavobacterium psychrophilum in salmonids. Rainbow trout (RBT) fry were vaccinated by immersion, and different parameters affecting vaccination such as fish size, vaccine delivery time, dose, duration of protection, booster regimes and vaccine growth incubation time were optimized. Specific anti-F. psychrophilum immune response was determined by ELISA. Protective efficacy was determined by challenging with a virulent strain of F. psychrophilum (CSF-259-93) and calculating cumulative percent mortality (CPM) and relative percent survival (RPS). All vaccinated fish developed significantly higher levels of serum antibody titers by week 8 when compared to their respective controls. Immersion vaccination for 3, 6 and 30 min produced significant protection with comparable RPS values of 47%, 53% and 52%, respectively. This vaccine provided significant protection for fish as small as 0.5 g with an RPS of 55%; larger fish of 1 g and 2 g yielded slightly higher RPS values of 59% and 60%, respectively. Fish vaccinated with higher vaccine doses of ∼10(10) and 10(8) colony forming units mL(-1) (cfu ml(-1)) were strongly protected out to at least 24 weeks with RPS values up to 70%. Fish vaccinated with lower doses (∼10(6) and 10(5) cfu mL(-1)) had good protection out to 12 weeks, but RPS values dropped to 36% and 34%, respectively by 24 weeks. Vaccine efficacy was optimum when the primary vaccination was followed by a single booster (week 12 challenge RPS = 61%) rather than two boosters (week 12 challenge RPS = 48%). Vaccination without a booster resulted in a lower RPS (13%) indicating the necessity of a single booster vaccination to maximize efficacy. This study presents key findings that demonstrate the efficacy and commercial potential for this live attenuated BCWD

  5. Potential for path-average rainfall estimation from combined microwave and optical attenuation measurements

    NASA Astrophysics Data System (ADS)

    Uijlenhoet, R.; Leijnse, H.

    2009-04-01

    On previous occasions we have demonstrated the potential and limitations of both microwave and optical links as path-average rain gauges. In this presentation we investigate the potential of combined microwave and optical attenuation measurements for improved path-average rainfall monitoring through theoretical analysis and numerical experiments.

  6. Sound attenuation from earmuffs and earplugs in combination: maximum benefits vs. missed information.

    PubMed

    Abel, Sharon M; Odell, Patricia

    2006-09-01

    Noise levels from military aircraft range from 100-130 dBA. Peak pressure levels from large caliber weapons may reach 180 dB SPL. To protect against hearing loss, individuals are encouraged to wear double hearing protection. This study determined ways to maximize benefit. Hearing thresholds from 0.25-8 kHz and consonant discrimination were assessed in normal-hearing subjects with ears unoccluded and fitted with highly rated earmuffs and earplugs, singly or in combination. The earplugs were available in two sizes. Selection was based on best fit. Attenuation values were derived from the threshold measurements. With the muff, plug, and muff and plug in combination, thresholds ranged from 35-48 dB SPL, 40-55 dB SPL, and 44-66 dB SPL, respectively, across the frequencies tested. The combination (without regard to size of plug) resulted in attenuation values of 38-54 dB. With the smaller of the two plugs, low-frequency values as high as 53-61 dB were realized. Consonant discrimination decreased by 6-8% with the devices worn singly and by 22% with the devices in combination, relative to unoccluded listening. Sufficient low-frequency attenuation may be achieved with muffs and plugs in combination to prevent hearing loss from operational noise. Attenuation may be maximized by choosing a smaller earplug to achieve a better fit. Possible downsides are reduced detection of warning sounds and speech intelligibility. To be heard warning sounds should surpass protected thresholds by at least 5 dB. Choosing devices which provide somewhat less attenuation may be necessary to preserve communication capability.

  7. Distinct Cross-reactive B-Cell Responses to Live Attenuated and Inactivated Influenza Vaccines

    PubMed Central

    Sasaki, Sanae; Holmes, Tyson H.; Albrecht, Randy A.; García-Sastre, Adolfo; Dekker, Cornelia L.; He, Xiao-Song; Greenberg, Harry B.

    2014-01-01

    Background. The immunological bases for the efficacies of the 2 currently licensed influenza vaccines, live attenuated influenza vaccine (LAIV) and inactivated influenza vaccine (IIV), are not fully understood. The goal of this study was to identify specific B-cell responses correlated with the known efficacies of these 2 vaccines. Methods. We compared the B-cell and antibody responses after immunization with 2010/2011 IIV or LAIV in young adults, focusing on peripheral plasmablasts 6–8 days after vaccination. Results. The quantities of vaccine-specific plasmablasts and plasmablast-derived polyclonal antibodies (PPAbs) in IIV recipients were significantly higher than those in LAIV recipients. No significant difference was detected in the avidity of vaccine-specific PPAbs between the 2 vaccine groups. Proportionally, LAIV induced a greater vaccine-specific immunoglobulin A plasmablast response, as well as a greater plasmablast response to the conserved influenza nuclear protein, than IIV. The cross-reactive plasmablast response to heterovariant strains, as indicated by the relative levels of cross-reactive plasmablasts and the cross-reactive PPAb binding reactivity, was also greater in the LAIV group. Conclusions. Distinct quantitative and qualitative patterns of plasmablast responses were induced by LAIV and IIV in young adults; a proportionally greater cross-reactive response was induced by LAIV. PMID:24676204

  8. Evaluation of YadC protein delivered by live attenuated Salmonella as a vaccine against plague.

    PubMed

    Sun, Wei; Olinzock, Joseph; Wang, Shifeng; Sanapala, Shilpa; Curtiss, Roy

    2014-03-01

    Yersinia pestis YadB and YadC are two new outer membrane proteins related to its pathogenicity. Here, codon-optimized yadC, yadC810 (aa 32-551), or yadBC antigen genes delivered by live attenuated Salmonella strains are evaluated in mice for induction of protective immune responses against Y. pestis CO92 through subcutaneous or intranasal challenge. Our findings indicate that mice immunized with Salmonella synthesizing YadC, YadC810, or YadBC develop significant serum IgG responses to purified recombinant YadC protein. For subcutaneous challenge (approximately 230 LD50 of Y. pestis CO92), mice immunized with Salmonella synthesizing YadC or YadC810 are afforded 50% protection, but no protection by immunization with the Salmonella strain synthesizing YadBC. None of these antigens provided protection against intranasal challenge (approximately 31 LD50 of Y. pestis CO92). In addition, subcutaneous immunization with purified YadC810 protein emulsified with alum adjuvant does not elicit a protective response against Y. pestis administered by either challenge route. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  9. Relaxation of purifying selection on the SAD lineage of live attenuated oral vaccines for rabies virus.

    PubMed

    Hughes, Austin L

    2009-09-01

    Analysis of patterns of nucleotide sequence diversity in wild-type rabies virus (RABV) genomes and in the SAD live attenuated oral vaccine lineage was used to test for the relaxation of purifying selection in the latter and provide evidence regarding the genomic regions where such relaxation of selection occurs. The wild-type sequences showed evidence of strong past and ongoing purifying selection both on nonsynonymous sites in coding regions and on non-coding regions, particularly the start, end and 5' UTR regions. SAD vaccine sequences showed a relaxation of purifying selection at nonsynonymous sites in coding regions, resulting a substantial number of amino acid sequence polymorphisms at sites that were invariant in the wild-type sequences. Moreover, SAD vaccine sequences showed high levels of mutation accumulation in the non-coding regions that were most conserved in the wild-type sequences. Understanding the biological effects of the unique mutations accumulated in the vaccine lineage is important because of their potential effects on antigenicity and effectiveness of the vaccine.

  10. Biodistribution and safety of a live attenuated tetravalent dengue vaccine in the cynomolgus monkey.

    PubMed

    Ravel, Guillaume; Mantel, Nathalie; Silvano, Jeremy; Rogue, Alexandra; Guy, Bruno; Jackson, Nicholas; Burdin, Nicolas

    2017-10-13

    The first licensed dengue vaccine is a recombinant, live, attenuated, tetravalent dengue virus vaccine (CYD-TDV; Sanofi Pasteur). This study assessed the biodistribution, shedding, and toxicity of CYD-TDV in a non-human primate model as part of the nonclinical safety assessment program for the vaccine. Cynomolgus monkeys were given one subcutaneous injection of either one human dose (5log10 CCID50/serotype) of CYD-TDV or saline control. Study endpoints included clinical observations, body temperature, body weight, food consumption, clinical pathology, immunogenicity, and post-mortem examinations including histopathology. Viral load, distribution, persistence, and shedding in tissues and body fluids were evaluated by quantitative reverse transcriptase polymerase chain reaction. The subcutaneous administration of CYD-TDV was well tolerated. There were no toxicological findings other than expected minor local reactions at the injection site. A transient low level of CYD-TDV viral RNA was detected in blood and the viral genome was identified primarily at the injection site and in the draining lymph nodes following immunization. These results, together with other data from repeat-dose toxicity and neurovirulence studies, confirm the absence of toxicological concern with CYD-TDV and corroborate clinical study observations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Safety and immunogenicity of live attenuated and inactivated influenza vaccines in children with cancer.

    PubMed

    Carr, Silvana; Allison, Kim J; Van De Velde, Lee-Ann; Zhang, Kelly; English, Elizabeth Y; Iverson, Amy; Daw, Najat C; Howard, Scott C; Navid, Fariba; Rodriguez-Galindo, Carlos; Yang, Jie; Adderson, Elisabeth E; McCullers, Jonathan A; Flynn, Patricia M

    2011-11-15

    The safety and immunogenicity of live, attenuated influenza vaccine (LAIV) has not been compared to that of the standard trivalent inactivated vaccine (TIV) in children with cancer. Randomized study of LAIV versus TIV in children with cancer, age 2-21 years, vaccinated according to recommendations based on age and prior vaccination. Data on reactogenicity and other adverse events and blood and nasal swab samples were obtained following vaccination. Fifty-five eligible subjects (mean age, 10.4 years) received vaccine (28 LAIV/27 TIV). Both vaccines were well tolerated. Rhinorrhea reported within 10 days of vaccination was similar in both groups (36% LAIV vs 33% TIV, P > .999). Ten LAIV recipients shed virus; the latest viral shedding was detected 7 days after vaccination. Immunogenicity data were available for 52 subjects, or 26 in each group. TIV induced significantly higher postvaccination geometric mean titers against influenza A viruses (P < .001), greater seroprotection against influenza A/H1N1 (P = .01), and greater seroconversion against A/H3N2 (P = .004), compared with LAIV. No differences after vaccination were observed against influenza B viruses. As expected, serum antibody response against influenza A strains were greater with TIV than with LAIV in children with cancer. Both vaccines were well tolerated, and prolonged viral shedding after LAIV was not detected. NCT00906750.

  12. Possible outcomes of reassortment in vivo between wild type and live attenuated influenza vaccine strains.

    PubMed

    Kiseleva, Irina; Dubrovina, Irina; Bazhenova, Ekaterina; Fedorova, Ekaterina; Larionova, Natalie; Rudenko, Larisa

    2012-12-07

    Reassortment of influenza viruses in nature has been well documented. Genetic reassortment plays a key role in emergence of new influenza A strains, including pandemic viruses. Permissive host can be simultaneously coinfected with multiple influenza viruses. During genetic reassortment gene segments are exchanged between parental viruses that may lead to some enhancement of virulence of reassortant progeny. At present, vaccination with live attenuated cold-adapted (ca) reassortant vaccine (LAIV) is used as an effective public health measure for influenza prophylaxis. However, there are concerns about a potential of simultaneous infection of human host with ca and wild type (wt) influenza viruses which might produce progeny that contain novel, more virulent genotypes. The aim of this study was to investigate potential consequences of reassortment of wt with LAIV strains in vivo. We demonstrated that reassortment of wt viruses with ca strains in guinea pigs have resulted in progeny virus which caused reduced macroscopic lesions of chicken embryos. According to phenotypical data 95% (19 out of 20) isolated reassortants were restricted in replication at elevated temperature of 40°C. None of reassortants were more virulent than wt parents, or revealed significantly higher macroscopic lesions than wt parental viruses. Our results suggest that genetic reassortment between wt and vaccine strain is unlikely to lead to virulent reassortant progeny. These findings provide additional support of LAIV safety data. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Room Temperature Stabilization of Oral, Live Attenuated Salmonella enterica serovar Typhi-Vectored Vaccines

    PubMed Central

    Ohtake, Satoshi; Martin, Russell; Saxena, Atul; Pham, Binh; Chiueh, Gary; Osorio, Manuel; Kopecko, Dennis; Xu, DeQi; Lechuga-Ballesteros, David; Truong-Le, Vu

    2011-01-01

    Foam drying, a modified freeze drying process, was utilized to produce a heat-stable, live attenuated Salmonella Typhi ‘Ty21a’ bacterial vaccine. Ty21a vaccine was formulated with pharmaceutically approved stabilizers, including sugars, plasticizers, amino acids, and proteins. Growth media and harvesting conditions of the bacteria were also studied to enhance resistance to desiccation stress encountered during processing as well as subsequent storage at elevated temperatures. The optimized Ty21a vaccine, formulated with trehalose, methionine, and gelatin, demonstrated stability for approximately 12 weeks at 37°C (i.e., time required for the vaccine to decrease in potency by 1log10 CFU) and no loss in titer at 4 and 25°C following storage for the same duration. Furthermore, the foam dried Ty21a elicited a similar immunogenic response in mice as well as protection in challenge studies compared to Vivotif™, the commercial Ty21a vaccine. The enhanced heat stability of the Ty21a oral vaccine, or Ty21a derivatives expressing foreign antigens (e.g. anthrax), could mitigate risks of vaccine potency loss during long term storage, shipping, delivery to geographical areas with warmer climates or during emergency distribution following a bioterrorist attack. Because the foam drying process is conducted using conventional freeze dryers and can be readily implemented at any freeze drying manufacturing facility, this technology appears ready and appropriate for large scale processing of foam dried vaccines. PMID:21300096

  14. Inactivated and live, attenuated influenza vaccines protect mice against influenza:Streptococcus pyogenes super-infections

    PubMed Central

    Chaussee, Michael S.; Sandbulte, Heather R.; Schuneman, Margaret J.; DePaula, Frank P.; Addengast, Leslie A.; Schlenker, Evelyn H.; Huber, Victor C.

    2011-01-01

    Mortality associated with influenza virus super-infections is frequently due to secondary bacterial complications. To date, super-infections with Streptococcus pyogenes have been studied less extensively than those associated with S. pneumoniae. This is significant because a vaccine for S. pyogenes is not clinically available, leaving vaccination against influenza virus as our only means for preventing these super-infections. In this study, we directly compared immunity induced by two types of influenza vaccine, either inactivated influenza virus (IIV) or live, attenuated influenza virus (LAIV), for the ability to prevent super-infections. Our data demonstrate that both IIV and LAIV vaccines induce similar levels of serum antibodies, and that LAIV alone induces IgA expression at mucosal surfaces. Upon super-infection, both vaccines have the ability to limit the induction of pro-inflammatory cytokines within the lung, including IFN-γ which has been shown to contribute to mortality in previous models of super-infection. Limiting expression of these pro-inflammatory cytokines within the lungs subsequently limits recruitment of macrophages and neutrophils to pulmonary surfaces, and ultimately protects both IIV- and LAIV-vaccinated mice from mortality. Despite their overall survival, both IIV- and LAIV-vaccinated mice demonstrated levels of bacteria within the lung tissue to levels that are similar to those seen in unvaccinated mice. Thus, influenza virus:bacteria super-infections can be limited by vaccine-induced immunity against influenza virus, but the ability to prevent morbidity is not complete. PMID:21440037

  15. Combined fluorescence and ultrastructural mapping of living cells

    NASA Astrophysics Data System (ADS)

    Kohen, Elli; Hirschberg, Joseph G.; Kohen, Cahide; Prince, Jeffrey; Suckewer, Szymon; Santus, Rene C.; Morliere, Patrice; Dubertret, Louis

    1990-05-01

    The topographic analysis of fluorescence distribution has been carried out pixel-by-pixel by one dimensional, two-dimensional microspectrofluorometry and three-dimensional confocal fluorescence microscopy. Fluorescence emission spectra of NAD(P)H and benzo(a)pyrene (or metabolites) were recorded at different excitation wavelengths. Cell bioenergetics are monitored in normal and malignant cells as well as cells with genetic defects by coenzyme responses to microinjections of substrates and modifiers from key metabolic pathways in presence and absence of inhibitors and drugs active on mitochondrial structure and function. Cooperative interactions between organelles involved in detoxification mechanisms are observed in cells treated with fluorescent cytotoxic agents. Such interactions can be directly mapped by the fluorescence of cytotoxic agents, their reaction products or vital probes such as NBD ceramide for the Golgi apparatus. To identify the organelles involved parallel electron microscopic studies are carried out in cells first treated with the cytotoxic agent and then incubated with an electron opaque material. A recently developed combined X-ray laser microscope (COXRALM) holds the promise of carrying out combined phase-fluorescence-and X-ray microscopic observations of fluorescence and ultrastructural correlations in live cell probing. As further versatility is gained in such methods it may become possible to obtain a very detailed structure and function mapping of living cells within the context of cytomatrix analysis, metabolic compartmentation and organelle interactions.

  16. 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.

  17. A Single Mutation at PB1 Residue 319 Dramatically Increases the Safety of PR8 Live Attenuated Influenza Vaccine in a Murine Model without Compromising Vaccine Efficacy

    PubMed Central

    Cox, Andrew

    2015-01-01

    The live attenuated influenza vaccine (LAIV) is preferentially recommended for use in most children yet remains unsafe for the groups most at risk. Here we have improved the safety of a mouse-adapted live attenuated influenza vaccine containing the same attenuating amino acid mutations as in human LAIV by adding an additional mutation at PB1 residue 319. This results in a vaccine with a 20-fold decrease in protective efficacy and a 10,000-fold increase in safety. PMID:26676793

  18. 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.

  19. Live attenuated herpes simplex virus 2 glycoprotein E deletion mutant as a vaccine candidate defective in neuronal spread.

    PubMed

    Awasthi, Sita; Zumbrun, Elizabeth E; Si, Huaxin; Wang, Fushan; Shaw, Carolyn E; Cai, Michael; Lubinski, John M; Barrett, Shana M; Balliet, John W; Flynn, Jessica A; Casimiro, Danilo R; Bryan, Janine T; Friedman, Harvey M

    2012-04-01

    A herpes simplex virus 2 (HSV-2) glycoprotein E deletion mutant (gE2-del virus) was evaluated as a replication-competent, attenuated live virus vaccine candidate. The gE2-del virus is defective in epithelial cell-to-axon spread and in anterograde transport from the neuron cell body to the axon terminus. In BALB/c and SCID mice, the gE2-del virus caused no death or disease after vaginal, intravascular, or intramuscular inoculation and was 5 orders of magnitude less virulent than wild-type virus when inoculated directly into the brain. No infectious gE2-del virus was recovered from dorsal root ganglia (DRG) after multiple routes of inoculation; however, gE2-del DNA was detected by PCR in lumbosacral DRG at a low copy number in some mice. Importantly, no recurrent vaginal shedding of gE2-del DNA was detected in immunized guinea pigs. Intramuscular immunization outperformed subcutaneous immunization in all parameters evaluated, although individual differences were not significant, and two intramuscular immunizations were more protective than one. Immunized animals had reduced vaginal disease, vaginal titers, DRG infection, recurrent genital lesions, and recurrent vaginal shedding of HSV-2 DNA; however, protection was incomplete. A combined modality immunization using live virus and HSV-2 glycoprotein C and D subunit antigens in guinea pigs did not totally eliminate recurrent lesions or recurrent vaginal shedding of HSV-2 DNA. The gE2-del virus used as an immunotherapeutic vaccine in previously HSV-2-infected guinea pigs greatly reduced the frequency of recurrent genital lesions. Therefore, the gE2-del virus is safe, other than when injected at high titer into the brain, and is efficacious as a prophylactic and immunotherapeutic vaccine.

  20. 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

  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

  2. Solar System Symphony: Combining astronomy with live classical music

    NASA Astrophysics Data System (ADS)

    Kremer, Kyle; WorldWide Telescope

    2017-01-01

    Solar System Symphony is an educational outreach show which combines astronomy visualizations and live classical music. As musicians perform excerpts from Holst’s “The Planets” and other orchestral works, visualizations developed using WorldWide Telescope and NASA images and animations are projected on-stage. Between each movement of music, a narrator guides the audience through scientific highlights of the solar system. The content of Solar System Symphony is geared toward a general audience, particularly targeting K-12 students. The hour-long show not only presents a new medium for exposing a broad audience to astronomy, but also provides universities an effective tool for facilitating interdisciplinary collaboration between two divergent fields. The show was premiered at Northwestern University in May 2016 in partnership with Northwestern’s Bienen School of Music and was recently performed at the Colburn Conservatory of Music in November 2016.

  3. H2N2 live attenuated influenza vaccine is safe and immunogenic for healthy adult volunteers

    PubMed Central

    Isakova-Sivak, Irina; Stukova, Marina; Erofeeva, Mariana; Naykhin, Anatoly; Donina, Svetlana; Petukhova, Galina; Kuznetsova, Victoria; Kiseleva, Irina; Smolonogina, Tatiana; Dubrovina, Irina; Pisareva, Maria; Nikiforova, Alexandra; Power, Maureen; Flores, Jorge; Rudenko, Larisa

    2015-01-01

    H2N2 influenza viruses have not circulated in the human population since 1968, but they are still being regularly detected in the animal reservoir, suggesting their high pandemic potential. To prepare for a possible H2N2 pandemic, a number of H2N2 vaccine candidates have been generated and tested in preclinical and clinical studies. Here we describe the results of a randomized, double-blind placebo-controlled phase 1 clinical trial of an H2N2 live attenuated influenza vaccine (LAIV) candidate prepared from a human influenza virus isolated in 1966. The vaccine candidate was safe and well-tolerated by healthy adults, and did not cause serious adverse events or an increased rate of moderate or severe reactogenicities. The H2N2 vaccine virus was infectious for Humans. It was shed by 78.6% and 74.1% volunteers after the first and second dose, respectively, most probably due to the human origin of the virus. Importantly, no vaccine virus transmission to unvaccinated subjects was detected during the study. We employed multiple immunological tests to ensure the adequate assessment of the H2N2 pandemic LAIV candidate and demonstrated that the majority (92.6%) of the vaccinated subjects responded to the H2N2 LAIV in one or more immunological tests, including 85.2% of subjects with antibody responses and 55.6% volunteers with cell-mediated immune responses. In addition, we observed strong correlation between the H2N2 LAIV virus replication in the upper respiratory tract and the development of antibody responses. PMID:25831405

  4. The use of live attenuated influenza vaccine ts-1(E) in man.

    PubMed

    Gwaltney, J M

    1976-01-01

    Live temperature-sensitive influenza virus vaccines were tested in two volunteer experiments. The vaccine virus was originally derived from a temperature-sensitive mutant of influenza A/Great Lakes/1965 (H2N2) produced by chemical mutagenesis with 5-fluorouracil. The ts lesions of this strain were subsequently transferred (HI) antibody. Only 9 men (13%) were infected, presumably as a result of over-attenuation of the virus and/or insufficient titer of the inoculum. In the second experiment (1974), 20 young adults were given 0.5 ml per nostril of vaccine containing a recombinant of influenza A/Udorn/307/72 clone 24 (10(5.5) TCID50/ml) with an in vitro shutoff temperature of 38 degree C. Virus was shed by seven volunteers (maximum titer, 10(2.5)TCID50/ml). None of 21 isolates contained revertant wild type virus. Serum HI and antieuraminidase (NI) and nasal wash neutralizing antibody responses occurred in 11 (55%), 7 (35%), and 8 (40%) volunteers, respectively. Post-vaccination serum HI and NI and nasal neutralizing antibody geometric mean titers were 3.0, 9.4, and 1.7 lob2, respectively. Seven volunteers judged they had colds (symptom scores 4-32). Rhinitis and mild pharyngeal discomfort were the only consistent complaints and fever was absent. The findings in the latter trial will be compared with results of volunteer experiments with Udorn/72 ts-1-(E) in other laboratories and to studies with standard inactivated influenza vaccines given parenterally.

  5. CANINE DISTEMPER VIRUS ANTIBODY TITERS IN DOMESTIC CATS AFTER DELIVERY OF A LIVE ATTENUATED VIRUS VACCINE.

    PubMed

    Ramsay, Edward; Sadler, Ryan; Rush, Robert; Seimon, Tracie; Tomaszewicz, Ania; Fleetwood, Ellen A; McAloose, Denise; Wilkes, Rebecca P

    2016-06-01

    Three methods for delivering a live attenuated canine distemper virus (CDV) vaccine to domestic cats ( Felis catus ) were investigated, as models for developing vaccination protocols for tigers (Panthera tigris). Twenty domestic cats were randomly divided into four treatment groups: saline injection (negative controls); and oral, intranasal, and subcutaneous vaccinates. Cats were injected with saline or a CDV vaccine (Nobivac DP, Merck) at wk 0 and 4. Blood and nasal swabs were collected at wk 0 (prior to the initial vaccination) and weekly thereafter for 9 wk. Urine samples were collected on wk 1 to 9 after initial vaccination. Forty-nine weeks following the initial vaccination series, three cats from the subcutaneous group and three cats from the intranasal group were revaccinated. Blood was collected immediately prior, and 7 and 21 days subsequent to revaccination. Nasal swabs and urine samples were collected from each cat prior to wk 49 revaccination and daily for 7 days thereafter. Nasal swabs and urine were analyzed by quantitative PCR for vaccine virus presence. Sera were tested for CDV antibodies by virus neutralization. All cats were sero-negative for CDV antibodies at the beginning of the study, and saline-injected cats remained sero-negative throughout the study. A dramatic anamnestic response was seen following wk 4 subcutaneous vaccinations, with titers peaking at wk 6 (geometric mean = 2,435.5). Following wk 49 revaccination, subcutaneous vaccinates again mounted impressive titers (wk 52 geometric mean = 2,048). Revaccination of the intranasal group cats at wk 49 produced a small increase in titers (wk 52 geometric mean = 203). CDV viral RNA was detected in six nasal swabs but no urine samples, demonstrating low viral shedding postvaccination. The strong antibody response to subcutaneous vaccination and the lack of adverse effects suggest this vaccine is safe and potentially protective against CDV infection in domestic cats.

  6. Immunogenicity and Safety of a Live Attenuated Zoster Vaccine (ZOSTAVAX™) in Korean Adults.

    PubMed

    Choi, Won Suk; Choi, Jung-Hyun; Choi, Jun Yong; Eom, Joong Sik; Kim, Sang Il; Pai, Hyunjoo; Peck, Kyong Ran; Sohn, Jang Wook; Cheong, Hee Jin

    2016-01-01

    A live attenuated zoster vaccine (ZOSTAVAX™, Merck & Co., Inc.) was approved by the Korea Ministry of Food and Drug Safety in 2009. However, the immunogenicity and safety of the vaccine has not been assessed in Korean population. This is multi-center, open-label, single-arm study performed with 180 healthy Korean adults ≥ 50 yr of age. The geometric mean titer (GMT) and geometric mean fold rise (GMFR) of varicella zoster virus (VZV) antibodies were measured by glycoprotein enzyme-linked immunosorbent assay (gpELISA) at 4 weeks post-vaccination. Subjects were followed for exposure to varicella or herpes zoster (HZ), the development of any varicella/varicella-like or HZ/HZ-like rashes, and any other clinical adverse experiences (AEs) for 42 days post-vaccination. For the 166 subjects included in the per-protocol population, the GMT at Day 1 was 66.9. At 4 weeks post-vaccination, the GMT for this population was 185.4, with a GMFR of 2.8 (95% CI, 2.5-3.1). Of the 180 subjects vaccinated, 62.8% experienced ≥ 1 AE, with 53.3% of subjects reporting injection-site AEs. The most frequently reported injection-site AEs were erythema (45.0%) with the majority being mild in intensity. Overall, 44 (24.4%) subjects experienced ≥ 1 systemic AE, 10 (5.5%) subjects experienced a systemic vaccine-related AE, and 3 (1.7%) subjects experienced ≥ 1 serious AE not related to vaccine. No subjects reported a VZV-like rash. There was no subject of death and no subject discontinued due to an adverse event. A single dose of zoster vaccine induced VZV-specific gpELISA antibody response and was generally well-tolerated in healthy Korean adults ≥50 yr of age (registry at www.clinicaltrial.gov No. NCT01556451).

  7. Inactivated and live, attenuated influenza vaccines protect mice against influenza: Streptococcus pyogenes super-infections.

    PubMed

    Chaussee, Michael S; Sandbulte, Heather R; Schuneman, Margaret J; Depaula, Frank P; Addengast, Leslie A; Schlenker, Evelyn H; Huber, Victor C

    2011-05-12

    Mortality associated with influenza virus super-infections is frequently due to secondary bacterial complications. To date, super-infections with Streptococcus pyogenes have been studied less extensively than those associated with Streptococcus pneumoniae. This is significant because a vaccine for S. pyogenes is not clinically available, leaving vaccination against influenza virus as our only means for preventing these super-infections. In this study, we directly compared immunity induced by two types of influenza vaccine, either inactivated influenza virus (IIV) or live, attenuated influenza virus (LAIV), for the ability to prevent super-infections. Our data demonstrate that both IIV and LAIV vaccines induce similar levels of serum antibodies, and that LAIV alone induces IgA expression at mucosal surfaces. Upon super-infection, both vaccines have the ability to limit the induction of pro-inflammatory cytokines within the lung, including IFN-γ which has been shown to contribute to mortality in previous models of super-infection. Limiting expression of these pro-inflammatory cytokines within the lungs subsequently limits recruitment of macrophages and neutrophils to pulmonary surfaces, and ultimately protects both IIV- and LAIV-vaccinated mice from mortality. Despite their overall survival, both IIV- and LAIV-vaccinated mice demonstrated levels of bacteria within the lung tissue that are similar to those seen in unvaccinated mice. Thus, influenza virus:bacteria super-infections can be limited by vaccine-induced immunity against influenza virus, but the ability to prevent morbidity is not complete. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Attenuation Correction for Flexible Magnetic Resonance Coils in Combined Magnetic Resonance/Positron Emission Tomography Imaging

    PubMed Central

    Eldib, Mootaz; Bini, Jason; Calcagno, Claudia; Robson, Philip M.; Mani, Venkatesh; Fayad, Zahi A.

    2014-01-01

    Introduction 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. Materials and Methods 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. Results 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

  9. 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

  10. Generation of a live rabies vaccine strain attenuated by multiple mutations and evaluation of its safety and efficacy.

    PubMed

    Nakagawa, Keisuke; Ito, Naoto; Masatani, Tatsunori; Abe, Masako; Yamaoka, Satoko; Ito, Yuki; Okadera, Kota; Sugiyama, Makoto

    2012-05-21

    An amino acid substitution at position 333 in rabies virus G protein is known to determine the pathogenicity: strains with Arg or Lys at that position kill adult mice after intracerebral inoculation, whereas strains with other amino acids cause non-lethal infection. Based on those findings, attenuated rabies virus strains have been established and used for oral vaccines mainly for wild animals. However, considering the possibility of back-mutation to the virulent phenotype, a strain that is attenuated by multiple mutations not only in the G protein but also in other viral proteins would be more appropriate as a safe live vaccine. We previously demonstrated that the fixed rabies virus Ni-CE strain, which causes only transient body weight loss in adult mice after intracerebral inoculation, is mainly attenuated by mutations in the N, P and M proteins, while this strain has virulent-type Arg at position 333 in the G protein. In this study, to obtain a live vaccine strain that is attenuated by multiple mutations, we generated Ni-CE mutant, Ni-CE(G333Glu) strain, which has an Arg-to-Glu mutation at position 333 in the G protein, and examined its pathogenicity and immunogenicity. We found that, in contrast to Ni-CE strain, Ni-CE(G333Glu) strain did not cause transient body weight loss in adult mice after intracerebral inoculation. The attenuated phenotype of Ni-CE(G333Glu) strain did not change even after 10 serial intracerebral passages in suckling mice. We also demonstrated that inoculation of Ni-CE(G333Glu) strain induced virus-neutralizing antibody in immunized mice and protected the mice from lethal challenge. These results indicate that Ni-CE(G333Glu) strain is a promising candidate for development of a live rabies vaccine with a high safety level.

  11. Plasmid containing CpG motifs enhances the efficacy of porcine reproductive and respiratory syndrome live attenuated vaccine.

    PubMed

    Guo, Xiaoyu; Zhang, Quan; Hou, Shaohua; Zhai, Guoqin; Zhu, Hongfei; Sánchez-Vizcaíno, J M

    2011-12-15

    Porcine reproductive and respiratory syndrome (PRRS) is now among the most important swine diseases that affect the Chinese swine industry. Both killed and live attenuated vaccines are currently used against the disease, but neither of them could provide full protection after vaccination. In the present study, the adjuvanticity of a plasmid containing CpG motifs (pUC18-CpG) was introduced to enhance the efficacy of a commercial PRRS live attenuated vaccine. After vaccination, PRRSV-specific antibodies, PRRSV-specific cytokines, and clinical parameters were studied and compared between different vaccinated groups. During a following challenge study, co-administration of pUC18-CpG with the vaccine could confer higher protection rate. Our results have shown that co-administration of pUC18-CpG with the vaccine could elicit more potent adaptive immune response and provide better protection. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Safety of Japanese encephalitis live attenuated vaccination in post-marketing surveillance in Guangdong, China, 2005-2012.

    PubMed

    Liu, Yu; Lin, Hualiang; Zhu, Qi; Wu, Chenggang; Zhao, Zhanjie; Zheng, Huizhen

    2014-03-26

    We reviewed the adverse events following immunization of live attenuated Japanese encephalitis vaccine in Guangdong Province, China. During the period of 2005-2012, 23 million doses of live attenuated Japanese encephalitis vaccine were used and 1426 adverse events were reported (61.24 per million doses); of which, 570 (40%) were classified as allergic reactions (24.48 per million doses), 31 (2%) were neurologic events (1.33 per million doses), and 36 (2.5%) were diagnosed as serious adverse events (1.55 per million doses). This study suggests that the JEV-L has a reasonable safety profile, most adverse events are relatively mild, with relatively rare neurologic events being observed.

  13. 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.

  14. Cross-Protection against Marburg Virus Strains by Using a Live, Attenuated Recombinant Vaccine

    DTIC Science & Technology

    2006-10-01

    considered to have potential as a biological weapon. Recently, we reported the development of a promising attenuated, replication -competent vaccine against...MARV infections, we recently described the development of a promising new replication -competent vaccine against MARV based on recombinant vesicular...reported the development of a promising attenuated, replication -competent vaccine against MARV based on recombinant vesicular stomatitis virus (VSV

  15. [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.

  16. CD8+ T Cells Define an Unexpected Role in Live-Attenuated Vaccine Protective Immunity against Chlamydia trachomatis infection

    PubMed Central

    Olivares-Zavaleta, Norma; Whitmire, William M.; Kari, Laszlo; Sturdevant, Gail L.; Caldwell, Harlan D.

    2014-01-01

    Trachoma, caused by the obligate intracellular organism Chlamydia trachomatis, is the world’s leading cause of preventable blindness for which a vaccine is needed. We have previously shown that a plasmid-deficient live-attenuated trachoma vaccine delivered ocularly to macaques elicited either solid or partial protective immunity against a virulent ocular challenge. Solidly protected macaques shared the same MHC class II alleles implicating CD4+ T cells in superior protective immunity. Understandably, we sought to define T cell immune correlates in these animals to potentially improve vaccine efficacy. Here, following a two year resting period, these macaques were boosted intramuscularly with the live-attenuated trachoma vaccine and their peripheral T cell anamnestic responses studied. Both solidly and partially protected macaques exhibited a CD4+ and CD8+ T cell anamnestic response following booster immunization. CD8+ but not CD4+ T cells from solidly protected macaques proliferated against soluble chlamydial antigen. We observed a more rapid T cell inflammatory cytokine response in tears of solidly protected animals following ocular re-challenge. Most notably, depletion of CD8+ T cells in solidly protected macaques completely abrogated protective immunity. Collectively, our findings support the conclusion that CD8+ T cells play an important but unexpected role in live-attenuated trachoma vaccine mediated protective immunity. PMID:24711617

  17. Stability of live attenuated rotavirus vaccine with selected preservatives and primary containers.

    PubMed

    Lal, Manjari; Jarrahian, Courtney; Zhu, Changcheng; Hosken, Nancy A; McClurkan, Chris L; Koelle, David M; Saxon, Eugene; Roehrig, Andrew; Zehrung, Darin; Chen, Dexiang

    2016-05-11

    Rotavirus infection, which can be prevented by vaccination, is responsible for a high burden of acute gastroenteritis disease in children, especially in low-income countries. An appropriate formulation, packaging, and delivery device for oral rotavirus vaccine has the potential to reduce the manufacturing cost of the vaccine and the logistical impact associated with introduction of a new vaccine, simplify the vaccination procedure, and ensure that the vaccine is safely and accurately delivered to children. Single-dose prefilled presentations can be easy to use; however, they are typically more expensive, can be a bottleneck during production, and occupy a greater volume per dose vis-à-vis supply chain storage and medical waste disposal, which is a challenge in low-resource settings. Multi-dose presentations used thus far have other issues, including increased wastage of vaccine and the need for separate delivery devices. In this study, the goals were to evaluate both the technical feasibility of using preservatives to develop a liquid multi-dose formulation and the primary packaging alternatives for orally delivered, liquid rotavirus vaccines. The feasibility evaluation included evaluation of commonly used preservatives for compatibility with rotavirus vaccines and stability testing of rotavirus vaccine in various primary containers, including Lameplast's plastic tubes, BD's oral dispenser version of Uniject™ (Uniject DP), rommelag's blow-fill-seal containers, and MEDInstill's multi-dose vial and pouch. These presentations were compared to a standard glass vial. The results showed that none of the preservatives tested were compatible with a live attenuated rotavirus vaccine because they had a detrimental effect on the viability of the virus. In the presence of preservatives, vaccine virus titers declined to undetectable levels within 1 month. The vaccine formulation without preservatives maintained a stability profile over 12 months in all primary containers

  18. Comparing live attenuated and inactivated hepatitis A vaccines: an immunogenicity study after one single dose.

    PubMed

    Zheng, Hui; Chen, Yuansheng; Wang, Fuzhen; Gong, Xiaohong; Wu, Zhenhua; Miao, Ning; Zhang, Xiaoshu; Li, Hui; Chen, Chao; Hou, Xiang; Cui, Fuqiang; Wang, Huaqing

    2011-11-08

    While three types of hepatitis A vaccines are available in China, little data are available to compare them in terms of early antibody response. We conducted a trial to compare antibody response at 7, 14 and 28 days. We randomized primary school children in Gansu and Jilin provinces into four groups to receive either (1) Chinese live attenuated hepatitis A vaccine (H2 strain), (2) domestic inactivated hepatitis A vaccine (Healive(®)), (3) imported inactivated hepatitis A vaccine (Havrix(®)) or (4) hepatitis B vaccine (Control group). We compared groups at 7, 14 and 28 days in terms of proportion of sero-conversions (≥10 mUI/ml), and Geometric Mean Concentration (GMC) of antibodies measured with a Microparticle Enzyme Immunoassay (MEIA). We compared rates of self-reported adverse events following immunization (AEFI) in the first three days. 204 children received the H2 vaccine, 208 received Healive(®), 214 received Havrix(®), and 215 received hepatitis B vaccine (no differences across groups in terms of age, sex, weight and height). At seven days, sero-conversion proportions were 25%, 35%, 27% and 2% (p<0.0001) with GMC of 6 mIU/ml, 8 mIU/ml, 6 mIU/ml and 3 mIU/ml, respectively for the four groups. At 28 days, sero-conversion proportions were 98%, 100%, 93% and 3% (p<0.0001) with GMC of 47 mIU/ml, 71 mIU/ml, 67 mIU/ml and 3 mIU/ml, respectively. AEFI were benign and did not differ across groups (p=0.94). While our study was not able to identify differences between Havrix(®), Healive(®) and H2 vaccine in terms of sero-conversion proportion and GMC between seven and 28 days, further studies should evaluate non-inferiority or equivalence of the Chinese vaccines, particularly with respect to the GMC concentration for the H2 vaccine since it could affect long-term protection. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Assessing Fever Frequency After Pediatric Live Attenuated Versus Inactivated Influenza Vaccination.

    PubMed

    Stockwell, Melissa S; Broder, Karen R; Lewis, Paige; Jakob, Kathleen; Iqbal, Shahed; Fernandez, Nadira; Sharma, Devindra; Barrett, Angela; LaRussa, Philip

    2017-09-01

    Some studies have found a higher frequency of fever with trivalent live attenuated influenza vaccine (LAIV) than with inactivated influenza vaccine (IIV), but quadrivalent LAIV has not been assessed. Understanding fever is important for safety reviews and for parents and providers. In addition, there have been only a limited number of studies in which text messaging was used for vaccine adverse-event (AE) surveillance. We conducted a prospective observational study in 3 community clinics in New York City to assess post-influenza vaccination fever in 24- to 59-month-olds during the 2013-2014 season. Enrolled families of children who received quadrivalent LAIV (LAIV4) or IIV (trivalent IIV3 or quadrivalent IIV4) replied to text messages that assessed their temperature on vaccination night and the next 10 nights (days 0 to 10); missing data were collected via telephone and a diary. We compared frequencies of fever (temperature ≥ 100.4°F) according to vaccine group on days 0 to 2 and 3 to 10 by using χ2 and multivariate log-binomial regression adjusted for age, previous influenza vaccination, and vaccine coadministration. We also assessed outcomes using all sources versus only text messages. Most (84.1% [n = 540]) eligible parents enrolled. Fever frequencies on days 0 to 2 did not differ between LAIV4 and any IIV (3.8% vs 5.7%, respectively; adjusted relative risk [aRR] [95% confidence interval], 0.60 [0.25-1.46]), between LAIV4 and IIV4 (4.2% vs 7.1%, respectively; aRR, 0.58 [0.19-1.72]), or between IIV4 and IIV3 (7.1% vs 6.0%, respectively; aRR, 1.02 [0.30-3.46]). The findings were similar when all data sources versus text-message data alone were used. There were no significant differences on days 3 to 10. Postvaccination fever frequencies were low overall and did not differ according to influenza vaccine type during the 2013-2014 influenza season. The similarity of results when data were limited to text messages lends support to its use for surveillance of

  20. Comparative Immunogenicities of Frozen and Refrigerated Formulations of Live Attenuated Influenza Vaccine in Healthy Subjects▿

    PubMed Central

    Block, Stan L.; Reisinger, Keith S.; Hultquist, Micki; Walker, Robert E.

    2007-01-01

    The frozen version of live attenuated influenza vaccine (LAIV; FluMist) was compared with a newly licensed, refrigerated formulation, the cold-adapted influenza vaccine, trivalent (CAIV-T), for their immunogenicity, safety, and tolerability in healthy subjects 5 to 49 years of age. Eligible subjects were randomized 1:1 to receive CAIV-T or frozen LAIV. Subjects 5 to 8 years of age received two doses of vaccine 46 to 60 days apart; subjects 9 to 49 years of age received one dose of vaccine. Equivalent immunogenicities were defined as serum hemagglutination inhibition (HAI) geometric mean titer (GMT) ratios >0.5 and <2.0 for each of the three vaccine-specific strains. A total of 376 subjects 5 to 8 years of age and 566 subjects 9 to 49 years of age were evaluable. Postvaccination HAI GMT ratios were equivalent for CAIV-T and LAIV. The GMT ratios of CAIV-T/LAIV for the H1N1, H3N2, and B strains were 1.24, 1.02, and 1.00, respectively, for the 5- to 8-year-old age group and 1.14, 1.12, and 0.96, respectively, for the 9- to 49-year-old age group. Seroresponse/seroconversion rates (fourfold or greater rise) were similar in both age groups for each of the three vaccine strains. Within 28 days, the most frequent reactogenicity event in the CAIV-T and LAIV groups was runny nose/nasal congestion, which occurred at higher rates after dose 1 (44% and 42%, respectively) than after dose 2 (41% and 29%, respectively) in the 5- to 8-year-old group. Otherwise, the rates of adverse events (AEs) were similar between the treatment groups and the two age cohorts, with no serious AEs related to the study vaccines. The immunogenicities, reactogenicity events, and AEs were comparable for refrigerated CAIV-T and frozen LAIV. PMID:17724151

  1. Enhancement of the safety of live influenza vaccine by attenuating mutations from cold-adapted hemagglutinin

    SciTech Connect

    Lee, Yoon Jae; Jang, Yo Han; Kim, Paul; Lee, Yun Ha; Lee, Young Jae; Byun, Young Ho; Lee, Kwang-Hee; Kim, Kyusik; Seong, Baik Lin

    2016-04-15

    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 amino 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.

  2. 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

  3. Path-average rainfall estimation using attenuation measurements: combining microwave and optical links

    NASA Astrophysics Data System (ADS)

    Uijlenhoet, R.; Leijnse, H.

    2009-09-01

    On previous occasions we have demonstrated the potential and limitations of single microwave and optical links as path-average rain gauges. In this presentation we investigate the potential of combined microwave and optical attenuation measurements for improved path-average rainfall monitoring through theoretical analyses and numerical experiments. We show theoretically that path-average rain rate can in principle be retrieved from the specific attenuations at microwave and optical wavelengths through a double power-law relation, of which the exponents are independent and the coefficient is only weakly dependent on the raindrop size distribution. Our calculations indicate further that the main gain of adding an optical link to an existing microwave link is in reducing the root-mean-square-error of the retrieved rain rate, particularly for microwave frequencies below 35 GHz.

  4. Bioventing and natural attenuation: The combination of in situ treatment technologies provide effective site remediation

    SciTech Connect

    Brown, K.; Malloy, J.; Sekerka, P.; Sibbett, B.; Thomas, M.; Tyner, L.; Zhong, J.; Caron, D.

    1995-12-31

    IT Corporation (IT) is evaluating the combination of free product removal, bioventing, and natural attenuation for remediation of jet fuel-impacted soil and groundwater at George Air Force Base, California. Remedial activities are focused on a 155-acre benzene and 27-acre free product plume which have resulted from a leaking liquid fuels distribution system. In situ remedial options are favored at this site due to the reduced yield of the aquifer, low groundwater velocity, large areal extent of contamination, reduced risk of exposure, and ongoing site operations. Following the completion of a long-term monitoring investigation including bioventing pilot operations, natural attenuation monitoring, and free product recovery, remedial designs will be formalized.

  5. Recoding of the vesicular stomatitis virus L gene by computer-aided design provides a live, attenuated vaccine candidate.

    PubMed

    Wang, Bingyin; Yang, Chen; Tekes, Gergely; Mueller, Steffen; Paul, Aniko; Whelan, Sean P J; Wimmer, Eckard

    2015-03-31

    Codon pair bias (CPB), which has been observed in all organisms, is a neglected genomic phenomenon that affects gene expression. CPB results from synonymous codons that are paired more or less frequently in ORFeomes regardless of codon bias. The effect of an individual codon pair change is usually small, but when it is amplified by large-scale genome recoding, strikingly altered biological phenotypes are observed. The utility of codon pair bias in the development of live attenuated vaccines was recently demonstrated by recodings of poliovirus (a positive-strand RNA virus) and influenza virus (a negative-strand segmented RNA virus). Here, the L gene of vesicular stomatitis virus (VSV), a nonsegmented negative-sense RNA virus, was partially recoded based on codon pair bias. Totals of 858 and 623 silent mutations were introduced into a 5'-terminal segment of the viral L gene (designated L1) to create sequences containing either overrepresented or underrepresented codon pairs, designated L1(sdmax) and L1(min), respectively. Analysis revealed that recombinant VSV containing the L1(min) sequence could not be recovered, whereas the virus with the sdmax sequence showed a modest level of attenuation in cell culture. More strikingly, in mice the L1(sdmax) virus was almost as immunogenic as the parental strain but highly attenuated. Taken together, these results open a new road to attain a balance between VSV virulence and immunogenicity, which could serve as an example for the attenuation of other negative-strand, nonsegmented RNA viruses. Vesicular stomatitis virus (VSV) is the prototypic rhabdovirus in the order Mononegavirales. A wide range of human pathogens belong to this family. Using a unique computer algorithm and large-scale genome synthesis, we attempted to develop a live attenuated vaccine strain for VSV, which could be used as an antigen delivery platform for humans. Recombinant VSVs with distinct codon pair biases were rationally designed, constructed, and

  6. 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

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

    PubMed

    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.

  8. Limited dissemination of pathogenic SIV after vaginal challenge of rhesus monkeys immunized with a live, attenuated lentivirus.

    PubMed

    Stone, Mars; Ma, Zhong-Min; Genescà, Meritxell; Fritts, Linda; Blozois, Shelley; McChesney, Michael B; Miller, Christopher J

    2009-09-30

    In non-human primate models of AIDS, attenuated lentiviruses provide the most reliable protection from challenge with pathogenic virus but the extent to which the vaccine virus replicates after challenge is unclear. At 7 and 14 days after vaginal challenge with pathogenic SIVmac239, plasma SIVenv RNA levels were significantly lower in female macaques immunized 6 months earlier with live, attenuated SHIV89.6 compared to unimmunized control animals. In 2 SHIV-immunized, unprotected macaques SIV replication produced moderate-level plasma viremia with dissemination of challenge virus to all tissues on day 14 after challenge. In protected, SHIV-immunized monkeys, SIV replication was controlled in all tissues, from the day of challenge through 14 days post-challenge. Further, in CD8(+) T cell-depleted SHIV-immunized animals, SIV replication and dissemination were more rapid than in control animals. These findings suggest that replication of a pathogenic AIDS virus can be controlled at the site of mucosal inoculation by live-attenuated lentivirus immunization.

  9. Shedding of Live Vaccine Virus, Comparative Safety, and Influenza-Specific Antibody Responses after Administration of Live Attenuated and Inactivated Trivalent Influenza Vaccines to HIV-Infected Children

    PubMed Central

    Levin, Myron J.; Song, Lin-Ye; Fenton, Terrence; Nachman, Sharon; Patterson, Julie; Walker, Robert; Kemble, George; Allende, Maria; Hultquist, Micki; Yi, Tingting; Nowak, Barbara; Weinberg, Adriana

    2008-01-01

    HIV-infected children (n = 243), ≥5 to <18 years old, receiving stable antiretroviral therapy, were stratified by immunologic status and randomly assigned to receive intranasal live attenuated influenza vaccine (LAIV) or intramuscular trivalent inactivated influenza vaccine (TIV). The safety profile after LAIV or TIV closely resembled the previously reported tolerability to these vaccines in children without HIV infection. Post-vaccination hemagglutination inhibition (HAI) antibody responses and shedding of LAIV virus were also similar, regardless of immunological stratum, to antibody responses and shedding previously reported for children without HIV infection. LAIV should be further evaluated for a role in immunizing HIV-infected children. PMID:18597900

  10. Identification of mutations contributing to the temperature-sensitive, cold-adapted, and attenuation phenotypes of the live-attenuated cold-passage 45 (cp45) human parainfluenza virus 3 candidate vaccine.

    PubMed

    Skiadopoulos, M H; Surman, S; Tatem, J M; Paschalis, M; Wu, S L; Udem, S A; Durbin, A P; Collins, P L; Murphy, B R

    1999-02-01

    The live-attenuated human parainfluenza virus 3 (PIV3) cold-passage 45 (cp45) candidate vaccine was shown previously to be safe, immunogenic, and phenotypically stable in seronegative human infants. Previous findings indicated that each of the three amino acid substitutions in the L polymerase protein of cp45 independently confers the temperature-sensitive (ts) and attenuation (att) phenotypes but not the cold-adaptation (ca) phenotype (29). cp45 contains 12 additional potentially important point mutations in other proteins (N, C, M, F, and hemagglutinin-neuraminidase [HN]) or in cis-acting sequences (the leader region and the transcription gene start [GS] signal of the N gene), and their contribution to these phenotypes was undefined. To further characterize the genetic basis for the ts, ca, and att phenotypes of this promising vaccine candidate, we constructed, using a reverse genetics system, a recombinant cp45 virus that contained all 15 cp45-specific mutations mentioned above, and found that it was essentially indistinguishable from the biologically derived cp45 on the basis of plaque size, level of temperature sensitivity, cold adaptation, level of replication in the upper and lower respiratory tract of hamsters, and ability to protect hamsters from subsequent wild-type PIV3 challenge. We then constructed recombinant viruses containing the cp45 mutations in individual proteins as well as several combinations of mutations. Analysis of these recombinant viruses revealed that multiple cp45 mutations distributed throughout the genome contribute to the ts, ca, and att phenotypes. In addition to the mutations in the L gene, at least one other mutation in the 3' N region (i.e., including the leader, N GS, and N coding changes) contributes to the ts phenotype. A recombinant virus containing all the cp45 mutations except those in L was more ts than cp45, illustrating the complex nature of this phenotype. The ca phenotype of cp45 also is a complex composite phenotype

  11. Identification of Mutations Contributing to the Temperature-Sensitive, Cold-Adapted, and Attenuation Phenotypes of the Live-Attenuated Cold-Passage 45 (cp45) Human Parainfluenza Virus 3 Candidate Vaccine

    PubMed Central

    Skiadopoulos, Mario H.; Surman, Sonja; Tatem, Joanne M.; Paschalis, Maribel; Wu, Shin-Lu; Udem, Stephen A.; Durbin, Anna P.; Collins, Peter L.; Murphy, Brian R.

    1999-01-01

    The live-attenuated human parainfluenza virus 3 (PIV3) cold-passage 45 (cp45) candidate vaccine was shown previously to be safe, immunogenic, and phenotypically stable in seronegative human infants. Previous findings indicated that each of the three amino acid substitutions in the L polymerase protein of cp45 independently confers the temperature-sensitive (ts) and attenuation (att) phenotypes but not the cold-adaptation (ca) phenotype (29). cp45 contains 12 additional potentially important point mutations in other proteins (N, C, M, F, and hemagglutinin-neuraminidase [HN]) or in cis-acting sequences (the leader region and the transcription gene start [GS] signal of the N gene), and their contribution to these phenotypes was undefined. To further characterize the genetic basis for the ts, ca, and att phenotypes of this promising vaccine candidate, we constructed, using a reverse genetics system, a recombinant cp45 virus that contained all 15 cp45-specific mutations mentioned above, and found that it was essentially indistinguishable from the biologically derived cp45 on the basis of plaque size, level of temperature sensitivity, cold adaptation, level of replication in the upper and lower respiratory tract of hamsters, and ability to protect hamsters from subsequent wild-type PIV3 challenge. We then constructed recombinant viruses containing the cp45 mutations in individual proteins as well as several combinations of mutations. Analysis of these recombinant viruses revealed that multiple cp45 mutations distributed throughout the genome contribute to the ts, ca, and att phenotypes. In addition to the mutations in the L gene, at least one other mutation in the 3′ N region (i.e., including the leader, N GS, and N coding changes) contributes to the ts phenotype. A recombinant virus containing all the cp45 mutations except those in L was more ts than cp45, illustrating the complex nature of this phenotype. The ca phenotype of cp45 also is a complex composite phenotype

  12. Use of RapidChek® SELECT™ Salmonella to detect shedding of live attenuated Salmonella enterica serovar Typhi vaccine strains.

    PubMed

    Brenneman, Karen E; McDonald, Caitlin; Kelly-Aehle, Sandra M; Roland, Kenneth L; Curtiss, Roy

    2012-05-01

    Identification of individuals shedding Salmonella enterica serovar Typhi in stool is imperative during clinical trial safety evaluations. Recovery of live attenuated S. Typhi vaccine strains can be difficult because the mutations necessary for safety in humans often compromise survival in stringent selective enrichment media. RapidChek® SELECT™ Salmonella is a highly sensitive detection method for S. enterica species which utilizes a bacteriophage cocktail designed to reduce the growth of competitor microbes in mildly selective enrichment medium. Detection of Salmonella is enhanced by means of a Salmonella-specific antibody strip targeted to lipopolysaccharide. The RapidChek® SELECT™ Salmonella method was compared to conventional enrichment and plating methods to determine the most sensitive method for detecting attenuated S. Typhi strains in human stool samples. Although traditional enrichment strategies were more sensitive to the presence of wild-type S. Typhi, RapidChek® SELECT™ Salmonella was superior at detecting attenuated strains of S. Typhi. Strains containing a wide variety of attenuating mutations were detected with equal sensitivity as the wild type by RapidChek® SELECT™ Salmonella. The presence of Vi capsule or mutations which affected O-antigen synthesis (Δpmi, ΔgalE) did not decrease the sensitivity of the RapidChek® SELECT™ Salmonella assay.

  13. Combined inhibition of TGFβ and PDGF signaling attenuates radiation-induced pulmonary fibrosis.

    PubMed

    Dadrich, Monika; Nicolay, Nils H; Flechsig, Paul; Bickelhaupt, Sebastian; Hoeltgen, Line; Roeder, Falk; Hauser, Kai; Tietz, Alexandra; Jenne, Jürgen; Lopez, Ramon; Roehrich, Manuel; Wirkner, Ute; Lahn, Michael; Huber, Peter E

    2016-05-01

    Background : Radiotherapy (RT) is a mainstay for the treatment of lung cancer, but the effective dose is often limited by the development of radiation-induced pneumonitis and pulmonary fibrosis. Transforming growth factor β (TGFβ) and platelet-derived growth factor (PDGF) play crucial roles in the development of these diseases, but the effects of dual growth factor inhibition on pulmonary fibrosis development remain unclear. Methods : C57BL/6 mice were treated with 20 Gy to the thorax to induce pulmonary fibrosis. PDGF receptor inhibitors SU9518 and SU14816 (imatinib) and TGFβ receptor inhibitor galunisertib were applied individually or in combinations after RT. Lung density and septal fibrosis were measured by high-resolution CT and MRI. Lung histology and gene expression analyses were performed and Osteopontin levels were studied. Results : Treatment with SU9518, SU14816 or galunisertib individually attenuated radiation-induced pulmonary inflammation and fibrosis and decreased radiological and histological signs of lung damage. Combining PDGF and TGFβ inhibitors showed to be feasible and safe in a mouse model, and dual inhibition significantly attenuated radiation-induced lung damage and extended mouse survival compared to blockage of either pathway alone. Gene expression analysis of irradiated lung tissue showed upregulation of PDGF and TGFβ-dependent signaling components by thoracic irradiation, and upregulation patterns show crosstalk between downstream mediators of the PDGF and TGFβ pathways. Conclusion : Combined small-molecule inhibition of PDGF and TGFβ signaling is a safe and effective treatment for radiation-induced pulmonary inflammation and fibrosis in mice and may offer a novel approach for treatment of fibrotic lung diseases in humans. Translational statement : RT is an effective treatment modality for cancer with limitations due to acute and chronic toxicities, where TGFβ and PDGF play a key role. Here, we show that a combined inhibition of

  14. Combined inhibition of TGFβ and PDGF signaling attenuates radiation-induced pulmonary fibrosis

    PubMed Central

    Dadrich, Monika; Nicolay, Nils H.; Flechsig, Paul; Bickelhaupt, Sebastian; Hoeltgen, Line; Roeder, Falk; Hauser, Kai; Tietz, Alexandra; Jenne, Jürgen; Lopez, Ramon; Roehrich, Manuel; Wirkner, Ute; Lahn, Michael; Huber, Peter E.

    2016-01-01

    ABSTRACT Background: Radiotherapy (RT) is a mainstay for the treatment of lung cancer, but the effective dose is often limited by the development of radiation-induced pneumonitis and pulmonary fibrosis. Transforming growth factor β (TGFβ) and platelet-derived growth factor (PDGF) play crucial roles in the development of these diseases, but the effects of dual growth factor inhibition on pulmonary fibrosis development remain unclear. Methods: C57BL/6 mice were treated with 20 Gy to the thorax to induce pulmonary fibrosis. PDGF receptor inhibitors SU9518 and SU14816 (imatinib) and TGFβ receptor inhibitor galunisertib were applied individually or in combinations after RT. Lung density and septal fibrosis were measured by high-resolution CT and MRI. Lung histology and gene expression analyses were performed and Osteopontin levels were studied. Results: Treatment with SU9518, SU14816 or galunisertib individually attenuated radiation-induced pulmonary inflammation and fibrosis and decreased radiological and histological signs of lung damage. Combining PDGF and TGFβ inhibitors showed to be feasible and safe in a mouse model, and dual inhibition significantly attenuated radiation-induced lung damage and extended mouse survival compared to blockage of either pathway alone. Gene expression analysis of irradiated lung tissue showed upregulation of PDGF and TGFβ-dependent signaling components by thoracic irradiation, and upregulation patterns show crosstalk between downstream mediators of the PDGF and TGFβ pathways. Conclusion: Combined small-molecule inhibition of PDGF and TGFβ signaling is a safe and effective treatment for radiation-induced pulmonary inflammation and fibrosis in mice and may offer a novel approach for treatment of fibrotic lung diseases in humans. Translational statement: RT is an effective treatment modality for cancer with limitations due to acute and chronic toxicities, where TGFβ and PDGF play a key role. Here, we show that a combined

  15. Enhancement of the safety of live influenza vaccine by attenuating mutations from cold-adapted hemagglutinin.

    PubMed

    Lee, Yoon Jae; Jang, Yo Han; Kim, Paul; Lee, Yun Ha; Lee, Young Jae; Byun, Young Ho; Lee, Kwang-Hee; Kim, Kyusik; Seong, Baik Lin

    2016-04-01

    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 amino 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. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. 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

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

    PubMed

    Cai, Yibin; Song, Haichen; Ye, Jianqiang; Shao, Hongxia; Padmanabhan, Rangarajan; Sutton, Troy C; Perez, Daniel R

    2011-01-21

    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.

  18. Enalapril and atenolol in essential hypertension: attenuation of hypotensive effects in combination.

    PubMed

    Wing, L M; Chalmers, J P; West, M J; Russell, A E; Morris, M J; Cain, M D; Bune, A J; Southgate, D O

    1988-01-01

    In 16 patients with essential hypertension the effects of enalapril 20 mg once daily were compared with those of atenolol 50 mg once daily, with the two drugs in combination and with placebo using a double-blind cross-over design with allocation of treatment order by randomised Latin squares. For each patient there were four treatment phases, each of four weeks duration, which together comprised a 2 x 2 factorial experiment. All blood pressure parameters were reduced in the three active treatment phases compared to placebo (p less than 0.001). Supine blood pressures (group means) were 171/97 (placebo), 147/85 (enalapril), 154/84 (atenolol) and 144/78 (enalapril plus atenolol) (S.E.M. +/- 2/+/- 1-ANOVA), and standing blood pressures were 170/105 (placebo), 146/92 (enalapril), 154/92 (atenolol) and 147/86 (enalapril plus atenolol) (S.E.M. +/- 3/+/- 1). In the combination phase there was an additional hypotensive response but the potential fully additive effects of the two agents were attenuated by 30-50%. The mechanism of the attenuated hypotensive effect of the combined agents has not been determined. Plasma atrial natriuretic peptide (ANP) concentration was doubled in the presence of atenolol (P less than 0.01) suggesting that ANP may contribute to the hypotensive effect of the beta-blocker.

  19. Inoculation of Balb/c mice with live attenuated tachyzoites protects against a lethal challenge of Neospora caninum.

    PubMed

    Bartley, P M; Wright, S; Chianini, F; Buxton, D; Innes, E A

    2008-01-01

    Neospora caninum tachyzoites attenuated through passage in tissue culture were tested for their ability to induce protective immunity against a lethal challenge dose of parasites. Balb/c mice were each inoculated with either 1x10(6) live virulent tachyzoites (Group 1) or 1x10(6) live attenuated tachyzoites (Group 2), while (Group 3) received a control inoculum. All mice were each challenged 28 days later with 5x10(6) virulent parasites. Histopathological lesions in the brains including necrosis and microgliosis were observed following post-mortem on day 28 post-challenge (p.c.) in 71% of Group 1 and 56% of Group 2. Immunohistochemistry (IHC) of these lesions showed tachyzoites and Neospora antigens to be associated with moderate brain lesions in 17% of Group 1, while in 11% of Group 2 N. caninum tissue cysts were detected, but these were not associated with lesions, Parasite DNA was detected by PCR in the brains of 86% of mice in Group 1 and 56% of mice in Group 2. Following challenge the mice in Group 3 showed high morbidity and 100% mortality within 17 days p.c. Positive IHC for N. caninum was seen in 88% of the Group 3 mice and parasite DNA was detected in all brain samples. This study shows that it is possible to protect against a lethal challenge of N. caninum through inoculation with attenuated or virulent tachyzoites. However, more severe pathology developed in mice initially inoculated with virulent parasites following a secondary challenge, compared to mice initially inoculated with attenuated parasites.

  20. Live attenuated Salmonella enterica serovar Choleraesuis vaccine vector displaying regulated delayed attenuation and regulated delayed antigen synthesis to confer protection against Streptococcus suis in mice.

    PubMed

    Ji, Zhenying; Shang, Jing; Li, Yuan; Wang, Shifeng; Shi, Huoying

    2015-09-11

    Salmonella enterica serotype Choleraesuis (S. Choleraesuis) and Streptococcus suis (S. suis) are important swine pathogens. Development of a safe and effective attenuated S. Choleraesuis vaccine vector would open a new window to prevent and control pig diseases. To achieve this goal, the mannose and arabinose regulated delayed attenuated systems (RDAS), Δpmi and ΔPcrp::TT araC PBADcrp, were introduced into the wild type S. Choleraesuis strain C78-3. We also introduced ΔrelA::araC PBADlacI TT to achieve regulated delayed antigen synthesis and ΔasdA to constitute a balanced-lethal plasmid system. The safety and immunogenicity of the resulted RDAS S. Choleraesuis strain rSC0011 carrying 6-phosphogluconate dehydrogenase (6-PGD) of S. suis serotype 2 (SS2) were evaluated in vitro and in vivo. Compared with the wild type parent strain C78-3 and vaccine strain C500, a live attenuated S. Choleraesuis vaccine licensed for piglet in China, the results showed that the survival curves of the vaccine strain rSC0011 were similar to those of strains C78-3 and C500 at the early stage of infection, but lower than those of C78-3 and higher than those of C500 at the later stage in both porcine alveolar macrophages and peripheral porcine monocytes. The LD50 of the RDAS strains rSC0011 by oral route in mice was close to that of C500 and 10,000-fold higher than that of C78-3. Similar results were achieved by intraperitoneal (i.p.) route, suggesting that the RDAS strains rSC0011 achieved similar attenuation as C500. However, the RDAS strain rSC0011 was superior to C500 in colonization of Peyer's patches. Adult mice orally immunized with strain rSC0011 carrying a plasmid expression 6-phosphogluconate dehydrogenase (6-PGD) gene from SS2 developed strong immune responses against 6-PGD and Salmonella antigens, and conferred high protection against i.p. challenge with SS2.

  1. 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

  2. 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

    ... et al., ``Development of Mutations Useful for Attenuating Dengue Viruses and Chimeric Dengue Viruses... Antigenic Chimeric Dengue Viruses 1,2,3, And 4'', United States Patent Application Number 10/970,640 (now...., ``Mutations which enhance the replication of dengue virus type 4 and an antigenic chimeric dengue virus type...

  3. Live Attenuated Recombinant Vaccine Protects Nonhuman Primates Against Ebola and Marburg Viruses

    DTIC Science & Technology

    2005-06-05

    Marburg virus (MARV). Here, we developed replication -competent vaccines against EBOV and MARV based on attenuated recombinant vesicular stomatitis...No evidence of EBOV or MARV replication was detected in any of the protected animals after challenge. Our data suggest that these vaccine...number of efforts have focused on developing vaccines against MARV. Alphavirus replicons expressing MARV proteins protected cynomolgus monkeys from

  4. Modifications in the polymerase genes of a swine-like triple-reassortant influenza virus to generate live attenuated vaccines against 2009 pandemic H1N1 viruses.

    PubMed

    Pena, Lindomar; Vincent, Amy L; Ye, Jianqiang; Ciacci-Zanella, Janice R; Angel, Matthew; Lorusso, Alessio; Gauger, Philip C; Janke, Bruce H; Loving, Crystal L; Perez, Daniel R

    2011-01-01

    On 11 June 2009, the World Health Organization (WHO) declared that the outbreaks caused by novel swine-origin influenza A (H1N1) virus had reached pandemic proportions. The pandemic H1N1 (H1N1pdm) virus is the predominant influenza virus strain in the human population. It has also crossed the species barriers and infected turkeys and swine in several countries. Thus, the development of a vaccine that is effective in multiple animal species is urgently needed. We have previously demonstrated that the introduction of temperature-sensitive mutations into the PB2 and PB1 genes of an avian H9N2 virus, combined with the insertion of a hemagglutinin (HA) tag in PB1, resulted in an attenuated (att) vaccine backbone for both chickens and mice. Because the new pandemic strain is a triple-reassortant (TR) virus, we chose to introduce the double attenuating modifications into a swine-like TR virus isolate, A/turkey/OH/313053/04 (H3N2) (ty/04), with the goal of producing live attenuated influenza vaccines (LAIV). This genetically modified backbone had impaired polymerase activity and restricted virus growth at elevated temperatures. In vivo characterization of two H1N1 vaccine candidates generated using the ty/04 att backbone demonstrated that this vaccine is highly attenuated in mice, as indicated by the absence of signs of disease, limited replication, and minimum histopathological alterations in the respiratory tract. A single immunization with the ty/04 att-based vaccines conferred complete protection against a lethal H1N1pdm virus infection in mice. More importantly, vaccination of pigs with a ty/04 att-H1N1 vaccine candidate resulted in sterilizing immunity upon an aggressive intratracheal challenge with the 2009 H1N1 pandemic virus. Our studies highlight the safety of the ty/04 att vaccine platform and its potential as a master donor strain for the generation of live attenuated vaccines for humans and livestock.

  5. 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

  6. A Single Mutation at PB1 Residue 319 Dramatically Increases the Safety of PR8 Live Attenuated Influenza Vaccine in a Murine Model without Compromising Vaccine Efficacy.

    PubMed

    Cox, Andrew; Dewhurst, Stephen

    2015-12-16

    The live attenuated influenza vaccine (LAIV) is preferentially recommended for use in most children yet remains unsafe for the groups most at risk. Here we have improved the safety of a mouse-adapted live attenuated influenza vaccine containing the same attenuating amino acid mutations as in human LAIV by adding an additional mutation at PB1 residue 319. This results in a vaccine with a 20-fold decrease in protective efficacy and a 10,000-fold increase in safety. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  7. 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

  8. Generation and Characterization of Live Attenuated Influenza A(H7N9) Candidate Vaccine Virus Based on Russian Donor of Attenuation.

    PubMed

    Shcherbik, Svetlana; Pearce, Nicholas; Balish, Amanda; Jones, Joyce; Thor, Sharmi; Davis, Charles Todd; Pearce, Melissa; Tumpey, Terrence; Cureton, David; Chen, Li-Mei; Villanueva, Julie; Bousse, Tatiana L

    2015-01-01

    Avian influenza A (H7N9) virus has emerged recently and continues to cause severe disease with a high mortality rate in humans prompting the development of candidate vaccine viruses. Live attenuated influenza vaccines (LAIV) are 6:2 reassortant viruses containing the HA and NA gene segments from wild type influenza viruses to induce protective immune responses and the six internal genes from Master Donor Viruses (MDV) to provide temperature sensitive, cold-adapted and attenuated phenotypes. LAIV candidate A/Anhui/1/2013(H7N9)-CDC-LV7A (abbreviated as CDC-LV7A), based on the Russian MDV, A/Leningrad/134/17/57 (H2N2), was generated by classical reassortment in eggs and retained MDV temperature-sensitive and cold-adapted phenotypes. CDC-LV7A had two amino acid substitutions N123D and N149D (H7 numbering) in HA and one substitution T10I in NA. To evaluate the role of these mutations on the replication capacity of the reassortants in eggs, the recombinant viruses A(H7N9)RG-LV1 and A(H7N9)RG-LV2 were generated by reverse genetics. These changes did not alter virus antigenicity as ferret antiserum to CDC-LV7A vaccine candidate inhibited hemagglutination by homologous A(H7N9) virus efficiently. Safety studies in ferrets confirmed that CDC-LV7A was attenuated compared to wild-type A/Anhui/1/2013. In addition, the genetic stability of this vaccine candidate was examined in eggs and ferrets by monitoring sequence changes acquired during virus replication in the two host models. No changes in the viral genome were detected after five passages in eggs. However, after ten passages additional mutations were detected in the HA gene. The vaccine candidate was shown to be stable in the ferret model; post-vaccination sequence data analysis showed no changes in viruses collected in nasal washes present at day 5 or day 7. Our data indicate that the A/Anhui/1/2013(H7N9)-CDC-LV7A reassortant virus is a safe and genetically stable candidate vaccine virus that is now available for

  9. Generation and Characterization of Live Attenuated Influenza A(H7N9) Candidate Vaccine Virus Based on Russian Donor of Attenuation

    PubMed Central

    Shcherbik, Svetlana; Pearce, Nicholas; Balish, Amanda; Jones, Joyce; Thor, Sharmi; Davis, Charles Todd; Pearce, Melissa; Tumpey, Terrence; Cureton, David; Chen, Li-Mei; Villanueva, Julie; Bousse, Tatiana L.

    2015-01-01

    Background Avian influenza A (H7N9) virus has emerged recently and continues to cause severe disease with a high mortality rate in humans prompting the development of candidate vaccine viruses. Live attenuated influenza vaccines (LAIV) are 6:2 reassortant viruses containing the HA and NA gene segments from wild type influenza viruses to induce protective immune responses and the six internal genes from Master Donor Viruses (MDV) to provide temperature sensitive, cold-adapted and attenuated phenotypes. Methodology/Principal Findings LAIV candidate A/Anhui/1/2013(H7N9)-CDC-LV7A (abbreviated as CDC-LV7A), based on the Russian MDV, A/Leningrad/134/17/57 (H2N2), was generated by classical reassortment in eggs and retained MDV temperature-sensitive and cold-adapted phenotypes. CDC-LV7A had two amino acid substitutions N123D and N149D (H7 numbering) in HA and one substitution T10I in NA. To evaluate the role of these mutations on the replication capacity of the reassortants in eggs, the recombinant viruses A(H7N9)RG-LV1 and A(H7N9)RG-LV2 were generated by reverse genetics. These changes did not alter virus antigenicity as ferret antiserum to CDC-LV7A vaccine candidate inhibited hemagglutination by homologous A(H7N9) virus efficiently. Safety studies in ferrets confirmed that CDC-LV7A was attenuated compared to wild-type A/Anhui/1/2013. In addition, the genetic stability of this vaccine candidate was examined in eggs and ferrets by monitoring sequence changes acquired during virus replication in the two host models. No changes in the viral genome were detected after five passages in eggs. However, after ten passages additional mutations were detected in the HA gene. The vaccine candidate was shown to be stable in the ferret model; post-vaccination sequence data analysis showed no changes in viruses collected in nasal washes present at day 5 or day 7. Conclusions/Significance Our data indicate that the A/Anhui/1/2013(H7N9)-CDC-LV7A reassortant virus is a safe and

  10. The use of live attenuated influenza vaccine (LAIV) in healthcare personnel (HCP): guidance from the Society for Healthcare Epidemiology of America (SHEA).

    PubMed

    Talbot, Thomas R; Babcock, Hilary; Cotton, Deborah; Maragakis, Lisa L; Poland, Gregory A; Septimus, Edward J; Tapper, Michael L; Weber, David J

    2012-10-01

    Because of the live viral backbone of live attenuated influenza vaccine (LAIV), questions have arisen regarding infection control precautions and restrictions surrounding its use in healthcare personnel (HCP). This document provides guidance from the Society for Healthcare Epidemiology of America regarding use of LAIV in HCP and the infection control precautions that are recommended with its use in this population.

  11. 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.

  12. Rational design of genetically stable, live-attenuated poliovirus vaccines of all three serotypes: relevance to poliomyelitis eradication.

    PubMed

    Macadam, Andrew J; Ferguson, Geraldine; Stone, David M; Meredith, Janet; Knowlson, Sarah; Auda, Ghazi; Almond, Jeffrey W; Minor, Philip D

    2006-09-01

    The global eradication of poliomyelitis caused by wild-type virus is likely to be completed within the next few years, despite immense logistic and political difficulties, and may ultimately be followed by the cessation of vaccination. However, the existing live-attenuated vaccines have the potential to revert to virulence, causing occasional disease, and viruses can be shed by immunocompromised individuals for prolonged periods of time. Moreover, several outbreaks of poliomyelitis have been shown to be caused by viruses derived from the Sabin vaccine strains. The appearance of such strains depends on the prevailing circumstances but poses a severe obstacle to strategies for stopping vaccination. Vaccine strains that are incapable of reversion at a measurable rate would provide a possible solution. Here, we describe the constructions of strains of type 3 poliovirus that are stabilized by the introduction of four mutations in the 5' noncoding region compared to the present vaccine. The strains are genetically and phenotypically stable under conditions where the present vaccine loses the attenuating mutation in the 5' noncoding region completely. Type 1 and type 2 strains in which the entire 5' noncoding regions of Sabin 1 and Sabin 2 were replaced exactly with that of one of the type 3 strains were also constructed. The genetic stability of 5' noncoding regions of these viruses matched that of the type 3 strains, but significant phenotypic reversion occurred, illustrating the potential limitations of a rational approach to the genetic stabilization of live RNA virus vaccines.

  13. Live Attenuated Francisella novicida Vaccine Protects against Francisella tularensis Pulmonary Challenge in Rats and Non-human Primates

    PubMed Central

    Chu, Ping; Cunningham, Aimee L.; Yu, Jieh-Juen; Nguyen, Jesse Q.; Barker, Jeffrey R.; Lyons, C. Rick; Wilder, Julie; Valderas, Michelle; Sherwood, Robert L.; Arulanandam, Bernard P.; Klose, Karl E.

    2014-01-01

    Francisella tularensis causes the disease tularemia. Human pulmonary exposure to the most virulent form, F. tularensis subsp. tularensis (Ftt), leads to high morbidity and mortality, resulting in this bacterium being classified as a potential biothreat agent. However, a closely-related species, F. novicida, is avirulent in healthy humans. No tularemia vaccine is currently approved for human use. We demonstrate that a single dose vaccine of a live attenuated F. novicida strain (Fn iglD) protects against subsequent pulmonary challenge with Ftt using two different animal models, Fischer 344 rats and cynomolgus macaques (NHP). The Fn iglD vaccine showed protective efficacy in rats, as did a Ftt iglD vaccine, suggesting no disadvantage to utilizing the low human virulent Francisella species to induce protective immunity. Comparison of specific antibody profiles in vaccinated rat and NHP sera by proteome array identified a core set of immunodominant antigens in vaccinated animals. This is the first report of a defined live attenuated vaccine that demonstrates efficacy against pulmonary tularemia in a NHP, and indicates that the low human virulence F. novicida functions as an effective tularemia vaccine platform. PMID:25340543

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

    SciTech Connect

    Gabriel, Benjamin; Fiebig, Uwe; Hohn, Oliver; Plesker, Roland; Coulibaly, Cheick; Cichutek, Klaus; Mühlebach, Michael D.; Bannert, Norbert; Kurth, Reinhard; Norley, Stephen

    2016-02-15

    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 subsequent 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.

  15. Cross-clade protective immune responses of NS1-truncated live attenuated H5N1 avian influenza vaccines.

    PubMed

    Shi, Shaohua; Chen, Sujuan; Han, Weizhou; Wu, Bai; Zhang, Xiaojian; Tang, Ying; Wang, Xiao; Zhu, Yinbiao; Peng, Daxin; Liu, Xiufan

    2016-01-12

    H5N1 highly pathogenic avian influenza (HPAI) has raised global concern for causing huge economic losses in poultry industry, and an effective vaccine against HPAI is highly desirable. Live attenuated influenza vaccine with trunctated NS1 protein as a potential strategy will be extremely useful for improving immune efficacy. A series of H5N1 avian influenza virus reassortants harboring amino-terminal 48, 70, 73, and 99 aa in NS1 proteins, along with a modified low pathogenic HA protein was generated, and named as S-HALo/NS48, S-HALo/NS70, S-HALo/NS73, and S-HALo/NS99, respectively. In addition, their biological and immunological characteristics were further analyzed. The viruses S-HALo/NS70, S-HALo/NS73, and S-HALo/NS99, but not S-HALo/NS48, had a comparable growth property with the full-length NS1 virus, S-HALo/NSFu. Mice and chickens studies demonstrated that the viruses with truncated NS1 protein were further attenuated when compared to the virus S-HALo/NSFu. Vaccination with the virus S-HALo/NS73 in chickens induced significant cross-protection against homologous clade 2.3.4 H5 virus and heterologous clade 7.2, 2.3.2.1, and 2.3.4.4 H5 viruses. A 70-aa amino-terminal fragment of NS1 protein may be long enough for viral replication. The recombinant virus S-HALo/NS73 is a broad-spectrum live attenuated H5N1 avian influenza vaccine candidate in chickens. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. A live attenuated Bordetella pertussis candidate vaccine does not cause disseminating infection in gamma interferon receptor knockout mice.

    PubMed

    Skerry, Ciaran M; Cassidy, Joseph P; English, Karen; Feunou-Feunou, Pascal; Locht, Camille; Mahon, Bernard P

    2009-09-01

    Bordetella pertussis is the cause of whooping cough and responsible for 300,000 infant deaths per annum. Current vaccines require 6 months to confer optimal immunity on infants, the population at highest risk. Recently, an attenuated strain of B. pertussis (BPZE1) has been developed to be used as a low-cost, live, intranasal, single-dose vaccine for newborns. Preclinical proof of concept has been established; however, it is necessary to evaluate the safety of BPZE1, especially in immunodeficient models, prior to human clinical trials. Here, the preclinical safety of BPZE1 was examined in well-characterized murine models. Immunocompetent and gamma interferon (IFN-gamma) receptor knockout mice were challenged by aerosol with either virulent B. pertussis or BPZE1. The two strains colonized the lung at equal levels, but inflammation was associated with carriage of only virulent bacteria. Virulent bacteria disseminated to the liver of IFN-gamma receptor-deficient mice, resulting in atypical pathology. In contrast, attenuated BPZE1 did not disseminate in either immunocompetent or immunodeficient mice and did not induce atypical pathology. In neonatal challenge models, virulent B. pertussis infection resulted in significant mortality of both immunodeficient and immunocompetent mice, whereas no mortality was observed for any neonatal mice challenged with BPZE1. BPZE1 was shown to elicit strong IFN-gamma responses in mice, equivalent to those elicited by the virulent streptomycin-resistant B. pertussis Tohama I derivative BPSM, also inducing immunoglobulin G2a, a process requiring TH1 cytokines in mice. These data indicate that a live attenuated whooping cough vaccine candidate shows no signs of disseminating infection in preclinical models but rather evokes an immunological profile associated with optimal protection against disease.

  17. 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...

  18. Heterogeneity of Groundwater Nitrogen Attenuation Elucidated by Combining Isotope Fluxes and Functional Gene Markers

    NASA Astrophysics Data System (ADS)

    Wells, N. S.; Knoeller, K.; Kappelmeyer, U.

    2014-12-01

    Reactive nitrogen (N) is a ubiquitous freshwater pollutant, but generating accurate catchment-scale measurements of its fate and transport remains elusive. Advances N isotope systematics and the detection of microbial populations provide potentially promising avenues for developing sensitive indicators of in-situ transformations. However, the use of isotopes in terrestrial systems is currently limited by difficulty in distinguishing variations in fractionation from source mixing, while relationships between microbial indicators and fluxes are inconsistent. Hypothesizing that these issues could be overcome by linking the two approaches across hydrologic flux data, we set out to develop an analytical framework for identifying where and how N is attenuated in cryptic groundwater systems. Variations in the isotopic composition of ammonium, nitrite, and nitrate and the genes associated with their oxidation/ reduction were measured in 50 wells distributed longitudinally across an ammonium plume (from 130 to 0 mg N l-1) three times over 12 months. Net isoflux calculations revealed the seasonal development of N attenuation hotspots along the plume fringe. The broad correlation of these hotspots with redox transition zones and ammonia oxidizing and nitrite reducing gene abundances corroborated the traditional view of N removal via coupled nitrification-denitrification. It was thus surprising that the relationships between the dual isotope ratios of nitrate and nitrite were not consistent with denitrification in two hotspots. Combining indicators, we found strong empirical proof that attenuation in these zones was driven by seasonal anaerobic ammonium oxidation: both zones had high relative and absolute abundance of nitrite reducing and anaerobic ammonium oxidizing genes alongside high δ18Onitriteand nitrite concentrations. The development and handling of this unique data set provides a practical template for up-scaling process level information to the whole aquifer by

  19. [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

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

    SciTech Connect

    Yamshchikov, Vladimir Manuvakhova, Marina; Rodriguez, Efrain

    2016-01-15

    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 analyzed 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.

  1. 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.

  2. Dose Reduction in Fluoroscopic Interventions Using a Combination of a Region of Interest (ROI) X-Ray Attenuator and Spatially-Different, Temporally-Variable Temporal Filtering.

    PubMed

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

    2013-03-06

    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.

  3. Dose Reduction in Fluoroscopic Interventions Using a Combination of a Region of Interest (ROI) X-Ray Attenuator and Spatially-Different, Temporally-Variable Temporal Filtering

    PubMed Central

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

    2013-01-01

    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. PMID:24817800

  4. Safety and immunogenicity of a live attenuated mumps vaccine: a phase I clinical trial.

    PubMed

    Liang, Yan; Ma, Jingchen; Li, Changgui; Chen, Yuguo; Liu, Longding; Liao, Yun; Zhang, Ying; Jiang, Li; Wang, Xuan-Yi; Che, Yanchun; Deng, Wei; Li, Hong; Cui, Xiaoyu; Ma, Na; Ding, Dong; Xie, Zhongping; Cui, Pingfang; Ji, Qiuyan; Wang, JingJing; Zhao, Yuliang; Wang, Junzhi; Li, Qihan

    2014-01-01

    Mumps, a communicable, acute and previously well-controlled disease, has had recent and occasional resurgences in some areas. A randomized, double-blind, controlled and multistep phase I study of an F-genotype attenuated mumps vaccine produced in human diploid cells was conducted. A total of 300 subjects were enrolled and divided into 4 age groups: 16-60 years, 5-16 years, 2-5 years and 8-24 months. The groups were immunized with one injection per subject. Three different doses of the F-genotype attenuated mumps vaccine, A (3.5 ± 0.25 logCCID50), B (4.25 ± 0.25 logCCID50) and C (5.0 ± 0.25 logCCID50), as well as a placebo control and a positive control of a licensed A-genotype vaccine (S79 strain) were used. The safety and immunogenicity of this vaccine were compared with those of the controls. The safety evaluation suggested that mild adverse reactions were observed in all groups. No serious adverse event (SAE) was reported throughout the trial. The immunogenicity test showed a similar seroconversion rate of the neutralizing and ELISA antibody in the 2- to 5-year-old and 8- to 24-month-old groups compared with the seroconversion rate in the positive control. The GMT of the neutralizing anti-F-genotype virus antibodies in the vaccine groups was slightly higher than that in the positive control group. The F-genotype attenuated mumps vaccine evaluated in this clinical trial was demonstrated to be safe and have effective immunogenicity vs. control.

  5. Construction of a live-attenuated HIV-1 vaccine through genetic code expansion.

    PubMed

    Wang, Nanxi; Li, Yue; Niu, Wei; Sun, Ming; Cerny, Ronald; Li, Qingsheng; Guo, Jiantao

    2014-05-05

    A safe and effective vaccine against human immunodeficiency virus type 1 (HIV-1) is urgently needed to combat the worldwide AIDS pandemic, but still remains elusive. The fact that uncontrolled replication of an attenuated vaccine can lead to regaining of its virulence creates safety concerns precluding many vaccines from clinical application. We introduce a novel approach to control HIV-1 replication, which entails the manipulation of essential HIV-1 protein biosynthesis through unnatural amino acid (UAA*)-mediated suppression of genome-encoded blank codon. We successfully demonstrate that HIV-1 replication can be precisely turned on and off in vitro.

  6. [Attenuation of a strain of rinderpest virus: potential homologous live vaccine].

    PubMed

    Diallo, A; Taylor, W P; Lefèvre, P C; Provost, A

    1989-01-01

    Peste des petits ruminants (PPR) is a highly contagious disease of small ruminants frequently associated with severe mortality in these hosts. In countries where it occurs, PPR represents an important constraint to the improved productivity of sheep and goats. Until now the only way to combat this plague has been the use of heterologous rinderpest vaccine; all attempts to develop a homologous vaccine have ended in failure. The present communication describes the attenuation of the Nigerian strain PPRV Nig 75/1 by serial passage in Vero cells. The avirulent virus obtained has the same characteristics as Plowright and Ferris' rinderpest vaccine. The virus is advanced as a potential homologous vaccine against PPR.

  7. Experimental study of a further attenuated live measles vaccine of the Sugiyama strain in Iran

    PubMed Central

    Mirchamsy, H.; Shafyi, A.; Rafyi, M. R.; Bahrami, S.; Nazari, P.; Fatemie, S.

    1974-01-01

    After encouraging results of the mass vaccination programme in Iran, in which 5 million children in rural areas were vaccinated with the Japanese Sugiyama strain at its 82nd passage in baby calf kidney, and a progressive decrease in the incidence of measles as well as a reduction of excessive infant mortality, a further attenuated vaccine, produced with the same strain, cloned in Japan, was compared in a field trial with the parent vaccine. The new strain caused fewer reactions than the original strain. Seroconversion with a geometric mean antibody titre of 6·1 was observed in 95% of susceptible children. PMID:4522721

  8. 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

  9. In Vivo Characterization of the Murine Intranasal Model for Assessing the Immunogenicity of Attenuated Salmonella enterica Serovar Typhi Strains as Live Mucosal Vaccines and as Live Vectors

    PubMed Central

    Pickett, Thames E.; Pasetti, Marcela F.; Galen, James E.; Sztein, Marcelo B.; Levine, Myron M.

    2000-01-01

    Attenuated Salmonella enterica serovar Typhi live vector vaccine strains are highly immunogenic in mice following intranasal but not orogastric inoculation. To elucidate the relationship between organs within which vaccine organisms are found and the induction of specific serum immunoglobulin G (IgG) antibodies, we examined the in vivo distribution of serovar Typhi vaccine strain CVD 908-htrA following intranasal administration. Vaccine organisms were cultured from the nasal lymphoid tissue (NALT), lungs, and Peyer's patches 2 min after intranasal inoculation. Vaccine organisms persisted longer in NALT than in other organs. By decreasing the volume of intranasal inoculum containing 109 CFU (from a single 30- or 10-μl dose to four 2.5-μl doses given over the course of 1 h), we were able to significantly reduce the number of vaccine organisms isolated from the lungs (P < 0.05) without reducing the number of vaccine organisms in NALT. Reducing the number of vaccine organisms in the lungs resulted in a significant decrease in the serum tetanus antitoxin response elicited by CVD 908-htrA expressing tetanus toxin fragment C under the control of the redox-responsive nir15 promoter. In contrast, a similar construct expressing tetanus toxin fragment C under control of the constitutive lpp promoter stimulated a strong serum IgG tetanus antitoxin response with both inoculation regimens. The data suggest that following intranasal inoculation, NALT is a sufficient inductive site for elicitation of an immune response against both the live vector and heterologous antigen and, as occurs following oral inoculation of humans, attenuated serovar Typhi vaccine organisms elicit serum IgG responses. PMID:10603389

  10. A Live Attenuated Vaccine for Lassa Fever Made by Reassortment of Lassa and Mopeia Viruses

    PubMed Central

    Lukashevich, Igor S.; Patterson, Jean; Carrion, Ricardo; Moshkoff, Dmitry; Ticer, Anysha; Zapata, Juan; Brasky, Kathleen; Geiger, Robert; Hubbard, Gene B.; Bryant, Joseph; Salvato, Maria S.

    2005-01-01

    Lassa virus (LASV) and Mopeia virus (MOPV) are closely related Old World arenaviruses that can exchange genomic segments (reassort) during coinfection. Clone ML29, selected from a library of MOPV/LASV (MOP/LAS) reassortants, encodes the major antigens (nucleocapsid and glycoprotein) of LASV and the RNA polymerase and zinc-binding protein of MOPV. Replication of ML29 was attenuated in guinea pigs and nonhuman primates. In murine adoptive-transfer experiments, as little as 150 PFU of ML29 induced protective cell-mediated immunity. All strain 13 guinea pigs vaccinated with clone ML29 survived at least 70 days after LASV challenge without either disease signs or histological lesions. Rhesus macaques inoculated with clone ML29 developed primary virus-specific T cells capable of secreting gamma interferon in response to homologous MOP/LAS and heterologous MOPV and lymphocytic choriomeningitis virus. Detailed examination of two rhesus macaques infected with this MOPV/LAS reassortant revealed no histological lesions or disease signs. Thus, ML29 is a promising attenuated vaccine candidate for Lassa fever. PMID:16254329

  11. Living Systematic Reviews:2. Combining Human and Machine Effort.

    PubMed

    Thomas, James; Noel-Storr, Anna; Marshall, Iain; Wallace, Byron; McDonald, Steven; Mavergames, Chris; Glasziou, Paul; Shemilt, Ian; Synnot, Anneliese; Turner, Tari; Elliott, Julian

    2017-09-01

    New approaches to evidence synthesis, which utilise human effort and machine automation in mutually reinforcing ways, can enhance the feasibility and sustainability of living systematic reviews. Human effort is a scarce and valuable resource, required when automation is impossible or undesirable, and includes contributions from online communities ('crowds') as well as more conventional contributions from review authors and information specialists. Automation can assist with some systematic review tasks, including searching, eligibility assessment, identification and retrieval of full text reports, extraction of data, and risk of bias assessment. Workflows can be developed in which human effort and machine automation can each enable the other to operate in more effective and efficient ways, offering substantial enhancement to the productivity of systematic reviews. This paper describes and discusses the potential - and limitations - of new ways of undertaking specific tasks in living systematic reviews, identifying areas where these human / machine 'technologies' are already in use, and where further research and development is needed. While the context is living systematic reviews, many of these enabling technologies apply equally to standard approaches to systematic reviewing. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  12. Development of a live attenuated antigenic marker classical swine fever vaccine

    USDA-ARS?s Scientific Manuscript database

    Classical Swine Fever, caused by Classical Swine Fever Virus (CSFV), is a highly contagious disease affecting swine worldwide. The two main strategies for disease control are prophylactic vaccination and non-vaccination “stamping out” policies. In a vaccination-to-live strategy, marker vaccines coul...

  13. A live attenuated equine H3N8 influenza vaccine is highly immunogenic and efficacious in mice and ferrets.

    PubMed

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

    2015-02-01

    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. 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

  14. 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

  15. 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

  16. Engineering and Preclinical Evaluation of Attenuated Nontyphoidal Salmonella Strains Serving as Live Oral Vaccines and as Reagent Strains▿†

    PubMed Central

    Tennant, Sharon M.; Wang, Jin-Yuan; Galen, James E.; Simon, Raphael; Pasetti, Marcela F.; Gat, Orit; Levine, Myron M.

    2011-01-01

    While nontyphoidal Salmonella (NTS) has long been recognized as a cause of self-limited gastroenteritis, it is becoming increasingly evident that multiple-antibiotic-resistant strains are also emerging as important causes of invasive bacteremia and focal infections, resulting in hospitalizations and deaths. We have constructed attenuated Salmonella enterica serovar Typhimurium and Salmonella enterica serovar Enteritidis strains that can serve as live oral vaccines and as “reagent strains” for subunit vaccine production in a safe and economical manner. Prototype attenuated vaccine strains CVD 1921 and CVD 1941, derived from the invasive wild-type strains S. Typhimurium I77 and S. Enteritidis R11, respectively, were constructed by deleting guaBA, encoding guanine biosynthesis, and clpP, encoding a master protease regulator. The clpP mutation resulted in a hyperflagellation phenotype. An additional deletion in fliD yielded reagent strains CVD 1923 and CVD 1943, respectively, which export flagellin monomers. Oral 50% lethal dose (LD50) analyses showed that the NTS vaccine strains were all highly attenuated in mice. Oral immunization with CVD 1921 or CVD 1923 protected mice against lethal challenge with wild-type S. Typhimurium I77. Immunization with CVD 1941 but not CVD 1943 protected mice against lethal infection with S. Enteritidis R11. Immune responses induced by these strains included high levels of serum IgG anti-lipopolysaccharide (LPS) and anti-flagellum antibodies, with titers increasing progressively during the immunization schedule. Since S. Typhimurium and S. Enteritidis are the most common NTS serovars associated with invasive disease, these findings can pave the way for development of a highly effective, broad-spectrum vaccine against invasive NTS. PMID:21807911

  17. Live Attenuated Mutants of Francisella tularensis Protect Rabbits against Aerosol Challenge with a Virulent Type A Strain

    PubMed Central

    Smith, Le'Kneitah P.; Cole, Kelly Stefano; Santiago, Araceli E.; Mann, Barbara J.; Barry, Eileen M.

    2014-01-01

    Francisella tularensis, a Gram-negative bacterium, is the causative agent of tularemia. No licensed vaccine is currently available for protection against tularemia, although an attenuated strain, dubbed the live vaccine strain (LVS), is given to at-risk laboratory personnel as an investigational new drug (IND). In an effort to develop a vaccine that offers better protection, recombinant attenuated derivatives of a virulent type A strain, SCHU S4, were evaluated in New Zealand White (NZW) rabbits. Rabbits vaccinated via scarification with the three attenuated derivatives (SCHU S4 ΔguaBA, ΔaroD, and ΔfipB strains) or with LVS developed a mild fever, but no weight loss was detected. Twenty-one days after vaccination, all vaccinated rabbits were seropositive for IgG to F. tularensis lipopolysaccharide (LPS). Thirty days after vaccination, all rabbits were challenged with aerosolized SCHU S4 at doses ranging from 50 to 500 50% lethal doses (LD50). All rabbits developed fevers and weight loss after challenge, but the severity was greater for mock-vaccinated rabbits. The ΔguaBA and ΔaroD SCHU S4 derivatives provided partial protection against death (27 to 36%) and a prolonged time to death compared to results for the mock-vaccinated group. In contrast, LVS and the ΔfipB strain both prolonged the time to death, but there were no survivors from the challenge. This is the first demonstration of vaccine efficacy against aerosol challenge with virulent type A F. tularensis in a species other than a rodent since the original work with LVS in the 1960s. The ΔguaBA and ΔaroD SCHU S4 derivatives warrant further evaluation and consideration as potential vaccines for tularemia and for identification of immunological correlates of protection. PMID:24614653

  18. WHO working group on the quality, safety and efficacy of japanese encephalitis vaccines (live attenuated) for human use, Bangkok, Thailand, 21-23 February 2012.

    PubMed

    Trent, Dennis W; Minor, Philip; Jivapaisarnpong, Teeranart; Shin, Jinho

    2013-11-01

    Japanese encephalitis (JE) is one of the most important viral encephalitides in Asia. Two live-attenuated vaccines have been developed and licensed for use in countries in the region. Given the advancement of immunization of humans with increasing use of live-attenuated vaccines to prevent JE, there is increased interest to define quality standards for their manufacture, testing, nonclinical studies, and clinical studies to assess their efficacy and safety in humans. To this end, WHO convened a meeting with a group of international experts in February 2012 to develop guidelines for evaluating the quality, safety and efficacy of live-attenuated JE virus vaccines for prevention of human disease. This report summarizes collective views of the participants on scientific and technical issues that need to be considered in the guidelines.

  19. 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.

  20. Safety and immunogenicity of a live-attenuated auxotrophic candidate vaccine against the intracellular pathogen Rhodococcus equi.

    PubMed

    Lopez, A M; Townsend, H G G; Allen, A L; Hondalus, M K

    2008-02-13

    Rhodococcus equi causes serious pneumonia in neonatal foals and is an opportunistic pathogen of people with compromised cellular immunity. No effective vaccine against R. equi disease in foals is available. We tested the safety and immunogenicity of a live, fully attenuated riboflavin auxotrophic candidate vaccine strain of R. equi (R. equi rib-). We demonstrated that R. equi rib- is immunogenic and capable of inducing IFN-gamma responses in immunocompetent BALB/c mice, yet it is safe even in an immunocompromised SCID mouse infection model. Moreover, it protects immunocompetent mice against virulent R. equi challenge. In foals, R. equi rib- was likewise safe and stimulated serum R. equi-specific immune responses. A preliminary immunization strategy did not afford protection against virulent R. equi challenge and therefore, optimization of the vaccine formulation and or vaccination protocol will be necessary.

  1. Development of a human live attenuated West Nile infectious DNA vaccine: conceptual design of the vaccine candidate.

    PubMed

    Yamshchikov, Vladimir

    2015-10-01

    West Nile virus has become an important epidemiological problem attracting significant attention of health authorities, mass media, and the public. Although there are promising advancements toward addressing the vaccine need, the perspectives of the commercial availability of the vaccine remain uncertain. To a large extent this is due to lack of a sustained interest for further commercial development of the vaccines already undergoing the preclinical and clinical development, and a predicted insignificant cost effectiveness of mass vaccination. There is a need for a safe, efficacious and cost effective vaccine, which can improve the feasibility of a targeted vaccination program. In the present report, we summarize the background, the rationale, and the choice of the development pathway that we selected for the design of a live attenuated human West Nile vaccine in a novel infectious DNA format.

  2. Evaluation of eight live attenuated vaccine candidates for protection against challenge with virulent Mycobacterium avium subspecies paratuberculosis in mice.

    PubMed

    Bannantine, John P; Everman, Jamie L; Rose, Sasha J; Babrak, Lmar; Katani, Robab; Barletta, Raúl G; Talaat, Adel M; Gröhn, Yrjö T; Chang, Yung-Fu; Kapur, Vivek; Bermudez, Luiz E

    2014-01-01

    Johne's disease is caused by Mycobacterium avium subsp. paratuberculosis (MAP), which results in serious economic losses worldwide in farmed livestock such as cattle, sheep, and goats. To control this disease, an effective vaccine with minimal adverse effects is needed. In order to identify a live vaccine for Johne's disease, we evaluated eight attenuated mutant strains of MAP using a C57BL/6 mouse model. The persistence of the vaccine candidates was measured at 6, 12, and 18 weeks post vaccination. Only strains 320, 321, and 329 colonized both the liver and spleens up until the 12-week time point. The remaining five mutants showed no survival in those tissues, indicating their complete attenuation in the mouse model. The candidate vaccine strains demonstrated different levels of protection based on colonization of the challenge strain in liver and spleen tissues at 12 and 18 weeks post vaccination. Based on total MAP burden in both tissues at both time points, strain 315 (MAP1566::Tn5370) was the most protective whereas strain 318 (intergenic Tn5367 insertion between MAP0282c and MAP0283c) had the most colonization. Mice vaccinated with an undiluted commercial vaccine preparation displayed the highest bacterial burden as well as enlarged spleens indicative of a strong infection. Selected vaccine strains that showed promise in the mouse model were moved forward into a goat challenge model. The results suggest that the mouse trial, as conducted, may have a relatively poor predictive value for protection in a ruminant host such as goats.

  3. 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.

  4. Generation of a safe and effective live viral vaccine by virus self-attenuation using species-specific artificial microRNA.

    PubMed

    Li, Junwei; Arévalo, Maria T; Diaz-Arévalo, Diana; Chen, Yanping; Choi, Jang-Gi; Zeng, Mingtao

    2015-06-10

    Vaccination with live attenuated vaccines (LAVs) is an effective way for prevention of infectious disease. While several methods are employed to create them, efficacy and safety are still a challenge. In this study, we evaluated the feasibility of creating a self-attenuated RNA virus expressing a functional species-specific artificial microRNA. Using influenza virus as a model, we produced an attenuated virus carrying a mammalian-specific miR-93 expression cassette that expresses a viral nucleoprotein (NP)-specific artificial microRNA from an insertion site within the non-structural (NS) gene segment. The resulting engineered live-attenuated influenza virus, PR8-amiR-93NP, produced mature and functional artificial microRNA against NP in mammalian cells, but not in avian cells. Furthermore, PR8-amiR-93NP was attenuated by 10(4) fold in mice compared with its wild-type counterpart. Importantly, intranasal immunization with PR8-amiR-93NP conferred cross-protective immunity against heterologous influenza virus strains. In short, this method provides a safe and effective platform for creation of live attenuated RNA viral vaccines.

  5. Live-attenuated tetravalent dengue vaccines: The needs and challenges of post-licensure evaluation of vaccine safety and effectiveness.

    PubMed

    Wichmann, Ole; Vannice, Kirsten; Asturias, Edwin J; de Albuquerque Luna, Expedito José; Longini, Ira; Lopez, Anna Lena; Smith, Peter G; Tissera, Hasitha; Yoon, In-Kyu; Hombach, Joachim

    2017-10-09

    Since December 2015, the first dengue vaccine has been licensed in several Asian and Latin American countries for protection against disease from all four dengue virus serotypes. While the vaccine demonstrated an overall good safety and efficacy profile in clinical trials, some key research questions remain which make risk-benefit-assessment for some populations difficult. As for any new vaccine, several questions, such as very rare adverse events following immunization, duration of vaccine-induced protection and effectiveness when used in public health programs, will be addressed by post-licensure studies and by data from national surveillance systems after the vaccine has been introduced. However, the complexity of dengue epidemiology, pathogenesis and population immunity, as well as some characteristics of the currently licensed vaccine, and potentially also future, live-attenuated dengue vaccines, poses a challenge for evaluation through existing monitoring systems, especially in low and middle-income countries. Most notable are the different efficacies of the currently licensed vaccine by dengue serostatus at time of first vaccination and by dengue virus serotype, as well as the increased risk of dengue hospitalization among young vaccinated children observed three years after the start of vaccination in one of the trials. Currently, it is unknown if the last phenomenon is restricted to younger ages or could affect also seronegative individuals aged 9years and older, who are included in the group for whom the vaccine has been licensed. In this paper, we summarize scientific and methodological considerations for public health surveillance and targeted post-licensure studies to address some key research questions related to live-attenuated dengue vaccines. Countries intending to introduce a dengue vaccine should assess their capacities to monitor and evaluate the vaccine's effectiveness and safety and, where appropriate and possible, enhance their surveillance

  6. Systematic annotation and analysis of “virmugens” - virulence factors whose mutants can be used as live attenuated vaccines

    PubMed Central

    Racz, Rebecca; Chung, Monica; Xiang, Zuoshuang; He, Yongqun

    2012-01-01

    Live attenuated vaccines are usually generated by mutation of genes encoding virulence factors. “Virmugen” is coined here to represent a gene that encodes for a virulent factor of a pathogen and has been proven feasible in animal models to make a live attenuated vaccine by knocking out this gene. Not all virulence factors are virmugens. VirmugenDB is a web-based virmugen database (http://www.violinet.org/virmugendb). Currently, VirmugenDB includes 225 virmugens that have been verified to be valuable for vaccine development against 57 bacterial, viral, and protozoan pathogens. Bioinformatics analysis has revealed significant patterns in virmugens. For example, 10 Gram-negative and one Gram-positive bacterial aroA genes are virmugens. A sequence analysis has revealed at least 50% of identities in the protein sequences of the 10 Gram-negative bacterial aroA virmugens. As a pathogen case study, Brucella virmugens were analyzed. Out of 15 verified Brucella virmugens, six are related to carbohydrate or nucleotide transport and metabolism, and two involving cell membrane biogenesis. In addition, 54 virmugens from 24 viruses and 12 virmugens from 4 parasites are also stored in VirmugenDB. Virmugens tend to involve metabolism of nutrients (e.g., amino acids, carbohydrates, and nucleotides) and cell membrane formation. Host genes whose expressions were regulated by virmugen mutation vaccines or wild type virulent pathogens have also been annotated and systematically compared. The bioinformatics annotation and analysis of virmugens helps elucidate enriched virmugen profiles and the mechanisms of protective immunity, and further supports rational vaccine design. PMID:23219434

  7. The administration of intranasal live attenuated influenza vaccine induces changes in the nasal microbiota and nasal epithelium gene expression profiles.

    PubMed

    Tarabichi, Y; Li, K; Hu, S; Nguyen, C; Wang, X; Elashoff, D; Saira, K; Frank, Bryan; Bihan, Monika; Ghedin, E; Methé, Barbara A; Deng, Jane C

    2015-12-15

    Viral infections such as influenza have been shown to predispose hosts to increased colonization of the respiratory tract by pathogenic bacteria and secondary bacterial pneumonia. To examine how viral infections and host antiviral immune responses alter the upper respiratory microbiota, we analyzed nasal bacterial composition by 16S ribosomal RNA (rRNA) gene sequencing in healthy adults at baseline and at 1 to 2 weeks and 4 to 6 weeks following instillation of live attenuated influenza vaccine or intranasal sterile saline. A subset of these samples was submitted for microarray host gene expression profiling. We found that live attenuated influenza vaccination led to significant changes in microbial community structure, diversity, and core taxonomic membership as well as increases in the relative abundances of Staphylococcus and Bacteroides genera (both p < 0.05). Hypergeometric testing for the enrichment of gene ontology terms in the vaccinated group reflected a robust up-regulation of type I and type II interferon-stimulated genes in the vaccinated group relative to controls. Translational murine studies showed that poly I:C administration did in fact permit greater nasal Staphylococcus aureus persistence, a response absent in interferon alpha/beta receptor deficient mice. Collectively, our findings demonstrate that although the human nasal bacterial community is heterogeneous and typically individually robust, activation of a type I interferon (IFN)-mediated antiviral response may foster the disproportionate emergence of potentially pathogenic species such as S. aureus. This study was registered with Clinicaltrials.gov on 11/3/15, NCT02597647 .

  8. Sex differences in attenuation of nicotine reinstatement after individual and combined treatments of progesterone and varenicline

    PubMed Central

    Swalve, Natashia; Smethells, John R.; Carroll, Marilyn E.

    2016-01-01

    Tobacco use is the largest cause of preventable mortality in the western world. Even after treatment, relapse rates for tobacco are high, and more effective pharmacological treatments are needed. Progesterone (PRO), a female hormone used in contraceptives, reduces stimulant use but its effects on tobacco addiction are unknown. Varenicline (VAR) is a commonly used medication that reduces tobacco use. The present study examined sex differences in the individual vs. combined effects of PRO and VAR on reinstatement of nicotine-seeking behavior in a rat model of relapse. Adult female and male Wistar rats self-administered nicotine (NIC, 0.03 mg/kg/infusion) for 14 days followed by 21 days of extinction when no cues or drug were present. Rats were then divided into 4 treatment groups: control (VEH+SAL), PRO alone (PRO+SAL), VAR alone (VEH+VAR) and the combination (PRO+VAR). Reinstatement of nicotine-seeking behavior induced by priming injections of NIC or caffeine (CAF), presentation of cues (CUES), and the combination of drugs and cues (e.g. NIC+CUES, CAF+CUES) was tested after extinction. Male and female rats did not differ in self-administration of nicotine or extinction responding, and both showed elevated levels of responding to the CAF+CUES condition. However, males, but not females, reinstated active lever-pressing to the NIC+CUES condition, and that was attenuated by both VAR and VAR+PRO treatment. Thus, males were more sensitive to NIC+CUE-induced reinstatement than females, and VAR alone and VAR combined with PRO effectively reduced nicotine relapse. PMID:27091301

  9. Infection-enhancing lipopeptides do not improve intranasal immunization of cotton rats with a delta-G candidate live-attenuated human respiratory syncytial virus vaccine.

    PubMed

    Tien Nguyen, D; Boes, Jolande; van Amerongen, Geert; van Remmerden, Yvonne; Yüksel, Selma; Guichelaar, Teun; Osterhaus, Albert D M E; de Swart, Rik L

    2013-12-01

    Development of live-attenuated human respiratory syncytial virus (HRSV) vaccines has proven to be difficult. Several vaccine candidates were found to be over-attenuated and displayed limited immunogenicity. Recently, we identified three synthetic cationic lipopeptides that enhanced paramyxovirus infections in vitro. The infection enhancement proved to be mediated by enhanced virus binding to target cells. We hypothesized that these lipopeptides can be used as adjuvants to promote immune responses induced by live-attenuated paramyxovirus vaccines. This hypothesis was tested in a vaccination and challenge model in cotton rats, using a previously described recombinant live-attenuated candidate HRSV vaccine lacking the gene encoding the G glycoprotein (rHRSVΔG). Surprisingly, intranasal vaccination of cotton rats with rHRSVΔG formulated in infection-enhancing lipopeptides resulted in reduced virus loads in nasopharyngeal lavages, reduced seroconversion levels and reduced protection from wild-type HRSV challenge. In conclusion, we were unable to demonstrate the feasibility of lipopeptides as adjuvants for a candidate live-attenuated HRSV vaccine in the cotton rat model.

  10. Development of a Live Attenuated Bivalent Oral Vaccine Against Shigella sonnei Shigellosis and Typhoid Fever.

    PubMed

    Wu, Yun; Chakravarty, Sumana; Li, Minglin; Wai, Tint T; Hoffman, Stephen L; Sim, B Kim Lee

    2017-01-15

    Shigella sonnei and Salmonella Typhi cause significant morbidity and mortality. We exploited the safety record of the oral, attenuated S. Typhi vaccine (Ty21a) by using it as a vector to develop a bivalent oral vaccine to protect against S. sonnei shigellosis and typhoid fever. We recombineered the S. sonnei form I O-antigen gene cluster into the Ty21a chromosome to create Ty21a-Ss, which stably expresses S. sonnei form I O antigen. To enhance survivability in the acid environment of the stomach, we created an acid-resistant strain, Ty21a-AR-Ss, by inserting Shigella glutaminase-glutamate decarboxylase systems coexpressed with S. sonnei form I O-antigen gene. Mice immunized intranasally with Ty21a-AR-Ss produced antibodies against S. sonnei and S. Typhi, and survived lethal intranasal S. sonnei challenge. This paves the way for proposed good manufacturing practices manufacture and clinical trials intended to test the clinical effectiveness of Ty21a-AR-Ss in protecting against S. sonnei shigellosis and typhoid fever, as compared with the current Ty21a vaccine. © 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.

  11. 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

  12. Evaluation of two live attenuated cold-adapted H5N1 influenza virus vaccines in healthy adults

    PubMed Central

    Karron, Ruth A.; Talaat, Kawsar; Luke, Catherine; Callahan, Karen; Thumar, Bhagvanji; DiLorenzo, Susan; McAuliffe, Josephine; Schappell, Elizabeth; Suguitan, Amorsolo; Mills, Kimberly; Chen, Grace; Lamirande, Elaine; Coelingh, Kathleen; Jin, Hong; Murphy, Brian R.; Kemble, George; Subbarao, Kanta

    2016-01-01

    Background Development of live attenuated influenza vaccines (LAIV) against avian viruses with pandemic potential is an important public health strategy. Methods and Findings We performed open-label trials to evaluate the safety, infectivity, and immunogenicity of H5N1 VN 2004 AA ca and H5N1 HK 2003 AA ca. Each of these vaccines contains a modified H5 hemagglutinin and unmodified N1 neuraminidase from the respective wild-type (wt) parent virus and the six internal protein gene segments of the A/Ann Arbor/6/60 cold-adapted (ca) master donor virus. The H5N1 VN 2004 AA ca vaccine virus was evaluated at dosages of 106.7 TCID50 and 107.5 TCID50, and the H5N1 HK 2003 AA ca vaccine was evaluated at a dosage of 107.5 TCID50. Two doses were administered intranasally to healthy adults in isolation at 4 to 8 week intervals. Vaccine safety was assessed through daily examinations and infectivity was assessed by viral culture and by realtime reverse transcription-polymerase chain reaction testing of nasal wash (NW) specimens. Immunogenicity was assessed by measuring hemagglutination-inhibition (HI) antibodies, neutralizing antibodies, and IgG or IgA antibodies to recombinant (r)H5 VN 2004 hemagglutinin (HA) in serum or NW. Fifty-nine participants were enrolled: 21 received 106.7 TCID50 and 21 received 107.5 TCID50 of H5N1 VN 2004 AA ca and 17 received H5N1 HK 2003 AA ca. Shedding of vaccine virus was minimal, as were HI and neutralizing antibody responses. Fifty-two percent of recipients of 107.5 TCID50 of H5N1 VN 2004 AA ca developed a serum IgA response to rH5 VN 2004 HA. Conclusions The live attenuated H5N1 VN 2004 and HK 2003 AA ca vaccines bearing avian H5 HA antigens were very restricted in replication and were more attenuated than seasonal LAIV bearing human H1, H3 or B HA antigens. The H5N1 AA ca LAIV elicited serum ELISA antibody but not HI or neutralizing antibody responses in healthy adults. (ClinicalTrials.gov Identifiers: NCT00347672 and NCT00488046). PMID:19540952

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

    PubMed

    Yamshchikov, Vladimir; Manuvakhova, Marina; Rodriguez, Efrain

    2016-01-01

    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 analyzed effects of E138K and K279M 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. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. 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

  15. 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.

  16. Efficacy for a new live attenuated Salmonella Enteritidis vaccine candidate to reduce internal egg contamination.

    PubMed

    Nandre, R; Matsuda, K; Lee, J H

    2014-02-01

    To evaluate the efficacy of a novel attenuated Salmonella Enteritidis (△lon△cpxR) vaccine candidate (JOL919), chickens were immunized through oral and intramuscular routes to reduce egg contamination against S. Enteritidis challenge. Birds were orally immunized with JOL919 on the first day of life and were subsequently boosted in the 6th and 16th weeks through oral (group B) or intramuscular (group C) route, while control birds were unimmunized (group A). The chickens of all groups were challenged intravenously with the virulent S. Enteritidis strain in the 24th week. The immunized groups B and C showed significantly higher plasma IgG and intestinal secretory IgA levels as compared to those of the control group. The lymphocyte proliferation response and CD45(+) CD3(+) T-cell number in the peripheral blood of the groups B and C were significantly increased. In addition, the egg contamination rates were significantly lower in the group B (0%, 10.7% and 0%) and the group C (3.6%, 14.3% and 3.6%) as compared to the group A (28.6%, 42.8% and 28.6%) in the 1st, 2nd and 3rd weeks post-challenge. All animals in the groups B and C showed lower organ lesion scores in the liver and spleen and lower bacterial counts in the liver, spleen and ovary at the 3rd week post-challenge. These results indicate that this vaccine candidate can be an efficient tool for prevention of Salmonella infections by inducing protective humoral and cellular immune responses. In addition, this vaccine did not prevent egg contamination, but did appear to reduce incidence. Booster immunizations, especially via oral administration route, showed an efficient protection against internal egg contamination with S. Enteritidis.

  17. Carbamazepine alone and in combination with doxycycline attenuates isoproterenol-induced cardiac hypertrophy.

    PubMed

    Errami, Mounir; Tassa, Amina T; Galindo, Cristi L; Skinner, Michael A; Hill, Joseph A; Garner, Harold R

    2010-06-23

    β-adrenergic signaling is involved in the development of cardiac hypertrophy (CH), justifying the use of β-blockers as a therapy to minimize and postpone the consequences of this disease. Evidence suggests that adenylate cyclase, a downstream effector of the β-adrenergic pathway, might be a therapeutic target. We examined the effects of the anti-epileptic drug carbamazepine (CBZ), an inhibitor of adenylate cyclase. In a murine cardiac hypertrophy model, carbamazepine significantly attenuates isoproteronol (ISO)-induced cardiac hypertrophy. Carbamazepine also has an effect in transverse aortic banding induced cardiac hypertrophy (TAB) (P=0.07). When carbamazepine was given in combination with the antibiotic doxycycline (DOX), which inhibits matrix metalloproteinases (MMPs), therapeutic outcome measured by heart weight-to-body weight and heart weight-to-tibia length ratios was improved compared to either drug alone. Additionally, the combination therapy resulted in an increase in the survival rate over a 56-day period compared to that of untreated mice with cardiac hypertrophy or either drug used alone. Moreover, in support of a role for carbamaze -pine as a β-adrenergic antagonist via cAMP inhibition, a lower heart rate and a lower level of the activated phosphorylated form of the cAMP Response Element-Binding (CREB) were observed in heart extracts from mice treated with carbamazepine. Gene expression analysis identified 19 genes whose expression is significantly altered in treated animals and might be responsible for the added benefit provided by the combination therapy. These results suggest that carbamazepine acts as a β-adrenergic antagonist. Carbamazepine and doxycycline are approved by the US Food and Drug Administration (FDA) as drugs that might complement medications for cardiac hypertrophy or serve as an alternative therapy to traditional β-blockers. Furthermore, these agents reproducibly impact the expression of genes that may serve as additional

  18. Carbamazepine alone and in combination with doxycycline attenuates isoproterenol-induced cardiac hypertrophy

    PubMed Central

    Errami, Mounir; Tassa, Amina T; Galindo, Cristi L; Skinner, Michael A.; Hill, Joseph A; Garner, Harold R

    2010-01-01

    β-adrenergic signaling is involved in the development of cardiac hypertrophy (CH), justifying the use of β-blockers as a therapy to minimize and postpone the consequences of this disease. Evidence suggests that adenylate cyclase, a downstream effector of the β-adrenergic pathway, might be a therapeutic target. We examined the effects of the anti-epileptic drug carbamazepine (CBZ), an inhibitor of adenylate cyclase. In a murine cardiac hypertrophy model, carbamazepine significantly attenuates isoproteronol (ISO)-induced cardiac hypertrophy. Carbamazepine also has an effect in transverse aortic banding induced cardiac hypertrophy (TAB) (P=0.07). When carbamazepine was given in combination with the antibiotic doxycycline (DOX), which inhibits matrix metalloproteinases (MMPs), therapeutic outcome measured by heart weight-to-body weight and heart weight-to-tibia length ratios was improved compared to either drug alone. Additionally, the combination therapy resulted in an increase in the survival rate over a 56-day period compared to that of untreated mice with cardiac hypertrophy or either drug used alone. Moreover, in support of a role for carbamaze -pine as a β-adrenergic antagonist via cAMP inhibition, a lower heart rate and a lower level of the activated phosphorylated form of the cAMP Response Element-Binding (CREB) were observed in heart extracts from mice treated with carbamazepine. Gene expression analysis identified 19 genes whose expression is significantly altered in treated animals and might be responsible for the added benefit provided by the combination therapy. These results suggest that carbamazepine acts as a β-adrenergic antagonist. Carbamazepine and doxycycline are approved by the US Food and Drug Administration (FDA) as drugs that might complement medications for cardiac hypertrophy or serve as an alternative therapy to traditional β-blockers. Furthermore, these agents reproducibly impact the expression of genes that may serve as additional

  19. Attenuation Correction for MR Coils in Combined PET/MR Imaging: A Review

    PubMed Central

    Eldib, Mootaz; Bini, Jason; Faul, David D.; Oesingmann, Niels; Tsoumpas, Charalampos; Fayad, Zahi A.

    2015-01-01

    Synopsis With the introduction of clinical PET/MR systems, novel attenuation correction methods are needed, as there are no direct or indirect MR methods to measure the attenuation of the objects in the FOV. A unique challenge for PET/MR attenuation correction is that coils for MR data acquisition are located in the FOV of the PET detector and could induce significant quantitative errors. In this review, we summarize and evaluate current methods and techniques to correct for the attenuation of a variety of coils. PMID:26952728

  20. Long-term safety assessment of live attenuated tetravalent dengue vaccines: deliberations from a WHO technical consultation.

    PubMed

    Bentsi-Enchill, Adwoa D; Schmitz, Julia; Edelman, Robert; Durbin, Anna; Roehrig, John T; Smith, Peter G; Hombach, Joachim; Farrar, Jeremy

    2013-05-28

    Dengue is a rapidly growing public health threat with approximately 2.5 billion people estimated to be at risk. Several vaccine candidates are at various stages of pre-clinical and clinical development. Thus far, live dengue vaccine candidates have been administered to several thousands of volunteers and were well-tolerated, with minimal short-term safety effects reported in Phase I and Phase II clinical trials. Based on the natural history of dengue, a theoretical possibility of an increased risk of severe dengue as a consequence of vaccination has been hypothesized but not yet observed. In October 2011, the World Health Organization (WHO) convened a consultation of experts in dengue, vaccine regulation and vaccine safety to review the current scientific evidence regarding safety concerns associated with live attenuated dengue vaccines and, in particular, to consider methodological approaches for their long-term evaluation. In this paper we summarize the scientific background and methodological considerations relevant to the safety assessment of these vaccines. Careful planning and a coordinated approach to safety assessment are recommended to ensure adequate long-term evaluation of dengue vaccines that will support their introduction and continued use.

  1. Combined early fluid resuscitation and hydrogen inhalation attenuates lung and intestine injury

    PubMed Central

    Liu, Wei; Shan, Li-Ping; Dong, Xue-Song; Liu, Xiao-Wei; Ma, Tao; Liu, Zhi

    2013-01-01

    observed in lung tissues, all of which were attenuated by Group C and further alleviated by Group D pretreatment. Septic shock also elicited a significant increase in the levels of MDA, MPO and DAO (6.54 ± 0.68 kU/L vs 4.32 ± 0.33 kU/L) in intestinal tissues, all of which were further increased by Group C, but significantly reduced by Group D pretreatment. Increased Chiu scoring and overexpression of IL-6, IL-8 and TNF-α were observed in intestinal tissues, all of which were attenuated by Group C and further attenuated by Group D pretreatment. CONCLUSION: Combined early fluid resuscitation and hydrogen inhalation may protect the lung and intestine of the septic shock rats from the damage induced by oxidative stress and the inflammatory reaction. PMID:23382627

  2. Combined early fluid resuscitation and hydrogen inhalation attenuates lung and intestine injury.

    PubMed

    Liu, Wei; Shan, Li-Ping; Dong, Xue-Song; Liu, Xiao-Wei; Ma, Tao; Liu, Zhi

    2013-01-28

    , all of which were attenuated by Group C and further alleviated by Group D pretreatment. Septic shock also elicited a significant increase in the levels of MDA, MPO and DAO (6.54 ± 0.68 kU/L vs 4.32 ± 0.33 kU/L) in intestinal tissues, all of which were further increased by Group C, but significantly reduced by Group D pretreatment. Increased Chiu scoring and overexpression of IL-6, IL-8 and TNF-α were observed in intestinal tissues, all of which were attenuated by Group C and further attenuated by Group D pretreatment. Combined early fluid resuscitation and hydrogen inhalation may protect the lung and intestine of the septic shock rats from the damage induced by oxidative stress and the inflammatory reaction.

  3. Taxa of the Nasal Microbiome Are Associated with Influenza-Specific IgA Response to Live Attenuated Influenza Vaccine

    PubMed Central

    Salk, Hannah M.; Simon, Whitney L.; Lambert, Nathaniel D.; Kennedy, Richard B.; Grill, Diane E.; Kabat, Brian F.; Poland, Gregory A.

    2016-01-01

    Live attenuated influenza vaccine (LAIV) has demonstrated varying levels of efficacy against seasonal influenza; however, LAIV may be used as a tool to measure interactions between the human microbiome and a live, replicating virus. To increase our knowledge of this interaction, we measured changes to the nasal microbiome in subjects who received LAIV to determine if associations between influenza-specific IgA production and the nasal microbiome exist after immunization with a live virus vaccine. The anterior nares of 47 healthy subjects were swabbed pre- (Day 0) and post- (Days 7 and 28) LAIV administration, and nasal washes were conducted on Days 0 and 28. We performed next-generation sequencing on amplified 16s rRNA genes and measured mucosal influenza-specific IgA titers via enzyme-linked immunosorbent assay (ELISA). A significant increase in alpha diversity was identified (Observed, CHAO, and ACE) between Days 7 vs 0 (p-values = 0.017, 0.005, 0.005, respectively) and between Days 28 vs 0 (p-values = 0.054, 0.030, 0.050, respectively). Several significant associations between the presence of different microbial species, including Lactobacillus helveticus, Prevotella melaninogenica, Streptococcus infantis, Veillonella dispar, and Bacteroides ovatus, and influenza-specific H1 and H3 IgA antibody response were demonstrated. These data suggest that LAIV alters the nasal microbiome, allowing several less-abundant OTUs to establish a community niche. Additionally, specific alterations in the nasal microbiome are significantly associated with variations in influenza-specific IgA antibody production and could be clinically relevant. PMID:27643883

  4. Safety and Immunogenicity of a Tetravalent Live-Attenuated Dengue Vaccine in Flavivirus-Naive Infants

    PubMed Central

    Watanaveeradej, Veerachai; Simasathien, Sriluck; Nisalak, Ananda; Endy, Timothy P.; Jarman, Richard G.; Innis, Bruce L.; Thomas, Stephen J.; Gibbons, Robert V.; Hengprasert, Sumetha; Samakoses, Rudiwilai; Kerdpanich, Angkool; Vaughn, David W.; Putnak, J. Robert; Eckels, Kenneth H.; Barrera, Rafael De La; Mammen, Mammen P.

    2011-01-01

    A Phase I/II observer-blind, randomized, controlled trial evaluated the safety and immunogenicity of a dengue virus (DENV) vaccine candidate in healthy Thai infants (aged 12–15 months) without measurable pre-vaccination neutralizing antibodies to DENV and Japanese encephalitis virus. Fifty-one subjects received two doses of either DENV (N = 34; four received 1/10th dose) or control vaccine (N = 17; dose 1, live varicella; dose 2, Haemophilus influenzae type b). After each vaccine dose, adverse events (AEs) were solicited for 21 days, and non-serious AEs were solicited for 30 days; serious AEs (SAEs) were recorded throughout the study. Laboratory safety assessments were performed at 10 and 30 days; neutralizing antibodies were measured at 30 days. The DENV vaccine was well-tolerated without any related SAEs. After the second dose, 85.7% of full-dose DENV vaccinees developed at least trivalent and 53.6% developed tetravalent neutralizing antibodies ≥ 1:10 to DENV (control group = 0%). This vaccine candidate, therefore, warrants continued development in this age group (NCT00322049; clinicaltrials.gov). PMID:21813857

  5. BA71ΔCD2: A new recombinant live attenuated African swine fever virus with cross-protective capabilities.

    PubMed

    Monteagudo, Paula L; Lacasta, Anna; López, Elisabeth; Bosch, Laia; Collado, Javier; Pina-Pedrero, Sonia; Correa-Fiz, Florencia; Accensi, Francesc; Navas, María Jesús; Vidal, Enric; Bustos, María J; Rodríguez, Javier M; Gallei, Andreas; Nikolin, Veljko; Salas, María L; Rodríguez, Fernando

    2017-08-16

    African swine fever is a highly contagious viral disease of mandatory declaration to the World Organization for Animal Health (OIE). Lack of available vaccines make its control difficult and thus ASFV represents a major threat to the swine industry. Inactivated vaccines do not confer solid protection against African swine fever virus (ASFV). Conversely, live attenuated viruses (LAV), either naturally isolated or obtained by genetic manipulation, have demonstrated reliable protection against homologous ASFV strains, albeit little or no protection has been demonstrated against heterologous viruses. Safety concerns are a major issue for the use of ASFV attenuated vaccine candidates, and has hampered their implementation in the field so far. While trying to develop safer and efficient ASFV vaccines, we found and demonstrate here that the deletion of the viral CD2v (EP402R) gene, highly attenuated the virulent BA71 strain in vivo. Inoculation of pigs with the deletion mutant virus BA71ΔCD2 conferred protection not only against the lethal challenge with the parental BA71 but also against the heterologous E75 (both genotype I strains). The protection induced was dose-dependent and the cross-protection observed in vivo correlated with the ability of BA71ΔCD2 to induce specific CD8(+) T-cells capable of recognizing both BA71 and E75 viruses in vitro Interestingly, 100% of the pigs immunized with BA71ΔCD2 also survived lethal challenge with Georgia 2007/1, the genotype II strain of ASFV currently circulating in Continental Europe. These results open new avenues to design ASFV cross-protective vaccines, essential to fight ASFV in endemic areas where multiple viruses are circulating.Importance African swine fever virus (ASFV) remains endemic in most countries of Sub-Saharan Africa, today representing a major threat for the development of their swine industry. The uncontrolled presence of ASFV has favored its periodic exportation to other countries, the last event being

  6. 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 Central

    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.

    2015-01-01

    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. PMID:26175027

  7. 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.

  8. Safety and immunogenicity of a rederived, live-attenuated dengue virus vaccine in healthy adults living in Thailand: a randomized trial.

    PubMed

    Watanaveeradej, Veerachai; Gibbons, Robert V; Simasathien, Sriluck; Nisalak, Ananda; Jarman, Richard G; Kerdpanich, Angkool; Tournay, Elodie; De La Barrerra, Rafael; Dessy, Francis; Toussaint, Jean-François; Eckels, Kenneth H; Thomas, Stephen J; Innis, Bruce L

    2014-07-01

    Safety and immunogenicity of two formulations of a live-attenuated tetravalent dengue virus (TDEN) vaccine produced using rederived master seeds from a precursor vaccine were tested against a placebo control in a phase II, randomized, double blind trial (NCT00370682). Two doses were administered 6 months apart to 120 healthy, predominantly flavivirus-primed adults (87.5% and 97.5% in the two vaccine groups and 92.5% in the placebo group). Symptoms and signs reported after vaccination were mild to moderate and transient. There were no vaccine-related serious adverse events or dengue cases reported. Asymptomatic, low-level viremia (dengue virus type 2 [DENV-2], DENV-3, or DENV-4) was detected in 5 of 80 vaccine recipients. One placebo recipient developed a subclinical natural DENV-1 infection. All flavivirus-unprimed subjects and at least 97.1% of flavivirus-primed subjects were seropositive to antibodies against all four DENV types 1 and 3 months post-TDEN dose 2. The TDEN vaccine was immunogenic with an acceptable safety profile in flavivirus-primed adults.

  9. C-type natriuretic peptide in combination with sildenafil attenuates proliferation of rhabdomyosarcoma cells.

    PubMed

    Zenitani, Masahiro; Nojiri, Takashi; Uehara, Shuichiro; Miura, Koichi; Hosoda, Hiroshi; Kimura, Toru; Nakahata, Kengo; Miyazato, Mikiya; Okuyama, Hiroomi; Kangawa, Kenji

    2016-05-01

    Rhabdomyosarcoma (RMS) is a malignant mesenchymal tumor and the most common soft tissue sarcoma in children. Because of several complications associated with intensive multimodal therapies, including growth disturbance and secondary cancer, novel therapies with less toxicity are urgently needed. C-type natriuretic peptide (CNP), an endogenous peptide secreted by endothelial cells, exerts antiproliferative effects in multiple types of mesenchymal cells. Therefore, we investigated whether CNP attenuates proliferation of RMS cells. We examined RMS patient samples and RMS cell lines. All RMS clinical samples expressed higher levels of guanylyl cyclase B (GC-B), the specific receptor for CNP, than RMS cell lines. GC-B expression in RMS cells decreased with the number of passages in vitro. Therefore, GC-B stable expression lines were established to mimic clinical samples. CNP increased cyclic guanosine monophosphate (cGMP) levels in RMS cells in a dose-dependent manner, demonstrating the biological activity of CNP. However, because cGMP is quickly degraded by phosphodiesterases (PDEs), the selective PDE5 inhibitor sildenafil was added to inhibit its degradation. In vitro, CNP, and sildenafil synergistically inhibited proliferation of RMS cells stably expressing GC-B and decreased Raf-1, Mitogen-activated protein kinase kinase (MEK), and extracellular signal-regulated kinase (ERK) phosphorylation. These results suggested that CNP in combination with sildenafil exerts antiproliferative effects on RMS cells by inhibiting the Raf/MEK/ERK pathway. This regimen exerted synergistic effects on tumor growth inhibition without severe adverse effects in vivo such as body weight loss. Thus, CNP in combination with sildenafil represents a promising new therapeutic approach against RMS. © 2016 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

  10. Orally administered live attenuated Salmonella Typhimurium protects mice against lethal infection with H1N1 influenza virus.

    PubMed

    Kamble, Nitin Machindra; Hajam, Irshad Ahmed; Lee, John Hwa

    2017-03-01

    Pre-stimulation of toll-like receptors (TLRs) by agonists has been shown to increase protection against influenza virus infection. In this study, we evaluated the protective response generated against influenza A/Puerto Rico/8/1934 (PR8; H1N1) virus by oral and nasal administration of live attenuated Salmonella enterica serovar Typhimurium, JOL911 strain, in mice. Oral and nasal inoculation of JOL911 significantly increased the mRNA copy number of TLR-2, TLR4 and TLR5, and downstream type I interferon (IFN) molecules, IFN-α and IFN-β, both in peripheral blood mononuclear cells (PBMCs) and in lung tissue. Similarly, the mRNA copy number of interferon-inducible genes (ISGs), Mx and ISG15, were significantly increased in both the orally and the nasally inoculated mice. Post PR8 virus lethal challenge, the nasal JOL911 and the PBS control group mice showed significant loss of body weight with 70% and 100% mortality, respectively, compared to only 30% mortality in the oral JOL911 group mice. Post sub-lethal challenge, the significant reduction in PR8 virus copy number in lung tissue was observed in oral [on day 4 and 6 post-challenge (dpc)] and nasal (on 4dpc) than the PBS control group mice. The lethal and sub-lethal challenge showed that the generated stimulated innate resistance (StIR) in JOL911 inoculated mice conferred resistance to acute and initial influenza infection but might not be sufficient to prevent the PR8 virus invasion and replication in the lung. Overall, the present study indicates that oral administration of attenuated S. Typhimurium can pre-stimulate multiple TLR pathways in mice to provide immediate early StIR against a lethal H1N1 virus challenge.

  11. Live probiotic cultures and the gastrointestinal tract: symbiotic preservation of tolerance whilst attenuating pathogenicity

    PubMed Central

    Vitetta, Luis; Hall, Sean; Linnane, Anthony W.

    2014-01-01

    Bacteria comprise the earliest form of independent life on this planet. Bacterial development has included co-operative symbiosis with plants (e.g., Leguminosae family and nitrogen fixing bacteria in soil) and animals (e.g., the gut microbiome). A fusion event of two prokaryotes evolutionarily gave rise to the eukaryote cell in which mitochondria may be envisaged as a genetically functional mosaic, a relic from one of the prokaryote cells. The discovery of bacterial inhibitors such chloramphenicol and others has been exploited to highlight mitochondria as arising from a bacterial progenitor. As such the evolution of human life has been complexly connected to bacterial activity. This is embodied, by the appearance of mitochondria in eukaryotes (alphaproteobacteria contribution), a significant endosymbiotic evolutionary event. During the twentieth century there was an increasing dependency on anti-microbials as mainline therapy against bacterial infections. It is only comparatively recently that the essential roles played by the gastrointestinal tract (GIT) microbiome in animal health and development has been recognized as opposed to the GIT microbiome being a toxic collection of micro-organisms. It is now well-documented that the GIT microbiome is comprised of a complex cohort of commensal and potentially pathogenic bacteria. Microbial interactions in the GIT provide the necessary cues for the development of regulated signals [in part by reactive oxygen species (ROS)] that promote immunological tolerance, metabolic regulation and stability, and other factors, which may then help control local and extra-intestinal end organ (e.g., kidneys) physiology. Pharmacobiotics, the administration of live probiotic cultures is an exciting growth area of potential therapeutics, developing together with an increased scientific understanding of GIT microbiome symbiosis in health and disease. Hence probiotic bacteria may provide a therapeutic connect with the GIT microbiome that

  12. Live probiotic cultures and the gastrointestinal tract: symbiotic preservation of tolerance whilst attenuating pathogenicity.

    PubMed

    Vitetta, Luis; Hall, Sean; Linnane, Anthony W

    2014-01-01

    Bacteria comprise the earliest form of independent life on this planet. Bacterial development has included co-operative symbiosis with plants (e.g., Leguminosae family and nitrogen fixing bacteria in soil) and animals (e.g., the gut microbiome). A fusion event of two prokaryotes evolutionarily gave rise to the eukaryote cell in which mitochondria may be envisaged as a genetically functional mosaic, a relic from one of the prokaryote cells. The discovery of bacterial inhibitors such chloramphenicol and others has been exploited to highlight mitochondria as arising from a bacterial progenitor. As such the evolution of human life has been complexly connected to bacterial activity. This is embodied, by the appearance of mitochondria in eukaryotes (alphaproteobacteria contribution), a significant endosymbiotic evolutionary event. During the twentieth century there was an increasing dependency on anti-microbials as mainline therapy against bacterial infections. It is only comparatively recently that the essential roles played by the gastrointestinal tract (GIT) microbiome in animal health and development has been recognized as opposed to the GIT microbiome being a toxic collection of micro-organisms. It is now well-documented that the GIT microbiome is comprised of a complex cohort of commensal and potentially pathogenic bacteria. Microbial interactions in the GIT provide the necessary cues for the development of regulated signals [in part by reactive oxygen species (ROS)] that promote immunological tolerance, metabolic regulation and stability, and other factors, which may then help control local and extra-intestinal end organ (e.g., kidneys) physiology. Pharmacobiotics, the administration of live probiotic cultures is an exciting growth area of potential therapeutics, developing together with an increased scientific understanding of GIT microbiome symbiosis in health and disease. Hence probiotic bacteria may provide a therapeutic connect with the GIT microbiome that

  13. Immune responses elicited to a live-attenuated influenza virus vaccine compared to a traditional whole-inactivated virus vaccine for pandemic H1N1in pigs

    USDA-ARS?s Scientific Manuscript database

    In the United States there are currently two influenza vaccine platforms approved for use in humans - conventional inactivated virus and live-attenuated influenza virus (LAIV). One of the major challenges for influenza vaccination is designing a platform that provides cross-protection across strains...

  14. Heightened adaptive immune responses following vaccination with a temperature-sensitive, live-attenuated influenza virus compared to adjuvanted, whole-inactivated virus in pigs

    USDA-ARS?s Scientific Manuscript database

    In the United States there are currently two influenza vaccine platforms approved for use in humans - conventional inactivated virus and live-attenuated influenza virus (LAIV). One of the major challenges for influenza A virus (IAV) vaccination is designing a platform that provides protection across...

  15. 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...

  16. Vaccination of full-sib channel catfish families against enteric septicemia of catfish with an oral live attenuated Edwardsiella ictaluri vaccine

    USDA-ARS?s Scientific Manuscript database

    The study evaluated the efficacy of an oral live-attenuated Edwardsiella ictaluri vaccine against enteric septicemia of catfish in 20 full-sib fingerling channel catfish families. Each family was split into vaccinated and non-vaccinated groups. The vaccine was delivered orally by feeding fish diet...

  17. A live attenuated Salmonella enterica serovar Typhimurium vaccine provides cross-protection against Salmonella serovars to reduce disease severity and pathogen transmission

    USDA-ARS?s Scientific Manuscript database

    A live attenuated Salmonella enterica serovar Typhimurium vaccine was developed to confer broad protection against multiple Salmonella serovars to prevent disease and reduce pathogen colonization and shedding. Two vaccine trials were performed in swine to determine the protection afforded by the vac...

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

    USDA-ARS?s Scientific Manuscript database

    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 ...

  19. Efficacy of a Russian-backbone live attenuated influenza vaccine among children in Senegal: a randomised, double-blind, placebo-controlled trial.

    PubMed

    Victor, John C; Lewis, Kristen D C; Diallo, Aldiouma; Niang, Mbayame N; Diarra, Bou; Dia, Ndongo; Ortiz, Justin R; Widdowson, Marc-Alain; Feser, Jodi; Hoagland, Rebecca; Emery, Shannon L; Lafond, Kathryn E; Neuzil, Kathleen M

    2016-12-01

    Live attenuated influenza vaccines have been shown to significantly reduce influenza in diverse populations of children, but no efficacy studies have been done in resource-poor tropical settings. In Senegal, we assessed the efficacy and safety of a live attenuated influenza vaccine based on Russian-derived master donor viruses and licensed as a single dose. In this double-blind, placebo-controlled, parallel group, single-centre trial done near Niakhar, Senegal, generally healthy children aged 2-5 years were randomly allocated (2:1) to receive a single intranasal dose of masked trivalent live attenuated influenza vaccine or placebo. The allocation sequence was computer-generated by PATH with block sizes of three. The manufacturer provided vaccine and placebo in coded vials to preserve blinding. Participants were monitored through the predictable influenza season in Senegal for adverse events and signs and symptoms of influenza using weekly home visits and surveillance in clinics. The primary outcome was symptomatic laboratory-confirmed influenza caused by any strain and occurring from 15 days post-vaccination to the end of the study. The primary analysis was per protocol. This study is registered with ClinicalTrials.gov, number NCT01854632. Between May 23, and July 1, 2013, 1761 children were randomly assigned, 1174 to receive live attenuated influenza vaccine and 587 to receive placebo. The per-protocol set included 1173 vaccinees and 584 placebo recipients followed up to Dec 20, 2013. Symptomatic influenza was laboratory-confirmed in 210 (18%) of 1173 recipients of live attenuated influenza vaccine and 105 (18%) of placebo recipients, giving a vaccine efficacy of 0·0% (95% CI -26·4 to 20·9). Adverse events were balanced between the study groups. Two girls who had received live attenuated influenza vaccine died, one due to anasarca 12 days postvaccination and one due to malnutrition 70 days postvaccination. Live attenuated influenza vaccine was well tolerated in

  20. Cost of production of live attenuated dengue vaccines: a case study of the Instituto Butantan, Sao Paulo, Brazil.

    PubMed

    Mahoney, R T; Francis, D P; Frazatti-Gallina, N M; Precioso, A R; Raw, I; Watler, P; Whitehead, P; Whitehead, S S

    2012-07-06

    A vaccine to prevent dengue disease is urgently needed. Fortunately, a few tetravalent candidate vaccines are in the later stages of development and show promise. But, if the cost of these candidates is too high, their beneficial potential will not be realized. The price of a vaccine is one of the most important factors affecting its ultimate application in developing countries. In recent years, new vaccines such as those for human papilloma virus and pneumococcal disease (conjugate vaccine) have been introduced with prices in developed countries exceeding $50 per dose. These prices are above the level affordable by developing countries. In contrast, other vaccines such as those against Japanese encephalitis (SA14-14-2 strain vaccine) and meningitis type A have prices in developing countries below one dollar per dose, and it is expected that their introduction and use will proceed more rapidly. Because dengue disease is caused by four related viruses, vaccines must be able to protect against all four. Although there are several live attenuated dengue vaccine candidates under clinical evaluation, there remains uncertainty about the cost of production of these tetravalent vaccines, and this uncertainty is an impediment to rapid progress in planning for the introduction and distribution of dengue vaccines once they are licensed. We have undertaken a detailed economic analysis, using standard industrial methodologies and applying generally accepted accounting practices, of the cost of production of a live attenuated vaccine, originally developed at the US National Institutes of Health (National Institute of Allergy and Infectious Diseases), to be produced at the Instituto Butantan in Sao Paulo, Brazil. We determined direct costs of materials, direct costs of personnel and labor, indirect costs, and depreciation. These were analyzed assuming a steady-state production of 60 million doses per year. Although this study does not seek to compute the price of the final

  1. The Matrix Gene Segment Destabilizes the Acid and Thermal Stability of the Hemagglutinin of Pandemic Live Attenuated Influenza Virus Vaccines

    PubMed Central

    O'Donnell, Christopher D.; Vogel, Leatrice; Matsuoka, Yumiko; Jin, Hong

    2014-01-01

    ABSTRACT The threat of future influenza pandemics and their potential for rapid spread, morbidity, and mortality has led to the development of pandemic vaccines. We generated seven reassortant pandemic live attenuated influenza vaccines (pLAIVs) with the hemagglutinin (HA) and neuraminidase (NA) genes derived from animal influenza viruses on the backbone of the six internal protein gene segments of the temperature sensitive, cold-adapted (ca) A/Ann Arbor/60 (H2N2) virus (AA/60 ca) of the licensed seasonal LAIV. The pLAIV viruses were moderately to highly restricted in replication in seronegative adults; we sought to determine the biological basis for this restriction. Avian influenza viruses generally replicate at higher temperatures than human influenza viruses and, although they shared the same backbone, the pLAIV viruses had a lower shutoff temperature than seasonal LAIV viruses, suggesting that the HA and NA influence the degree of temperature sensitivity. The pH of HA activation of highly pathogenic avian influenza viruses was greater than human and low-pathogenicity avian influenza viruses, as reported by others. However, pLAIV viruses had a consistently higher pH of HA activation and reduced HA thermostability compared to the corresponding wild-type parental viruses. From studies with single-gene reassortant viruses bearing one gene segment from the AA/60 ca virus in recombinant H5N1 or pH1N1 viruses, we found that the lower HA thermal stability and increased pH of HA activation were associated with the AA/60 M gene. Together, the impaired HA acid and thermal stability and temperature sensitivity likely contributed to the restricted replication of the pLAIV viruses we observed in seronegative adults. IMPORTANCE There is increasing evidence that the HA stability of influenza viruses depends on the virus strain and host species and that HA stability can influence replication, virulence, and transmission of influenza A viruses in different species. We

  2. Combined Pharmacotherapy and Cognitive-Behavioral Therapy for Anxiety Disorders: Medication Effects, Glucocorticoids, and Attenuated Treatment Outcomes

    PubMed Central

    Otto, Michael W.; McHugh, R. Kathryn; Kantak, Kathleen M.

    2015-01-01

    Despite the success of both pharmacologic and cognitive-behavioral interventions for the treatment of anxiety disorders, the combination of these modalities in adults has not resulted in substantial improvements in outcome relative to either strategy alone, raising questions about whether there are interfering effects that attenuate the magnitude of combination treatment benefits. In this article, we introduce an accounting of potential interference effects that expands upon arguments asserting the necessity of arousal for successful fear exposure. Specifically, recent advances in the study of the effects of cortisol on memory--suggesting that glucocorticoids are crucial to the learning of emotional material--have led us to posit that the attenuation of glucocorticoid activity by anxiolytic medications may interfere with extinction learning in exposure-based therapies. Implications for the efficacy of combination treatments for the anxiety disorders are discussed. PMID:26855480

  3. Construction and Evaluation of V. cholerae O139 Mutant, VCUSM21P, as a Safe Live Attenuated Cholera Vaccine

    PubMed Central

    Murugaiah, Chandrika; Nik Mohd Noor, Nik Zuraina; Mustafa, Shyamoli; Manickam, Ravichandran; Pattabhiraman, Lalitha

    2014-01-01

    Cholera is a major infectious disease, affecting millions of lives annually. In endemic areas, implementation of vaccination strategy against cholera is vital. As the use of safer live vaccine that can induce protective immunity against Vibrio cholerae O139 infection is a promising approach for immunization, we have designed VCUSM21P, an oral cholera vaccine candidate, which has ctxA that encodes A subunit of ctx and mutated rtxA/C, ace and zot mutations. VCUSM21P was found not to disassemble the actin of HEp2 cells. It colonized the mice intestine approximately 1 log lower than that of the Wild Type (WT) strain obtained from Hospital Universiti Sains Malaysia. In the ileal loop assay, unlike WT challenge, 1×106 and 1×108 colony forming unit (CFU) of VCUSM21P was not reactogenic in non-immunized rabbits. Whereas, the reactogenicity caused by the WT in rabbits immunized with 1×1010 CFU of VCUSM21P was found to be reduced as evidenced by absence of fluid in loops administered with 1×102–1×107 CFU of WT. Oral immunization using 1×1010 CFU of VCUSM21P induced both IgA and IgG against Cholera Toxin (CT) and O139 lipopolysaccharides (LPS). The serum vibriocidal antibody titer had a peak rise of 2560 fold on week 4. Following Removable Intestinal Tie Adult Rabbit Diarrhoea (RITARD) experiment, the non-immunized rabbits were found not to be protected against lethal challenge with 1×109 CFU WT, but 100% of immunized rabbits survived the challenge. In the past eleven years, V. cholerae O139 induced cholera has not been observed. However, attenuated VCUSM21P vaccine could be used for vaccination program against potentially fatal endemic or emerging cholera caused by V. cholerae O139. PMID:24505241

  4. Combining Live Video and Audio Broadcasting, Synchronous Chat, and Asynchronous Open Forum Discussions in Distance Education

    ERIC Educational Resources Information Center

    Teng, Tian-Lih; Taveras, Marypat

    2004-01-01

    This article outlines the evolution of a unique distance education program that began as a hybrid--combining face-to-face instruction with asynchronous online teaching--and evolved to become an innovative combination of synchronous education using live streaming video, audio, and chat over the Internet, blended with asynchronous online discussions…

  5. Combining Live Video and Audio Broadcasting, Synchronous Chat, and Asynchronous Open Forum Discussions in Distance Education

    ERIC Educational Resources Information Center

    Teng, Tian-Lih; Taveras, Marypat

    2004-01-01

    This article outlines the evolution of a unique distance education program that began as a hybrid--combining face-to-face instruction with asynchronous online teaching--and evolved to become an innovative combination of synchronous education using live streaming video, audio, and chat over the Internet, blended with asynchronous online discussions…

  6. Development of Clade-Specific and Broadly Reactive Live Attenuated Influenza Virus Vaccines against Rapidly Evolving H5 Subtype Viruses.

    PubMed

    Boonnak, Kobporn; Matsuoka, Yumiko; Wang, Weijia; Suguitan, Amorsolo L; Chen, Zhongying; Paskel, Myeisha; Baz, Mariana; Moore, Ian; Jin, Hong; Subbarao, Kanta

    2017-08-01

    We have developed pandemic live attenuated influenza vaccines (pLAIVs) against clade 1 H5N1 viruses on an Ann Arbor cold-adapted (ca) backbone that induced long-term immune memory. In 2015, many human infections caused by a new clade (clade 2.2.1.1) of goose/Guangdong (gs/GD) lineage H5N1 viruses were reported in Egypt, which prompted updating of the H5N1 pLAIV. We explored two strategies to generate suitable pLAIVs. The first approach was to modify the hemagglutinin gene of a highly pathogenic wild-type (wt) clade 2.2.1.1 virus, A/Egypt/N03434/2009 (Egy/09) (H5N1), with its unmodified neuraminidase (NA) gene; this virus was designated Egy/09 ca The second approach was to select a low-pathogenicity avian influenza H5 virus that elicited antibodies that cross-reacted with a broad range of H5 viruses, including the Egypt H5N1 viruses, and contained a novel NA subtype for humans. We selected the low-pathogenicity A/duck/Hokkaido/69/2000 (H5N3) (dk/Hok/00) virus for this purpose. Both candidate vaccines were attenuated and immunogenic in ferrets, inducing antibodies that neutralized homologous and heterologous H5 viruses with different degrees of cross-reactivity; Egy/09 ca vaccine antisera were more specific for the gs/GD lineage viruses but did not neutralize recent North American isolates (clade 2.3.4.4), whereas antisera from dk/Hok/69 ca-vaccinated ferrets cross-reacted with clade 2.3.4.4 and 2.2.1 viruses but not clade 1 or 2.1 viruses. When vaccinated ferrets were challenged with homologous and heterologous H5 viruses, challenge virus replication was reduced in the respiratory tract. Thus, the two H5 pLAIV candidates are suitable for clinical development to protect humans from infection with different clades of H5 viruses.IMPORTANCE In response to the continuing evolution of H5N1 avian influenza viruses and human infections, new candidate H5 live attenuated vaccines were developed by using two different approaches: one targeted a specific circulating strain in

  7. Protective efficacy of a live attenuated Mycoplasma hyopneumoniae vaccine with an ISCOM-matrix adjuvant in pigs.

    PubMed

    Xiong, Qiyan; Wei, Yanna; Feng, Zhixin; Gan, Yuan; Liu, Zhanjun; Liu, Maojun; Bai, Fangfang; Shao, Guoqing

    2014-02-01

    An attenuated Mycoplasma hyopneumoniae vaccine that requires intrathoracic administration is commercially available for use against mycoplasmal pneumonia in China. Given the limitations of such a route of administration, this study was undertaken to assess the capacity of an ISCOM-matrix adjuvant to enhance immunogenicity following intramuscular use. Immune responses in pigs following vaccination and subsequent intra-tracheal bacterial inoculation were examined using lymphocyte proliferation, serology and mucosal IgA in both nasal and saliva swabs. Vaccination induced clear lymphocyte proliferation, but only slight serum antibody responses although these were significantly increased following experimental infection. Mucosal IgA was not detected in either nasal or salivary secretions. Following bacterial challenge, animals vaccinated with the adjuvant-containing live vaccine exhibited less severe pulmonary lesions (median score 3.67) than unvaccinated pigs (median score 13.58). The degree of ciliary loss on the respiratory tract surface was reduced in vaccinated pigs compared with experimentally infected controls. The findings indicated that the adjuvant vaccine administered IM provided protection against experimentally induced mycoplasmal pneumonia and could have commercial potential.

  8. Comparison of the trivalent live attenuated vs. inactivated influenza vaccines among U.S. military service members.

    PubMed

    Eick, Angelia A; Wang, Zhong; Hughes, Hayley; Ford, Stephen M; Tobler, Steven K

    2009-06-02

    Limited effectiveness data are available comparing live attenuated influenza vaccine (LAIV) to inactivated influenza vaccine (TIV) among adults. To compare the incidence of influenza-like illness following immunization of adults with LAIV vs. TIV, we conducted a retrospective cohort analysis of active component U.S. military personnel for the 2005-2006 and 2006-2007 influenza seasons. Recruits experienced a much higher burden of disease compared to non-recruits, with crude incidence rates of influenza-like illness 2-16 times higher than non-recruits depending on the season and cohort. For both seasons, a slightly greater protection from influenza-like illness was found for non-recruits who received TIV compared to LAIV (adjusted incidence rate ratio, 1.17 (95% CI, 1.14-1.20) and 1.33 (95% CI, 1.30-1.36), 2005-2006 and 2006-2007 influenza seasons, respectively). However, for Army and Air Force recruits, LAIV was found to provide significantly greater protection from influenza-like illnesses compared to TIV, with adjusted incidence rates of influenza-like illness 22-51% and 18-47% lower among LAIV compared to TIV recipients for the 2005-2006 and 2006-2007 influenza seasons, respectively. Possible reasons for differences in recruit and non-recruit findings include differences in pre-existing influenza antibody levels, differing respiratory disease burden, and/or unmeasured confounding. Consideration of these findings should be made when developing influenza immunization policies.

  9. Genetic variations of live attenuated plague vaccine strains (Yersinia pestis EV76 lineage) during laboratory passages in different countries.

    PubMed

    Cui, Yujun; Yang, Xianwei; Xiao, Xiao; Anisimov, Andrey P; Li, Dongfang; Yan, Yanfeng; Zhou, Dongsheng; Rajerison, Minoarisoa; Carniel, Elisabeth; Achtman, Mark; Yang, Ruifu; Song, Yajun

    2014-08-01

    Plague, one of the most devastating infectious diseases in human history, is caused by the bacterial species Yersinia pestis. A live attenuated Y. pestis strain (EV76) has been widely used as a plague vaccine in various countries around the world. Here we compared the whole genome sequence of an EV76 strain used in China (EV76-CN) with the genomes of Y. pestis wild isolates to identify genetic variations specific to the EV76 lineage. We identified 6 SNPs and 6 Indels (insertions and deletions) differentiating EV76-CN from its counterparts. Then, we screened these polymorphic sites in 28 other strains of EV76 lineage that were stored in different countries. Based on the profiles of SNPs and Indels, we reconstructed the parsimonious dissemination history of EV76 lineage. This analysis revealed that there have been at least three independent imports of EV76 strains into China. Additionally, we observed that the pyrE gene is a mutation hotspot in EV76 lineages. The fine comparison results based on whole genome sequence in this study provide better understanding of the effects of laboratory passages on the accumulation of genetic polymorphisms in plague vaccine strains. These variations identified here will also be helpful in discriminating different EV76 derivatives. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. In vitro analysis of virus particle subpopulations in candidate live-attenuated influenza vaccines distinguishes effective from ineffective vaccines.

    PubMed

    Marcus, Philip I; Ngunjiri, John M; Sekellick, Margaret J; Wang, Leyi; Lee, Chang-Won

    2010-11-01

    Two effective (vac+) and two ineffective (vac-) candidate live-attenuated influenza vaccines (LAIVs) derived from naturally selected genetically stable variants of A/TK/OR/71-delNS1[1-124] (H7N3) that differed only in the length and kind of amino acid residues at the C terminus of the nonstructural NS1 protein were analyzed for their content of particle subpopulations. These subpopulations included total physical particles (measured as hemagglutinating particles [HAPs]) with their subsumed biologically active particles of infectious virus (plaque-forming particles [PFPs]) and different classes of noninfectious virus, namely, interferon-inducing particles (IFPs), noninfectious cell-killing particles (niCKPs), and defective interfering particles (DIPs). The vac+ variants were distinguished from the vac- variants on the basis of their content of viral subpopulations by (i) the capacity to induce higher quantum yields of interferon (IFN), (ii) the generation of an unusual type of IFN-induction dose-response curve, (iii) the presence of IFPs that induce IFN more efficiently, (iv) reduced sensitivity to IFN action, and (v) elevated rates of PFP replication that resulted in larger plaques and higher PFP and HAP titers. These in vitro analyses provide a benchmark for the screening of candidate LAIVs and their potential as effective vaccines. Vaccine design may be improved by enhancement of attributes that are dominant in the effective (vac+) vaccines.

  11. Boosting of Cross-Reactive and Protection-Associated T Cells in Children After Live Attenuated Influenza Vaccination.

    PubMed

    Mohn, Kristin G I; Zhou, Fan; Brokstad, Karl A; Sridhar, Saranya; Cox, Rebecca J

    2017-05-15

    Live attenuated influenza vaccines (LAIVs) stimulate a multifaceted immune response including cellular immunity, which may provide protection against newly emerging strains. This study shows proof of concept that LAIVs boost preexisting, cross-reactive T cells in children to genetically diverse influenza A virus (IAV) strains to which the children had not been exposed. We studied the long-term cross-reactive T-cell response in 14 trivalent LAIV-vaccinated children using the fluorescent immunospot assay (FluoroSpot) with heterologous H1N1 and H3N2 IAVs and CD8+ peptides from the internal proteins (matrix protein 1 [M1], nucleoprotein [NP], polymerase basic protein 1 [PB1]). Serum antibody responses were determined by means of hemagglutination inhibition assay. Blood samples were collected before vaccination and up to 1 year after vaccination. Preexisting cross-reactive T cells to genetically diverse IAV strains were found in the majority of the children, which were further boosted in 50% of them after receipt of LAIV. Further analyses of these T cells showed significant increases in CD8+ T cells, mainly dominated by NP-specific responses. After vaccination with LAIV, the youngest children showed the highest increase in T-cell responses. LAIV boosts durable, cross-reactive T-cell responses in children and may have a clinically protective effect at the population level. LAIV may be a first step toward the desired universal influenza vaccine.

  12. Recent advances in the study of live attenuated cell-cultured smallpox vaccine LC16m8.

    PubMed

    Eto, Akiko; Saito, Tomoya; Yokote, Hiroyuki; Kurane, Ichiro; Kanatani, Yasuhiro

    2015-11-09

    LC16m8 is a live, attenuated, cell-cultured smallpox vaccine that was developed and licensed in Japan in the 1970s, but was not used in the campaign to eradicate smallpox. In the early 2000s, the potential threat of bioterrorism led to reconsideration of the need for a smallpox vaccine. Subsequently, LC16m8 production was restarted in Japan in 2002, requiring re-evaluation of its safety and efficacy. Approximately 50,000 children in the 1970s and about 3500 healthy adults in the 2000s were vaccinated with LC16m8 in Japan, and 153 adults have been vaccinated with LC16m8 or Dryvax in phase I/II clinical trials in the USA. These studies confirmed the safety and efficacy of LC16m8, while several studies in animal models have shown that LC16m8 protects the host against viral challenge. The World Health Organization Strategic Advisory Group of Experts on Immunization recommended LC16m8, together with ACAM2000, as a stockpile vaccine in 2013. In addition, LC16m8 is expected to be a viable alternative to first-generation smallpox vaccines to prevent human monkeypox.

  13. Development of one-step real-time PCR assay for titrating trivalent live attenuated influenza vaccines

    PubMed Central

    Zang, Yang; Du, Dongchuan; Ge, Peng; Xu, Yongqing; Liu, Xintao; Zhang, Yan; Su, Weiheng; Kiseleva, Irina; Rudenko, Larisa; Xu, Fei; Kong, Wei; Jiang, Chunlai

    2014-01-01

    Traditionally, infectivity of a trivalent live attenuated influenza vaccines (LAIVs) is titrated by determining the 50% egg infectious dose assay (EID50) or plaque forming units (PFU), which requires specific monoclonal antibodies to neutralize 2 strains while estimating the titer of the non-neutralized strain. Compared to this time-consuming, laborious, subjective and variable process, reverse transcription-quantitative real-time PCR (RT-qPCR) technology has advantages of rapidity, sensitivity, reproducibility and reduced contamination, thus has been applied widely for detecting pathogens and measuring viral titers. In this study, the critical harvest time was determined to be 18 h post-infection (hpi) for type A influenza and 12 hpi for type B influenza, but no significant difference between titers at 12 hpi and 18 hpi for the type B strain was observed. In conclusion, trivalent LAIVs can be titrated simultaneously within 24 h by this one-step RT-qPCR assay, which yielded titers comparable to those obtained by the traditional EID50 assay. Therefore, the RT-qPCR assay may be used as a highly specific, sensitive, precise and rapid alternative to the EID50 assay for titering LAIVs. PMID:25483696

  14. Clinical and serologic effects of live attenuated serum inhibitor-resistant influenza B vaccine in seronegative adults.

    PubMed

    Miller, L W; Togo, Y; Hornick, R B

    1977-01-01

    The clinical effects, nasal and serum antibody responses, and virus excretion of a live attenuated serum inhibitor-resistant influenza B virus vaccine, R75, was evaluated in 43 seronegative healthy adults by a random double-blind study. Symptom responses were minimal and were not significantly different between vaccine and placebo groups. No fevers, abnormalities in physical examination or laboratory testing developed during 4 weeks of observation. Among vaccinees, 10 (48%) developed serum hemagglutination-inhibition (HI) antibodies, 16 (76%) developed serum neutralization (N) antibodies and 4 (19%) developed nasal N antibodies. The GMT responses from study day 0 to day 28 were 4.0 to 10.4 for serum HI, 1.8 to 9.8 for serum N, and 1.0 to 1.4 for nasal N. There were no significant titer changes in the placebo group. No virus excretion was detected. Although there are some questions concerning the relationship of antibody levels to protection, the low antibody responses in this study are an indication that R75 is not sufficiently immunogenic.

  15. Development and approval of live attenuated influenza vaccines based on Russian master donor viruses: Process challenges and success stories.

    PubMed

    Rudenko, Larisa; Yeolekar, Leena; Kiseleva, Irina; Isakova-Sivak, Irina

    2016-10-26

    Influenza is a viral infection that affects much of the global population each year. Vaccination remains the most effective tool for preventing the disease. Live attenuated influenza vaccine (LAIV) has been used since the 1950s to protect humans against seasonal influenza. LAIVs developed by the Institute of Experimental Medicine (IEM), Saint Petersburg, Russia, have been successfully used in Russia since 1987. In 2006, the World Health Organization (WHO) announced a Global action plan for influenza vaccines (GAP). WHO, recognizing potential advantages of LAIV over the inactivated influenza vaccine in a pandemic situation, included LAIV in the GAP. BioDiem Ltd., a vaccine development company based in Melbourne, Australia which held the rights for the Russian LAIV, licensed this technology to WHO in 2009. WHO was permitted to grant sub-licenses to vaccine manufacturers in newly industrialized and developing countries to use the Russian LAIV for the development, manufacture, use and sale of pandemic and seasonal LAIVs. To date, WHO has granted sub-licenses to vaccine manufacturers in China (Changchun BCHT Biotechnology Co., Ltd.), India (Serum Institute of India Pvt. Ltd.) and Thailand (Government Pharmaceutical Organization). In parallel, in 2009, IEM signed an agreement with WHO, under which IEM committed to supply pandemic and seasonal candidate vaccine viruses to the sub-licensees. This paper describes the progress made by collaborators from China, India, Russia and Thailand in developing preventive measures, including LAIV against pandemic influenza.

  16. Combination of epidural anesthesia and general anesthesia attenuates stress response to renal transplantation surgery.

    PubMed

    Hadimioglu, N; Ulugol, H; Akbas, H; Coskunfirat, N; Ertug, Z; Dinckan, A

    2012-12-01

    Choice of the anesthestic technique can reduce or even eliminate stress responses to surgery and decrease the incidence of complications. Our aim was to compare a combination of epidural anesthesia+general anesthesia with general anesthesia alone as regards perioperative insulin resistance and inflammatory activation among renal transplant recipients. Forty-six nondiabetic patients undergoing renal transplantation were prospectively randomized to the epidural anesthesia + general anesthesia group (n = 21), or general anesthesia alone group (n = 25). Plasma levels of glucose, insulin, interleukin (IL)-6, tumour necrosis factor (TNF)-α, resistin, and adiponectin were measured at baseline (T1), end of surgery (T2), postoperative first hour (T3), postoperative second hour (T4) and postoperative 24th hour (T5). Homeostasis model assessment-estimated insulin resistance (HOMA-IR) scores were calculated at every time point that the blood samples were collected. Glucose levels (P < .001) and insulin levels at the end of surgery (P = .048) and at postoperative first hour (P = .005) and HOMA-IR levels at the end of surgery (P = .012) and at postoperative first hour (P = .010) showed significantly higher values among the general anesthesia alone group when compared with the epidural+general anesthesia group. TNF-α levels at postoperative 2nd and at 24th hour (P = .005 and P = .004, respectively) and IL-6 levels at postoperative 1st and 2nd hours (P = .002 and P = .045, respectively) were significantly higher in the general anesthesia alone group when compared with the epidural+general anesthesia group. The TNF-α levels were significantly less at all time points when compared with baseline only in the epidural+general anesthesia group (T1, 33.36 vs 37.25; T2, 18.45 vs 76.52; T3, 15.18 vs 78.27; T4, 10.75 vs 66.64; T5, 2.98 vs 36.32) Hospital stays were significantly shorter among the epidural+general anesthesia group (P = .022). We showed partly attenuated surgical stress

  17. Live attenuated Salmonella displaying HIV-1 10E8 epitope on fimbriae: systemic and mucosal immune responses in BALB/c mice by mucosal administration

    PubMed Central

    Li, Qing-Hai; Jin, Gang; Wang, Jia-Ye; Li, Hai-Ning; Liu, Huidi; Chang, Xiao-Yun; Wang, Fu-Xiang; Liu, Shu-Lin

    2016-01-01

    The HIV-1 membrane proximal external region (MPER) that is targeted by several broadly neutralizing antibodies (BNAbs) has been considered a potential immunogen for vaccine development. However, to date the immunogenicity of these BNAb epitopes has not been made sufficiently adequate. In the present work, we used live attenuated Salmonella as a platform to present the HIV-1 MPER 10E8 epitope in the fimbriae. The insertion of the 10E8 epitope into the fimbriae had no significant influence on the expression and the absorption capacity of bacterial fimbriae, nor on the virulence and invasiveness of the attenuated Salmonella. After oral administration of the vaccine construct to mice followed by 10E8 epitope peptide boost, specific antibody responses in serum and mucosa as well as memory lymphocytes in spleen and plasma cells in bone marrow were induced. We also found that the live attenuated Salmonella vector directed the immunity toward Th1 bias, induced Th1 and Th2 cytokine responses and stimulated significant B cell differentiation into GC B, memory B and plasma cells. Therefore, we propose that the live attenuated Salmonella constitutively expressing HIV-1 BNAb epitopes on the fimbriae will be an effective approach to improving immune microenvironment and enhancing the immunogenicity of HIV-1 epitope vaccines. PMID:27411313

  18. Dioscorea bulbifera polysaccharide and cyclophosphamide combination enhances anti-cervical cancer effect and attenuates immunosuppression and oxidative stress in mice.

    PubMed

    Cui, Hongxia; Li, Ting; Wang, Liping; Su, Yan; Xian, Cory J

    2016-01-12

    Cyclophosphamide (CTX) is commonly used in cancer chemotherapy, which causes immunosuppression and tissue oxidative stress at high doses. As potential protective agents, some polysaccharides were shown to have anti-tumor, anti-inflammatory and/or anti-oxidant properties. This study explored potential effects of oral treatment of Dioscorea bulbifera polysaccharides (DBLP at 100 or 150 mg/kg) in U14 cervical tumor-bearing mice treated with CTX (25 mg/kg). While CTX suppressed tumor growth (65.4% inhibition) and DBLP alone also inhibited tumor (25.6% at 100 mg/kg or 37.6% at 150 mg/kg), CTX+DBLP combination produced tumor inhibition rates of 5.6 (for 100 mg/kg DBLP) or 9% (for 150 mg/kg) higher than CTX alone. While tumor itself and CTX treatment reduced thymus and/or spleen/body weight indices, DBLP alone or CTX + DBLP combination attenuated this reduction. DBLP lowered peripheral blood T-cell subpopulation CD(4+)/CD(8+) ratio, and DBLP+CTX combination attenuated CTX effect in lifting CD(4+)/CD(8+) ratio. Tumor itself and CTX treatment heightened oxidative stress (with decreased superoxide dismutase but increased lactate dehydrogenase and malondialdehyde levels in serum and tissues), which was attenuated by DBLP treatment, and DBLP+CTX combination suppressed CTX-induced oxidative stress. Combination use of DBLP with CTX can potentially enhance CTX anti-tumor effect and can attenuate CTX-induced immunosuppression and oxidative stress in U14 cervical tumor-bearing mice.

  19. Dioscorea bulbifera polysaccharide and cyclophosphamide combination enhances anti-cervical cancer effect and attenuates immunosuppression and oxidative stress in mice

    PubMed Central

    Cui, Hongxia; Li, Ting; Wang, Liping; Su, Yan; Xian, Cory J.

    2016-01-01

    Cyclophosphamide (CTX) is commonly used in cancer chemotherapy, which causes immunosuppression and tissue oxidative stress at high doses. As potential protective agents, some polysaccharides were shown to have anti-tumor, anti-inflammatory and/or anti-oxidant properties. This study explored potential effects of oral treatment of Dioscorea bulbifera polysaccharides (DBLP at 100 or 150 mg/kg) in U14 cervical tumor-bearing mice treated with CTX (25 mg/kg). While CTX suppressed tumor growth (65.4% inhibition) and DBLP alone also inhibited tumor (25.6% at 100 mg/kg or 37.6% at 150 mg/kg), CTX+DBLP combination produced tumor inhibition rates of 5.6 (for 100 mg/kg DBLP) or 9% (for 150 mg/kg) higher than CTX alone. While tumor itself and CTX treatment reduced thymus and/or spleen/body weight indices, DBLP alone or CTX + DBLP combination attenuated this reduction. DBLP lowered peripheral blood T-cell subpopulation CD4+/CD8+ ratio, and DBLP+CTX combination attenuated CTX effect in lifting CD4+/CD8+ ratio. Tumor itself and CTX treatment heightened oxidative stress (with decreased superoxide dismutase but increased lactate dehydrogenase and malondialdehyde levels in serum and tissues), which was attenuated by DBLP treatment, and DBLP+CTX combination suppressed CTX-induced oxidative stress. Combination use of DBLP with CTX can potentially enhance CTX anti-tumor effect and can attenuate CTX-induced immunosuppression and oxidative stress in U14 cervical tumor-bearing mice. PMID:26753518

  20. Control of Salmonella Enteritidis and Salmonella Gallinarum in birds by using live vaccine candidate containing attenuated Salmonella Gallinarum mutant strain.

    PubMed

    Penha Filho, Rafael Antonio Casarin; de Paiva, Jacqueline Boldrin; da Silva, Mariana Dias; de Almeida, Adriana Maria; Berchieri, Angelo

    2010-04-01

    The ideal live vaccine to control Salmonella in commercial chicken flocks should engender protection against various strains. The purpose of the present study was to confirm the attenuation of a Salmonella Gallinarum (SG) mutant strain with deletion on genes cobS and cbiA, that are involved in the biosynthesis of cobalamin. Furthermore, evaluate its use as a live vaccine against Salmonella. For the evaluation of the vaccine efficacy, two experiments were conducted separately. Birds from a commercial brown line of chickens were used to perform challenge with SG wild type strain and birds from a commercial white line of chickens were used to perform challenge with Salmonella Enteritidis (SE) wild type strain. In both experiments, the birds were separated in three groups (A, B and C). Birds were orally vaccinated with the SG mutant as the following programme: group A, one dose at 5 days of age; group B, one dose at 5 days of age and a second dose at 25 days of age; and group C, birds were kept unvaccinated as controls. At 45 days of age, birds from all groups, including the control, were challenged orally by SG wild type (brown line) or SE wild type (white line). Lastly, another experiment was performed to evaluate the use of the SG mutant strain to prevent caecal colonization by SE wild type on 1-day-old broiler chicks. Mortality and systemic infection by SG wild type strain were assessed in brown chickens; faecal shedding and systemic infection by SE wild type were assessed in white chickens and caecal colonization was assessed in broiler chicks. Either vaccination with one or two doses of SG mutant, were capable to protect brown chickens against SG wild type. In the experiment with white chickens, only vaccination with two doses of SG mutant protected the birds against challenge with SE wild type. Although, SG mutant could not prevent caecal colonization in 1-day-old broiler chicks by the challenge strain SE wild type. Overall, the results indicated that SG mutant

  1. Comparison of the immunogenicity and safety of measles vaccine administered alone or with live, attenuated Japanese encephalitis SA 14-14-2 vaccine in Philippine infants.

    PubMed

    Gatchalian, Salvacion; Yao, Yafu; Zhou, Benli; Zhang, Lei; Yoksan, Sutee; Kelly, Kim; Neuzil, Kathleen M; Yaïch, Mansour; Jacobson, Julie

    2008-04-24

    Japanese encephalitis (JE) virus is a major cause of disease, disability, and death in Asia. An effective, live, attenuated JE vaccine (LJEV) is available; however, its use in routine immunization schedules is hampered by lack of data on concomitant administration with measles vaccine (MV). This study evaluated the immunogenicity and reactogenicity of LJEV and MV when administered at the same or separate study visits in infants younger than 1 year of age. Three groups of healthy infants were randomized to receive LJEV at age of 8 months and MV at 9 months (Group 1; n=100); MV and LJEV together at 9 months (Group 2; n=236); or MV and LJEV at 9 and 10 months, respectively (Group 3; n=235). Blood was obtained 4 weeks after each vaccine administration to determine antibody levels for measles and JE. Reactogenicity was assessed by parental diaries and clinic visits. Four weeks after immunization, measles seroprotection rates (defined as > or =340 mIU/ml) were high and comparable in all three groups and specifically, rates in the combined MV-LJEV (Group 2) were not statistically inferior to those in Group 3 receiving MV separately (96% versus 100%, respectively). Likewise, the LJEV seroprotection rates were high and similar between the three groups. The reactogenicity profiles of the three vaccine schedules were also analogous. LJEV and MV administered together are well tolerated and immunogenic in infants younger than 1 year. These results should facilitate incorporation of LJEV into routine immunization schedules with MV.

  2. 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.

  3. [Molecular mechanisms of reversions to the ts+ -phenotype of cold-adapted influenza virus A strains--attenuation donors for live influenza reassortant vaccines].

    PubMed

    Markushin, S G; Akopova, I I; Koptiaeva, I B; Tsfasman, T M; Gendon, Iu Z

    2006-01-01

    A ts+ revertant of cold-adapted (ca) strain A/Leningrad/134/47/57--the attenuation donor for live influenza reassortant vaccines--was obtained by passages of the ca strain in chick embryos at nonpermissive temperatures. The ts+ revertant acquired the ability to grow in chick embryos at 40 degrees C and lost the capacity to reproduce there at 25 degrees C. A complementation-recombination test using the fowl plague virus (FPV0 ts-mutants showed the loss of the ts-phenotype in the RNA-segments of ts+ revertants' genome coding for PB2, NP, and NS (NS2) proteins. However, PCR-restriction analysis revealed a true reversion in RNA-segment coding for PB2 protein only. All the investigated mutations in the ts+ revertant genome were preserved. This phenomenon could be explained by the appearance of intragenic and extragenic suppression mutations in the ts+ revertant genome. The data of the complementation-recombination test suggest that reversion of ts-phenotype occurs more frequently due to extra- or intragenic suppression rather than as a result of a true mutation loss. Estimation of the genetic stability of vaccine ca strains of influenza virus should be based on the combined use of PCR-restriction and complementation tests.

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

    PubMed Central

    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

    Background 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. Methods 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. Results 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. Conclusions 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. Trial Registration clinicaltrials.gov (NCT01656200) PMID:28135273

  5. 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).

  6. 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.

  7. 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

  8. 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

  9. MOVING BEYOND PUMP AND TREAT TOWARD ENHANCED ATTENUATION AND COMBINED REMEDIES T-AREA, SAVANNAH RIVER SITE

    SciTech Connect

    Looney, B; Brian Riha, B; Warren Hyde, W; Jay Noonkester, J; Gerald Blount, G

    2008-04-03

    Groundwater beneath T-Area, a former laboratory and semiworks operation at the Department of Energy (DOE) Savannah River Site, is contaminated by chlorinated solvents (cVOCs). Since the contamination was detected in the 1980s, the cVOCs at T-Area have been treated by a combination of soil vapor extraction and groundwater pump and treat. The site has received approval to discontinue the active treatments and implement a full scale test of enhanced attenuation--an engineering and regulatory strategy that has recently been developed by DOE and the Interstate Technology and Regulatory Council. Enhanced attenuation uses active engineering solutions to alter the target site in such a way that the contaminant plume will passively stabilize and shrink and to document that the action will be effective, timely, and sustainable. The paradigm recognizes that attenuation remedies are fundamentally based on a mass balance. Thus, long-term plume dynamics can be altered either by reducing the contaminant loading from the source or by increasing the rate of natural attenuation processes within all, or part of, the plume volume. The combination of technologies that emerged for T-Area included: (1) neat (pure) vegetable oil deployment in the deep vadose zone in the former source area, (2) emulsified vegetable oil deployment within the footprint of the groundwater plume, and (3) identification of attenuation mechanisms and rates for the distal portion of the plume. In the first part, neat oil spreads laterally forming a thin layer on the water table to intercept and reduce future cVOC loading (via partitioning) and reduce oxygen inputs (via biostimulation). In the second and third parts, emulsified oil forms active bioremediation reactor zones within the plume footprint to degrade existing groundwater contamination (via reductive dechlorination) and stimulates long-term attenuation capacity in the distal plume (via cometabolism). For T-Area, the enhanced attenuation development

  10. Development and clinical evaluation of multiple investigational monovalent DENV vaccines to identify components for inclusion in a live attenuated tetravalent DENV vaccine.

    PubMed

    Durbin, Anna P; Kirkpatrick, Beth D; Pierce, Kristen K; Schmidt, Alexander C; Whitehead, Stephen S

    2011-09-23

    The Laboratory of Infectious Diseases at the National Institute of Allergy and Infectious Diseases, National Institutes of Health has been engaged in an effort to develop a safe, efficacious, and affordable live attenuated tetravalent dengue vaccine (LATV) for more than ten years. Numerous recombinant monovalent DENV vaccine candidates have been evaluated in the SCID-HuH-7 mouse and in rhesus macaques to identify those candidates with a suitable attenuation phenotype. In addition, the ability of these candidates to infect and disseminate in Aedes mosquitoes had also been determined. Those candidates that were suitably attenuated in SCID-HuH-7 mice, rhesus macaques, and mosquitoes were selected for further evaluation in humans. This review will describe the generation of multiple candidate vaccines directed against each DENV serotype, the preclinical and clinical evaluation of these candidates, and the process of selecting suitable candidates for inclusion in a LATV dengue vaccine.

  11. Live attenuated influenza viruses produced in a suspension process with avian AGE1.CR.pIX cells.

    PubMed

    Lohr, Verena; Genzel, Yvonne; Jordan, Ingo; Katinger, Dietmar; Mahr, Stefan; Sandig, Volker; Reichl, Udo

    2012-10-30

    Current influenza vaccines are trivalent or quadrivalent inactivated split or subunit vaccines administered intramuscularly, or live attenuated influenza vaccines (LAIV) adapted to replicate at temperatures below body temperature and administered intranasally. Both vaccines are considered safe and efficient, but due to differences in specific properties may complement each other to ensure reliable vaccine coverage. By now, licensed LAIV are produced in embryonated chicken eggs. In the near future influenza vaccines for human use will also be available from adherent MDCK or Vero cell cultures, but a scalable suspension process may facilitate production and supply with vaccines. We evaluated the production of cold-adapted human influenza virus strains in the duck suspension cell line AGE1.CR.pIX using a chemically-defined medium. One cold-adapted A (H1N1) and one cold-adapted B virus strain was tested, as well as the reference strain A/PR/8/34 (H1N1). It is shown that a medium exchange is not required for infection and that maximum virus titers are obtained for 1 × 10⁻⁶ trypsin units per cell. 1 L bioreactor cultivations showed that 4 × 10⁶ cells/mL can be infected without a cell density effect achieving titers of 1 × 10⁸ virions/mL after 24 h. Overall, this study demonstrates that AGE1.CR.pIX cells support replication of LAIV strains in a chemically-defined medium using a simple process without medium exchanges. Moreover, the process is fast with peak titers obtained 24 h post infection and easily scalable to industrial volumes as neither microcarriers nor medium replacements are required.

  12. The live attenuated dengue vaccine TV003 elicits complete protection against dengue in a human challenge model.

    PubMed

    Kirkpatrick, Beth D; Whitehead, Stephen S; Pierce, Kristen K; Tibery, Cecilia M; Grier, Palmtama L; Hynes, Noreen A; Larsson, Catherine J; Sabundayo, Beulah P; Talaat, Kawsar R; Janiak, Anna; Carmolli, Marya P; Luke, Catherine J; Diehl, Sean A; Durbin, Anna P

    2016-03-16

    A dengue human challenge model can be an important tool to identify candidate dengue vaccines that should be further evaluated in large efficacy trials in endemic areas. Dengue is responsible for about 390 million infections annually. Protective efficacy results for the most advanced dengue vaccine candidate (CYD) were disappointing despite its ability to induce neutralizing antibodies against all four dengue virus (DENV) serotypes. TV003 is a live attenuated tetravalent DENV vaccine currently in phase 2 evaluation. To better assess the protective efficacy of TV003, a randomized double-blind, placebo-controlled trial in which recipients of TV003 or placebo were challenged 6 months later with a DENV-2 strain, rDEN2Δ30, was conducted. The primary endpoint of the trial was protection against dengue infection, defined as rDEN2Δ30 viremia. Secondary endpoints were protection against rash and neutropenia. All 21 recipients of TV003 who were challenged with rDEN2Δ30 were protected from infection with rDEN2Δ30. None developed viremia, rash, or neutropenia after challenge. In contrast, 100% of the 20 placebo recipients who were challenged with rDEN2Δ30 developed viremia, 80% developed rash, and 20% developed neutropenia. TV003 induced complete protection against challenge with rDEN2Δ30 administered 6 months after vaccination. TV003 will be further evaluated in dengue-endemic areas. The controlled dengue human challenge model can accelerate vaccine development by evaluating the protection afforded by the vaccine, thereby eliminating poor candidates from further consideration before the initiation of large efficacy trials.

  13. Human transcriptome response to immunization with live-attenuated Venezuelan equine encephalitis virus vaccine (TC-83): Analysis of whole blood

    PubMed Central

    Erwin-Cohen, Rebecca A.; Porter, Aimee I.; Pittman, Phillip R.; Rossi, Cynthia A.; DaSilva, Luis

    2017-01-01

    ABSTRACT Venezuelan equine encephalitis virus (VEEV) is an important human and animal alphavirus pathogen transmitted by mosquitoes. The virus is endemic in Central and South America, but has also caused equine outbreaks in southwestern areas of the United States. In an effort to better understand the molecular mechanisms of the development of immunity to this important pathogen, we performed transcriptional analysis from whole, unfractionated human blood of patients who had been immunized with the live-attenuated vaccine strain of VEEV, TC-83. We compared changes in the transcriptome between naïve individuals who were mock vaccinated with saline to responses of individuals who received TC-83. Significant transcriptional changes were noted at days 2, 7, and 14 following vaccination. The top canonical pathways revealed at early and intermediate time points (days 2 and 7) included the involvement of the classic interferon response, interferon-response factors, activation of pattern recognition receptors, and engagement of the inflammasome. By day 14, the top canonical pathways included oxidative phosphorylation, the protein ubiquitination pathway, natural killer cell signaling, and B-cell development. Biomarkers were identified that differentiate between vaccinees and control subjects, at early, intermediate, and late stages of the development of immunity as well as markers which were common to all 3 stages following vaccination but distinct from the sham-vaccinated control subjects. The study represents a novel examination of molecular processes that lead to the development of immunity against VEEV in humans and which may be of value as diagnostic targets, to enhance modern vaccine design, or molecular correlates of protection. PMID:27870591

  14. Experience with live attenuated varicella vaccine (Oka strain) in healthy Japanese subjects; 10-year survey at pediatric clinic.

    PubMed

    Ozaki, T; Nishimura, N; Kajita, Y

    2000-05-08

    Live attenuated varicella vaccine (Oka strain, Biken Institute, Osaka, Japan) was administered to 973 healthy individuals over a 10-year period (1987-1997) at the pediatric clinic of Showa Hospital in Japan. We evaluated the relevant serological and clinical data, which were collected by questionnaire. Seroconversion by the immune adherence hemagglutination method was documented in 94% (805/860) of the initially seronegative subjects. Of the initially seropositive subjects, 56% (63/113) showed enhancement of antibody after vaccination. Reactions to the vaccine were generally insignificant, except for a rash at the injection site, seen in the first 3 days post-administration in 17% (41/241) of the recently vaccinated subjects. In March 1998, we conducted a survey of 559 of the initially seronegative subjects who had received the vaccine 0.6-10. 8 (mean 5.4) years earlier. Of these subjects, 21% (119/559) contracted breakthrough varicella. However, their symptoms were milder than those caused by natural varicella seen in unvaccinated children. Seroconversion was demonstrated in 92% (109/119) of these cases. The incidence of breakthrough disease decreased with a rise in postvaccination antibody titer to >==32. Four of the subjects (0.7% of 559) developed herpes zoster following vaccination, two of whom had earlier exhibited breakthrough varicella. Lesions in one case of zoster, without breakthrough varicella, appeared on the cervical dermatome at the injection site. The vaccine was safe and effective. However, there was a relatively high incidence of rash at the injection site with certain lot numbers used in recent years which warrants investigation.

  15. Effect of Broccoli Sprouts on Nasal Response to Live Attenuated Influenza Virus in Smokers: A Randomized, Double-Blind Study

    PubMed Central

    Noah, Terry L.; Zhang, Hongtao; Zhou, Haibo; Glista-Baker, Ellen; Müller, Loretta; Bauer, Rebecca N.; Meyer, Megan; Murphy, Paula C.; Jones, Shannon; Letang, Blanche; Robinette, Carole; Jaspers, Ilona

    2014-01-01

    Background Smokers have increased susceptibility and altered innate host defense responses to influenza virus infection. Broccoli sprouts are a source of the Nrf2 activating agentsulforaphane, and short term ingestion of broccoli sprout homogenates (BSH) has been shown to reduce nasal inflammatory responses to oxidant pollutants. Objectives Assess the effects of BSH on nasal cytokines, virus replication, and Nrf2-dependent enzyme expression in smokers and nonsmokers. Methods We conducted a randomized, double-blind, placebo-controlled trial comparing the effects of BSH on serially sampled nasal lavage fluid (NLF) cytokines, viral sequence quantity, and Nrf2-dependent enzyme expression in NLF cells and biopsied epithelium. Healthy young adult smokers and nonsmokers ingested BSH or placebo (alfalfa sprout homogenate) for 4 days, designated Days -1, 0, 1, 2. On Day 0 they received standard vaccine dose of live attenuated influenza virus (LAIV) intranasally. Nasal lavage fluids and nasal biopsies were collected serially to assess response to LAIV. Results In area under curve analyses, post-LAIV IL-6 responses (P = 0.03) and influenza sequences (P = 0.01) were significantly reduced in NLF from BSH-treated smokers, whileNAD(P)H: quinoneoxidoreductasein NLF cells was significantly increased. In nonsmokers, a similar trend for reduction in virus quantity with BSH did not reach statistical significance. Conclusions In smokers, short term ingestion of broccoli sprout homogenates appears to significantly reduce some virus-induced markers of inflammation, as well as reducing virus quantity. Nutritional antioxidant interventions have promise as a safe, low-cost strategy for reducing influenza risk among smokers and other at risk populations. Trial Registration ClinicalTrials.gov NCT01269723 PMID:24910991

  16. Evaluation of the Salmonella enterica Serovar Pullorum Pathogenicity Island 2 Mutant as a Candidate Live Attenuated Oral Vaccine

    PubMed Central

    Yin, Junlei; Cheng, Zhao; Wang, Xiaochun; Xu, Lijuan; Li, Qiuchun; Geng, Shizhong

    2015-01-01

    Salmonella enterica serovar Pullorum (S. Pullorum) is a highly adapted pathogen that causes pullorum disease (PD), an important systemic disease of poultry that causes severe economic losses in developing countries. In the interests of developing a safe and immunogenic oral vaccine, the efficacy of a Salmonella pathogenicity island 2 (SPI2)-deleted mutant of S. Pullorum (S06004ΔSPI2) was evaluated in chickens. S06004ΔSPI2 was severely less virulent than the parental wild-type strain S06004 as determined by the 50% lethal dose (LD50) for 3-day-old chickens when injected intramuscularly. Two-day-old chickens immunized with a single oral dose of S06004ΔSPI2 showed no differences in body weight or clinical symptoms compared with those in the negative-control group. S06004ΔSPI2 bacteria were not isolated from livers or spleens of immunized chickens after a short period of time, and specific humoral and cellular immune responses were significantly induced. Immunized chickens were challenged with S. Pullorum strain S06004 and Salmonella enterica serovar Gallinarum (S. Gallinarum) strain SG9 at 10 days postimmunization (dpi), and efficient protection against the challenges was observed. None of the immunized chickens died, the clinical symptoms were slight and temporary following challenge in immunized chickens compared with those in the control group, and these chickens recovered by 3 to 5 dpi. Overall, these results demonstrate that S06004ΔSPI2 can be used as a live attenuated oral vaccine. PMID:25924763

  17. Live attenuated influenza viruses produced in a suspension process with avian AGE1.CR.pIX cells

    PubMed Central

    2012-01-01

    Background Current influenza vaccines are trivalent or quadrivalent inactivated split or subunit vaccines administered intramuscularly, or live attenuated influenza vaccines (LAIV) adapted to replicate at temperatures below body temperature and administered intranasally. Both vaccines are considered safe and efficient, but due to differences in specific properties may complement each other to ensure reliable vaccine coverage. By now, licensed LAIV are produced in embryonated chicken eggs. In the near future influenza vaccines for human use will also be available from adherent MDCK or Vero cell cultures, but a scalable suspension process may facilitate production and supply with vaccines. Results We evaluated the production of cold-adapted human influenza virus strains in the duck suspension cell line AGE1.CR.pIX using a chemically-defined medium. One cold-adapted A (H1N1) and one cold-adapted B virus strain was tested, as well as the reference strain A/PR/8/34 (H1N1). It is shown that a medium exchange is not required for infection and that maximum virus titers are obtained for 1 × 10-6 trypsin units per cell. 1 L bioreactor cultivations showed that 4 × 106 cells/mL can be infected without a cell density effect achieving titers of 1 × 108 virions/mL after 24 h. Conclusions Overall, this study demonstrates that AGE1.CR.pIX cells support replication of LAIV strains in a chemically-defined medium using a simple process without medium exchanges. Moreover, the process is fast with peak titers obtained 24 h post infection and easily scalable to industrial volumes as neither microcarriers nor medium replacements are required. PMID:23110398

  18. Single-dose live-attenuated Nipah virus vaccines confer complete protection by eliciting antibodies directed against surface glycoproteins

    PubMed Central

    DeBuysscher, Blair L.; Scott, Dana; Marzi, Andrea; Prescott, Joseph; Feldmann, Heinz

    2016-01-01

    Background Nipah virus (NiV), a zoonotic pathogen causing severe respiratory illness and encephalitis in humans, emerged in Malaysia in 1998 with subsequent outbreaks on an almost annual basis since 2001 in parts of the Indian subcontinent. The high case fatality rate, human-to-human transmission, wide-ranging reservoir distribution and lack of licensed intervention options are making NiV a serious regional and potential global public health problem. The objective of this study was to develop a fast-acting, single-dose NiV vaccine that could be implemented in a ring vaccination approach during outbreaks. Methods In this study we have designed new live-attenuated vaccine vectors based on recombinant vesicular stomatitis viruses (rVSV) expressing NiV glycoproteins (G or F) or nucleoprotein (N) and evaluated their protective efficacy in Syrian hamsters, an established NiV animal disease model. We further characterized the humoral immune response to vaccination in hamsters using ELISA and neutralization assays and performed serum transfer studies. Results Vaccination of Syrian hamsters with a single dose of the rVSV vaccine vectors resulted in strong humoral immune responses with neutralizing activities found only in those animals vaccinated with rVSV expressing NiV G or F proteins. Vaccinated animals with neutralizing antibody responses were completely protected from lethal NiV disease, whereas animals vaccinated with rVSV expressing NiV N showed only partial protection. Protection of NiV G or F vaccinated animals was conferred by antibodies, most likely the neutralizing fraction, as demonstrated by serum transfer studies. Protection of N-vaccinated hamsters was not antibody-dependent indicating a role of adaptive cellular responses for protection. Conclusions The rVSV vectors expressing Nipah virus G or F are prime candidates for new ‘emergency vaccines’ to be utilized for NiV outbreak management. PMID:24631094

  19. Comparative efficacy of various chemical stabilizers on the thermostability of a live-attenuated peste des petits ruminants (PPR) vaccine.

    PubMed

    Sarkar, J; Sreenivasa, B P; Singh, R P; Dhar, P; Bandyopadhyay, S K

    2003-12-01

    Thermostability of a live-attenuated peste des petits ruminants (PPR) vaccine recently developed at Indian Veterinary Research Institute was studied using conventional lyophilization conditions. A total of four stabilizers viz., lactalbumin hydrolysate-sucrose (LS), Weybridge medium (WBM), buffered gelatin-sorbitol (BUGS) and trehalose dihydrate (TD) were used to prepare the lyophilized vaccine. The study revealed that the PPR vaccine lyophilized with either LS or TD is more stable than rest of the stabilizers having an expiry period of at least 45 days (so far studied) at 4 degrees C, 15-19 days at 25 degrees C and 1-2 days at 37 degrees C. However, at a temperature of 45 degrees C, BUGS had a marginal superiority, although lasted for few hours, followed by TD and LS with respect to shelf-life, LS and TD with respect to half-life. On the basis of half-life also LS followed by TD appeared superior at a temperature of 4, 25 and 37 degrees C. Reconstitution of vaccine with distilled water or 1M MgSO(4) or 0.85% NaCl maintained the required virus titre (2.5log(10)TCID(50) per dose) up to 8h at 37 degrees C and 7h at 45 degrees C. Among the three diluents, 1M MgSO(4) appeared to be the better diluent for reconstitution of lyophilized PPR vaccine, as the loss on dilution was lowest and maintain the required virus titre for a longer period. Investigation suggests for using LS as stabilizer for lyophilization and 1M MgSO(4) as vaccine diluent for the newly developed PPR vaccine.

  20. Protection induced by commercially available live-attenuated and recombinant viral vector vaccines against infectious laryngotracheitis virus in broiler chickens.

    PubMed

    Vagnozzi, Ariel; Zavala, Guillermo; Riblet, Sylva M; Mundt, Alice; García, Maricarmen

    2012-01-01

    Viral vector vaccines using fowl poxvirus (FPV) and herpesvirus of turkey (HVT) as vectors and carrying infectious laryngotracheitis virus (ILTV) genes are commercially available to the poultry industry in the USA. Different sectors of the broiler industry have used these vaccines in ovo or subcutaneously, achieving variable results. The objective of the present study was to determine the efficacy of protection induced by viral vector vaccines as compared with live-attenuated ILTV vaccines. The HVT-LT vaccine was more effective than the FPV-LT vaccine in mitigating the disease and reducing levels of challenge virus when applied in ovo or subcutaneously, particularly when the challenge was performed at 57 days rather than 35 days of age. While the FPV-LT vaccine mitigated clinical signs more effectively when administered subcutaneously than in ovo, it did not reduce the concentration of challenge virus in the trachea by either application route. Detection of antibodies against ILTV glycoproteins expressed by the viral vectors was a useful criterion to assess the immunogenicity of the vectors. The presence of glycoprotein I antibodies detected pre-challenge and post challenge in chickens vaccinated with HVT-LT indicated that the vaccine induced a robust antibody response, which was paralleled by significant reduction of clinical signs. The chicken embryo origin vaccine provided optimal protection by significantly mitigating the disease and reducing the challenge virus in chickens vaccinated via eye drop. The viral vector vaccines, applied in ovo and subcutaneously, provided partial protection, reducing to some degree clinical signs, and challenge VIRUS replication in the trachea.

  1. Live attenuated African swine fever viruses as ideal tools to dissect the mechanisms involved in viral pathogenesis and immune protection.

    PubMed

    Lacasta, Anna; Monteagudo, Paula L; Jiménez-Marín, Ángeles; Accensi, Francesc; Ballester, María; Argilaguet, Jordi; Galindo-Cardiel, Iván; Segalés, Joaquim; Salas, María L; Domínguez, Javier; Moreno, Ángela; Garrido, Juan J; Rodríguez, Fernando

    2015-11-20

    African swine fever virus (ASFV) is the causal agent of African swine fever, a hemorrhagic and often lethal porcine disease causing enormous economical losses in affected countries. Endemic for decades in most of the sub-Saharan countries and Sardinia, the risk of ASFV-endemicity in Europe has increased since its last introduction into Europe in 2007. Live attenuated viruses have been demonstrated to induce very efficient protective immune responses, albeit most of the time protection was circumscribed to homologous ASFV challenges. However, their use in the field is still far from a reality, mainly due to safety concerns. In this study we compared the course of the in vivo infection caused by two homologous ASFV strains: the virulent E75 and the cell cultured adapted strain E75CV1, obtained from adapting E75 to grow in the CV1 cell-line. Interestingly, the kinetics of both viruses not only differed on the clinical signs that they caused and in the virus loads found, but also in the immunological pathways activated throughout the infections. Furthermore, E75CV1 confirmed its protective potential against the homologous E75 virus challenge and allowed the demonstration of poor cross-protection against BA71, thus defining it as heterologous. The in vitro specificity of the CD8(+) T-cells present at the time of lethal challenge showed a clear activation against the homologous virus (E75) but not against BA71. These findings will be of utility for a better understanding of ASFV pathogenesis and for the rational designing of safe and efficient vaccines against this virus.

  2. Estimating Cleanup Times Associated with Combining Source-Area Remediation with Monitored Natural Attenuation

    DTIC Science & Technology

    2008-06-01

    Station MCL maximum contaminant level MCLG maximum contaminant level goal MNA monitored natural attenuation MODFLOW Modular Three-Dimensional...Groundwater Flow Model ( MODFLOW ). The solution provided by NAS is tailored to estimate the length of time required by a given NAPL mass to dissolve and

  3. tRNA modification by GidA/MnmE is necessary for Streptococcus pyogenes virulence: a new strategy to make live attenuated strains.

    PubMed

    Cho, Kyu Hong; Caparon, Michael G

    2008-07-01

    Studies directed at vaccine development and mucosal immunity against Streptococcus pyogenes would benefit from the availability of live attenuated strains. Our approach for production of candidate live attenuated strains was to identify mutations that did not alter growth in vitro and did not alter the overall complement of virulence factors produced but did result in reduced levels of expression of multiple secreted virulence factors. A global reduction but not elimination of expression would likely lead to attenuation while maximizing the number of antigenic targets available for stimulation of immunity. Adaptation of Tn5-based transposome mutagenesis to S. pyogenes with initial screening for reduced expression of the SpeB protease resulted in identification of mutations in gidA, which encodes an enzyme involved in tRNA modification. Reduced SpeB expression was due to delayed onset of speB transcription resulting from reduced translation efficiency of the message for RopB, a transcriptional activator. Overall, GidA(-) mutants had a nearly normal global transcription profile but expressed significantly reduced levels of multiple virulence factors due to impaired translation efficiencies. A translation defect was supported by the observation that mutants lacking MnmE, which functions in the same tRNA modification pathway as GidA, phenocopied GidA deficiency. The mutants stimulated a cytokine response in cultured macrophages identical to that in the wild type, with the exception of reduced levels of tumor necrosis factor alpha and interleukin-23. Significantly, GidA(-) mutants were highly attenuated in the murine ulcer model of soft tissue infection. These characteristics suggest that GidA pathway tRNA modification mutants are attractive candidates for further evaluation as live attenuated strains.

  4. 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.

    PubMed

    Yamshchikov, Vladimir; Manuvakhova, Marina; Rodriguez, Efrain; Hébert, Charles

    2017-01-01

    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 (Yamshchikov et al., 2016). 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 vaccine 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. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. An open‐label phase I trial of a live attenuated H2N2 influenza virus vaccine in healthy adults

    PubMed Central

    Talaat, Kawsar R.; Karron, Ruth A.; Liang, Philana H.; McMahon, Bridget A.; Luke, Catherine J.; Thumar, Bhagvanji; Chen, Grace L.; Min, Ji‐Young; Lamirande, Elaine W.; Jin, Hong; Coelingh, Kathy L.; Kemble, George W.; Subbarao, Kanta

    2012-01-01

    Please cite this paper as: Talaat et al. (2012) An open‐label phase I trial of a live attenuated H2N2 influenza virus vaccine in healthy adults. Influenza and Other Respiratory Viruses DOI: 10.1111/j.1750‐2659.2012.00350.x. Background  Live attenuated influenza vaccines (LAIV) against a variety of strains of pandemic potential are being developed and tested. We describe the results of an open‐label phase I trial of a live attenuated H2N2 virus vaccine. Objectives  To evaluate the safety, infectivity, and immunogenicity of a live attenuated H2N2 influenza virus vaccine. Participants/methods  The A/Ann Arbor/6/60 (H2N2) virus used in this study is the attenuated, cold‐adapted, temperature‐sensitive strain that provides the genetic backbone of seasonal LAIV (MedImmune). We evaluated the safety, infectivity, and immunogenicity of two doses of 107 TCID50 of this vaccine administered by nasal spray 4 weeks apart to normal healthy seronegative adults. Results  Twenty‐one participants received a first dose of the vaccine; 18 participants received a second dose. No serious adverse events occurred during the trial. The most common adverse events after vaccination were headache and musculoskeletal pain. The vaccine was restricted in replication: 24% and 17% had virus detectable by culture or rRT‐PCR after the first and second dose, respectively. Antibody responses to the vaccine were also restricted: 24% of participants developed an antibody response as measured by either hemagglutination‐inhibition assay (10%), or ELISA for H2 HA‐specific serum IgG (24%) or IgA (16%) after either one or two doses. None of the participants had a neutralizing antibody response. Vaccine‐specific IgG‐secreting cells as measured by enzyme‐linked immunospot increased from a mean of 0·5 to 2·0/106 peripheral blood mononuclear cells (PBMCs); vaccine‐specific IgA‐secreting cells increased from 0·1 to 0·5/106 PBMCs. Conclusions  The live attenuated H2N2

  6. Removal and attenuation of sewage effluent combined tracer signals of phosphorus, caffeine and saccharin in soil.

    PubMed

    Richards, Samia; Withers, Paul J A; Paterson, Eric; McRoberts, Colin W; Stutter, Marc

    2017-04-01

    Contaminants in septic tank effluent (STE) are expected to be removed by the soil system before discharging to the environment. However, potential contaminants such as phosphorus (P), caffeine and artificial sweeteners do find their way to watercourses impacting aquatic eco systems. In this study, the attenuation of STE P, caffeine and saccharin were investigated in untreated soil and in soil with reduced microbial activity, in aqueous solutions and in the complex matrix of STE. Time series sorption and desorption experiments using batch equilibrium and a column experiment of STE P attenuation were conducted. The results revealed that the soil distribution coefficients (Kd) were: P 81.57 > caffeine 22.16 > saccharin 5.98 cm(3)/g, suggesting greater soil affinity to P adsorption. The data revealed that 80% of saccharin and 33% of caffeine attenuation was associated with microbial activities rather than adsorption processes. However, a complete removal of saccharin and caffeine did not occur during the equilibration period, suggesting their leaching potential. The dominant mechanism of P attenuation was adsorption (chemical and physical), yielding P retention of >73% and 35% for P in aqueous solution and in STE matrix, respectively, for batch equilibrium. The soil in the column acted as effluent P sink retaining 125 μg P/g soil of effluent P. The attenuation of P, caffeine and saccharin in the aqueous solution was greater than in STE, suggesting that the complex composition of STE reduced soil adsorption ability, and that other substances present in STE may be competing for soil binding sites. The data revealed that caffeine and P had similarities in the interaction with soils and thus caffeine may be considered as a STE tracer of anthropogenic source of P in receiving waters. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. 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.

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

    PubMed

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

    2016-01-06

    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 10-10(4)-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.

  9. Generation and preclinical evaluation of a DENV-1/2 prM+E chimeric live attenuated vaccine candidate with enhanced prM cleavage.

    PubMed

    Keelapang, Poonsook; Nitatpattana, Narong; Suphatrakul, Amporn; Punyahathaikul, Surat; Sriburi, Rungtawan; Pulmanausahakul, Rojjanaporn; Pichyangkul, Sathit; Malasit, Prida; Yoksan, Sutee; Sittisombut, Nopporn

    2013-10-17

    In the absence of a vaccine or sustainable vector control measures, illnesses caused by dengue virus infection remain an important public health problem in many tropical countries. During the export of dengue virus particles, furin-mediated cleavage of the prM envelope protein is usually incomplete, thus generating a mixture of immature, partially mature and mature extracellular particles. Variations in the arrangement and conformation of the envelope proteins among these particles may be associated with their different roles in shaping the antibody response. In an attempt to improve upon live, attenuated dengue vaccine approaches, a mutant chimeric virus, with enhanced prM cleavage, was generated by introducing a cleavage-enhancing substitution into a chimeric DENV-1/2 virus genome, encoding the prM+E sequence of a recent DENV-1 isolate under an attenuated DENV-2 genetic background. A modest increase in virus specific infectivity observed in the mutant chimeric virus affected neither the attenuation phenotype, when assessed in the suckling mouse neurovirulence model, nor multiplication in mosquitoes. The two chimeric viruses induced similar levels of anti-DENV-1 neutralizing antibody response in mice and rhesus macaques, but more efficient control of viremia during viral challenge was observed in macaques immunized with the mutant chimeric virus. These results indicate that the DENV-1/2 chimeric virus, with enhanced prM cleavage, could be useful as an alternative live, attenuated vaccine candidate for further tests in humans.

  10. 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) (...

  11. Phase-I study MEDI-534, of a live, attenuated intranasal vaccine against respiratory syncytial virus and parainfluenza-3 virus in seropositive children.

    PubMed

    Gomez, Margarita; Mufson, Maurice A; Dubovsky, Filip; Knightly, Conor; Zeng, Wen; Losonsky, Genevieve

    2009-07-01

    A live, attenuated respiratory syncytial virus and parainfluenza virus type 3 vaccine was evaluated in healthy respiratory syncytial virus/parainfluenza virus type 3 seropositive children aged 1 to 9 years. Three cohorts of 40 children were randomized 1:1 to receive 10, 10, or 10 median tissue culture infectious dose50 MEDI-534 vaccine or placebo. The vaccine's safety profile was similar to placebo, no viral shedding was detected, and the vaccine was minimally immunogenic.

  12. 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

    Vaccine 23 (2005) 3139–3147 Genetically engineered, live, attenuated vaccines protect nonhuman primates against aerosol challenge with a virulent IE...Prattb, Michael D. Parkerb a Center for Aerobiological Sciences, U.S. Army Medical Research Institute of Infectious Diseases, 1425 Porter Street, Fort...Received 27 August 2004; received in revised form 22 December 2004; accepted 23 December 2004 Available online 21 January 2005 Abstract d w h o a w s f P

  13. Mucosal Immunization with the Live Attenuated Vaccine SPY1 Induces Humoral and Th2-Th17-Regulatory T Cell Cellular Immunity and Protects against Pneumococcal Infection

    PubMed Central

    Xu, Xiuyu; Wang, Hong; Liu, Yusi; Wang, Yiping; Zeng, Lingbing; Wu, Kaifeng; Wang, Jianmin; Ma, Feng; Xu, Wenchun; Yin, Yibing

    2014-01-01

    Mucosal immunization with attenuated vaccine can protect against pneumococcal invasion infection, but the mechanism was unknown. Our study found that mucosal delivery with the live attenuated SPY1 vaccine strain can confer T cell- and B cell-dependent protection against pneumococcal colonization and invasive infection; yet it is still unclear which cell subsets contribute to the protection, and their roles in pneumococcal colonization and invasion remain elusive. Adoptive transfer of anti-SPY1 antibody conferred protection to naive μMT mice, and immune T cells were indispensable to protection examined in nude mice. A critical role of interleukin 17A (IL-17A) in colonization was demonstrated in mice lacking IL-17A, and a vaccine-specific Th2 immune subset was necessary for systemic protection. Of note, we found that SPY1 could stimulate an immunoregulatory response and that SPY1-elicited regulatory T cells participated in protection against colonization and lethal infection. The data presented here aid our understanding of how live attenuated strains are able to function as effective vaccines and may contribute to a more comprehensive evaluation of live vaccines and other mucosal vaccines. PMID:25312946

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

    SciTech Connect

    Guerbois, Mathilde; Moris, Arnaud; Combredet, Chantal; Najburg, Valerie; Ruffie, Claude; Fevrier, Michele; Cayet, Nadege; Brandler, Samantha; Schwartz, Olivier; Tangy, Frederic

    2009-05-25

    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 to 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.

  15. An Innovative Teacher Training Approach: Combine Live Instruction with a Web-Based Reflection System.

    ERIC Educational Resources Information Center

    Chuang, Wen-Hao

    2002-01-01

    Describes a program developed by Hong Kong universities for training primary and secondary school teachers as part of government efforts to promote a paradigm shift in education to promote a knowledge economy. Explains a combination of live instruction with Web-based systems that focuses on the use of information technology. (Author/LRW)

  16. Respiratory Syncytial Virus Modified by Deletions of the NS2 Gene and Amino Acid S1313 of the L Polymerase Protein Is a Temperature-Sensitive, Live-Attenuated Vaccine Candidate That Is Phenotypically Stable at Physiological Temperature

    PubMed Central

    Luongo, Cindy; Winter, Christine C.; Collins, Peter L.

    2013-01-01

    Human respiratory syncytial virus (RSV) is the leading viral cause of lower respiratory tract disease in infants and children worldwide. In previous work to develop point mutations in RSV with improved genetic stability, we observed that an attenuating mutation at amino acid position 1321 in the L polymerase protein was subject to deattenuation by a spontaneous second-site compensatory mutation at position 1313 (C. Luongo, C. C. Winter, P. L. Collins, and U. J. Buchholz, J. Virol. 86:10792–10804, 2012). In the present study, we found that deletion of position 1313 (Δ1313), irrespective of the presence of an attenuating mutation at position 1321, provided a new attenuating mutation. RSV bearing Δ1313 replicated in cell culture as efficiently as wild-type virus at 32°C, was restricted for replication at 37°C, and was restricted 50-fold and 150-fold in the upper and lower respiratory tracts, respectively, of mice. We combined the Δ1313 deletion with the previously described, attenuating NS2 gene deletion (ΔNS2) to produce the recombinant live-attenuated RSV vaccine candidate ΔNS2/Δ1313. During in vitro stress tests involving serial passage at incrementally increasing temperatures, a second-site compensatory mutation was detected in close proximity of Δ1313, namely, I1314T. This site was genetically and phenotypically stabilized by an I1314L substitution. Combination of I1314L with ΔNS2/Δ1313 yielded a virus, ΔNS2/Δ1313/1314L, with genetic stability at physiological temperature. This stabilized vaccine candidate was moderately temperature sensitive and had a level of restriction in chimpanzees comparable to that of MEDI-559, a promising RSV vaccine candidate that presently is in clinical trials but lacks stabilized attenuating mutations. The level of attenuation and genetic stability identify ΔNS2/Δ1313/1314L as a promising candidate for evaluation in pediatric phase I studies. PMID:23236065

  17. Estimating Cleanup Times Associated With Combining Source-Area Remediation With Monitored Natural Attenuation

    DTIC Science & Technology

    2008-02-01

    1994, Chiou and Kile (USGS, 2000) 3.2.2 Source Characteristics The source area was based on estimates of the locations where contaminants were...values for Koc and solubility for some of the SVOC’s appear in published literature (Chiou and Kile , 2000), which suggests a larger range of...Monitored Natural Attenuation. United States Geological Survey Water Resources Investigations Report 03-4057. Chiou, C.T. and Kile , D.E., 2000

  18. Corrections for the combined effects of decay and dead time in live-timed counting of short-lived radionuclides.

    PubMed

    Fitzgerald, R

    2016-03-01

    Studies and calibrations of short-lived radionuclides, for example (15)O, are of particular interest in nuclear medicine. Yet counting experiments on such species are vulnerable to an error due to the combined effect of decay and dead time. Separate decay corrections and dead-time corrections do not account for this issue. Usually counting data are decay-corrected to the start time of the count period, or else instead of correcting the count rate, the mid-time of the measurement is used as the reference time. Correction factors are derived for both those methods, considering both extending and non-extending dead time. Series approximations are derived here and the accuracy of those approximations are discussed. Published by Elsevier Ltd.

  19. Combined inhibition of complement C5 and CD14 markedly attenuates inflammation, thrombogenicity, and hemodynamic changes in porcine sepsis.

    PubMed

    Barratt-Due, Andreas; Thorgersen, Ebbe B; Egge, Kjetil; Pischke, Søren; Sokolov, Andrey; Hellerud, Bernt C; Lindstad, Julie K; Pharo, Anne; Bongoni, Anjan K; Rieben, Robert; Nunn, Miles; Scott, Helge; Mollnes, Tom E

    2013-07-15

    Complement and the TLR family constitute two important branches of innate immunity. We previously showed attenuating effects on inflammation and thromogenicity by inhibiting the TLR coreceptor CD14 in porcine sepsis. In the present study, we explored the effect of the C5 and leukotriene B4 inhibitor Ornithodoros moubata complement inhibitor (OmCI; also known as coversin) alone and combined with anti-CD14 on the early inflammatory, hemostatic, and hemodynamic responses in porcine Escherichia coli-induced sepsis. Pigs were randomly allocated to negative controls (n = 6), positive controls (n = 8), intervention with OmCI (n = 8), or with OmCI and anti-CD14 (n = 8). OmCI ablated C5 activation and formation of the terminal complement complex and significantly decreased leukotriene B4 levels in septic pigs. Granulocyte tissue factor expression, formation of thrombin-antithrombin complexes (p < 0.001), and formation of TNF-α and IL-6 (p < 0.05) were efficiently inhibited by OmCI alone and abolished or strongly attenuated by the combination of OmCI and anti-CD14 (p < 0.001 for all). Additionally, the combined therapy attenuated the formation of plasminogen activator inhibitor-1 (p < 0.05), IL-1β, and IL-8, increased the formation of IL-10, and abolished the expression of wCD11R3 (CD11b) and the fall in neutrophil cell count (p < 0.001 for all). Finally, OmCI combined with anti-CD14 delayed increases in heart rate by 60 min (p < 0.05) and mean pulmonary artery pressure by 30 min (p < 0.01). Ex vivo studies confirmed the additional effect of combining anti-CD14 with OmCI. In conclusion, upstream inhibition of the key innate immunity molecules, C5 and CD14, is a potential broad-acting treatment regimen in sepsis as it efficiently attenuated inflammation and thrombogenicity and delayed hemodynamic changes.

  20. Short-Lived Effector CD8 T Cells Induced by Genetically Attenuated Malaria Parasite Vaccination Express CD11c

    PubMed Central

    Cooney, Laura A.; Gupta, Megha; Thomas, Sunil; Mikolajczak, Sebastian; Choi, Kimberly Y.; Gibson, Claire; Jang, Ihn K.; Danziger, Sam; Aitchison, John; Gardner, Malcolm J.; Kappe, Stefan H. I.

    2013-01-01

    Vaccination with a single dose of genetically attenuated malaria parasites can induce sterile protection against sporozoite challenge in the rodent Plasmodium yoelii model. Protection is dependent on CD8+ T cells, involves perforin and gamma interferon (IFN-γ), and is correlated with the expansion of effector memory CD8+ T cells in the liver. Here, we have further characterized vaccine-induced changes in the CD8+ T cell phenotype and demonstrated significant upregulation of CD11c on CD3+ CD8b+ T cells in the liver, spleen, and peripheral blood. CD11c+ CD8+ T cells are predominantly CD11ahi CD44hi CD62L−, indicative of antigen-experienced effector cells. Following in vitro restimulation with malaria-infected hepatocytes, CD11c+ CD8+ T cells expressed inflammatory cytokines and cytotoxicity markers, including IFN-γ, tumor necrosis factor alpha (TNF-α), interleukin-2 (IL-2), perforin, and CD107a. CD11c− CD8+ T cells, on the other hand, expressed negligible amounts of all inflammatory cytokines and cytotoxicity markers tested, indicating that CD11c marks multifunctional effector CD8+ T cells. Coculture of CD11c+, but not CD11c−, CD8+ T cells with sporozoite-infected primary hepatocytes significantly inhibited liver-stage parasite development. Tetramer staining for the immunodominant circumsporozoite protein (CSP)-specific CD8+ T cell epitope demonstrated that approximately two-thirds of CSP-specific cells expressed CD11c at the peak of the CD11c+ CD8+ T cell response, but CD11c expression was lost as the CD8+ T cells entered the memory phase. Further analyses showed that CD11c+ CD8+ T cells are primarily KLRG1+ CD127− terminal effectors, whereas all KLRG1− CD127+ memory precursor effector cells are CD11c− CD8+ T cells. Together, these results suggest that CD11c marks a subset of highly inflammatory, short-lived, antigen-specific effector cells, which may play an important role in eliminating infected hepatocytes. PMID:23980113

  1. Dietary live yeast and mannan-oligosaccharide supplementation attenuate intestinal inflammation and barrier dysfunction induced by Escherichia coli in broilers.

    PubMed

    Wang, Weiwei; Li, Zhui; Han, Qiqi; Guo, Yuming; Zhang, Bo; D'inca, Romain

    2016-12-01

    The effects of live yeast (LY) and mannan-oligosaccharide (MOS) supplementation on intestinal disruption induced by Escherichia coli in broilers were investigated. The experimental design was a 3×2 factorial arrangement with three dietary treatments (control, 0·5 g/kg LY (Saccharomyces cerevisiae, 1·0×1010 colony-forming units/g), 0·5 g/kg MOS) and two immune treatments (with or without E. coli challenge from 7 to 11 d of age). Samples were collected at 14 d of age. The results showed that E. coli challenge impaired (P<0·05) growth performance during the grower period (1-21 d) and the overall period (1-35 d) of broilers, increased (P<0·05) serum endotoxin and diamine oxidase levels coupled with ileal myeloperoxidase and lysozyme activities, whereas reduced (P<0·05) maltase activity, and compromised the morphological structure of the ileum. Besides, it increased (P<0·05) the mRNA expressions of several inflammatory genes and reduced occludin expression in the ileum. Dietary treatment with both LY and MOS reduced (P<0·05) serum diamine oxidase and ileal myeloperoxidase levels, but elevated villus height (P<0·10) and the ratio of villus height:crypt depth (P<0·05) of the ileum. It also alleviated (P<0·05) E. coli-induced increases (P<0·05) in ileal Toll-like receptor 4, NF-κ B and IL-1 β expressions. Moreover, LY supplementation reduced (P<0·05) feed conversion ratio of birds during the grower period and enhanced (P<0·05) the community diversity (Shannon and Simpson indices) of ileal microbiota, whereas MOS addition counteracted (P<0·05) the decreased ileal IL-10 and occludin expressions in challenged birds. In conclusion, both LY and MOS supplementation could attenuate E. coli-induced intestinal disruption by alleviating intestinal inflammation and barrier dysfunction in broilers. Moreover, LY addition could improve intestinal microbial community structure and feed efficiency of broilers.

  2. Role of Occult and Post-acute Phase Replication in Protective Immunity Induced with a Novel Live Attenuated SIV Vaccine

    PubMed Central

    Ham, Claire; Ferguson, Deborah; Tudor, Hannah; Mattiuzzo, Giada; Klaver, Bep; Page, Mark; Stebbings, Richard; Das, Atze T.; Berkhout, Ben; Almond, Neil; Cranage, Martin P.

    2016-01-01

    In order to evaluate the role of persisting virus replication during occult phase immunisation in the live attenuated SIV vaccine model, a novel SIVmac239Δnef variant (SIVrtTA) genetically engineered to replicate in the presence of doxycycline was evaluated for its ability to protect against wild-type SIVmac239. Indian rhesus macaques were vaccinated either with SIVrtTA or with SIVmac239Δnef. Doxycycline was withdrawn from 4 of 8 SIVrtTA vaccinates before challenge with wild-type virus. Unvaccinated challenge controls exhibited ~107 peak plasma viral RNA copies/ml persisting beyond the acute phase. Six vaccinates, four SIVmac239Δnef and two SIVrtTA vaccinates exhibited complete protection, defined by lack of wild-type viraemia post-challenge and virus-specific PCR analysis of tissues recovered post-mortem, whereas six SIVrtTA vaccinates were protected from high levels of viraemia. Critically, the complete protection in two SIVrtTA vaccinates was associated with enhanced SIVrtTA replication in the immediate post-acute vaccination period but was independent of doxycycline status at the time of challenge. Mutations were identified in the LTR promoter region and rtTA gene that do not affect doxycycline-control but were associated with enhanced post-acute phase replication in protected vaccinates. High frequencies of total circulating CD8+T effector memory cells and a higher total frequency of SIV-specific CD8+ mono and polyfunctional T cells on the day of wild-type challenge were associated with complete protection but these parameters were not predictive of outcome when assessed 130 days after challenge. Moreover, challenge virus-specific Nef CD8+ polyfunctional T cell responses and antigen were detected in tissues post mortem in completely-protected macaques indicating post-challenge control of infection. Within the parameters of the study design, on-going occult-phase replication may not be absolutely required for protective immunity. PMID:28002473

  3. Safety Overview of a Recombinant Live-Attenuated Tetravalent Dengue Vaccine: Pooled Analysis of Data from 18 Clinical Trials

    PubMed Central

    Gailhardou, Sophia; Skipetrova, Anna; Dayan, Gustavo H.; Jezorwski, John; Saville, Melanie; Van der Vliet, Diane; Wartel, T. Anh

    2016-01-01

    A recombinant live attenuated tetravalent dengue vaccine (CYD-TDV) has been shown to be efficacious in preventing virologically-confirmed dengue disease, severe dengue disease and dengue hospitalization in children aged 2–16 years in Asia and Latin America. We analyzed pooled safety data from 18 phase I, II and III clinical trials in which the dengue vaccine was administered to participants aged 2–60 years, including long-term safety follow-up in three efficacy trials. The participants were analyzed according to their age at enrollment. The percentage of participants aged 2–60 years reporting ≥1 solicited injection-site or systemic reactions was slightly higher in the CYD-TDV group than in the placebo group. The most common solicited injection-site reactions were pain. Headache and malaise were the most common solicited systemic reactions. In both groups 0.3% of participants discontinued for safety reasons. The most common unsolicited adverse events were injection-site reactions, gastrointestinal disorders, and infections. Reactogenicity did not increase with successive doses of CYD-TDV. The frequency and nature of SAEs occurring within 28 days of any dose were similar in the CYD-TDV and placebo groups and were common medical conditions that could be expected as a function of age. Baseline dengue virus serostatus did not appear to influence the safety profile. No vaccine-related anaphylactic reactions, neurotropic events or viscerotropic events were reported. In year 3 after dose 1, an imbalance for dengue hospitalization, including for severe dengue, observed in participants aged <9 years in the CYD-TDV group compared with the placebo group was not observed for participants aged ≥9 years. In Year 4, this imbalance in participants aged <9 years was less marked, giving an overall lower risk of dengue hospitalization or severe dengue from dose 1 to Year 4 in the CYD-TDV group. These results have contributed to the definition of the target population for

  4. Replication of live attenuated cold-adapted H2N2 influenza virus vaccine candidates in non human primates.

    PubMed

    Broadbent, Andrew J; Santos, Celia P; Paskel, Myeisha; Matsuoka, Yumiko; Lu, Janine; Chen, Zhongying; Jin, Hong; Subbarao, Kanta

    2015-01-01

    The development of an H2N2 vaccine is a priority in pandemic preparedness planning. We previously showed that a single dose of a cold-adapted (ca) H2N2 live attenuated influenza vaccine (LAIV) based on the influenza A/Ann Arbor/6/60 (AA ca) virus was immunogenic and efficacious in mice and ferrets. However, in a Phase I clinical trial, viral replication was restricted and immunogenicity was poor. In this study, we compared the replication of four H2N2 LAIV candidate viruses, AA ca, A/Tecumseh/3/67 (TEC67 ca), and two variants of A/Japan/305/57 (JAP57 ca) in three non-human primate (NHP) species: African green monkeys (AGM), cynomolgus macaques (CM) and rhesus macaques (RM). One JAP57 ca virus had glutamine and glycine at HA amino acid positions 226 and 228 (Q-G) that binds to α2-3 linked sialic acids, and one had leucine and serine that binds to α2-3 and α2-6 linked residues (L-S). The replication of all ca viruses was restricted, with low titers detected in the upper respiratory tract of all NHP species, however replication was detected in significantly more CMs than AGMs. The JAP57 ca Q-G and TEC67 ca viruses replicated in a significantly higher percentage of NHPs than the AA ca virus, with the TEC67 ca virus recovered from the greatest percentage of animals. Altering the receptor specificity of the JAP57 ca virus from α2-3 to both α2-3 and α2-6 linked sialic acid residues did not significantly increase the number of animals infected or the titer to which the virus replicated. Taken together, our data show that in NHPs the AA ca virus more closely reflects the human experience than mice or ferret studies. We suggest that CMs and RMs may be the preferred species for evaluating H2N2 LAIV viruses, and the TEC67 ca virus may be the most promising H2N2 LAIV candidate for further evaluation.

  5. Replication of live attenuated cold-adapted H2N2 influenza virus vaccine candidates in non human primates

    PubMed Central

    Broadbent, Andrew J.; Santos, Celia P.; Paskel, Myeisha; Matsuoka, Yumiko; Lu, Janine; Chen, Zhongying; Jin, Hong; Subbarao, Kanta

    2014-01-01

    The development of an H2N2 vaccine is a priority in pandemic preparedness planning. We previously showed that a single dose of a cold-adapted (ca) H2N2 live attenuated influenza vaccine (LAIV) based on the influenza A/Ann Arbor/6/60 (AA ca) virus was immunogenic and efficacious in mice and ferrets. However, in a Phase I clinical trial, viral replication was restricted and immunogenicity was poor. In this study, we compared the replication of four H2N2 LAIV candidate viruses, AA ca, A/Tecumseh/3/67 (TEC67 ca), and two variants of A/Japan/305/57 (JAP57 ca) in three non-human primate (NHP) species: African green monkeys (AGM), cynomolgus macaques (CM) and rhesus macaques (RM). One JAP57 ca virus had glutamine and glycine at HA amino acid positions 226 and 228 (Q-G) that binds to α2-3 linked sialic acids, and one had leucine and serine that binds to α2-3 and α2-6 linked residues (L-S). The replication of all ca viruses was restricted, with low titers detected in the upper respiratory tract of all NHP species, however replication was detected in significantly more CMs than AGMs. The JAP57 ca Q-G and TEC67 ca viruses replicated in a significantly higher percentage of NHPs than the AA ca virus, with the TEC67 ca virus recovered from the greatest percentage of animals. Altering the receptor specificity of the JAP57 ca virus from α2-3 to both α2-3 and α2-6 linked sialic acid residues did not significantly increase the number of animals infected or the titer to which the virus replicated. Taken together, our data show that in NHPs the AA ca virus more closely reflects the human experience than mice or ferret studies. We suggest that CMs and RMs may be the preferred species for evaluating H2N2 LAIV viruses, and the TEC67 ca virus may be the most promising H2N2 LAIV candidate for further evaluation. PMID:25444799

  6. Short-lived effector CD8 T cells induced by genetically attenuated malaria parasite vaccination express CD11c.

    PubMed

    Cooney, Laura A; Gupta, Megha; Thomas, Sunil; Mikolajczak, Sebastian; Choi, Kimberly Y; Gibson, Claire; Jang, Ihn K; Danziger, Sam; Aitchison, John; Gardner, Malcolm J; Kappe, Stefan H I; Wang, Ruobing

    2013-11-01

    Vaccination with a single dose of genetically attenuated malaria parasites can induce sterile protection against sporozoite challenge in the rodent Plasmodium yoelii model. Protection is dependent on CD8(+) T cells, involves perforin and gamma interferon (IFN-γ), and is correlated with the expansion of effector memory CD8(+) T cells in the liver. Here, we have further characterized vaccine-induced changes in the CD8(+) T cell phenotype and demonstrated significant upregulation of CD11c on CD3(+) CD8b(+) T cells in the liver, spleen, and peripheral blood. CD11c(+) CD8(+) T cells are predominantly CD11a(hi) CD44(hi) CD62L(-), indicative of antigen-experienced effector cells. Following in vitro restimulation with malaria-infected hepatocytes, CD11c(+) CD8(+) T cells expressed inflammatory cytokines and cytotoxicity markers, including IFN-γ, tumor necrosis factor alpha (TNF-α), interleukin-2 (IL-2), perforin, and CD107a. CD11c(-) CD8(+) T cells, on the other hand, expressed negligible amounts of all inflammatory cytokines and cytotoxicity markers tested, indicating that CD11c marks multifunctional effector CD8(+) T cells. Coculture of CD11c(+), but not CD11c(-), CD8(+) T cells with sporozoite-infected primary hepatocytes significantly inhibited liver-stage parasite development. Tetramer staining for the immunodominant circumsporozoite protein (CSP)-specific CD8(+) T cell epitope demonstrated that approximately two-thirds of CSP-specific cells expressed CD11c at the peak of the CD11c(+) CD8(+) T cell response, but CD11c expression was lost as the CD8(+) T cells entered the memory phase. Further analyses showed that CD11c(+) CD8(+) T cells are primarily KLRG1(+) CD127(-) terminal effectors, whereas all KLRG1(-) CD127(+) memory precursor effector cells are CD11c(-) CD8(+) T cells. Together, these results suggest that CD11c marks a subset of highly inflammatory, short-lived, antigen-specific effector cells, which may play an important role in eliminating infected

  7. 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

  8. Complementary and Alternative Medicine Among Persons living with HIV in the Era of Combined Antiretroviral Treatment.

    PubMed

    Halpin, Sean N; Carruth, Edwin Clayton; Rai, Ramona P; Jennifer Edelman, E; Fiellin, David A; Gibert, Cynthia; Gordon, Kirsha S; Huang, Wei; Justice, Amy; Marconi, Vincent C; Rimland, David; Perkins, Molly M

    2017-07-21

    Complementary and alternative medicine (CAM), often pursued independent of prescribing clinicians, may interact with traditional treatments, yet CAM use has not been well characterized among people living with HIV (PLWH) in the combined antiretroviral therapy (ART) era. We analyzed data from the Veterans Aging Cohort Study (October 2012-April 2015) to characterize CAM use in PLWH on ART. CAM users were more likely to have lived longer with HIV, report more bothersome symptoms, be prescribed more benzodiazepines and opioids, and consume less nicotine and alcohol. Given its high prevalence, clinicians should routinely assess for CAM use and its impact among PLWH.

  9. Noise characterization of combined Bellini-type attenuation correction and frequency-distance principle restoration filtering [SPECT

    NASA Astrophysics Data System (ADS)

    Soares, E. J.; Glick, S. J.; King, M. A.

    1996-12-01

    We investigate how successive processing of the projection data with Bellini-type (BT) attenuation correction, frequency distance principle (FDP) restoration filtering, and filtered-backprojection (FBP) reconstruction propagates noise into the reconstructed image. The BT methods, which are Fourier-domain correction techniques, are all exact solutions to the attenuated Radon transform under the constraints of uniform attenuation and a convex object contour. The FDP states that points in the object at a specified distance from the center-of-rotation will contribute predominantly to particular regions of the Fourier transform-series expansion of the sinogram. Using this frequency-distance information, the nonstationary response of the collimator can ideally be deconvolved using an inverse filter. In the presence of noise, however, the FDP filter needs to be regularized in order to control noise amplification caused by the deconvolution. The noise is characterized by calculating the population covariance matrix of the projection data after successive processing with BT attenuation correction and FDP filtering and of the reconstructed image after FBP reconstruction. This is done for a simulated point-source located near the edge of an elliptical, uniformly attenuating medium. In our study, we consider the two implementational combinations of BT correction and FDP filtering that allow for sequential processing of the projection data, which we call mirroring and no mirroring. The results show that the mirroring strategy introduces local positive angular noise correlations in the processed sinogram that are caused by smoothing of the data in the projection angular direction. Furthermore, mirroring highly correlates the noise in opposing projection views. The impact on the image covariance is the presence of positive angular (arc-like) noise correlations. In contrast, the no mirroring strategy yields local positive and negative noise correlations with negative side-lobes in

  10. Multiscale segmentation of the skull in MR images for MRI-based attenuation correction of combined MR/PET

    PubMed Central

    Yang, Xiaofeng; Fei, Baowei

    2013-01-01

    Background and objective Combined magnetic resonance/positron emission tomography (MR/PET) is a relatively new, hybrid imaging modality. MR-based attenuation correction often requires segmentation of the bone on MR images. In this study, we present an automatic segmentation method for the skull on MR images for attenuation correction in brain MR/PET applications. Materials and methods Our method transforms T1-weighted MR images to the Radon domain and then detects the features of the skull image. In the Radon domain we use a bilateral filter to construct a multiscale image series. For the repeated convolution we increase the spatial smoothing in each scale and make the width of the spatial and range Gaussian function doubled in each scale. Two filters with different kernels along the vertical direction are applied along the scales from the coarse to fine levels. The results from a coarse scale give a mask for the next fine scale and supervise the segmentation in the next fine scale. The use of the multiscale bilateral filtering scheme is to improve the robustness of the method for noise MR images. After combining the two filtered sinograms, the reciprocal binary sinogram of the skull is obtained for the reconstruction of the skull image. Results This method has been tested with brain phantom data, simulated brain data, and real MRI data. For real MRI data the Dice overlap ratios are 92.2%±1.9% between our segmentation and manual segmentation. Conclusions The multiscale segmentation method is robust and accurate and can be used for MRI-based attenuation correction in combined MR/PET. PMID:23761683

  11. Immunogenicity and protective efficacy of a live attenuated vaccine against the 2009 pandemic A H1N1 in mice and ferrets.

    PubMed

    Yang, PengHui; Duan, YueQiang; Wang, Cheng; Xing, Li; Gao, Xiao; Tang, Chong; Luo, DeYan; Zhao, ZhongPeng; Jia, Weihong; Peng, Daxin; Liu, Xiufan; Wang, Xiliang

    2011-01-17

    A novel 2009 influenza A (H1N1) virus was transmitted from humans to humans worldwide. The live attenuated monovalent A H1N1 vaccine (LAMV) for intranasal administration has shown promising immunogenicity and safety in clinical trials and for human use, but the experimental data based on LAMV is incomplete. In this study, using reverse genetic technology, we produced a cold-adapted (ca), live attenuated BJ/AA ca that contained hemagglutinin (HA) and neuraminidase (NA) genes from a 2009 pandemic A H1N1 isolate, A/Beijing/501/2009 virus (BJ501), and the remaining six internal gene segments from the cold-adapted influenza H2N2 A/Ann Arbor/6/60 virus (AA virus). BJ/AA ca exhibited phenotypes of temperature sensitivity (ts), ca, and attenuation (att). The candidate BJ/AA ca was immunogenic in mice and induced strong mucosal secretory IgA (sIgA) in the respiratory tract. Two dosages of intranasal immunization induced robust HI antibodies and offered efficient protection against challenge by the wild-type (wt) 2009 pandemic A H1N1 (A/Beijing/501/2009 or A/California/07/2009) in mice and ferrets. These results support the evaluation of this vaccine made from a wt strain isolated in China for clinical trials. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.

  12. A Live Attenuated H7N3 Influenza Virus Vaccine is Well-tolerated and Immunogenic in a Phase I Trial in Healthy Adults

    PubMed Central

    Talaat, Kawsar R.; Karron, Ruth A.; Callahan, Karen A.; Luke, Catherine J.; DiLorenzo, Susan C.; Chen, Grace L.; Lamirande, Elaine W.; Jin, Hong; Coelingh, Kathy L.; Murphy, Brian R.; Kemble, George; Subbarao, Kanta

    2009-01-01

    Background Live attenuated influenza vaccines (LAIV) are being developed and tested against a variety of influenza viruses with pandemic potential. We describe the results of an open label Phase I trial of a live attenuated H7N3 virus vaccine. Methods and Findings The H7N3 BC 2004/AA ca virus is a live attenuated, cold-adapted, temperature-sensitive influenza virus derived by reverse genetics from the wild-type low pathogenicity avian influenza virus A/chicken/British Columbia/CN-6/2004 (H7N3) and the A/AA/6/60 ca (H2N2) virus that is the Master Donor Virus of the live, intranasal seasonal influenza vaccine. We evaluated the safety, infectivity, and immunogenicity of two doses of 107.5 TCID50 of the vaccine administered by nasal spray 5 weeks apart to normal healthy seronegative adult volunteers in an inpatient isolation unit. The subjects were followed for 2 months after 1 dose of vaccine or for 4 weeks after the second dose. Twenty-one subjects received the first dose of the vaccine, and 17 subjects received two doses. The vaccine was generally well tolerated. No serious adverse events occurred during the trial. The vaccine was highly restricted in replication: 6 (29%) subjects had virus recoverable by culture or by rRT-PCR after the first dose. Replication of vaccine virus was not detected following the second dose. Despite the restricted replication of the vaccine, 90% of the subjects developed an antibody response as measured by any assay: 62% by hemagglutination inhibition assay, 48% by microneutralization assay, 48% by ELISA for H7 HA-specific serum IgG or 71% by ELISA for H7 HA-specific serum IgA, after either one or two doses. Following the first dose, vaccine-specific IgG secreting cells as measured by ELISPOT increased from a mean of 0.1 to 41.6/106 PBMCs; vaccine specific IgA secreting cells increased from 2 to 16.4/106 PBMCs. The antibody secreting cell response after the second dose was less vigorous, which is consistent with the observed low

  13. Risks associated with the use of live-attenuated vaccine poliovirus strains and the strategies for control and eradication of paralytic poliomyelitis.

    PubMed

    Pliaka, Vaia; Kyriakopoulou, Zaharoula; Markoulatos, Panayotis

    2012-05-01

    The Global Polio Eradication Initiative was launched in 1988 with the aim to eliminate paralytic poliomyelitis. Two effective vaccines are available: inactivated polio vaccine (IPV) and oral polio vaccine (OPV). Since 1964, OPV has been used instead of IPV in most countries due to several economic and biological advantages. However, in rare cases, the live-attenuated Sabin strains of OPV revert to neurovirulence and cause vaccine-associated paralytic poliomyelitis in vaccinees or lead to emergence of vaccine-derived poliovirus strains. Attenuating mutations and recombination events have been associated with the reversion of vaccine strains to neurovirulence. The substitution of OPV with an improved new-generation IPV and the availability of new specific drugs against polioviruses are considered as future strategies for outbreak control and the eradication of paralytic poliomyelitis worldwide.

  14. Attenuation of rotenone toxicity in SY5Y cells by taurine and N-acetyl cysteine alone or in combination.

    PubMed

    Alkholifi, Faisal K; Albers, David S

    2015-10-05

    There is accumulating evidence that supports the involvement of reactive oxygen species (ROS), mitochondrial dysfunction and inflammation in the pathogenesis of neurodegenerative diseases. Thus, it is plausible that a multi-targeted therapeutic approach may be a more effective strategy to retard or even potentially halt the progression of the disease. Taurine is an organic acid that has a role in the regulation of oxidative stress and promoting mitochondrial normal functions, and N-Acetyl cysteine (NAC) is a well-known anti-oxidant and glutathione precursor. The main purpose of this study was to examine the cytoprotective effects of taurine alone or in combination with NAC against rotenone-induced toxicity in the SH-SY5Y neuroblastoma cell line. Taurine treatment produced a concentration-dependent reduction in rotenone-induced cell death. From this, we tested sub-effective concentrations of taurine in combination with low, sub-effective concentrations of NAC against rotenone toxicity, and found the combined treatment afforded greater cytoprotection than either treatment alone. The combined taurine/NAC treatment also attenuated rotenone-induced reductions in aconitase activity suggesting the cytoprotection afforded by the combined treatment may be associated with anti-oxidative mechanisms. Together, our data suggest that a multi-targeted approach may yield new avenues of research exploring the utility of combining therapeutic agents with different mechanisms of actions at concentrations lower than previously tested and shown to be cytoprotective. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Anti-chlamydial immunity in ewes conferred by vaccination with a combination of three live chlamydia, brucella and salmonella vaccines.

    PubMed

    Souriau, A; Bosseray, N; Rodolakis, A; Lantier, F; Plommet, M

    1988-07-02

    Live attenuated vaccines against Chlamydia psittaci var ovis, Brucella melitensis and Salmonella abortus ovis have previously been shown to be compatible in mice by subcutaneous administration. Immunity against challenge with virulent chlamydia was, however, slightly decreased in associations including the B melitensis Rev 1 vaccine. The chlamydia strain 1B vaccine was administered to four- to five-month-old female lambs, either alone or in combination with the B melitensis Rev1 and the S abortus ovis Rv6 vaccines. Clinical, serological and bacteriological observations demonstrated the compatibility of the three vaccines. Control, singly and triply vaccinated ewes were challenged with a virulent strain of chlamydia during their second pregnancy, 15 months after vaccination. Five of the 12 control ewes lambed normally and 10 of them were infected, as shown by the excretion of the challenge chlamydia in genital secretions. Sixteen of the 17 ewes in the triple vaccine group lambed normally and none was infected. All 12 in the single vaccine group lambed normally and three of the 12 were infected. In spite of this unusually poor protection by the single vaccine, antichlamydial immunity was clearly not decreased by the association with the two other vaccines.

  16. Chloroethene dechlorination in acidic groundwater: Implications for combining fenton's treatment with natural attenuation

    USGS Publications Warehouse

    Bradley, Paul M.; Singletary , Michael A.; Chapelle, Francis H.

    2007-01-01

    A sulfuric acid leak in 1988 at a chloroethene-contaminated groundwater site at the Naval Air Station Pensacola has resulted in a long-term record of the behavior of chloroethene contaminants at low pH and a unique opportunity to assess the potential impact of source area treatment technologies, which involve acidification of the groundwater environment (e.g., Fenton's-based in situ chemical oxidation), on downgradient natural attenuation processes. The greater than 75 percent decrease in trichloroethene (TCE) concentrations and the shift in contaminant composition toward predominantly reduced daughter products (dichloroethene [DCE] and vinyl chloride [VC]) that were observed along a 30-m groundwater flow path characterized by highly acidic conditions (pH = 3.5 ± 0.4) demonstrated that chloroethene reductive dechlorination can continue to be efficient under persistent acidic conditions. The detection of Dehalococcoides-type bacteria within the sulfuric acid/chloroethene co-contaminant plume was consistent with biotic chloroethene reductive dechlorination. Microcosm studies conducted with 14C-TCE and 14C-VC confirmed biotic reductive dechlorination in sediment collected from within the sulfuric acid/chloroethene co-contaminant plume. Microcosms prepared with sediment from two other locations within the acid plume, however, demonstrated only a limited mineralization to 14CO2 and 14CO, which was attributed to abiotic degradation because no significant differences were observed between experimental and autoclaved control treatments. These results indicated that biotic and abiotic mechanisms contributed to chloroethene attenuation in the acid plume at NAS Pensacola and that remediation techniques involving acidification of the groundwater environment (e.g., Fenton's-based source area treatment) do not necessarily preclude efficient chloroethene degradation.

  17. 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

  18. Simvastatin combined with antioxidant attenuates the cerebral vascular endothelial inflammatory response in a rat traumatic brain injury.

    PubMed

    Wang, Kuo-Wei; Wang, Hao-Kuang; Chen, Han-Jung; Liliang, Po-Chou; Liang, Cheng-Loong; Tsai, Yu-Duan; Cho, Chung-Lung; Lu, Kang

    2014-01-01

    Traumatic brain injury (TBI) leads to important and deleterious neuroinflammation, as evidenced by indicators such as edema, cytokine production, induction of nitric oxide synthase, and leukocyte infiltration. After TBI, cerebral vascular endothelial cells play a crucial role in the pathogenesis of inflammation. In our previous study, we proved that simvastatin could attenuate cerebral vascular endothelial inflammatory response in a rat traumatic brain injury. This purpose of this study was to determine whether simvastatin combined with an antioxidant could produce the same effect or greater and to examine affected surrogate biomarkers for the neuroinflammation after traumatic brain injury in rat. In our study, cortical contusions were induced, and the effect of acute and continuous treatment of simvastatin and vitamin C on behavior and inflammation in adult rats following experimental TBI was evaluated. The results demonstrated that simvastatin combined with an antioxidant could provide neuroprotection and it may be attributed to a dampening of cerebral vascular endothelial inflammatory response.

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

    PubMed

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

    2017-04-01

    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. Copyright © 2017 American Society for Microbiology.

  20. 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...

  1. 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...

  2. Modifications in the Polymerase Genes of a Swine-Like Triple-Reassortant Influenza Virus To Generate Live Attenuated Vaccines against 2009 Pandemic H1N1 Viruses▿ †

    PubMed Central

    Pena, Lindomar; Vincent, Amy L.; Ye, Jianqiang; Ciacci-Zanella, Janice R.; Angel, Matthew; Lorusso, Alessio; Gauger, Philip C.; Janke, Bruce H.; Loving, Crystal L.; Perez, Daniel R.

    2011-01-01

    On 11 June 2009, the World Health Organization (WHO) declared that the outbreaks caused by novel swine-origin influenza A (H1N1) virus had reached pandemic proportions. The pandemic H1N1 (H1N1pdm) virus is the predominant influenza virus strain in the human population. It has also crossed the species barriers and infected turkeys and swine in several countries. Thus, the development of a vaccine that is effective in multiple animal species is urgently needed. We have previously demonstrated that the introduction of temperature-sensitive mutations into the PB2 and PB1 genes of an avian H9N2 virus, combined with the insertion of a hemagglutinin (HA) tag in PB1, resulted in an attenuated (att) vaccine backbone for both chickens and mice. Because the new pandemic strain is a triple-reassortant (TR) virus, we chose to introduce the double attenuating modifications into a swine-like TR virus isolate, A/turkey/OH/313053/04 (H3N2) (ty/04), with the goal of producing live attenuated influenza vaccines (LAIV). This genetically modified backbone had impaired polymerase activity and restricted virus growth at elevated temperatures. In vivo characterization of two H1N1 vaccine candidates generated using the ty/04 att backbone demonstrated that this vaccine is highly attenuated in mice, as indicated by the absence of signs of disease, limited replication, and minimum histopathological alterations in the respiratory tract. A single immunization with the ty/04 att-based vaccines conferred complete protection against a lethal H1N1pdm virus infection in mice. More importantly, vaccination of pigs with a ty/04 att-H1N1 vaccine candidate resulted in sterilizing immunity upon an aggressive intratracheal challenge with the 2009 H1N1 pandemic virus. Our studies highlight the safety of the ty/04 att vaccine platform and its potential as a master donor strain for the generation of live attenuated vaccines for humans and livestock. PMID:20962084

  3. Advantage of live attenuated cold-adapted influenza A virus over inactivated vaccine for A/Washington/80 (H3N2) wild-type virus infection.

    PubMed

    Clements, M L; Betts, R F; Murphy, B R

    1984-03-31

    The efficacy of live attenuated cold-adapted (ca) reassortant influenza virus vaccine against experimental challenge with homologous wild-type virus 5 to 8 weeks after vaccination was compared with that of licensed inactivated vaccine in 81 seronegative (haemagglutination-inhibition antibody titre less than or equal to 1:8) college students. At a dose of 10(7.5) 50% tissue culture infectious dose (TCID50) (70 HID50, human 50% infectious doses) the live virus vaccine, given intranasally, completely protected against illness caused by wild-type virus, whereas the inactivated vaccine, administered intramuscularly, provided 72% protection. Wild-type virus was recovered from only 13% of live virus vaccinees (10(7.5) TCID50 dose of ca virus) compared with 63% of inactivated virus vaccinees and the few infected live virus vaccinees shed 1000 times less wild-type virus than did infected inactivated virus vaccinees or unvaccinated controls. This striking reduction in virus shedding suggests that influenza transmission may be more efficiently interrupted with live than with inactivated virus vaccination.

  4. Combination curcumin and vitamin E treatment attenuates diet-induced steatosis in Hfe-/- mice

    PubMed Central

    Heritage, Mandy; Jaskowski, Lesley; Bridle, Kim; Campbell, Catherine; Briskey, David; Britton, Laurence; Fletcher, Linda; Vitetta, Luis; Subramaniam, V Nathan; Crawford, Darrell

    2017-01-01

    AIM To investigate the synergistic hepato-protective properties of curcumin and vitamin E in an Hfe-/- high calorie diet model of steatohepatitis. METHODS Hfe-/- C57BL/6J mice were fed either a high calorie diet or a high calorie diet with 1 mg/g curcumin; 1.5 mg/g vitamin E; or combination of 1 mg/g curcumin + 1.5 mg/g vitamin E for 20 wk. Serum and liver tissue were collected at the completion of the experiment. Liver histology was graded by a pathologist for steatosis, inflammation and fibrosis. RNA and protein was extracted from liver tissue to examine gene and protein expression associated with fatty acid oxidation, mitochondrial biogenesis and oxidative stress pathways. RESULTS Hfe-/- mice fed the high calorie diet developed steatohepatitis and pericentral fibrosis. Combination treatment with curcumin and vitamin E resulted in a greater reduction of percent steatosis than either vitamin E or curcumin therapy alone. Serum alanine aminotransferase and non-alcoholic fatty liver disease (NAFLD) activity score were decreased following combination therapy with curcumin and vitamin E compared with high calorie diet alone. No changes were observed in inflammatory or fibrosis markers following treatment. Epididymal fat pad weights were significantly reduced following combination therapy, however total body weight and liver weight were unchanged. Combination therapy increased the mRNA expression of AdipoR2, Ppar-α, Cpt1a, Nrf-1 and Tfb2m suggesting enhanced fatty acid oxidation and mitochondrial biogenesis. In addition, combination treatment resulted in increased catalase activity in Hfe-/- mice. CONCLUSION Combination curcumin and vitamin E treatment decreases liver injury in this steatohepatitis model, indicating that combination therapy may be of value in NAFLD. PMID:28573069

  5. Combination curcumin and vitamin E treatment attenuates diet-induced steatosis in Hfe(-/-) mice.

    PubMed

    Heritage, Mandy; Jaskowski, Lesley; Bridle, Kim; Campbell, Catherine; Briskey, David; Britton, Laurence; Fletcher, Linda; Vitetta, Luis; Subramaniam, V Nathan; Crawford, Darrell

    2017-05-15

    To investigate the synergistic hepato-protective properties of curcumin and vitamin E in an Hfe(-/-) high calorie diet model of steatohepatitis. Hfe(-/-) C57BL/6J mice were fed either a high calorie diet or a high calorie diet with 1 mg/g curcumin; 1.5 mg/g vitamin E; or combination of 1 mg/g curcumin + 1.5 mg/g vitamin E for 20 wk. Serum and liver tissue were collected at the completion of the experiment. Liver histology was graded by a pathologist for steatosis, inflammation and fibrosis. RNA and protein was extracted from liver tissue to examine gene and protein expression associated with fatty acid oxidation, mitochondrial biogenesis and oxidative stress pathways. Hfe(-/-) mice fed the high calorie diet developed steatohepatitis and pericentral fibrosis. Combination treatment with curcumin and vitamin E resulted in a greater reduction of percent steatosis than either vitamin E or curcumin therapy alone. Serum alanine aminotransferase and non-alcoholic fatty liver disease (NAFLD) activity score were decreased following combination therapy with curcumin and vitamin E compared with high calorie diet alone. No changes were observed in inflammatory or fibrosis markers following treatment. Epididymal fat pad weights were significantly reduced following combination therapy, however total body weight and liver weight were unchanged. Combination therapy increased the mRNA expression of AdipoR2, Ppar-α, Cpt1a, Nrf-1 and Tfb2m suggesting enhanced fatty acid oxidation and mitochondrial biogenesis. In addition, combination treatment resulted in increased catalase activity in Hfe(-/-) mice. Combination curcumin and vitamin E treatment decreases liver injury in this steatohepatitis model, indicating that combination therapy may be of value in NAFLD.

  6. Combined administration of captopril with an antihypertensive Val-Tyr di-peptide to spontaneously hypertensive rats attenuates the blood pressure lowering effect.

    PubMed

    Matsui, Toshiro; Zhu, Xiao Lin; Watanabe, Keisuke; Tanaka, Keisuke; Kusano, Yoko; Matsumoto, Kiyoshi

    2006-11-25

    Some di-peptides have been proven to exert an antihypertensive effect in mild-hypertensive subjects. The aim of this study was to clarify whether combined administration of an ACE inhibitor, captopril, with an antihypertensive di-peptide Val-Tyr (VY) would alter their potent antihypertensive effects in spontaneously hypertensive rats (SHRs). Single oral administration of captopril (2.5 mg/kg), VY (25 mg/kg), or captopril (2.5 mg/kg)+VY (25 mg/kg) to 18-week-old male SHRs was performed. Systolic blood pressure (SBP) was measured up to 9 h, and plasma captopril concentrations were determined. A transport study of captopril and/or VY across living rat jejunum from SHRs was also performed to evaluate the kinetics of absorption. Combined administration of captopril with VY failed to lower the BP during the 9-h experiment. A transport study of captopril or VY revealed that VY inhibited captopril transport, and vice versa, in a competitive manner and exhibited an approximately 1/3-fold lower Ki value for captopril compared with that for VY; indicating that both compounds compete for the same membrane transport pathway. A 50% decrease in plasma captopril levels by combined administration with VY supported that the attenuation of the BP lowering effect was due to inhibition of captopril uptake by VY. Consequently, our findings suggest that subjects treated with ACE inhibitors for hypertension should avoid combined-intake with antihypertensive foods that are rich in small peptides due to the competitive inhibition of drug uptake by these peptides.

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

    SciTech Connect

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

    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 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.

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

    PubMed

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

    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 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.

  9. CD8+ T-cell Responses in Flavivirus-Naive Individuals Following Immunization with a Live-Attenuated Tetravalent Dengue Vaccine Candidate.

    PubMed

    Chu, Haiyan; George, Sarah L; Stinchcomb, Dan T; Osorio, Jorge E; Partidos, Charalambos D

    2015-11-15

    We are developing a live-attenuated tetravalent dengue vaccine (TDV) candidate based on an attenuated dengue 2 virus (TDV-2) and 3 chimeric viruses containing the premembrane and envelope genes of dengue viruses (DENVs) -1, -3, and -4 expressed in the context of the attenuated TDV-2 genome (TDV-1, TDV-3, and TDV-4, respectively). In this study, we analyzed and characterized the CD8(+) T-cell response in flavivirus-naive human volunteers vaccinated with 2 doses of TDV 90 days apart via the subcutaneous or intradermal routes. Using peptide arrays and intracellular cytokine staining, we demonstrated that TDV elicits CD8(+) T cells targeting the nonstructural NS1, NS3, and NS5 proteins of TDV-2. The cells were characterized by the production of interferon-γ, tumor necrosis factor-α, and to a lesser extent interleukin-2. Responses were highest on day 90 after the first dose and were still detectable on 180 days after the second dose. In addition, CD8(+) T cells were multifunctional, producing ≥2 cytokines simultaneously, and cross-reactive to NS proteins of the other 3 DENV serotypes. Overall, these findings describe the capacity of our candidate dengue vaccine to elicit cellular immune responses and support the further evaluation of T-cell responses in samples from future TDV clinical trials.

  10. 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.

  11. Danhong Huayu Koufuye combined with metformin attenuated diabetic retinopathy in Zucker diabetic fatty rats

    PubMed Central

    Chen, Wen-Pei; Wang, Yan-Dong; Ma, Yan; Zhang, Zi-Yang; Hu, Lu-Yun; Lin, Jun-Li; Lin, Bao-Qin

    2015-01-01

    AIM To evaluate effects of Danhong Huayu Koufuye (DHK, a Chinese medicinal formulae) alone or combined with metformin on diabetic retinopathy (DR) in Zucker diabetic fatty (ZDF) rats, an animal model of obese type-2 diabetes, and then to investigate the mechanisms. METHODS ZDF (fa/fa) rats were administered with vehicle (distilled water), metformin, DHK, and DHK plus metformin. Electrophysiological and histological analysis were applied to evaluated effects of DHK alone or combined with metformin on DR. The levels of fasting blood glucose (FBG) and glycosylated hemoglobin (HbA1c) in blood were measured to evaluate the antihyperglycemic activity of DHK. Furthermore, levels of nitric oxide (NO), malondialdehyde (MDA) and activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) in serum were measured to study effects of DHK on oxidative stress in ZDF rats. In addition, body weight, lipidic indexes and insulin level were also assessed. RESULTS DHK combined with metformin significantly reversed the prolongation of latency times of flash electroretinogram (FERG) and oscillatory potentials (OPs) in diabetic rats. Furthermore, DHK alone or combined with metformin showed a remarkable suppression of retinal neovascularization and amelioration of retinal internal limiting membrane morphology. Moreover, DHK alone or plus metformin reduced FBG (P<0.05), HbA1c (P<0.01) and MDA (P<0.01) levels in diabetic rats. In addition, reductions in levels of triglycerides (TG) (P<0.01) and low density lipoprotein cholesterol (LDL-c) (P<0.01 and P<0.05, respectively) were also observed in diabetic rats treated with DHK alone or plus metformin. CONCLUSION DHK in combination with metformin had a preventive and therapeutic effect on DR in type-2 diabetic rats, and the possible mechanisms may be alleviating hyperglycemia, reducing oxidative stress and improving lipid metabolism. PMID:26682154

  12. ATTENUATION OF STATISTICAL RELATIONSHIPS FROM PM COMMUNITY TIME-SERIES EPIDEMIOLOGY DUE TO USE OF COMBINED, RATHER THAN SEPARATE, INDICATORS OF EXPOSURE AND MORTALITY

    EPA Science Inventory

    Attenuation of the statistical relationships between PM and health outcomes may arise from 1) combining exposure indicators, e.g., PM10 instead of PM2.5 and PM10-2.5 or 2) from combining different types of mortality. The Phoenix, AZ data base on air quality offers an opportunity...

  13. ATTENUATION OF STATISTICAL RELATIONSHIPS FROM PM COMMUNITY TIME-SERIES EPIDEMIOLOGY DUE TO USE OF COMBINED, RATHER THAN SEPARATE, INDICATORS OF EXPOSURE AND MORTALITY

    EPA Science Inventory

    Attenuation of the statistical relationships between PM and health outcomes may arise from 1) combining exposure indicators, e.g., PM10 instead of PM2.5 and PM10-2.5 or 2) from combining different types of mortality. The Phoenix, AZ data base on air quality offers an opportunity...

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

    PubMed

    Holinka, Lauren G; O'Donnell, Vivian; Risatti, Guillermo R; Azzinaro, Paul; Arzt, Jonathan; Stenfeldt, Carolina; Velazquez-Salinas, Lauro; Carlson, Jolene; Gladue, Douglas P; Borca, Manuel V

    2017-01-01

    Prophylactic vaccination using live attenuated classical swine fever (CSF) vaccines has been a very effective method to control the disease in endemic regions and during outbreaks in previously disease-free areas. These vaccines confer effective protection against the disease at early times post-vaccination although the mechanisms mediating the protection are poorly characterized. Here we present the events occurring after the administration of our in-house developed live attenuated marker vaccine, FlagT4Gv. We previously reported that FlagT4Gv intramuscular (IM) administered conferred effective protection against intranasal challenge with virulent CSFV (BICv) as early as 7 days post-vaccination. Here we report that FlagT4Gv is able to induce protection against disease as early as three days post-vaccination. Immunohistochemical testing of tissues from FlagT4Gv-inoculated animals showed that tonsils were colonized by the vaccine virus by day 3 post-inoculation. There was a complete absence of BICv in tonsils of FlagT4Gv-inoculated animals which had been intranasal (IN) challenged with BICv 3 days after FlagT4Gv infection, confirming that FlagT4Gv inoculation confers sterile immunity. Analysis of systemic levels of 19 different cytokines in vaccinated animals demonstrated an increase of IFN-α three days after FlagT4Gv inoculation compared with mock infected controls.

  15. Development and identification of a new Vero cell-based live attenuated influenza B vaccine by a modified classical reassortment method.

    PubMed

    Yang, Fan; Ma, Lei; Zhou, Jian; Wu, Yinjie; Gao, Jingxia; Song, Shaohui; Geng, Xingliang; Guo, Qi; Li, Zhuofan; Li, Weidong; Liao, Guoyang; Li, Yufeng

    2017-08-01

    It was to generate a new Vero and cold-adapted live attenuated influenza B vaccine with enough safety and immunogenicity. According to modified classical reassortment method, the donor strain was B/Yunnan/2/2005Vca(B), and the parental virus strain was B/Brisbane/60/2008wt. After co-infection in Vero cells, the prepared antibody serum inhibited the donor strain growth, and screening conditions inhibited the parental virus growth, which induced the growth of the new reassortant virus B/Brisbane/60/2008Vca(B) grow. Through intraperitoneal injection (i.j.) and intranasal injection (n.j.) we evaluated the safety and immunogenicity of the vaccine. A high-yield of the reassortant virus was produced in Vero cells at 25°C, similar to the donor strains. After sequencing, it was found that B/Brisbane/60/2008Vca(B) Hemagglutinin (HA) and Neuraminidase (NA) gene fragments were from B/Brisbane/60/2008wt, while the other 6 gene fragments were from B/Yunnan/2/2005Vca(B). The n.j. immune pathway experiments showed no significant differences between the treatment and the PBS control group with respect to weight changes (P > 0.5). Furthermore, the new strain had a sufficient geometric mean titter (GMT) against B/Brisbane/60/2008wt. The new reassortant live attenuated influenza B vaccine was safe and having enough immune stimulating ability.

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

    PubMed Central

    Risatti, Guillermo R.; Azzinaro, Paul; Arzt, Jonathan; Stenfeldt, Carolina; Velazquez-Salinas, Lauro; Carlson, Jolene; Gladue, Douglas P.

    2017-01-01

    Prophylactic vaccination using live attenuated classical swine fever (CSF) vaccines has been a very effective method to control the disease in endemic regions and during outbreaks in previously disease-free areas. These vaccines confer effective protection against the disease at early times post-vaccination although the mechanisms mediating the protection are poorly characterized. Here we present the events occurring after the administration of our in-house developed live attenuated marker vaccine, FlagT4Gv. We previously reported that FlagT4Gv intramuscular (IM) administered conferred effective protection against intranasal challenge with virulent CSFV (BICv) as early as 7 days post-vaccination. Here we report that FlagT4Gv is able to induce protection against disease as early as three days post-vaccination. Immunohistochemical testing of tissues from FlagT4Gv-inoculated animals showed that tonsils were colonized by the vaccine virus by day 3 post-inoculation. There was a complete absence of BICv in tonsils of FlagT4Gv-inoculated animals which had been intranasal (IN) challenged with BICv 3 days after FlagT4Gv infection, confirming that FlagT4Gv inoculation confers sterile immunity. Analysis of systemic levels of 19 different cytokines in vaccinated animals demonstrated an increase of IFN-α three days after FlagT4Gv inoculation compared with mock infected controls. PMID:28542321

  17. [High dose cinobufocini in attenuation and treatment of infection and granulocytopenia during combined chemotherapy of malignant blood diseases].

    PubMed

    Yue, B B

    1992-03-01

    The use of high dose Cinobufocini in attenuation and treatment of infection and granulocytopenia during combined chemotherapy was observed in patients with malignant blood diseases. The study was designed in such a way that each patient served as self control. The patients, 18 males and 12 females, aged 16-66 (average 34), 62 experiments in 20 patients with acute leukemia, 8 with malignant lymphoma and 2 with multiple myeloma were observed. In patients with the treatment of high dose Cinobufocini, infection was significantly decreased and the number of granulocytes was not markedly changed before and after the treatment. The observation demonstrated that high dose Cinobufocini can significantly reduce the risk of infection and degree and duration of granulocytopenia associated with chemotherapy of patients with malignant blood diseases. The use of high dose Cinobufocini is simple and convenient and with very little side effects.

  18. Virus recovery rates for wild-type and live-attenuated vaccine strains of African horse sickness virus serotype 7 in orally infected South African Culicoides species.

    PubMed

    Venter, G J; Paweska, J T

    2007-12-01

    Previously reported virus recovery rates from Culicoides (Avaritia) imicola Kieffer and Culicoides (Avaritia) bolitinos Meiswinkel (Diptera, Ceratopogonidae) orally infected with vaccine strain of African horse sickness virus serotype 7 (AHSV-7) were compared with results obtained from concurrently conducted oral infections with five recent AHSV-7 isolates from naturally infected horses from various localities in South Africa. Culicoides were fed sheep bloods spiked with 10(7.6) TCID(50)/mL of a live-attenuated vaccine strain AHSV-7, and with five field isolates in which virus titre in the bloodmeals ranged from 10(7.1) to 10(8.2) TCID(50)/mL). After an extrinsic incubation of 10 days at 23.5 degrees C, virus recovery rates were significantly higher in C. imicola (13.3%) and C. bolitinos (4.2%) infected with the live-attenuated virus than in midges infected with any of the field isolates. The virus recovery rates for the latter groups ranged from 0% to 9.5% for C. imicola and from 0% to 1.5% for C. bolitinos. The C. imicola population at Onderstepoort was significantly more susceptible to infection with AHSV-7 isolated at Onderstepoort than to the virus strains isolated from other localities. Results of this study suggest that tissue culture attenuation of AHSV-7 does not reduce its ability to orally infect competent Culicoides species and may even lead to enhanced replication in the vector. Furthermore, oral susceptibility in a midge population appears to vary for geographically distinct isolates of AHSV-7.

  19. Combination therapy of mesenchymal stem cells and serelaxin effectively attenuates renal fibrosis in obstructive nephropathy.

    PubMed

    Huuskes, Brooke M; Wise, Andrea F; Cox, Alison J; Lim, Ee X; Payne, Natalie L; Kelly, Darren J; Samuel, Chrishan S; Ricardo, Sharon D

    2015-02-01

    Chronic kidney disease (CKD) results from the development of fibrosis, ultimately leading to end-stage renal disease (ESRD). Although human bone marrow-derived mesenchymal stem cells (MSCs) can accelerate renal repair following acute injury, the establishment of fibrosis during CKD may affect their potential to influence regeneration capacity. Here we tested the novel combination of MSCs with the antifibrotic serelaxin to repair and protect the kidney 7 d post-unilateral ureteral obstruction (UUO), when fibrosis is established. Male C57BL6 mice were sham-operated or UUO-inured (n = 4-6) and received vehicle, MSCs (1 × 10(6)), serelaxin (0.5 mg/kg per d), or the combination of both. In vivo tracing studies with luciferin/enhanced green fluorescent protein (eGFP)-tagged MSCs showed specific localization in the obstructed kidney where they remained for 36 h. Combination therapy conferred significant protection from UUO-induced fibrosis, as indicated by hydroxyproline analysis (P < 0.001 vs. vehicle, P < 0.05 vs. MSC or serelaxin alone). This was accompanied by preserved structural architecture, decreased tubular epithelial injury (P < 0.01 vs. MSCs alone), macrophage infiltration, and myofibroblast localization in the kidney (both P < 0.01 vs. vehicle). Combination therapy also stimulated matrix metalloproteinase (MMP)-2 activity over either treatment alone (P < 0.05 vs. either treatment alone). These results suggest that the presence of an antifibrotic in conjunction with MSCs ameliorates established kidney fibrosis and augments tissue repair to a greater extent than either treatment alone.

  20. Introduction of silent mutations into the NP gene of influenza A viruses as a possible strategy for the creation of a live attenuated vaccine.

    PubMed

    Anhlan, Darisuren; Hrincius, Eike-Roman; Scholtissek, Christoph; Ludwig, Stephan

    2012-06-22

    The nucleoprotein (NP) of influenza A virus (IAV) is associated with many different functions including host range restriction. Multiple sequence alignment analyses of 748 NP gene sequences from GenBank revealed a highly conserved region of 60 nucleotides within the ORF at the 3'-ends of the cRNA, in some codons even silent mutations were not found. This suggests that the RNA structure integrity within this region is crucial for IAV replication. To explore the impact of these conserved nucleotides for viral replication we created mutant viruses with one or more silent mutations in the respective region of the NP gene of the IAV strain A/WSN/33 (H1N1) (WSN). Assessment of viral replication of these WSN mutant viruses showed significant growth disadvantages when compared to the corresponding parental strain. On the basis of these findings we tested whether the attenuation of IAV by introduction of silent mutations into the NP gene may serve as a strategy to create a live attenuated vaccine. Mice vaccinated with the attenuated WSN mutant survived a lethal challenge dose of wild type WSN virus or the mouse adapted pandemic H1N1v strain A/Hamburg/4/2009. Thus, introduction of silent mutations in the NP of IAV is a feasible approach for a novel vaccination strategy allowing attenuation of the master strain but leaves the antigenicity of the gene product unaltered. This principle is potentially applicable for all viruses with segmented genomes. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Combination of tadalafil and diltiazem attenuates renal ischemia reperfusion-induced acute renal failure in rats.

    PubMed

    El-Sisi, Alaa E; Sokar, Samia S; Abu-Risha, Sally E; Ibrahim, Hanaa A

    2016-12-01

    Life threatening conditions characterized by renal ischemia/reperfusion (RIR) such as kidney transplantation, partial nephrectomy, renal artery angioplasty, cardiopulmonary bypass and aortic bypass surgery, continue to be among the most frequent causes of acute renal failure. The current study investigated the possible protective effects of tadalafil alone and in combination with diltiazem in experimentally-induced renal ischemia/reperfusion injury in rats. Possible underlying mechanisms were also investigated such as oxidative stress and inflammation. Rats were divided into sham-operated and I/R-operated groups. Anesthetized rats (urethane 1.3g/kg) were subjected to bilateral ischemia for 30min by occlusion of renal pedicles, then reperfused for 6h. Rats in the vehicle I/R group showed a significant (p˂0.05) increase in kidney malondialdehyde (MDA) content; myeloperoxidase (MPO) activity; TNF-α and IL-1β contents. In addition significant (p˂0.05) increase in intercellular adhesion molecule-1(ICAM-1) content, BUN and creatinine levels, along with significant decrease in kidney superoxide dismutase (SOD) activity. In addition, marked diffuse histopathological damage and severe cytoplasmic staining of caspase-3 were detected. Pretreatment with combination of tadalafil (5mg/kg bdwt) and diltiazem (5mg/kg bdwt) resulted in reversal of the increased biochemical parameters investigated. Also, histopathological examination revealed partial return to normal cellular architecture. In conclusion, pretreatment with tadalafil and diltiazem combination protected against RIR injury.

  2. Combining living anionic polymerization with branching reactions in an iterative fashion to design branched polymers.

    PubMed

    Higashihara, Tomoya; Sugiyama, Kenji; Yoo, Hee-Soo; Hayashi, Mayumi; Hirao, Akira

    2010-06-16

    This paper reviews the precise synthesis of many-armed and multi-compositional star-branched polymers, exact graft (co)polymers, and structurally well-defined dendrimer-like star-branched polymers, which are synthetically difficult, by a commonly-featured iterative methodology combining living anionic polymerization with branched reactions to design branched polymers. The methodology basically involves only two synthetic steps; (a) preparation of a polymeric building block corresponding to each branched polymer and (b) connection of the resulting building unit to another unit. The synthetic steps were repeated in a stepwise fashion several times to successively synthesize a series of well-defined target branched polymers.

  3. Living Donor Liver Transplantation for Combined Hepatocellular Carcinoma and Cholangiocarcinoma: Experience of a Single Center.

    PubMed

    Chang, Cheng-Chih; Chen, Ying-Ju; Huang, Tzu-Hao; Chen, Chun-Han; Kuo, Fang-Ying; Eng, Hock-Liew; Yong, Chee-Chien; Liu, Yueh-Wei; Lin, Ting-Lung; Li, Wei-Feng; Lin, Yu-Hung; Lin, Chih-Che; Wang, Chih-Chi; Chen, Chao-Long

    2017-02-28

    BACKGROUND Because the outcome of liver transplantation for cholangiocarcinoma is often poor, cholangiocarcinoma is a contraindication for liver transplantation in most centers. Combined hepatocellular carcinoma and cholangiocarcinoma is a rare type of primary hepatic malignancy containing features of hepatocellular carcinoma and cholangiocarcinoma. Diagnosing combined hepatocellular carcinoma and cholangiocarcinoma pre-operatively is difficult. Because of sparse research presentations worldwide, we report our experience with living donor liver transplantation for combined hepatocellular carcinoma and cholangiocarcinoma. MATERIAL AND METHODS A total of 710 patients underwent living donor liver transplantation at our institution from April 2006 to June 2014; 377 of them received transplantation because of hepatocellular carcinoma with University of California San Francisco (UCSF) staging criteria fulfilled pre-operatively. Eleven patients (2.92%) were diagnosed with combined hepatocellular carcinoma and cholangiocarcinoma confirmed pathologically from explant livers; we reviewed these cases retrospectively. Long-term survival was compared between patients diagnosed with combined hepatocellular carcinoma and cholangiocarcinoma and patients diagnosed with hepatocellular carcinoma. RESULTS The mean age of the patients in our series was 60.2 years, and the median follow-up period was 23.9 months. Four patients were diagnosed with a recurrence during the follow-up period, including one intra-hepatic and three extra-hepatic recurrences. Four patients died due to tumor recurrence. Except for patients with advanced-stage cancer, disease-free survival of patients with combined hepatocellular carcinoma and cholangiocarcinoma compared with that of patients with hepatocellular carcinoma was 80% versus 97.2% in 1 year, and 46.7% versus 92.5% in 3 years (p<0.001), and overall survival was 90% versus 97.2% in 1 year, and 61.7% versus 95.1% in 3 years (p<0.001). CONCLUSIONS

  4. Live-Attenuated Lentivirus Immunization Modulates Innate Immunity and Inflammation while Protecting Rhesus Macaques from Vaginal Simian Immunodeficiency Virus Challenge

    PubMed Central

    Genescà, Meritxell; Ma, Zhong-Min; Wang, Yichuan; Assaf, Basel; Qureshi, Huma; Fritts, Linda; Huang, Ying; McChesney, Michael B.

    2012-01-01

    Immunization with attenuated lentiviruses is the only reliable method of protecting rhesus macaques (RM) from vaginal challenge with pathogenic simian immunodeficiency virus (SIV). CD8+ lymphocyte depletion prior to SIVmac239 vaginal challenge demonstrated that a modest, Gag-specific CD8+ T cell response induced by immunization with simian-human immunodeficiency virus 89.6 (SHIV89.6) protects RM. Although CD8+ T cells are required for protection, there is no anamnestic expansion of SIV-specific CD8+ T cells in any tissues except the vagina after challenge. Further, SHIV immunization increased the number of viral target cells in the vagina and cervix, suggesting that the ratio of target cells to antiviral CD8+ T cells was not a determinant of protection. We hypothesized that persistent replication of the attenuated vaccine virus modulates inflammatory responses and limits T cell activation and expansion by inducing immunoregulatory T cell populations. We found that attenuated SHIV infection decreased the number of circulating plasmacytoid dendritic cells, suppressed T cell activation, decreased mRNA levels of proinflammatory mediators, and increased mRNA levels of immunoregulatory molecules. Three days after SIV vaginal challenge, SHIV-immunized RM had significantly more T regulatory cells in the vagina than the unimmunized RM. By day 14 postchallenge, immune activation and inflammation were characteristic of unimmunized RM but were minimal in SHIV-immunized RM. Thus, a modest vaccine-induced CD8+ T cell response in the context of immunoregulatory suppression of T cell activation may protect against vaginal HIV transmission. PMID:22696662

  5. Live-attenuated lentivirus immunization modulates innate immunity and inflammation while protecting rhesus macaques from vaginal simian immunodeficiency virus challenge.

    PubMed

    Genescà, Meritxell; Ma, Zhong-Min; Wang, Yichuan; Assaf, Basel; Qureshi, Huma; Fritts, Linda; Huang, Ying; McChesney, Michael B; Miller, Christopher J

    2012-09-01

    Immunization with attenuated lentiviruses is the only reliable method of protecting rhesus macaques (RM) from vaginal challenge with pathogenic simian immunodeficiency virus (SIV). CD8(+) lymphocyte depletion prior to SIVmac239 vaginal challenge demonstrated that a modest, Gag-specific CD8(+) T cell response induced by immunization with simian-human immunodeficiency virus 89.6 (SHIV89.6) protects RM. Although CD8(+) T cells are required for protection, there is no anamnestic expansion of SIV-specific CD8(+) T cells in any tissues except the vagina after challenge. Further, SHIV immunization increased the number of viral target cells in the vagina and cervix, suggesting that the ratio of target cells to antiviral CD8(+) T cells was not a determinant of protection. We hypothesized that persistent replication of the attenuated vaccine virus modulates inflammatory responses and limits T cell activation and expansion by inducing immunoregulatory T cell populations. We found that attenuated SHIV infection decreased the number of circulating plasmacytoid dendritic cells, suppressed T cell activation, decreased mRNA levels of proinflammatory mediators, and increased mRNA levels of immunoregulatory molecules. Three days after SIV vaginal challenge, SHIV-immunized RM had significantly more T regulatory cells in the vagina than the unimmunized RM. By day 14 postchallenge, immune activation and inflammation were characteristic of unimmunized RM but were minimal in SHIV-immunized RM. Thus, a modest vaccine-induced CD8(+) T cell response in the context of immunoregulatory suppression of T cell activation may protect against vaginal HIV transmission.

  6. Live Cell Analysis and Mathematical Modeling Identify Determinants of Attenuation of Dengue Virus 2’-O-Methylation Mutant

    PubMed Central

    Ruggieri, Alessia; Acosta, Eliana Gisela; Bartenschlager, Marie; Reuter, Antje; Fischl, Wolfgang; Harder, Nathalie; Bergeest, Jan-Philip; Flossdorf, Michael; Rohr, Karl; Höfer, Thomas; Bartenschlager, Ralf

    2015-01-01

    Dengue virus (DENV) is the most common mosquito-transmitted virus infecting ~390 million people worldwide. In spite of this high medical relevance, neither a vaccine nor antiviral therapy is currently available. DENV elicits a strong interferon (IFN) response in infected cells, but at the same time actively counteracts IFN production and signaling. Although the kinetics of activation of this innate antiviral defense and the timing of viral counteraction critically determine the magnitude of infection and thus disease, quantitative and kinetic analyses are lacking and it remains poorly understood how DENV spreads in IFN-competent cell systems. To dissect the dynamics of replication versus antiviral defense at the single cell level, we generated a fully viable reporter DENV and host cells with authentic reporters for IFN-stimulated antiviral genes. We find that IFN controls DENV infection in a kinetically determined manner that at the single cell level is highly heterogeneous and stochastic. Even at high-dose, IFN does not fully protect all cells in the culture and, therefore, viral spread occurs even in the face of antiviral protection of naïve cells by IFN. By contrast, a vaccine candidate DENV mutant, which lacks 2’-O-methylation of viral RNA is profoundly attenuated in IFN-competent cells. Through mathematical modeling of time-resolved data and validation experiments we show that the primary determinant for attenuation is the accelerated kinetics of IFN production. This rapid induction triggered by mutant DENV precedes establishment of IFN-resistance in infected cells, thus causing a massive reduction of virus production rate. In contrast, accelerated protection of naïve cells by paracrine IFN action has negligible impact. In conclusion, these results show that attenuation of the 2’-O-methylation DENV mutant is primarily determined by kinetics of autocrine IFN action on infected cells. PMID:26720415

  7. Combined inhibition of aromatase activity and dihydrotestosterone supplementation attenuates renal injury in male streptozotocin (STZ)-induced diabetic rats.

    PubMed

    Manigrasso, Michaele B; Sawyer, R Taylor; Hutchens, Zachary M; Flynn, Elizabeth R; Maric-Bilkan, Christine

    2012-05-01

    Our previous studies showed that streptozotocin (STZ)-induced diabetic male rats have increased estradiol and decreased testosterone levels that correlate with renal injury (Xu Q, Wells CC, Garman GH, Asico L, Escano CS, Maric C. Hypertension 51: 1218-1224, 2008). We further showed that either supplementing dihydrotestosterone (DHT) or inhibiting estradiol biosynthesis in these diabetic rats was only partially renoprotective (Manigrasso MB, Sawyer RT, Marbury DC, Flynn ER, Maric C. Am J Physiol Renal Physiol 301: F634-F640, 2011; Xu Q, Prabhu A, Xu S, Manigrassso MB, Maric C. Am J Physiol 297: F307-F315, 2009). The aim of this study was to test the hypothesis that the combined therapy of DHT supplementation and inhibition of estradiol synthesis would afford better renoprotection than either treatment alone. The study was performed in 12-wk-old male nondiabetic (ND), STZ-induced diabetic (D), and STZ-induced diabetic rats that received the combined therapy of 0.75 mg/day of DHT along with 0.15 mg · kg(-1) · day(-1) of an aromatase inhibitor, anastrozole (Dta), for 12 wk. Treatment with the combined therapy resulted in attenuation of albuminuria by 84%, glomerulosclerosis by 55%, and tubulointerstitial fibrosis by 62%. In addition, the combined treatment decreased the density of renal cortical CD68-positive cells by 70% and decreased protein expression of transforming growth factor-β protein expression by 60%, collagen type IV by 65%, TNF-α by 55%, and IL-6 by 60%. We conclude that the combined treatment of DHT and blocking aromatase activity in diabetic male STZ-induced diabetic rats provides superior treatment than either treatment alone in the prevention of diabetic renal disease.

  8. Dose reduction technique using a combination of a region of interest (ROI) material x-ray attenuator and spatially different temporal filtering for fluoroscopic interventions

    NASA Astrophysics Data System (ADS)

    Swetadri Vasan, S. N.; Panse, A.; Jain, A.; Sharma, P.; Ionita, Ciprian N.; Titus, A. H.; Cartwright, A. N.; Bednarek, D. R.; Rudin, S.

    2012-03-01

    We demonstrate a novel approach for achieving patient dose savings during image-guided neurovascular interventions, involving a combination of a material x-ray region of interest (ROI) attenuator and a spatially different ROI temporal filtering technique. The part of the image under the attenuator is reduced in dose but noisy and less bright due to fewer x-ray quanta reaching the detector, as compared to the non-attenuating (or less attenuating) region. First the brightness is equalized throughout the image by post processing and then a temporal filter with higher weights is applied to the high attenuating region to reduce the noise, at the cost of increased lag; however, in the regions where less attenuation is present, a lower temporal weight is needed and is applied to preserve temporal resolution. A simulation of the technique is first presented on an actual image sequence obtained from an endovascular image guided interventional (EIGI) procedure. Then the actual implementation of the technique with a physical ROI attenuator is presented. Quantitative analysis including noise analysis and integral dose calculations are presented to validate the proposed technique.

  9. Dose Reduction Technique Using a Combination of a Region of Interest (ROI) Material X-Ray Attenuator and Spatially Different Temporal Filtering for Fluoroscopic Interventions

    PubMed Central

    Vasan, S.N Swetadri; Panse, A.; Jain, A.; Sharma, P.; Ionita, Ciprian N.; Titus, A.H.; Cartwright, A.N.; Bednarek, D.R; Rudin, S.

    2012-01-01

    We demonstrate a novel approach for achieving patient dose savings during image-guided neurovascular interventions, involving a combination of a material x-ray region of interest (ROI) attenuator and a spatially different ROI temporal filtering technique. The part of the image under the attenuator is reduced in dose but noisy and less bright due to fewer x-ray quanta reaching the detector, as compared to the non-attenuating (or less attenuating) region. First the brightness is equalized throughout the image by post processing and then a temporal filter with higher weights is applied to the high attenuating region to reduce the noise, at the cost of increased lag; however, in the regions where less attenuation is present, a lower temporal weight is needed and is applied to preserve temporal resolution. A simulation of the technique is first presented on an actual image sequence obtained from an endovascular image guided interventional (EIGI) procedure. Then the actual implementation of the technique with a physical ROI attenuator is presented. Quantitative analysis including noise analysis and integral dose calculations are presented to validate the proposed technique. PMID:24027617

  10. Dose Reduction Technique Using a Combination of a Region of Interest (ROI) Material X-Ray Attenuator and Spatially Different Temporal Filtering for Fluoroscopic Interventions.

    PubMed

    Vasan, S N Swetadri; Panse, A; Jain, A; Sharma, P; Ionita, Ciprian N; Titus, A H; Cartwright, A N; Bednarek, D R; Rudin, S

    2012-02-23

    We demonstrate a novel approach for achieving patient dose savings during image-guided neurovascular interventions, involving a combination of a material x-ray region of interest (ROI) attenuator and a spatially different ROI temporal filtering technique. The part of the image under the attenuator is reduced in dose but noisy and less bright due to fewer x-ray quanta reaching the detector, as compared to the non-attenuating (or less attenuating) region. First the brightness is equalized throughout the image by post processing and then a temporal filter with higher weights is applied to the high attenuating region to reduce the noise, at the cost of increased lag; however, in the regions where less attenuation is present, a lower temporal weight is needed and is applied to preserve temporal resolution. A simulation of the technique is first presented on an actual image sequence obtained from an endovascular image guided interventional (EIGI) procedure. Then the actual implementation of the technique with a physical ROI attenuator is presented. Quantitative analysis including noise analysis and integral dose calculations are presented to validate the proposed technique.

  11. 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

  12. Use of the live attenuated Japanese Encephalitis vaccine SA 14-14-2 in children: A review of safety and tolerability studies.

    PubMed

    Ginsburg, Amy Sarah; Meghani, Ankita; Halstead, Scott B; Yaich, Mansour

    2017-08-25

    Japanese encephalitis (JE) is the leading cause of viral neurological disease and disability in Asia. Some 50-80% of children with clinical JE die or have long-term neurologic sequelae. Since there is no cure, human vaccination is the only effective long-term control measure, and the World Health Organization recommends that at-risk populations receive a safe and effective vaccine. Four different types of JE vaccines are currently available: inactivated mouse brain-derived vaccines, inactivated Vero cell vaccines, live attenuated SA 14-14-2 vaccines and a live recombinant (chimeric) vaccine. With the rapidly increasing demand for and availability and use of JE vaccines, countries face an important decision in the selection of a JE vaccine. This article provides a comprehensive review of the available safety literature for the live attenuated SA 14-14-2 JE vaccine (LAJEV), the most widely used new generation JE vaccine. With well-established effectiveness data, a single dose of LAJEV protects against clinical JE disease for at least 5 years, providing a long duration of protection compared with inactivated mouse brain-derived vaccines. Since 1988, about 700 million doses of the LAJEV have been distributed globally. Our review found that LAJEV is well tolerated across a wide age range and can safely be given to children as young as 8 months of age. While serious adverse events attributable to LAJEV have been reported, independent experts have not found sufficient evidence for causality based on the available data.

  13. Chemically Attenuated Blood-Stage Plasmodium yoelii Parasites Induce Long-Lived and Strain-Transcending Protection

    PubMed Central

    Raja, Amber I.; Cai, Yeping; Reiman, Jennifer M.; Groves, Penny; Chakravarty, Sumana; McPhun, Virginia; Doolan, Denise L.; Cockburn, Ian; Hoffman, Stephen L.; Stanisic, Danielle I.

    2016-01-01

    The development of a vaccine is essential for the elimination of malaria. However, despite many years of effort, a successful vaccine has not been achieved. Most subunit vaccine candidates tested in clinical trials have provided limited efficacy, and thus attenuated whole-parasite vaccines are now receiving close scrutiny. Here, we test chemically attenuated Plasmodium yoelii 17X and demonstrate significant protection following homologous and heterologous blood-stage challenge. Protection against blood-stage infection persisted for at least 9 months. Activation of both CD4+ and CD8+ T cells was shown after vaccination; however, in vivo studies demonstrated a pivotal role for both CD4+ T cells and B cells since the absence of either cell type led to loss of vaccine-induced protection. In spite of significant activation of circulating CD8+ T cells, liver-stage immunity was not evident. Neither did vaccine-induced CD8+ T cells contribute to blood-stage protection; rather, these cells contributed to pathogenesis, since all vaccinated mice depleted of both CD4+ and CD8+ T cells survived a challenge infection. This study provides critical insight into whole-parasite vaccine-induced immunity and strong support for testing whole-parasite vaccines in humans. PMID:27245410

  14. Association of the Host Immune Response with Protection Using a Live Attenuated African Swine Fever Virus Model

    PubMed Central

    Carlson, Jolene; O’Donnell, Vivian; Alfano, Marialexia; Velazquez Salinas, Lauro; Holinka, Lauren G.; Krug, Peter W.; Gladue, Douglas P.; Higgs, Stephen; Borca, Manuel V.

    2016-01-01

    African swine fever (ASF) is a lethal hemorrhagic disease of swine caused by a double-stranded DNA virus, ASF virus (ASFV). There is no vaccine to prevent the disease and current control measures are limited to culling and restricting animal movement. Swine infected with attenuated strains are protected against challenge with a homologous virulent virus, but there is limited knowledge of the host immune mechanisms generating that protection. Swine infected with Pretoriuskop/96/4 (Pret4) virus develop a fatal severe disease, while a derivative strain lacking virulence-associated gene 9GL (Pret4Δ9GL virus) is completely attenuated. Swine infected with Pret4Δ9GL virus and challenged with the virulent parental virus at 7, 10, 14, 21, and 28 days post infection (dpi) showed a progressive acquisition of protection (from 40% at 7 dpi to 80% at 21 and 28 dpi). This animal model was used to associate the presence of host immune response (ASFV-specific antibody and interferon (IFN)-γ responses, or specific cytokine profiles) and protection against challenge. With the exception of ASFV-specific antibodies in survivors challenged at 21 and 28 dpi, no association between the parameters assessed and protection could be established. These results, encompassing data from 65 immunized swine, underscore the complexity of the system under study, suggesting that protection relies on the concurrence of different host immune mechanisms. PMID:27782090

  15. Safety of a modified-live combination vaccine against respiratory and reproductive diseases in pregnant cows.

    PubMed

    Ellsworth, Michael A; Brown, Martha J; Fergen, Brian J; Ficken, Martin D; Tucker, Cassius M; Bierman, Patrick; TerHune, Terry N

    2003-01-01

    A combination vaccine (Bovi-Shield FP4 + L5, Pfizer Animal Health) containing modified-live virus (MLV) components against bovine herpesvirus-1 (BHV-1), bovine viral diarrhea virus BVDV), parainfluenza virus-3 (PI3), bovine respiratory syncytial virus (BRSV), and inactivated cultures of Leptospira canicola, grippotyphosa, hardjo, icterohaemorrhagiae, and pomona was evaluated for safety in pregnant beef and dairy animals. Heifers vaccinated prebreeding with the minimum immunizing dose (lowest antigen level initiating immunizing effects) of the vaccine's MLV BHV-1 or BVDV components and during pregnancy (approximately 200 days of gestation) with vaccine containing 10x doses of the same BHV-1 and BVDV components delivered live, healthy calves that were determined to be serologically negative (titer less than 1:2) for neutralizing antibodies to BHV-1 and BVDV prior to nursing. Additionally, in three field safety studies, previously vaccinated cows and heifers that received a field dose (vaccine containing antigen levels required for commercial sale of the MLV combination vaccine during either the first, second, or third trimester of pregnancy had abortion rates similar to those of pregnant cows and heifers vaccinated during the same stage of pregnancy with sterile water diluent.

  16. 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 Central

    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

  17. 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 Central

    2014-01-01

    Background 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. Results 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

  18. Evaluation of eight live attenuated vaccine candidates for protection against challenge with virulent Mycobacterium avium subspecies paratuberculosis in mice

    USDA-ARS?s Scientific Manuscript database

    Johne’s disease is caused by Mycobacterium avium subsp. paratuberculosis (MAP), which results in serious economic losses worldwide in farmed livestock such as cattle, sheep and goats. To control this disease, an effective vaccine with minimal adverse effects is needed. In order to identify a live va...

  19. Nucleotide sequence analysis of the respiratory syncytial virus subgroup A cold-passaged (cp) temperature sensitive (ts) cpts-248/404 live attenuated virus vaccine candidate.

    PubMed

    Firestone, C Y; Whitehead, S S; Collins, P L; Murphy, B R; Crowe, J E

    1996-11-15

    The complete nucleotide sequence of the RSV cpts-248/404 live attenuated vaccine candidate was determined from cloned cDNA and was compared to that of the RSV A2/HEK7 wild-type, cold-passaged cp-RSV, and cpts-248 virus, which constitute the series of progenitor viruses. RSV cpts-248/404 is more attenuated and more temperature sensitive (ts) (shut-off temperature 36 degrees) than its cpts-248 parent virus (shut-off temperature 38 degrees) and is currently being evaluated in phase I clinical trials in humans. Our ultimate goal is to identify the genetic basis for the host range attenuation phenotype exhibited by cp-RSV (i.e., efficient replication in tissue culture but decreased replication in chimpanzees and humans) and for the ts and attenuation phenotypes of its chemically mutagenized derivatives, cpts-248 and cpts-248/404. Compared with its cpts-248 parent, the cpts-248/404 virus possesses an amino acid change in the polymerase (L) protein and a single nucleotide substitution in the M2 gene start sequence. In total, the cpts-248/404 mutant differs from its wild-type RSV A2/HEK7 progenitor in seven amino acids [four in the polymerase (L) protein, two in the fusion (F) glycoprotein, and one in the (N) nucleoprotein] and one nucleotide difference in the M2 gene start sequence. Heterogeneity at nucleotide position 4 (G or C, negative sense, compared to G in the RSV A2/HEK7 progenitor) in the leader region of vRNA developed during passage of the cpts-248/404 in tissue culture. Biologically cloned derivatives of RSV cpts-248/404 virus that differed at position 4 possessed the same level of temperature sensitivity and exhibited the same level of replication in the upper and lower respiratory tract of mice, suggesting that heterogeneity at this position is not clinically relevant. The determination of the nucleotide sequence of the cpts-248/404 virus will allow evaluation of the stability of the eight mutations that are associated with the attenuation phenotype during

  20. The temperature-sensitive (ts) phenotype of a cold-passaged (cp) live attenuated respiratory syncytial virus vaccine candidate, designated cpts530, results from a single amino acid substitution in the L protein.

    PubMed

    Juhasz, K; Whitehead, S S; Bui, P T; Biggs, J M; Crowe, J E; Boulanger, C A; Collins, P L; Murphy, B R

    1997-08-01

    cpts530, a candidate live-virus vaccine, is an attenuated strain of human respiratory syncytial virus (RSV). It was derived by subjecting a cold-passaged (cp) strain of RSV to a single round of chemical mutagenesis. cpts530 is a temperature-sensitive (ts) mutant that is attenuated in mice and chimpanzees, and its ts phenotype exhibits a high level of stability during replication in both species. In the present study, the complete nucleotide sequence of cpts530 RSV was determined. The five mutations known to be present in the parent cpRSV were retained in its cpts530 derivative, and one additional nucleotide change was identified at nucleotide (nt) 10060, which resulted in a phenylalanine-to-leucine change at amino acid 521 in the large polymerase (L) protein. To determine if this single amino acid substitution was indeed responsible for the ts phenotype of cpts530, it was introduced alone or in combination with the cp mutations into the full-length cDNA clone of the wild-type A2 RSV. Analysis of infectious viruses recovered from mutant cDNAs indicated that this single mutation specified complete restriction of plaque formation of recombinant cp530 in HEp-2 cell monolayer cultures at 40 degrees C, and the level of temperature sensitivity was not influenced by the presence of the five cpRSV mutations. These findings identify the phenylalanine-to-leucine change at amino acid 521 in the L protein as the mutation that specifies the ts phenotype of cpts530. Furthermore, these findings illustrate the feasibility of using the cDNA-based recovery system to analyze and construct defined attenuated vaccine viruses.

  1. d-Cycloserine combined with cue exposure therapy fails to attenuate subjective and physiological craving in cocaine dependence

    PubMed Central

    Santa Ana, Elizabeth J.; Prisciandaro, James J.; Saladin, Michael E.; McRae-Clark, Aimee L.; Shaftman, Stephanie R.; Nietert, Paul J.; Brady, Kathleen T.

    2014-01-01

    Background Based on preclinical studies showing that the partial N-methyl-d-aspartate (NMDA) agonist d-cycloserine (DCS) facilitates extinction of cocaine self-administration and cocaine-induced conditioned place preference, we evaluated whether 50 mg of DCS would reduce craving to cocaine cues when combined with cue exposure (CE) in cocaine dependent humans. Methods In this double-blind placebo-controlled pilot study, 47 cocaine dependent participants were randomized to DCS or placebo (PBO), plus CE. Participants received DCS or PBO 30 minutes prior to two CE sessions, conducted one day apart. Craving and heart rate was assessed prior to CE sessions, during CE trials, and after CE trials. These measures were assessed again at a 1-week follow-up (session 3) after the second CE session. Results DCS failed to significantly attenuate cocaine cue reactivity based on subjective craving and physiological reactivity (heart rate) compared to PBO. The CE protocol, consisting of repeated exposure to drug cues combined with skills training, resulted in extinction to cocaine cues as suggested by decreased craving within and between sessions in both treatment conditions. All participants exhibited elevated heart rate with repeated exposures, demonstrating a potentiation in heart rate between sessions. PMID:25808169

  2. Dengue type 4 live-attenuated vaccine viruses passaged in vero cells affect genetic stability and dengue-induced hemorrhaging in mice.

    PubMed

    Lee, Hsiang-Chi; Yen, Yu-Ting; Chen, Wen-Yu; Wu-Hsieh, Betty A; Wu, Suh-Chin

    2011-01-01

    Most live-attenuated tetravalent dengue virus vaccines in current clinical trials are produced from Vero cells. In a previous study we demonstrated that an infectious cDNA clone-derived dengue type 4 (DEN-4) virus retains higher genetic stability in MRC-5 cells than in Vero cells. For this study we investigated two DEN-4 viruses: the infectious cDNA clone-derived DEN-4 2A and its derived 3' NCR 30-nucleotide deletion mutant DEN-4 2AΔ30, a vaccine candidate. Mutations in the C-prM-E, NS2B-NS3, and NS4B-NS5 regions of the DEN genome were sequenced and compared following cell passages in Vero and MRC-5 cells. Our results indicate stronger genetic stability in both viruses following MRC-5 cell passages, leading to significantly lower RNA polymerase error rates when the DEN-4 virus is used for genome replication. Although no significant increases in virus titers were observed following cell passages, DEN-4 2A and DEN-4 2AΔ30 virus titers following Vero cell passages were 17-fold to 25-fold higher than titers following MRC-5 cell passages. Neurovirulence for DEN-4 2A and DEN-4 2AΔ30 viruses increased significantly following passages in Vero cells compared to passages in MRC-5 cells. In addition, more severe DEN-induced hemorrhaging in mice was noted following DEN-4 2A and DEN-4 2AΔ30 passages in Vero cells compared to passages in MRC-5 cells. Target mutagenesis performed on the DEN-4 2A infectious clone indicated that single point mutation of E-Q(438)H, E-V(463)L, NS2B-Q(78)H, and NS2B-A(113)T imperatively increased mouse hemorrhaging severity. The relationship between amino acid mutations acquired during Vero cell passage and enhanced DEN-induced hemorrhages in mice may be important for understanding DHF pathogenesis, as well as for the development of live-attenuated dengue vaccines. Taken together, the genetic stability, virus yield, and DEN-induced hemorrhaging all require further investigation in the context of live-attenuated DEN vaccine development.

  3. Dengue Type 4 Live-Attenuated Vaccine Viruses Passaged in Vero Cells Affect Genetic Stability and Dengue-Induced Hemorrhaging in Mice

    PubMed Central

    Lee, Hsiang-Chi; Yen, Yu-Ting; Chen, Wen-Yu; Wu-Hsieh, Betty A.; Wu, Suh-Chin

    2011-01-01

    Most live-attenuated tetravalent dengue virus vaccines in current clinical trials are produced from Vero cells. In a previous study we demonstrated that an infectious cDNA clone-derived dengue type 4 (DEN-4) virus retains higher genetic stability in MRC-5 cells than in Vero cells. For this study we investigated two DEN-4 viruses: the infectious cDNA clone-derived DEN-4 2A and its derived 3′ NCR 30-nucleotide deletion mutant DEN-4 2AΔ30, a vaccine candidate. Mutations in the C-prM-E, NS2B-NS3, and NS4B-NS5 regions of the DEN genome were sequenced and compared following cell passages in Vero and MRC-5 cells. Our results indicate stronger genetic stability in both viruses following MRC-5 cell passages, leading to significantly lower RNA polymerase error rates when the DEN-4 virus is used for genome replication. Although no significant increases in virus titers were observed following cell passages, DEN-4 2A and DEN-4 2AΔ30 virus titers following Vero cell passages were 17-fold to 25-fold higher than titers following MRC-5 cell passages. Neurovirulence for DEN-4 2A and DEN-4 2AΔ30 viruses increased significantly following passages in Vero cells compared to passages in MRC-5 cells. In addition, more severe DEN-induced hemorrhaging in mice was noted following DEN-4 2A and DEN-4 2AΔ30 passages in Vero cells compared to passages in MRC-5 cells. Target mutagenesis performed on the DEN-4 2A infectious clone indicated that single point mutation of E-Q438H, E-V463L, NS2B-Q78H, and NS2B-A113T imperatively increased mouse hemorrhaging severity. The relationship between amino acid mutations acquired during Vero cell passage and enhanced DEN-induced hemorrhages in mice may be important for understanding DHF pathogenesis, as well as for the development of live-attenuated dengue vaccines. Taken together, the genetic stability, virus yield, and DEN-induced hemorrhaging all require further investigation in the context of live-attenuated DEN vaccine development. PMID:22053180

  4. 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.

  5. Longitudinal study to assess the safety and efficacy of a live-attenuated SHIV vaccine in long term immunized rhesus macaques

    SciTech Connect

    Yankee, Thomas M. Sheffer, Darlene; Liu Zhengian; Dhillon, Sukhbir; Jia Fenglan; Chebloune, Yahia; Stephens, Edward B.; Narayan, Opendra

    2009-01-05

    Live-attenuated viruses derived from SIV and SHIV have provided the most consistent protection against challenge with pathogenic viruses, but concerns regarding their long-term safety and efficacy have hampered their clinical usefulness. We report a longitudinal study in which we evaluated the long-term safety and efficacy of {delta}vpuSHIV{sub PPC}, a live virus vaccine derived from SHIV{sub PPC}. Macaques were administered two inoculations of {delta}vpuSHIV{sub PPC}, three years apart, and followed for eight years. None of the five vaccinated macaques developed an AIDS-like disease from the vaccine. At eight years, macaques were challenged with pathogenic SIV and SHIV. None of the four macaques with detectable cellular-mediated immunity prior to challenge had detectable viral RNA in the plasma. This study demonstrates that multiple inoculations of a live vaccine virus can be used safely and can significantly extend the efficacy of the vaccine, as compared to a single inoculation, which is efficacious for approximately three years.

  6. 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

  7. 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.

  8. Evaluation in mice of Brucella ovis attenuated mutants for use as live vaccines against B. ovis infection.

    PubMed

    Sancho, Pilar; Tejedor, Carmen; Sidhu-Muñoz, Rebeca S; Fernández-Lago, Luis; Vizcaíno, Nieves

    2014-06-04

    Brucella ovis causes ram contagious epididymitis, a disease for which a specific vaccine is lacking. Attenuated Brucella melitensis Rev 1, used as vaccine against ovine and caprine brucellosis caused by B. melitensis, is also considered the best vaccine available for the prophylaxis of B. ovis infection, but its use for this purpose has serious drawbacks. In this work, two previously characterized B. ovis attenuated mutants (Δomp25d and Δomp22) were evaluated in mice, in comparison with B. melitensis Rev 1, as vaccines against B. ovis. Similarities, but also significant differences, were found regarding the immune response induced by the three vaccines. Mice vaccinated with the B. ovis mutants developed anti-B. ovis antibodies in serum of the IgG1, IgG2a and IgG2b subclasses and their levels were higher than those observed in Rev 1-vaccinated mice. After an antigen stimulus with B. ovis cells, splenocytes obtained from all vaccinated mice secreted similar levels of TNF-α and IL12(p40) and remarkably high amounts of IFN-γ, a crucial cytokine in protective immunity against other Brucella species. By contrast, IL-1α -an enhancer of T cell responses to antigen- was present at higher levels in mice vaccinated with the B. ovis mutants, while IL-10, an anti-inflammatory cytokine, was significantly more abundant in Rev 1-vaccinated mice. Additionally, the B. ovis mutants showed appropriate persistence, limited splenomegaly and protective efficacy against B. ovis similar to that observed with B. melitensis Rev 1. These characteristics encourage their evaluation in the natural host as homologous vaccines for the specific prophylaxis of B. ovis infection.

  9. The effect of diatomaceous earth in live, attenuated infectious bronchitis vaccine, immune responses, and protection against challenge.

    PubMed

    Nazmi, Ali; Hauck, Rüdiger; Corbeil, Lynette B; Gallardo, Rodrigo A

    2017-04-17

    Live virus vaccines are commonly used in poultry production, particularly in broilers. Massive application and generation of a protective local mucosal and humoral immunity with no adverse effects is the main goal for this strategy. Live virus vaccines can be improved by adding adjuvants to boost mucosal innate and adaptive responses. In a previous study we showed that diatomaceous earth (DE) can be used as adjuvant in inactivated vaccines. The aim of this study was to test DE as adjuvant in an Ark-DPI live infectious bronchitis virus (IBV) vaccine after ocular or spray application. Titrating the virus alone or after addition of DE showed that DE had no detrimental effect on the vaccine virus. However, adding DE to the vaccine did not induce higher IgG titers in the serum and IgA titers in tears. It also did not affect the frequency of CD4+ T cells, CD8+ T cells and monocytes/macrophages in the blood and the spleen determined by flow cytometry. In addition, protection generated against IBV homologous challenges, measured by viral load in tears, respiratory signs and histopathology in tracheas, did not vary when DE was present in the vaccine formulation. Finally, we confirmed through our observations that Ark vaccines administered by hatchery spray cabinet elicit weaker immune responses and protection against an IBV homologous challenge compared to the same vaccine delivered via ocular route. © 2017 Poultry Science Association Inc.

  10. Combined treatment with olmesartan medoxomil and amlodipine besylate attenuates atherosclerotic lesion progression in a model of advanced atherosclerosis.

    PubMed

    Sievers, Philipp; Uhlmann, Lorenz; Korkmaz-Icöz, Sevil; Fastner, Christian; Bea, Florian; Blessing, Erwin; Katus, Hugo A; Preusch, Michael R

    2015-01-01

    =10; P<0.01). Furthermore, all sections revealed morphological signs of calcification, but no difference could be detected. Treatment with the combination of olmesartan medoxomil and amlodipine besylate showed no effect on lesion composition. Electrophoretic mobility shift assays of nuclear extracts demonstrated reduced activity of the transcription factor NF-κB when treated with olmesartan medoxomil, amlodipine besylate, or their combination, as compared to controls. Combined treatment with olmesartan medoxomil and amlodipine besylate attenuated atherosclerotic lesion progression, possibly due to anti-inflammatory mechanisms. Our data support the hypothesis that even in advanced atherosclerosis anti-inflammatory treatment, using angiotensin II type 1 receptor blockers and calcium channel antagonists of the dihydropyridine type can attenuate atherosclerotic lesion progression.

  11. 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.

  12. Safety, dose, immunogenicity, and transmissibility of an oral live attenuated Shigella flexneri 2a vaccine candidate (SC602) among healthy adults and school children in Matlab, Bangladesh.

    PubMed

    Rahman, Kazi Mizanur; Arifeen, Shams El; Zaman, K; Rahman, Mahbubur; Raqib, Rubhana; Yunus, Mohammad; Begum, Nazma; Islam, Md Shaheenul; Sohel, Badrul Munir; Rahman, Muntasirur; Venkatesan, Malabi; Hale, Thomas L; Isenbarger, Daniel W; Sansonetti, Philippe J; Black, Robert E; Baqui, Abdullah H

    2011-02-01

    In double-blind trials in Bangladesh, 88 adults, and 79 children (8-10 years) were randomized to receive either a single oral dose of 1 × 10(4), 1 × 10(5) or 1 × 10(6)CFU of SC602 (a live, attenuated Shigella flexneri 2a strain vaccine) or placebo. In the adult outpatient 1 × 10(6) CFU group, severe joint pain and body aches were reported by one and two vaccinees respectively. In the adult inpatient trial, SC602 was isolated from 3 volunteers, pre-vaccination antibody titers were high, and fourfold increases in serum IgG anti-LPS responses were observed in 2 of 5 subjects of the 1 × 10(6)CFU group. None of the volunteers developed diarrhea. Overall, SC602 was found to be associated with minimal vaccine shedding, minimal reactogenicity, no transmission risk, and low immune stimulation.

  13. 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

  14. Clinical and serologic effects of Alice strain live attenuated influenza A (H3N2) virus vaccine in an adult population.

    PubMed

    Miller, L W; Togo, Y; Hornick, R B

    1975-12-30

    Alice strain live attenuated influenza A (H3N2) virus was evaluated in prison volunteers. By random double blind allocation, 94 volunteers received Alice strain vaccine (AS) intranasally and 97 received placebo. The vaccine was well tolerated, and there was no serious morbidity. The number, type, duration, and severity of symptoms was not significantly different between the vaccine and placebo groups. Seventy-five per cent of vaccines with initial HAI titers less than or equal to 1:8 had 4 fold or greater titer responses on day 30. Placebo recipients experienced no titer changes. The GMT among vaccinees increased from 23.5 prior to vaccination 59.7 30 days later. Surveillance activities failed to document influenza A (H3N2) infection in the volunteer population during a 6 month follow-up period. Additional studies on the protective effects of the vaccine are required before efficacy can be determined.

  15. Live, attenuated simian immunodeficiency virus vaccines elicit potent resistance against a challenge with a human immunodeficiency virus type 1 chimeric virus.

    PubMed Central

    Shibata, R; Siemon, C; Czajak, S C; Desrosiers, R C; Martin, M A

    1997-01-01

    Three rhesus macaques, previously immunized with SIVdelta3 or SIVdelta2, each an attenuated derivative of SIVmac239, and two naive monkeys were challenged with 30,000 50% tissue culture infective doses of SHIV, an SIV/human immunodeficiency virus type 1 (HIV-1) chimeric virus bearing the dual-tropic envelope of HIV-1DH12. By several criteria, including virus isolation, serological assays, and PCR (both DNA and reverse transcriptase), SHIV levels were reduced to barely detectable levels in the circulating blood of vaccinated animals. The resistant SIV-vaccinated macaques had no preexisting neutralizing antibodies directed against SHIV, nor did they produce neutralizing antibodies at any time over a 14-month observation period following SHIV challenge. Interestingly, SIV sequences, derived from the vaccine, could be amplified from numerous tissue samples collected at the conclusion of the experiment, 60 weeks postchallenge, but SHIV-specific sequences (viz., HIV-1 env) could not. These results demonstrate that live attenuated SIV vaccines provide strong long-term protection even against challenge strains with highly divergent envelope sequences. PMID:9343164

  16. Extended safety and efficacy studies of a live attenuated double leucine and pantothenate auxotroph of Mycobacterium tuberculosis as a vaccine candidate

    PubMed Central

    Sampson, Samantha L.; Mansfield, Keith G.; Carville, Angela; Magee, D. Mitchell; Quitugua, Teresa; Howerth, Elizabeth W.; Bloom, Barry R.; Hondalus, Mary K.

    2011-01-01

    We have previously described the development of a live, fully attenuated Mycobacterium tuberculosis (Mtb) vaccine candidate strain with two independent attenuating auxotrophic mutations in leucine and pantothenate biosynthesis. In the present work, those studies have been extended to include testing for protective efficacy in a long-term guinea pig survival model and safety testing in the highly tuberculosis susceptible Rhesus macaque. To model the safety of the ΔleuD ΔpanCD strain in HIV-infected human populations, a Simian Immunodeficiency Virus (SIV)-infected Rhesus macaque group was included. Immunization with the non-replicating ΔleuD ΔpanCD conferred long-term protection against challenge with virulent M. tuberculosis equivalent to that afforded by BCG as measured by guinea pig survival. In safety studies, clinical, hematological and bacteriological monitoring of both SIV-positive and SIV-negative Rhesus macaques immunized with ΔleuD ΔpanCD, revealed no vaccine-associated adverse effects. The results support the further development of the ΔleuD ΔpanCD strain as a viable tuberculosis (TB) vaccine candidate. PMID:21549795

  17. Evaluating the effectiveness, impact and safety of live attenuated and seasonal inactivated influenza vaccination: protocol for the Seasonal Influenza Vaccination Effectiveness II (SIVE II) study

    PubMed Central

    Lone, Nazir I; Kavanagh, Kimberley; Robertson, Chris; McMenamin, Jim; von Wissmann, Beatrix; Vasileiou, Eleftheria; Butler, Chris; Ritchie, Lewis D; Gunson, Rory; Schwarze, Jürgen; Sheikh, Aziz

    2017-01-01

    Introduction Seasonal (inactivated) influenza vaccination is recommended for all individuals aged 65+ and in individuals under 65 who are at an increased risk of complications of influenza infection, for example, people with asthma. Live attenuated influenza vaccine (LAIV) was recommended for children as they are thought to be responsible for much of the transmission of influenza to the populations at risk of serious complications from influenza. A phased roll-out of the LAIV pilot programme began in 2013/2014. There is limited evidence for vaccine effectiveness (VE) in the populations targeted for influenza vaccination. The aim of this study is to examine the safety and effectiveness of the live attenuated seasonal influenza vaccine programme in children and the inactivated seasonal influenza vaccination programme among different age and at-risk groups of people. Methods and analysis Test negative and cohort study designs will be used to estimate VE. A primary care database covering 1.25 million people in Scotland for the period 2000/2001 to 2015/2016 will be linked to the Scottish Immunisation Recall Service (SIRS), Health Protection Scotland virology database, admissions to Scottish hospitals and the Scottish death register. Vaccination status (including LAIV uptake) will be determined from the primary care and SIRS database. The primary outcome will be influenza-positive real-time PCR tests carried out in sentinel general practices and other healthcare settings. Secondary outcomes include influenza-like illness and asthma-related general practice consultations, hospitalisations and death. An instrumental variable analysis will be carried out to account for confounding. Self-controlled study designs will be used to estimate the risk of adverse events associated with influenza vaccination. Ethics and dissemination We obtained approval from the National Research Ethics Service Committee, West Midlands—Edgbaston. The study findings will be presented at

  18. Live attenuated measles and mumps viral strain-containing vaccines and hearing loss: Vaccine Adverse Event Reporting System (VAERS), United States, 1990--2003.

    PubMed

    Asatryan, Armenak; Pool, Vitali; Chen, Robert T; Kohl, Katrin S; Davis, Robert L; Iskander, John K

    2008-02-26

    Hearing loss (HL) is a known complication of wild measles and mumps viral infections. As vaccines against measles and mumps contain live attenuated viral strains, it is biologically plausible that in some individuals HL could develop as a complication of vaccination against measles and/or mumps. Our objectives for this study were: to find and describe all cases of HL reported in the scientific literature and to the US Vaccine Adverse Events Reporting System (VAERS) for the period 1990--2003; and to determine reporting rate of HL after live attenuated measles and/or mumps viral strain-containing vaccines (MMCV) administration. We searched published reports for cases of HL identified after vaccination with MMCV. We also searched for reports of HL after MMCV administration submitted to VAERS from 1990 through 2003 and determined the dose-adjusted reporting rate of HL. Our main outcome measure was reported cases of HL after immunization with MMCV which were classified as idiopathic. We found 11 published case reports of HL following MMCV. The review of the VAERS reports identified 44 cases of likely idiopathic sensorineural HL after MMCV administration. The onset of HL in the majority of VAERS and published cases was consistent with the incubation periods of wild measles and mumps viruses. Based on the annual usage of measles-mumps-rubella (MMR) vaccine, we estimated the reporting rate of HL to be 1 case per 6-8 million doses. Thus, HL following MMCV has been reported in the literature and to the VAERS. Further studies are needed to better understand if there is a causal relationship between MMCV and HL.

  19. Safety and immunogenicity of a mutagenized, live attenuated Rift Valley fever vaccine, MP-12, in a Phase 1 dose escalation and route comparison study in humans.

    PubMed

    Pittman, Phillip R; McClain, David; Quinn, Xiaofei; Coonan, Kevin M; Mangiafico, Joseph; Makuch, Richard S; Morrill, John; Peters, Clarence J

    2016-01-20

    Rift Valley fever (RVF) poses a risk as a potential agent in bioterrorism or agroterrorism. A live attenuated RVF vaccine (RVF MP-12) has been shown to be safe and protective in animals and showed promise in two initial clinical trials. In the present study, healthy adult human volunteers (N=56) received a single injection of (a) RVF MP-12, administered subcutaneously (SQ) at a concentration of 10(4.7) plaque-forming units (pfu) (SQ Group); (b) RVF MP-12, administered intramuscularly (IM) at 10(3.4)pfu (IM Group 1); (c) RVF MP-12, administered IM at 10(4.4)pfu (IM Group 2); or (d) saline (Placebo Group). The vaccine was well tolerated by volunteers in all dose and route groups. Infrequent and minor adverse events were seen among recipients of both placebo and RVF MP-12. One subject had viremia detectable by direct plaque assay, and six subjects from IM Group 2 had transient low-titer viremia detectable only by nucleic acid amplification. Of the 43 vaccine recipients, 40 (93%) achieved neutralizing antibodies (measured as an 80% plaque reduction neutralization titer [PRNT80]) as well as RVF-specific IgM and IgG. The highest peak geometric mean PRNT80 titers were observed in IM Group 2. Of 34 RVF MP-12 recipients available for testing 1 year following inoculation, 28 (82%) remained seropositive (PRNT80≥1:20); this included 20 of 23 vaccinees (87%) from IM Group 2. The live attenuated RVF MP-12 vaccine was safe and immunogenic at the doses and routes studied. Given the need for an effective vaccine against RVF virus, further evaluation in humans is warranted.

  20. Safety and immunogenicity of single dose live attenuated varicella vaccine (VR 795 Oka strain) in healthy Indian children: A randomized controlled study

    PubMed Central

    Mitra, Monjori; Faridi, Mma; Ghosh, Apurba; Shah, Nitin; Shah, Raju; Chaterjee, Suparna; Narang, Manish; Bhattacharya, Nisha; Bhat, Gandhali; Choudhury, Harish; Kadhe, Ganesh; Mane, Amey; Roy, Sucheta

    2015-01-01

    Varicella, an acute viral systemic infection that may cause lifelong latent infection with the potential for causing clinical reactivation, may be prevented by immunization. The present study was an open label, randomized, controlled, phase III, multicentre trial, conducted to evaluate and compare the safety, tolerability and immunogenicity of a freeze dried live attenuated Oka strain Varicella Vaccine (VR 795 Oka strain) with Varilrix (Oka-RIT strain) in children. A total of 268 healthy Indian children aged 12 months to 12 y with baseline VZV IgG antibody (<100 mIU/ mL) were enrolled, and 256 children completed the study. The extent of rise of VZV IgG antibody titer assessed as 3-fold and 4-fold rise from baseline was found to be significantly higher (89.1% and 85.2%) in the test group as compared to control group (73.4% and 61.7%). The post-vaccination GMT of the test group was significantly higher (112.5 mIU/mL) as compared with the control group (67.8 mIU/mL) (P < 0.001). The seroconversion rate considering the 5 gp ELISA units/ml equivalent to 10mIU/ml were similar in the control (96.5%) and the test (98.3%) groups. The adverse events were not different in the control and test groups (P > 0.05). The test live attenuated vaccine was found to be highly immunogenic, safe and comparable to Varilrix used in control arm. PMID:25692656

  1. [Long-term immunogenicity and effectiveness of live attenuated hepatitis A vaccine (H2-strain)-a study on the result of 15 years' follow up].

    PubMed

    Zhuang, Fang-cheng; Mao, Zi-an; Jiang, Li-min; Wu, Jie; Chen, Yue-qing; Jiang, Qi; Chen, Nian-liang; Chai, Shao-ai; Mao, Jiang-sen

    2010-12-01

    To evaluate the long-term immunogenicity and effectiveness of live attenuated hepatitis A (HA) vaccine (H2 strain) after one dose injection, through a 15 years' follow up observation. A total of 220 children with negative anti-HAV antibody (aged 1-3 y) were involved and followed up in Jiaojiang district, Taizhou city, Zhejiang province. Indicators would include seroconversion and geometric mean titer (GMT) levels after inoculation the vaccine with single dose at 2 m, 12 m, 6 years, 10 years and 15 years. Epidemiological observation was carried out within the 15 years to evaluate the relationship between vaccine coverage, the incidence of HA and the overall effectiveness. In the studied population, serum was tested by ELISA (calibrated by WHO international reference) and ABBOTT Axsym HAVAB mEIA. Seroconversion rates were found to be 98.6% and 81.3% after 2 months and 15 years of inoculation and slowly decreased. GMT level was 128 mIU/ml after 15 years, significantly higher than the required protective level of 20 mIU/ml, recommended by WHO experts. Effectiveness through the 15-year follow up program showed a significant correlation between vaccine coverage and incidence of HA in 1-15 years aged group (Kendall-Rank test, τ =-0.931, P<0.01). There was no HA case seen among the observed accumulated 236 413 person-year vaccines, compared to 4 HA cases discovered in the 27 206 person-year of the non-vaccinees. The overall protective rate reached 100%. Through a mass vaccination program on children, the whole population established an immune-defence to enable the incidence of HA decreased by 96.7%. The long-term immunogenicity and effectiveness of live attenuated hepatitis A vaccine (H2 strain) after one dose injection could last as long as 15 years.

  2. Long term follow-up study to evaluate immunogenicity and safety of a single dose of live attenuated hepatitis a vaccine in children.

    PubMed

    Mitra, Monjori; Shah, Nitin; Faridi, Mma; Ghosh, Apurba; Sankaranarayanan, V S; Aggarwal, Anju; Chatterjee, Suparna; Bhattacharyya, Nisha; Kadhe, Ganesh; Vishnoi, Gaurav; Mane, Amey

    2015-01-01

    Worldwide, viral hepatitis continues to be a cause of considerable morbidity and mortality. Mass immunization with a single dose of live attenuated HAV has been shown to significantly reduce disease burden in the community. This was a phase IV, 5-year follow up study carried out at 4 centers (Kolkata, Delhi, Mumbai and Chennai) across India. The subjects with antibody titer <20 mIU/mL at baseline were evaluated for long term immunogenicity. Of the 503 subjects enrolled, 349 subjects were baseline seronegative with an anti-HAV antibody titer <20 mIU/mL. Overall, 343 subjects could be followed up at some point of time during this 5 y post vaccination period. In the last year (60 months) of follow-up, 108 subjects (97.3%) of 111 subjects (who came for follow-up at the end of 5 y) had a protective antibody titer (anti-HAV antibody titer >20 mIU/mL). The seroconversion rates considering seroprotection levels of anti-HAV antibody titer >20 mIU/mL, following vaccination starting from 6 weeks, 6 months, 12 months, 24 months, 36 months, 48 months and 60 months were 95.1%, 97.9%, 98.3%, 96.2%, 97.8%, 92.6% and 97.3%, respectively. The geometric mean concentration (GMC) over the years increased from 64.9 mIU/mL at 6 weeks to 38.1 mIU/mL and 135.2 mIU/mL at 6 months and 12 months, respectively and was maintained at 127.1 mIU/mL at 60 months. In conclusion, the result of this 5-year follow up study showed that the single dose of live attenuated vaccine is well tolerated and provides long-term immunogenicity in healthy Indian children.

  3. A carAB mutant of avian pathogenic Escherichia coli serogroup O2 is attenuated and effective as a live oral vaccine against colibacillosis in turkeys.

    PubMed Central

    Kwaga, J K; Allan, B J; van der Hurk, J V; Seida, H; Potter, A A

    1994-01-01

    Colibacillosis is a serious and economically important disease of the respiratory tract of chickens and turkeys. The serogroups of Escherichia coli commonly associated with colibacillosis in poultry are O1, O2, and O78. Although previous attempts to develop a vaccine have not been very successful, vaccination is still considered the most effective way of controlling the disease. Therefore, our laboratory has been involved in the development of an attenuated live vaccine that will be effective in the prevention of colibacillosis. The carAB operon coding for carbamoyl-phosphate synthetase, an essential enzyme in arginine and pyrimidine metabolism, was selected for study. Generalized transduction was used to transfer a Tn10-generated mutation from a laboratory strain to virulent avian field isolates of E. coli. Molecular techniques were used to determine the point of Tn10 insertion within the carAB operon. The insertion mutants were then cured of the tetracycline resistance gene of the transposon to select for antibiotic-sensitive and stable carAB mutants. The degree of attenuation obtained by the mutation was determined in day-old chickens. Typically, when 100-fold the 50% lethal dose (for the wild type) was given, no more than 50% mortality in the day-old chickens was observed. The deletion mutant of serotype O2 was also found to be avirulent in turkeys rendered susceptible to infection with hemorrhagic enteritis virus A. Turkey poults vaccinated orally at 4 weeks old with either the wild-type E. coli EC317 strain or its carAB mutant EC751 were completely protected from infection following challenge with the homologous wild-type strain. Our data indicate that carAB mutants of virulent avian strains of E. coli will be effective and safe as live oral vaccines for prevention of colibacillosis in poultry. Images PMID:8063392

  4. Application of real time RT-PCR for the genetic homogeneity and stability tests of the seed candidates for live attenuated influenza vaccine production.

    PubMed

    Shcherbik, Svetlana; Sergent, Sheila B; Davis, William G; Shu, Bo; Barnes, John; Kiseleva, Irina; Larionova, Natalie; Klimov, Alexander; Bousse, Tatiana

    2014-01-01

    Development and improvement of quality control tests for live attenuated vaccines are a high priority because of safety concerns. Live attenuated influenza vaccine (LAIV) viruses are 6:2 reassortants containing the hemagglutinin (HA) and neuraminidase (NA) gene segments from circulating influenza viruses to induce protective immune responses, and the six internal gene segments from a cold-adapted Master Donor Virus (MDV). LAIV candidate viruses for the 2012-2013 seasons, A/Victoria/361/2011-CDC-LV1 (LV1) and B/Texas/06/2011-CDC-LV2B (LV2B), were created by classical reassortment of A/Victoria/361/2011 and MDV-A A/Leningrad/134/17/57 (H2N2) or B/Texas/06/2011 and MDV-B B/USSR/60/69. In an attempt to provide better identity and stability testing for quality control of LV1 and LV2B, sensitive real-time RT-PCR assays (rRT-PCR) were developed to detect the presence of undesired gene segments (HA and NA from MDV and the six internal genes from the seasonal influenza viruses). The sensitivity of rRT-PCR assays designed for each gene segment ranged from 0.08 to 0.8EID50 (50% of Egg Infectious Dose) per reaction for the detection of undesired genes in LV1 and from 0.1 to 1EID50 per reaction for the detection of undesired genes in LV2B. No undesired genes were detected either before or after five passages of LV1 or LV2B in eggs. The complete genome sequencing of LV1 and LV2B confirmed the results of rRT-PCR, demonstrating the utility of the new rRT-PCR assays to provide the evidence for the homogeneity of the prepared vaccine candidate. Published by Elsevier B.V.

  5. Safety and immunogenicity of single dose live attenuated varicella vaccine (VR 795 Oka strain) in healthy Indian children: a randomized controlled study.

    PubMed

    Mitra, Monjori; Faridi, Mma; Ghosh, Apurba; Shah, Nitin; Shah, Raju; Chaterjee, Suparna; Narang, Manish; Bhattacharya, Nisha; Bhat, Gandhali; Choudhury, Harish; Kadhe, Ganesh; Mane, Amey; Roy, Sucheta

    2015-01-01

    Varicella, an acute viral systemic infection that may cause lifelong latent infection with the potential for causing clinical reactivation, may be prevented by immunization. The present study was an open label, randomized, controlled, phase III, multicentre trial, conducted to evaluate and compare the safety, tolerability and immunogenicity of a freeze dried live attenuated Oka strain Varicella Vaccine (VR 795 Oka strain) with Varilrix (Oka-RIT strain) in children. A total of 268 healthy Indian children aged 12 months to 12 y with baseline VZV IgG antibody (<100 mIU/ mL) were enrolled, and 256 children completed the study. The extent of rise of VZV IgG antibody titer assessed as 3-fold and 4-fold rise from baseline was found to be significantly higher (89.1% and 85.2%) in the test group as compared to control group (73.4% and 61.7%). The post-vaccination GMT of the test group was significantly higher (112.5 mIU/mL) as compared with the control group (67.8 mIU/mL) (P < 0.001). The seroconversion rate considering the 5 gp ELISA units/ml equivalent to 10mIU/ml were similar in the control (96.5%) and the test (98.3%) groups. The adverse events were not different in the control and test groups (P > 0.05). The test live attenuated vaccine was found to be highly immunogenic, safe and comparable to Varilrix used in control arm.

  6. LcrV delivered via type III secretion system of live attenuated Yersinia pseudotuberculosis enhances immunogenicity against pneumonic plague.

    PubMed

    Sun, Wei; Sanapala, Shilpa; Henderson, Jeremy C; Sam, Shandiin; Olinzock, Joseph; Trent, M Stephen; Curtiss, Roy

    2014-10-01

    Here, we constructed a Yersinia pseudotuberculosis mutant strain with arabinose-dependent regulated and delayed shutoff of crp expression (araC P(BAD) crp) and replacement of the msbB gene with the Escherichia coli msbB gene to attenuate it. Then, we inserted the asd mutation into this construction to form χ10057 [Δasd-206 ΔmsbB868::P(msbB) msbB(EC) ΔP(crp21)::TT araC P(BAD) crp] for use with a balanced-lethal Asd-positive (Asd(+)) plasmid to facilitate antigen synthesis. A hybrid protein composed of YopE (amino acids [aa]1 to 138) fused with full-length LcrV (YopE(Nt138)-LcrV) was synthesized in χ10057 harboring an Asd(+) plasmid (pYA5199, yopE(Nt138)-lcrV) and could be secreted through a type III secretion system (T3SS) in vitro and in vivo. Animal studies indicated that mice orally immunized with χ10057(pYA5199) developed titers of IgG response to whole-cell lysates of Y. pestis (YpL) and subunit LcrV similar to those seen with χ10057(pYA3332) (χ10057 plus an empty plasmid). However, only immunization of mice with χ10057(pYA5199) resulted in a significant secretory IgA response to LcrV. χ10057(pYA5199) induced a higher level of protection (80% survival) against intranasal (i.n.) challenge with ~240 median lethal doses (LD50) (2.4 × 10(4) CFU) of Y. pestis KIM6+(pCD1Ap) than χ10057(pYA3332) (40% survival). Splenocytes from mice vaccinated with χ10057(pYA5199) produced significant levels of gamma interferon (IFN-γ), tumor necrosis factor alpha (TNF-α), and interleukin-17 (IL-17) after restimulation with LcrV and YpL antigens. Our results suggest that it is possible to use an attenuated Y. pseudotuberculosis strain delivering the LcrV antigen via the T3SS as a potential vaccine candidate against pneumonic plague. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  7. Limitation of Activities of Daily Living and Quality of Life Based on COPD Combin