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Sample records for live vaccine strain

  1. Live Attenuated Rubella Vaccine (Cendehill Strain) in School Children

    PubMed Central

    Hutchison, Patricia A.; Izumi, Toshiaki; Davidson, W. George; Grocott, H. C.; Martin, Hulda M.

    1970-01-01

    The purpose of this study was to further determine the efficacy and safety in school children of the Cendehill strain of live attenuated rubella vaccine. Parental permission was requested for 255 children in Grades I, II and VI, attending two adjacent schools, to have blood taken for rubella hemagglutination-inhibition studies at the beginning and end of the study, and for each child seronegative on initial testing to participate as a vaccinee or a control. Vaccinees received either 0.5 ml. (full recommended dose) or 0.25 ml. of rubella virus vaccine, live attenuated, Cendehill strain (Smith Kline & French). Eighty-one per cent of the parents consented to have their child take part. Seventy-nine per cent of Grade I and II pupils and 41% of Grade VI pupils were found to be susceptible to rubella at the time of the initial test (HI titres [unk] 8). Eighty children received rubella vaccine and 98.7% showed at least a four-fold rise in antibody titre. One child who received 0.25 ml. showed only a two-fold rise. Clinical reactions to the vaccine were absent or minimal. Thirty-eight controls remained serologically negative during the study. The good response to half-doses of Cendehill vaccine is not significant because there were >3000 TCID50 in a full dose (three times the dose recommended). This information was unknown by the investigators until the termination of the study. PMID:5506107

  2. Transmission of a live Eimeria acervulina vaccine strain and response to infection in vaccinated and contact-vaccinated broilers.

    PubMed

    Velkers, Francisca C; Bouma, Annemarie; Stegeman, J Arjan; de Jong, Mart C M

    2012-01-01

    Live vaccines for coccidiosis control are infrequently used in broilers, mainly due to variability in efficacy and relatively high costs. More insight in transmission of vaccine and wild-type strains can facilitate optimization of vaccination strategies and might increase its use as an alternative for anticoccidial drugs. The aim of this study was to quantify transmission of a live Eimeria acervulina vaccine strain and to determine the degree of protection against a subsequent infection with a wild-type E. acervulina strain. An experiment was carried out with 4 groups of 22 SPF broilers. At 2 days of age, 11 birds of groups 2 to 4 were vaccinated directly by oral application of E. acervulina oocysts of the Paracox™ vaccine and 11 birds were placed in contact with these birds (contact-vaccinated). Birds in group 1 remained unvaccinated (controls) and were not exposed to vaccinated birds. At day 28 of age, 6 groups of 10 birds were formed, with 2 groups (duplo) for each treatment group, i.e. vaccinated, contact-vaccinated or unvaccinated control birds. Five birds of each group were orally inoculated with wild-type E. acervulina oocysts and five were contact-exposed. Single droppings were examined daily from days 5 to 49 of age for oocyst output and to determine the time of infection. The transmission rate of the vaccine strain was estimated to be 1.6 per day and of the wild-type strain 2.3, 8.7 and 20.8 per day for vaccinated, contact-vaccinated and unvaccinated birds, respectively. Although transmission of wild-type coccidia was not significantly reduced in vaccinated or contact-vaccinated groups, both groups were equally protected against high oocyst output after infection compared to unvaccinated groups. These results suggest that factors influencing transmission of live vaccine strains in flocks may be important targets for improvement of vaccine efficacy and warrant further research. PMID:22075084

  3. The efficacy of Mycoplasma gallisepticum K-strain live vaccine in broiler and layer chickens.

    PubMed

    Ferguson-Noel, N M; Williams, S M

    2015-01-01

    The efficacy of a live Mycoplasma gallisepticum (MG) vaccine candidate (K-strain) was compared to commercially available vaccines in broiler-type chickens (Trial 1) and layer-type chickens (Trial 2). In Trial 1, three-week-old broiler-type chickens were vaccinated via aerosol with K-strain or an F-strain vaccine. The vaccinated chickens and 10 non-vaccinated controls were subsequently challenged with virulent R-strain via aerosol at six weeks post vaccination; both K-strain and F-strain vaccination resulted in significant protection from air sac and tracheal lesions, as well as R-strain colonization (P ≤ 0.05). In Trial 2, commercial layer-type chickens were vaccinated with ts-11 (via eye drop) or K-strain (via aerosol) at 12 weeks of age. At 25 weeks of age these birds were challenged with R-strain via aerosol. The ts-11 and K-strain vaccinated groups both had significantly lower air sac lesion scores and a lower prevalence of ovarian regression after challenge as compared to non-vaccinated chickens (P ≤ 0.05). K-strain vaccination also prevented significant tracheal lesions and R-strain colonization (P ≤ 0.05). K-strain shows great potential as a highly efficacious live MG vaccine in broiler and layer-type chickens for protection of the respiratory and reproductive systems as well as prevention of infection with field strains. PMID:25571953

  4. Transcriptional profiling of recall responses to Francisella live vaccine strain.

    PubMed

    Paranavitana, Chrysanthi; DaSilva, Luis; Vladimirova, Antoaneta; Pittman, Phillip R; Velauthapillai, Mahendran; Nikolich, Mikeljon

    2014-03-01

    Global gene expression profile changes were monitored in human peripheral blood mononuclear cells (PBMCs) after challenge with the live vaccine strain (LVS) of Francisella tularensis. Because these PBMCs were from individuals previously immunized with LVS, stimulating these cells with LVS should activate memory responses. The Ingenuity Pathway Analysis tool identified pathways, functions, and networks associated with this in vitro recall response, including novel pathways triggered by the memory response. Dendritic cell (DC) maturation was the most significant among the more than 25 relevant pathways discovered. Interleukin 15, granulocyte-macrophage colony-stimulating factor, and triggering receptor expressed on myeloid cells 1 signaling pathways were also significant. Pathway analysis indicated that Class 1 antigen presentation may not be optimal with LVS vaccination. The top three biological functions were antigen presentation, cell-mediated and humoral immune responses. Network analysis revealed that the top network associated with these functions had IFNγ and TNFα in central interactive positions. Our results suggest that DC maturation is a key factor in the recall responses and that more effective antigen processing and presentation is needed for cytotoxic T lymphocyte responses. Taken together, these considerations are critical for future tularemia vaccine development studies. PMID:24453125

  5. Isolation of rifampicin resistant Flavobacterium psychrophilum strains and their potential as live attenuated vaccine candidates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous studies have demonstrated that passage of pathogenic bacteria on increasing concentrations of the antibiotic rifampicin leads to the attenuation of virulence and these resistant strains may serve as live attenuated vaccines. Two rifampicin resistant strains of Flavobacterium psychrophilum,...

  6. Identification of over-expressed genes in modified live vaccine strain of Edwardsiella ictaluri compared to virulent strain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Using PCR-select subtractive cDNA hybridization technique, 41 expressed sequence tags (ESTs) were isolated from a modified live vaccine strain (AQUAVAC-ESC, formerly RE-33) vs a virulent parent strain (EILO) of Edwardsiella ictaluri. Transcriptional levels of the 41 ESTs in the vaccine strain and th...

  7. Identification of upregulated genes in a modified live vaccine strain of Edwardsiella ictaluri compared to a virulent parent strain and characterization of novel DNA vaccine candidates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Using PCR-select subtractive cDNA hybridization technique, 41 expressed sequence tags (EST's) were isolated from a modified live vaccine strain (AQUAVAC-ESC formerly RD-33) vs a virulent parent strain (EILO) of Edwardsiella ictaluri. Transcriptional levels of the 41 ESTs in the vaccine strain and th...

  8. Conjunctival and intramuscular vaccination of pigs with a live avirulent strain of Salmonella cholerae-suis.

    PubMed

    Kramer, T T; Pardon, P; Marly, J; Bernard, S

    1987-07-01

    An avirulent mutant strain of Salmonella cholerae-suis was cloned for resistance to streptomycin and nalidixic acid. The mutant strain 33-13 also was used because of its avirulence and immunogenicity in mice. Weaned pigs were vaccinated with live strain 33-13; 5 pigs were vaccinated by conjunctivally administered 5.5 X 10(7) organisms (low dose), 5 were conjunctivally administered 5.5 X 10(9) organisms (high dose), and 5 pigs were administered 5.5 X 10(9) organisms (high dose) IM. Transient fever and transient fecal shedding of the vaccine strain developed in pigs vaccinated IM, but not in 2 groups of pigs vaccinated conjunctivally. After intratracheal administration of virulent strain 38-9, nonvaccinated control pigs (n = 9) developed persistent high fever, anorexia, bacteremia, diarrhea, and fecal shedding of strain 38-9, whereas vaccinated pigs remained afebrile and clinically normal. Nonvaccinated and uninfected sentinel pigs (n = 8) were kept in units of 2 pigs with each group of experimental pigs, and remained healthy throughout the experiment. Thirteen vaccinated and 7 nonvaccinated control pigs were killed 42 days after vaccination, and 2 vaccinated, 2 nonvaccinated, and 8 sentinel control pigs were killed 58 days after vaccination. Ten organs were evaluated by quantitative bacteriology on necropsy of all pigs for the presence of vaccine strain 33-13, and for virulent strain 38-9. Strain 33-13 was not found. Lung and liver, lesions were found in most of the nonvaccinated control pigs, with a high frequency of recovery of large numbers of strain 38-9 from the mesenteric lymph nodes, lungs, liver, and ileum.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3631689

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  10. Development and Characterization of Rifampicin Resistant Flavobacterium Psychrophilum Strains and Their Potential as Live Attenuated Vaccine Candidates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous studies have demonstrated that passage of pathogenic bacteria on increasing concentrations of the antibiotic rifampicin leads to the attenuation of virulence and these resistant strains may serve as live attenuated vaccines. Two rifampicin resistant strains of Flavobacterium psychrophilum,...

  11. Efficacy, Safety, and Interactions of a Live Infectious Bursal Disease Virus Vaccine for Chickens Based on Strain IBD V877.

    PubMed

    Geerligs, Harm J; Ons, Ellen; Boelm, Gert Jan; Vancraeynest, Dieter

    2015-03-01

    Infectious bursal disease (IBD) is a highly contagious disease in young chickens which can result in high morbidity and mortality and also in great economic losses. The main target for the virus is the lymphoid tissue with a special predilection for the bursa of Fabricius. Several vaccines are available to control the disease. Intermediate plus vaccines are used in chickens with high maternal antibody titers which face high infection pressure. An example of an intermediate plus vaccine is a live vaccine based on IBD strain V877. The results of an efficacy study in commercial broilers with different levels of maternally derived antibodies (MDA) showed that the V877-based IBD vaccine can break through maternal antibody titers of higher than 1100 as determined by an IBD ELISA. The safety of the vaccine was demonstrated in a study in which specific-pathogen-free (SPF) chickens were vaccinated with a tenfold dose of the vaccine strain and a tenfold dose of the vaccine strain after five back passages in SPF chickens. The vaccine virus caused lesions, as could be expected for an intermediate plus vaccine, but the scores were not much higher than the maximal scores allowed for mild IBD vaccines in the European Pharmacopoeia, and reversion to virulence was absent. In studies in SPF chickens, there were no negative impacts by the IBD V877 vaccine on the efficacy of a live QX-like IB vaccine and a live Newcastle disease La Sota vaccine in vaccination challenge studies, although the IBD vaccine had a negative effect on the antibody response generated by the QX-like IB vaccine. It is concluded that the IBD V877 vaccine has the capacity to break through high levels of MDA, has a satisfactory safety profile, and interactions with other live vaccines are limited. In order to limit bursal lesions after vaccination it is recommended to confirm the presence of MDA before vaccinating with the V877 vaccine. PMID:26292544

  12. Response of layer and broiler strain chickens to parenteral administration of a live Salmonella Typhimurium vaccine.

    PubMed

    Groves, Peter J; Sharpe, Sue M; Cox, Julian M

    2015-07-01

    Responses to the parenteral administration of a live aroA deletion Salmonella serovar Typhimurium vaccine given to three brown egg layer strains and two broiler strains were studied. Twenty-five birds of each strain were reared together in floor pens to 6 weeks of age and then moved as individual strains to new floor pens and injected with 10(8) colony forming units (CFU) per bird of the vaccine bacteria intramuscularly or subcutaneously, 10(6) CFU per bird subcutaneously, or phosphate buffered saline (PBS) subcutaneously as a vaccination control. Three birds of one layer strain were injected intramuscularly with 0.5mg/ bird S. Typhimurium lipopolysaccharide (LPS) to evaluate whether response was similar for vaccine and endotoxin. Birds were weighed, and rectal temperatures recorded at the time of injection, then observed over 24 hours. Rectal temperatures were measured and blood samples collected for serum IL-6 assay at 3 hours post injection (PI). At 12 hours PI blood samples were drawn for analyses for plasma phosphorus (P), glucose (Glu), cholesterol (Cho), aspartate transaminase (AST), total protein (Ptn) and creatinine kinase (CK). Blood was sampled 14 days PI and tested for serum antibody to S. Typhimurium. Vaccination resulted in significant seroconversion by 14 days PI in all strains compared to the controls. The three layer strains exhibited a clinical malaise, evident within 90 minutes of injection, lasting for 12 hours, with complete recovery by 24 hours PI. Only the 10(8) CFU dose given subcutaneously produced an increase in rectal temperature 3 hours PI. Vaccination had no effect on IL-6 or Ptn. All vaccine doses increased P and the higher dose by either route decreased Cho in all bird strains. The 10(8) vaccine dose increased Glu and intramuscular injection markedly elevated CK only in the layer strains. The response was not completely congruous with that to LPS alone. The results highlight the need for consideration of differences in response of

  13. Cell-mediated and humoral immune responses after vaccination of human volunteers with the live vaccine strain of Francisella tularensis.

    PubMed

    Waag, D M; McKee, K T; Sandstrom, G; Pratt, L L; Bolt, C R; England, M J; Nelson, G O; Williams, J C

    1995-03-01

    The specific humoral and cell-mediated immune responses of human volunteers vaccinated with the Francisella tularensis live vaccine strain (LVS) were evaluated. In the search for an optimal antigen to measure the immunogenicity of the vaccine in an enzyme-linked immunosorbent assay, we tested irradiation-killed LVS, an aqueous ether extract of the LVS (EEx), lipopolysaccharide (LPS) from LVS, and a virulent strain (SCHU4). Volunteers were immunized with LVS by scarification. Immunoglobulin G (IgG) responses to LVS and LPS gave the highest background titers when tested with sera from unimmunized volunteers, whereas IgA, IgG, and IgM background titers to EEx and SCHU4 were low. Vaccination caused a significant rise (P < 0.01) in IgA, IgG, and IgM titers to all antigens tested, except for the IgG response to LPS. Eighty percent of vaccinated volunteers developed a positive IgG response to EEx 14 days postvaccination, while 50% were positive to LVS. By day 14 after vaccination, 70% of immunized volunteers exhibited a positive response to EEx in an in vitro peripheral blood lymphocyte proliferation assay. EEx, a specific and sensitive antigen for evaluating immune responses of vaccinated volunteers, may be a superior antigen for the diagnosis of tularemia. PMID:7697521

  14. Live Virus Smallpox Vaccine

    MedlinePlus

    ... Index SMALLPOX FACT SHEET The Live Virus Smallpox Vaccine The vaccinia virus is the "live virus" used ... cannot cause smallpox. What is a "live virus" vaccine? A "live virus" vaccine is a vaccine that ...

  15. Identification of in vitro upregulated genes in a modified live vaccine strain of Edwardsiella ictaluri compared to a virulent parent strain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Using PCR-select subtractive cDNA hybridization technique, 41 expressed sequence tags (ESTs) were isolated from a modified live vaccine strain (AQUAVAC-ESC©, formerly RE-33) vs a virulent parent strain (EILO) of Edwardsiella ictaluri. Transcriptional levels of the 41 ESTs in the vaccine strain and t...

  16. Complete Genome Sequences of Five Bluetongue Virus (BTV) Vaccine Strains from a Commercial Live Attenuated Vaccine, a BTV-4 Field Strain from South Africa, and a Reassortant Strain Isolated from Experimentally Vaccinated Cattle

    PubMed Central

    Coetzee, Peter; le Grange, Misha; Venter, Estelle H.

    2016-01-01

    This is a report of the complete genome sequences of plaque-selected isolates of each of the five virus strains included in a South African commercial trivalent bluetongue virus (BTV) attenuated live virus vaccine, a BTV-4 field strain isolated from Rustenburg, South Africa, in 2011, and a bluetongue reassortant (bluetongue virus 4 strain 4/O. aries-tc/ZAF/11/OBP-115) isolated from experimentally vaccinated cattle. Full-genome sequencing and phylogenetic analyses show that the bluetongue virus 9 strain 9/B. taurus-tc/ZAF/15/Onderstepoort_B02b is a reassortant virus containing segments from both BTV-9 and BTV-8. PMID:27340051

  17. Complete Genome Sequences of the Three African Horse Sickness Virus Strains from a Commercial Trivalent Live Attenuated Vaccine

    PubMed Central

    Coetzee, Peter; Martin, Darren P.; Lourens, Carina W.; Venter, Estelle H.; Weyer, Camilla T.; Joone, Christopher; le Grange, Misha; Harper, Cindy K.; Howell, Peter G.; MacLachlan, N. James

    2015-01-01

    This is a report of the complete genome sequences of plaque-selected isolates of each of the three virus strains included in a South African commercial trivalent African horse sickness attenuated live virus vaccine. PMID:26294618

  18. Complete Genome Sequences of Four African Horse Sickness Virus Strains from a Commercial Tetravalent Live Attenuated Vaccine

    PubMed Central

    Coetzee, Peter; Martin, Darren P.; Lourens, Carina W.; Venter, Estelle H.; Weyer, Camilla T.; Joone, Christopher; le Grange, Misha; Harper, Cindy K.; Howell, Peter G.; MacLachlan, N. James

    2015-01-01

    This is a report of the complete genome sequences of plaque-selected isolates of each of the four virus strains included in a South African commercial tetravalent African horse sickness attenuated live virus vaccine. PMID:26607890

  19. Characterization of attenuated Renibacterium salmoninarum strains and their use as live vaccines.

    PubMed

    Daly, J G; Griffiths, S G; Kew, A K; Moore, A R; Olivier, G

    2001-03-01

    Two nutritionally mutant strains of Renibacterium salmoninarum (Rs) were isolated that grew on tryticase soy agar (Rs TSA1) or brain heart infusion agar (Rs BHI1). These 2 strains could be continuously cultured on these media, whereas typical R. salmoninarum would only grow on KDM-2 agar. We determined no other phenotypic difference that could be used to distinguish them from wild-type R. salmoninarum. Both strains were found to be avirulent when 5 x 10(6) bacteria were intraperitoneally (i.p.) injected into Atlantic salmon. Rs TSA1, Rs BHI1, and Rs MT-239 (a R. salmoninarum strain previously shown to be attenuated) were tested as live vaccines in 2 separate trials. The best protection was seen with Rs TSA1. Vaccinated Atlantic salmon had relative percent survival (RPS) of 50 at 74 d post-challenge in Trial 1 and 76 at 60 d post-challenge in Trial 2. In both trials, 100% of the control salmon died from bacterial kidney disease (BKD) (within 40 d for Trial 1 and 50 d for Trial 2) after i.p. challenge with 5 x 10(6) live cells of the virulent isolate Rs Margaree. PMID:11324812

  20. Live Attenuated Shigella dysenteriae Type 1 Vaccine Strains Overexpressing Shiga Toxin B Subunit ▿

    PubMed Central

    Wu, Tao; Grassel, Christen; Levine, Myron M.; Barry, Eileen M.

    2011-01-01

    Shigella dysenteriae serotype 1 (S. dysenteriae 1) is unique among the Shigella species and serotypes in the expression of Shiga toxin which contributes to more severe disease sequelae and the ability to cause explosive outbreaks and pandemics. S. dysenteriae 1 shares characteristics with other Shigella species, including the capability of causing clinical illness with a very low inoculum (10 to 100 CFU) and resistance to multiple antibiotics, underscoring the need for efficacious vaccines and therapeutics. Following the demonstration of the successful attenuating capacity of deletion mutations in the guaBA operon in S. flexneri 2a vaccine strains in clinical studies, we developed a series of S. dysenteriae 1 vaccine candidates containing the fundamental attenuating mutation in guaBA. All strains are devoid of Shiga toxin activity by specific deletion of the gene encoding the StxA subunit, which encodes enzymatic activity. The StxB subunit was overexpressed in several derivatives by either plasmid-based constructs or chromosomal manipulation to include a strong promoter. All strains are attenuated for growth in vitro in the HeLa cell assay and for plaque formation and were safe in the Serény test and immunogenic in the guinea pigs. Each strain induced robust serum and mucosal anti-S. dysenteriae 1 lipopolysaccharide (LPS) responses and protected against wild-type challenge. Two strains engineered to overexpress StxB induced high titers of Shiga toxin neutralizing antibodies. These candidates demonstrate the potential for a live attenuated vaccine to protect against disease caused by S. dysenteriae 1 and potentially to protect against the toxic effects of other Shiga toxin 1-expressing pathogens. PMID:21969003

  1. Genome sequences of three live attenuated vaccine strains of Brucella species and implications for pathogenesis and differential diagnosis.

    PubMed

    Wang, Yufei; Ke, Yuehua; Wang, Zhoujia; Yuan, Xitong; Qiu, Yefeng; Zhen, Qing; Xu, Jie; Li, Tiefeng; Wang, Dali; Huang, Liuyu; Chen, Zeliang

    2012-11-01

    Live attenuated vaccines play essential roles in the prevention of brucellosis. Here, we report the draft genome sequences of three vaccine strains, Brucella melitensis M5-10, B. suis S2-30, and B. abortus 104M. Primary genome sequence analysis identified mutations, deletions, and insertions which have implications for attenuation and signatures for differential diagnosis. PMID:23045513

  2. 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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  4. T-bet regulates immunity to Francisella tularensis live vaccine strain infection, particularly in lungs.

    PubMed

    Melillo, Amanda A; Foreman, Oded; Bosio, Catharine M; Elkins, Karen L

    2014-04-01

    Upregulation of the transcription factor T-bet is correlated with the strength of protection against secondary challenge with the live vaccine strain (LVS) of Francisella tularensis. Thus, to determine if this mediator had direct consequences in immunity to LVS, we examined its role in infection. Despite substantial in vivo gamma interferon (IFN-γ) levels, T-bet-knockout (KO) mice infected intradermally (i.d.) or intranasally (i.n.) with LVS succumbed to infection with doses 2 log units less than those required for their wild-type (WT) counterparts, and exhibited significantly increased bacterial burdens in the lung and spleen. Lungs of LVS-infected T-bet-KO mice contained fewer lymphocytes and more neutrophils and interleukin-17 than WT mice. LVS-vaccinated T-bet-KO mice survived lethal LVS intraperitoneal secondary challenge but not high doses of LVS i.n. challenge, independently of the route of vaccination. Immune T lymphocytes from the spleens of i.d. LVS-vaccinated WT or KO mice controlled intracellular bacterial replication in an in vitro coculture system, but cultures with T-bet-KO splenocyte supernatants contained less IFN-γ and increased amounts of tumor necrosis factor alpha. In contrast, immune T-bet-KO lung lymphocytes were greatly impaired in controlling intramacrophage growth of LVS; this functional defect is the likely mechanism underpinning the lack of respiratory protection. Taken together, T-bet is important in host resistance to primary LVS infection and i.n. secondary challenge. Thus, T-bet represents a true, useful correlate for immunity to LVS. PMID:24421047

  5. T-bet Regulates Immunity to Francisella tularensis Live Vaccine Strain Infection, Particularly in Lungs

    PubMed Central

    Melillo, Amanda A.; Foreman, Oded; Bosio, Catharine M.

    2014-01-01

    Upregulation of the transcription factor T-bet is correlated with the strength of protection against secondary challenge with the live vaccine strain (LVS) of Francisella tularensis. Thus, to determine if this mediator had direct consequences in immunity to LVS, we examined its role in infection. Despite substantial in vivo gamma interferon (IFN-γ) levels, T-bet-knockout (KO) mice infected intradermally (i.d.) or intranasally (i.n.) with LVS succumbed to infection with doses 2 log units less than those required for their wild-type (WT) counterparts, and exhibited significantly increased bacterial burdens in the lung and spleen. Lungs of LVS-infected T-bet-KO mice contained fewer lymphocytes and more neutrophils and interleukin-17 than WT mice. LVS-vaccinated T-bet-KO mice survived lethal LVS intraperitoneal secondary challenge but not high doses of LVS i.n. challenge, independently of the route of vaccination. Immune T lymphocytes from the spleens of i.d. LVS-vaccinated WT or KO mice controlled intracellular bacterial replication in an in vitro coculture system, but cultures with T-bet-KO splenocyte supernatants contained less IFN-γ and increased amounts of tumor necrosis factor alpha. In contrast, immune T-bet-KO lung lymphocytes were greatly impaired in controlling intramacrophage growth of LVS; this functional defect is the likely mechanism underpinning the lack of respiratory protection. Taken together, T-bet is important in host resistance to primary LVS infection and i.n. secondary challenge. Thus, T-bet represents a true, useful correlate for immunity to LVS. PMID:24421047

  6. 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

    2016-03-01

    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. PMID:26851733

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. A variety of novel lipid A structures obtained from Francisella tularensis live vaccine strain.

    PubMed

    Beasley, Ashley S; Cotter, Robert J; Vogel, Stefanie N; Inzana, Thomas J; Qureshi, Asaf A; Qureshi, Nilofer

    2012-04-01

    F. tularensis is a Gram-negative coccobacillus that causes tularemia. Its LPS has nominal biological activity. Currently, there is controversy regarding the structure of the lipid A obtained from F. tularensis live vaccine strain (LVS). Therefore, to resolve this controversy, the purification and structural identification of this LPS was crucial. To achieve this, LPS from F. tularensis LVS was acid hydrolyzed to obtain crude lipid A that was methylated and purified by HPLC and the fractions were analyzed by MALDI-TOF MS. The structure of the major lipid A species was composed of a glucosamine disaccharide backbone substituted with four fatty acyl groups and a phosphate (1-position) with a molecular mass of 1505. The major lipid A component contained 18:0[3-O(16:0)] in the distal subunit and two 18:0(3-OH) fatty acyl chains at the 2- or 3-positions of the reducing subunit. Additional variations in the lipid A species include: heterogeneity in fatty acyl groups, a phosphate or a phosphoryl galactosamine at the 1-position, and a hexose at the 4' or 6' position, some of which have not been previously described for F. tularensis LVS. This analysis revealed that lipid A from F. tularensis LVS is far more complex than originally believed. PMID:21709054

  9. Novel Attenuated Salmonella enterica Serovar Choleraesuis Strains as Live Vaccine Candidates Generated by Signature-Tagged Mutagenesis

    PubMed Central

    Ku, Yu-We; McDonough, Sean P.; Palaniappan, Raghavan U. M.; Chang, Chao-Fu; Chang, Yung-Fu

    2005-01-01

    Salmonella enterica serovar Choleraesuis is a host-adapted pathogen that causes swine paratyphoid. Signature-tagged mutagenesis (STM) was used to understand the pathogenicity of S. enterica serovar Choleraesuis in its natural host and also to develop novel attenuated live vaccine candidates against this disease. A library of 960 signature-tagged mutants of S. enterica serovar Choleraesuis was constructed and screened for attenuation in pigs. Thirty-three mutants were identified by the STM screening, and these mutants were further screened for attenuation by in vivo and in vitro competitive growth. Of these, 20 mutants targeting the outer membrane, type III secretion, transporter, lipopolysaccharide biosynthesis, and other unknown proteins were confirmed for attenuation. Five highly attenuated mutants (SC2D2 [ssaV], SC4A9 [gifsy-1], SC6F9 [dgoT], SC12B12 [ssaJ], and SC10B1[spiA]) were selected and evaluated for safety and protective efficacy in pigs by comparison with a commercially available vaccine strain. STM-attenuated live vaccine strains SC4A9 (gifsy-1) and SC2D2 (ssaV) were superior to commercially available live vaccine because they provided both safety and a protective immune response against challenge in pigs. PMID:16299315

  10. IL-10 Restrains IL-17 to Limit Lung Pathology Characteristics following Pulmonary Infection with Francisella tularensis Live Vaccine Strain

    PubMed Central

    Slight, Samantha R.; Monin, Leticia; Gopal, Radha; Avery, Lyndsay; Davis, Marci; Cleveland, Hillary; Oury, Tim D.; Rangel-Moreno, Javier; Khader, Shabaana A.

    2014-01-01

    IL-10 production during intracellular bacterial infections is generally thought to be detrimental because of its role in suppressing protective T-helper cell 1 (Th1) responses. Francisella tularensis is a facultative intracellular bacterium that activates both Th1 and Th17 protective immune responses. Herein, we report that IL-10–deficient mice (Il10−/−), despite having increased Th1 and Th17 responses, exhibit increased mortality after pulmonary infection with F. tularensis live vaccine strain. We demonstrate that the increased mortality observed in Il10−/−-infected mice is due to exacerbated IL-17 production that causes increased neutrophil recruitment and associated lung pathology. Thus, although IL-17 is required for protective immunity against pulmonary infection with F. tularensis live vaccine strain, its production is tightly regulated by IL-10 to generate efficient induction of protective immunity without mediating pathology. These data suggest a critical role for IL-10 in maintaining the delicate balance between host immunity and pathology during pulmonary infection with F. tularensis live vaccine strain. PMID:24007881

  11. Efficacy of Fostera PRRS modified live virus vaccine against a Canadian heterologous virulent field strain of porcine reproductive and respiratory syndrome virus

    PubMed Central

    Savard, Christian; Alvarez, Fernando; Provost, Chantale; Chorfi, Younes; D’Allaire, Sylvie; Benoit-Biancamano, Marie-Odile; Gagnon, Carl A.

    2016-01-01

    Vaccination is a useful option to control infection with porcine reproductive and respiratory syndrome virus (PRRSV), and several modified live-PRRSV vaccines have been developed. These vaccines have shown some efficacy in reducing the incidence and severity of clinical disease as well as the duration of viremia and virus shedding but have failed to provide sterilizing immunity. The efficacy of modified live-virus (MLV) vaccines is greater against a homologous strain compared with heterologous PRRSV strains. The objective of this study was to evaluate the efficacy of Fostera PRRS MLV vaccine in protecting against challenge with a heterologous field strain widely circulating in the swine herds of eastern Canada. Forty-six piglets were divided into 4 groups: nonvaccinated-nonchallenged; nonvaccinated-challenged; vaccinated-challenged; and vaccinated-nonchallenged. The animals were vaccinated at 23 d of age with Fostera PRRS and challenged 23 d later with a heterologous field strain of PRRSV (FMV12-1425619). Overall, the vaccine showed some beneficial effects in the challenged animals by reducing the severity of clinical signs and the viral load. A significant difference between nonvaccinated and vaccinated animals was detected for some parameters starting 11 to 13 d after challenge, which suggested that the cell-mediated immune response or other delayed responses could be more important than pre-existing PRRSV antibodies in vaccinated animals within the context of protection against heterologous strains. PMID:26732457

  12. Genetic characteristics of Neisseria meningitidis serogroup B strains carried by adolescents living in Milan, Italy: implications for vaccine efficacy.

    PubMed

    Esposito, Susanna; Zampiero, Alberto; Terranova, Leonardo; Montinaro, Valentina; Scala, Alessia; Ansuini, Valentina; Principi, Nicola

    2013-11-01

    Before a protein vaccine is introduced into a country, it is essential to evaluate its potential impact and estimate its benefits and costs. The aim of this study was to determine the genetic characteristics of Neisseria meningitidis B (NmB) in the pharyngeal secretions of 1375 healthy adolescents aged 13-19 y living in Milan, Italy, in September 2012, and the possible protection offered by the two currently available NmB protein vaccines. Ninety-one subjects were Nm carriers (6.6%), 29 (31.9%) of whom carried the NmB capsular gene. The 29 identified strains belonged to eight clonal complexes (CCs), the majority of which were in the ST-41/44/Lin.3 CC (n = 11; 37.9%). All of the identified strains harboured ƒHbp alleles representing a total of 15 sub-variants: the gene for NHBA protein was found in all but three of the studied strains (10.3%) with 13 identified sub-variants. There were 15 porA sub-types, seven of which were identified in just one CC. The findings of this study seem to suggest that both of the protein vaccines proposed for the prevention of invasive disease due to NmB (the 4-protein and the 2-protein products) have a composition that can evoke a theoretically effective antibody response against the meningococcal strains currently carried by adolescents living in Northern Italy. The genetic characteristics of NmB strains can be easily evaluated by means of molecular methods, the results of which can provide an albeit approximate estimate of the degree of protection theoretically provided by the available vaccines, and the possible future need to change their composition. PMID:23880917

  13. Stable Listeria monocytogenes live vaccine candidate strains with graded attenuation on the mouse model.

    PubMed

    Linde, K; Abraham, A A; Beer, J

    1991-02-01

    Metabolic drift (antibiotics resistance) mutations were used to construct stable two (and three) marker vaccine candidate strains of the predominant Listeria monocytogenes serotypes 1/2a and 4b by stepwise selection. Derived from wild-type strains, spontaneous chromosomal streptomycin-resistant clones with their i.p. LD50 elevated from less than or equal to 10(5.0) c.f.u. to approximately 10(6.1) c.f.u. were used in the second step to isolate the rifampicin-resistant mutants with i.p. LD50 values ranging from 10(6.6) to 10(7.4). On i.p. immunization with fully tolerated doses (less than or equal to 1% LD50), these potential vaccine strains were found to protect not less than 95% of the mice against a lethal (approximately 100 LD50) challenge with the homologous wild-type strain. Further elevation of the i.p. LD50 to greater than 10(8.3) c.f.u. by means of a third attenuating fosfomycin-resistance marker resulted in overattenuation and reduced protective capacity. PMID:1905446

  14. Brucella suis S2, brucella melitensis Rev. 1 and Brucella abortus S19 living vaccines: residual virulence and immunity induced against three Brucella species challenge strains in mice.

    PubMed

    Bosseray, N; Plommet, M

    1990-10-01

    Live attenuated Brucella suis S2 vaccine was compared to living vaccines B. abortus S19 and B. melitensis Rev. 1 in mice. Residual virulence was estimated by ability to multiply and persist in spleen and lymph nodes. Immunogenicity was estimated by spleen counts of control and vaccinated mice challenged either with the reference B. abortus 544 strain or with virulent B. melitensis H38 and B. suis 1330 strains. S2 vaccine had lower residual virulence; expressed as 50% recovery time, persistence was 4.3 weeks, compared to 7.1 and 9.0 weeks for S19 and Rev. 1 vaccines. Immunity induced by the three vaccines was similar 45 days after vaccination. At 150 days, immunity by S19 and Rev.1 was still similar against the three challenge strains. In contrast, immunity induced by S2 had declined against the B. melitensis strain. Thus, a recall vaccination may be required for vaccination of sheep to confer a long-lasting immunity. PMID:2123586

  15. Pigs immunized with Chinese highly pathogenic PRRS virus modified live vaccine are protected from challenge with North American PRRSV strain NADC-20.

    PubMed

    Galliher-Beckley, Amy; Li, Xiangdong; Bates, John T; Madera, Rachel; Waters, Andrew; Nietfeld, Jerome; Henningson, Jamie; He, Dongsheng; Feng, Wenhai; Chen, Ruiai; Shi, Jishu

    2015-07-01

    Modified live virus (MLV) vaccines developed to protect against PRRSV circulating in North America (NA) offer limited protection to highly pathogenic (HP) PRRSV strains that are emerging in Asia. MLV vaccines specific to HP-PRRSV strains commercially available in China provide protection to HP-PRRSV; however, the efficacy of these HP-PRRSV vaccines to current circulating NA PRRS viruses has not been reported. The aim of this study is to investigate whether pigs vaccinated with attenuated Chinese HP-PRRSV vaccine (JXA1-R) are protected from infection by NA PRRSV strain NADC-20. We found that pigs vaccinated with JXA1-R were protected from challenges with HV-PRRSV or NADC-20 as shown by fewer days of clinical fever, reduced lung pathology scores, and lower PRRS virus load in the blood. PRRSV-specific antibodies, as measured by IDEXX ELISA, appeared one week after vaccination and virus neutralizing antibodies were detected four weeks post vaccination. Pigs vaccinated with JXA1-R developed broadly neutralizing antibodies with high titers to NADC-20, JXA1-R, and HV-PRRSV. In addition, we also found that IFN-α and IFN-β occurred at higher levels in the lungs of pigs vaccinated with JXA1-R. Taken together, our studies provide the first evidence that JXA1-R can confer protection in pigs against the heterologous NA PRRSV strain NADC-20. PMID:26049004

  16. Development and evaluation of an experimental vaccination program using a live avirulent Salmonella typhimurium strain to protect immunized chickens against challenge with homologous and heterologous Salmonella serotypes.

    PubMed Central

    Hassan, J O; Curtiss, R

    1994-01-01

    A stable live avirulent, genetically modified delta cya delta crp Salmonella typhimurium vaccine strain, chi 3985, was used in several vaccination strategies to evaluate its use in the control of Salmonella infection in chickens. Oral vaccination of chickens at 1 and at 14 days of age with 10(8) CFU of chi 3985 protected against invasion of spleen, ovary, and bursa of Fabricius and colonization of the ileum and cecum in chickens challenged with 10(6) CFU of virulent homologous Salmonella strains from group B. Chickens challenged with heterologous Salmonella strains from groups C, D, and E were protected against visceral invasion of spleen and ovary, while invasion of the bursa of Fabricius and colonization of ileum and cecum was reduced in vaccinated chickens. Oral vaccination at 2 and at 4 weeks of age induced an excellent protection against challenge with virulent group B Salmonella serotypes and very good protection against challenge with group D or E Salmonella serotypes, while protection against challenge with group C Salmonella serotypes was marginal but significant. Vaccination at 2 and at 4 weeks of age also protected vaccinated chickens against challenge with 10(8) CFU of highly invasive S. typhimurium or S. enteritidis strains. The protection of chickens vaccinated with chi 3985 against challenge with homologous and heterologous Salmonella serotypes is outstanding, and the complete protection against ovarian invasion in chickens challenged with 10(8) CFU of highly invasive S. typhimurium or S. enteritidis strains suggests that vaccination of chickens with chi 3985 can complement the present hygiene- and sanitation-based Salmonella control measures. This paper reports a breakthrough in the use of live avirulent vaccine to control Salmonella carriers in chickens. PMID:7960134

  17. Use of Green Fluorescent Protein To Tag Lactic Acid Bacterium Strains under Development as Live Vaccine Vectors

    PubMed Central

    Geoffroy, Marie-Claude; Guyard, Cyril; Quatannens, Brigitte; Pavan, Sonia; Lange, Marc; Mercenier, Annick

    2000-01-01

    The lactic acid bacteria (LAB) are safe microorganisms which are mainly used for the preparation of fermented foods and for probiotic applications. The potential of LAB as live vehicles for the production and delivery of therapeutic molecules such as antigens is also being actively investigated today. However, very little is known about the fate of live LAB when administered in vivo and about the interaction of these microorganisms with the nasal or gastrointestinal ecosystem. For future applications, it is essential to be able to discriminate the biotherapeutic strain from the endogenous microflora and to unravel the mechanisms underlying the postulated health-beneficial effect. We therefore started to investigate both aspects in a mouse model with two LAB species presently under development as live vaccine vectors, i.e., Lactococcus lactis and Lactobacillus plantarum. We have constructed different expression vectors carrying the gfp (green fluorescent protein [GFP]) gene from the jellyfish Aequoria victoria, and we found that this visible marker was best expressed when placed under the control of the inducible strong nisA promoter from L. lactis. Notably, a threshold amount of GFP was necessary to obtain a bright fluorescent phenotype. We further demonstrated that fluorescent L. plantarum NCIMB8826 can be enumerated and sorted by flow cytometry. Moreover, tagging of this strain with GFP allowed us to visualize its phagocytosis by macrophages in vitro and ex vivo and to trace it in the gastrointestinal tract of mice upon oral administration. PMID:10618252

  18. Evaluation of the protection elicited by direct and indirect exposure to live attenuated infectious laryngotracheitis virus vaccines against a recent challenge strain from the United States.

    PubMed

    Rodríguez-Avila, Andrés; Oldoni, Ivomar; Riblet, Sylva; Garcia, Maricarmen

    2008-06-01

    In a recent study (Oldoni & García, 2007), some field strains of infectious laryngotracheitis viruses (ILTV) were characterized as genotypically different (group VI) from ILT vaccine strains. The objective of this study was to evaluate the protection elicited by one chicken embryo origin (CEO) and one tissue culture origin (TCO) vaccine against a field isolate from group VI after direct and indirect exposure to ILTV live attenuated vaccines. In phase 1 of the experiment, non-vaccinated chickens were placed into contact with the eye drop vaccinates for a period of four weeks after vaccination. Transmission of the vaccine virus to these in-contact birds was demonstrated by real time PCR and antibody production, although the in-contact birds did not become protected against disease when subsequently challenged in phase 2 of the experiment. This emphasized the importance of uniform vaccination to obtain adequate protection, both to avoid the occurrence of susceptible chickens, and to minimize the potential for reversion to virulence of live-attenuated vaccines. In phase 2, protection against challenge with a group VI field virus was assessed four weeks after vaccination by scoring clinical signs and mortality, and quantifying weight gain. Sentinel birds were added to the groups one day after challenge to assess shedding of challenge virus, using real time PCR and virus isolation, during the period 2 to 12 days post challenge. The results showed that the CEO and TCO eye drop-vaccinated chickens were protected against challenge with the group VI virus, even though it was genetically different from the vaccine strains, and that challenge virus was not transmitted from these protected birds to the sentinels. PMID:18568655

  19. Generation and Characterization of an Attenuated Mutant in a Response Regulator Gene of Francisella tularensis Live Vaccine Strain (LVS)

    PubMed Central

    Sammons-Jackson, Wendy L.; McClelland, Karen; Manch-Citron, Jean N.; Metzger, Dennis W.; Bakshi, Chandra Shekhar; Garcia, Emilio; Rasley, Amy

    2008-01-01

    Francisella tularensis is a zoonotic bacterium that must exist in diverse environments ranging from arthropod vectors to mammalian hosts. To better understand how virulence genes are regulated in these different environments, a transcriptional response regulator gene (genome locus FTL0552) was deleted in F. tularensis live vaccine strain (LVS). The FTL0552 deletion mutant exhibited slightly reduced rates of extracellular growth but was unable to replicate or survive in mouse macrophages and was avirulent in the mouse model using either BALB/c or C57BL/6 mice. Mice infected with the FTL0552 mutant produced reduced levels of inflammatory cytokines, exhibited reduced histopathology, and cleared the bacteria quicker than mice infected with LVS. Mice that survived infection with the FTL0552 mutant were afforded partial protection when challenged with a lethal dose of the virulent SchuS4 strain (4 of 10 survivors, day 21 postinfection) when compared to naive mice (0 of 10 survivors by day 7 postinfection). Microarray experiments indicate that 148 genes are regulated by FTL0552. Most of the genes are downregulated, indicating that FTL0552 controls transcription of genes in a positive manner. Genes regulated by FTL0552 include genes located within the Francisella pathogenicity island that are essential for intracellular survival and virulence of F. tularensis. Further, a mutant in FTL0552 or the comparable locus in SchuS4 (FTT1557c) may be an alternative candidate vaccine for tularemia. PMID:18613792

  20. Molecular typing of Iranian field isolates Mycoplasma synoviae and their differentiation from the live commercial vaccine strain MS-H using vlhA gene.

    PubMed

    Bayatzadeh, Mohammad Ali; Pourbakhsh, Seyed Ali; Ashtari, Abass; Abtin, Ali Reza; Abdoshah, Mohammad

    2014-01-01

    1. The single-copy domain of the N-terminal region of the vlhA gene of Mycoplasma synoviae was sequenced, analysed and verified and used to type Iranian field isolates of M. synoviae and the MS-H live vaccine strain. In addition, a restriction fragment length polymorphism (RFLP) method was developed to differentiate between field isolates of Iranian and MS-H vaccine strains. 2. All sequences were analysed and aligned; the percentage similarity of the DNA was calculated and dendrograms were constructed. Based on single nucleotide polymorphism (SNP) that existed in all field isolates in Iran, the PCR-RFLP method allowed the differentiation of all M. synoviae field isolates from the vaccine strain. 3. Using phylogenetic analysis, the isolates were assigned to 8 unique genotypes and, within each group, DNA had a high level of similarity. 4. DNA sequence analysis and PCR-RFLP of the amplicon based on percent similarity and evolutionary relationship appeared to be useful tools for strain differentiation whether M. synoviae clinical isolates from infected chickens were derived from the vaccine strain or wild-type strains. 5. This study confirms the potential value of strain typing for epidemiological purposes and suggests that phylogenetic studies are essential to understand the true relationships between strains. PMID:24405029

  1. 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

  2. Cell-mediated and humoral immune responses induced by scarification vaccination of human volunteers with a new lot of the live vaccine strain of Francisella tularensis.

    PubMed Central

    Waag, D M; Galloway, A; Sandstrom, G; Bolt, C R; England, M J; Nelson, G O; Williams, J C

    1992-01-01

    Tularemia is a disease caused by the facultative intracellular bacterium Francisella tularensis. We evaluated a new lot of live F. tularensis vaccine for its immunogenicity in human volunteers. Scarification vaccination induced humoral and cell-mediated immune responses. Indications of a positive immune response after vaccination included an increase in specific antibody levels, which were measured by enzyme-linked immunosorbent and immunoblot assays, and the ability of peripheral blood lymphocytes to respond to whole F. tularensis bacteria as recall antigens. Vaccination caused a significant rise (P less than 0.05) in immunoglobulin A (IgA), IgG, and IgM titers. Lymphocyte stimulation indices were significantly increased (P less than 0.01) in vaccinees 14 days after vaccination. These data verify that this new lot of live F. tularensis vaccine is immunogenic. Images PMID:1400988

  3. A Colanic Acid Operon Deletion Mutation Enhances Induction of Early Antibody Responses by Live Attenuated Salmonella Vaccine Strains

    PubMed Central

    Wang, Shifeng; Shi, Huoying; Li, Yuhua; Shi, Zhaoxing; Zhang, Xin; Baek, Chang-Ho; Mothershead, Tabor

    2013-01-01

    Colanic acid (CA) is a common exopolysaccharide produced by many genera in the Enterobacteriaceae. It is critical for biofilm formation on HEp-2 cells and on chicken intestinal tissue by Salmonella. In this study, we generated different CA synthesis gene mutants and evaluated the immune responses induced by these mutants. One of these mutations, Δ(wza-wcaM)8, which deleted the whole operon for CA synthesis, was introduced into two Salmonella vaccine strains attenuated by auxotrophic traits or by the regulated delayed attenuation strategy (RDAS). The mice immunized with the auxotrophic Salmonella vaccine strain with the deletion mutation Δ(wza-wcaM)8 developed higher vaginal IgA titers against the heterologous protective antigen and higher levels of antigen-specific IgA secretion cells in lungs. In Salmonella vaccine strains with RDAS, the strain with the Δ(wza-wcaM)8 mutation resulted in higher levels of protective antigen production during in vitro growth. Mice immunized with this strain developed higher serum IgG and mucosal IgA antibody responses at 2 weeks. This strain also resulted in better gamma interferon (IFN-γ) responses than the strain without this deletion at doses of 108 and 109 CFU. Thus, the mutation Δ(wza-wcaM)8 will be included in various recombinant attenuated Salmonella vaccine (RASV) strains with RDAS derived from Salmonella enterica serovar Paratyphi A and Salmonella enterica serovar Typhi to induce protective immunity against bacterial pathogens. PMID:23774599

  4. A colanic acid operon deletion mutation enhances induction of early antibody responses by live attenuated Salmonella vaccine strains.

    PubMed

    Wang, Shifeng; Shi, Huoying; Li, Yuhua; Shi, Zhaoxing; Zhang, Xin; Baek, Chang-Ho; Mothershead, Tabor; Curtiss, Roy

    2013-09-01

    Colanic acid (CA) is a common exopolysaccharide produced by many genera in the Enterobacteriaceae. It is critical for biofilm formation on HEp-2 cells and on chicken intestinal tissue by Salmonella. In this study, we generated different CA synthesis gene mutants and evaluated the immune responses induced by these mutants. One of these mutations, Δ(wza-wcaM)8, which deleted the whole operon for CA synthesis, was introduced into two Salmonella vaccine strains attenuated by auxotrophic traits or by the regulated delayed attenuation strategy (RDAS). The mice immunized with the auxotrophic Salmonella vaccine strain with the deletion mutation Δ(wza-wcaM)8 developed higher vaginal IgA titers against the heterologous protective antigen and higher levels of antigen-specific IgA secretion cells in lungs. In Salmonella vaccine strains with RDAS, the strain with the Δ(wza-wcaM)8 mutation resulted in higher levels of protective antigen production during in vitro growth. Mice immunized with this strain developed higher serum IgG and mucosal IgA antibody responses at 2 weeks. This strain also resulted in better gamma interferon (IFN-γ) responses than the strain without this deletion at doses of 10(8) and 10(9) CFU. Thus, the mutation Δ(wza-wcaM)8 will be included in various recombinant attenuated Salmonella vaccine (RASV) strains with RDAS derived from Salmonella enterica serovar Paratyphi A and Salmonella enterica serovar Typhi to induce protective immunity against bacterial pathogens. PMID:23774599

  5. Assessment of Live Plague Vaccine Candidates.

    PubMed

    Feodorova, Valentina A; Sayapina, Lidiya V; Motin, Vladimir L

    2016-01-01

    Since its creation in the early twentieth century, live plague vaccine EV has been successfully applied to millions of people without severe complications. This vaccine has been proven to elicit protection against both bubonic and pneumonic plague, and it is still in use in populations at risk mainly in the countries of the former Soviet Union. Despite extensive efforts in developing subunit vaccines, there is a reviving interest in creation of a precisely attenuated strain of Yersinia pestis superior to the EV that can serve as a live plague vaccine with improved characteristics. Here we summarize decades of experience of the Russian anti-plague research in developing a standard protocol for early-stage evaluation of safety and immunogenicity of live plague vaccines. This protocol allows step-by-step comparison of the novel test candidates with the EV vaccine by using subcutaneous immunization and bubonic plague infection models in two animal species, e.g., guinea pigs and mice. PMID:27076149

  6. Rapid and Reliable Single Nucleotide Polymorphism-Based Differentiation of Brucella Live Vaccine Strains from Field Strains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Brucellosis is a major zoonotic disease responsible for substantial social and economic problems, particularly in the developing world. One element that can implemented as part of control programs tackling animal disease is the use of one of the OIE recommended vaccines to protect against either Bru...

  7. Comparison of the efficacy of Brucella suis strain 2 and Brucella melitensis Rev. 1 live vaccines against a Brucella melitensis experimental infection in pregnant ewes.

    PubMed

    Verger, J M; Grayon, M; Zundel, E; Lechopier, P; Olivier-Bernardin, V

    1995-02-01

    The comparative efficacy of Brucella suis strain 2 (S2) and Brucella melitensis strain Rev. 1 (Rev. 1) live vaccines in protecting sheep against B. melitensis infection was evaluated by clinical and bacteriological examination of ewes vaccinated conjunctivally with a dose of 1 x 10(9) c.f.u. when 4 months old and then challenged with 5 x 10(7) c.f.u. of the B. melitensis virulent strain 53H38 (H38) at the middle of the first or second pregnancy following vaccination. Animals were considered to be protected when no abortion, no excretion of the challenge strain and no infection at slaughter occurred. The percentages of protection in Rev. 1-vaccinated groups challenged during either first (80%) or second (62%) pregnancy were significantly different (p < 0.001 and p < 0.05, respectively) compared with those of the relevant unvaccinated control groups. In contrast no significant difference in protection was found between the S2-vaccinated and control groups. PMID:7625115

  8. Mycoplasma gallisepticum: Control by live attenuated vaccines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  9. Developing live vaccines against Yersinia pestis

    PubMed Central

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

    2014-01-01

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

  10. 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

    2016-05-01

    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. PMID:27060051

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

    PubMed Central

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

    2016-01-01

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

  12. 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

    2016-01-01

    Anthrax is a lethal disease caused by the gram-positive spore-producing bacterium Bacillus anthracis. Live attenuated vaccines, such as the nonencapsulated Sterne strain, do not meet the safety standards mandated for human use in the Western world and are approved for veterinary purposes only. Here we demonstrate that disrupting the htrA gene, encoding the chaperone/protease HtrA (High Temperature Requirement A), in the virulent Bacillus anthracis Vollum strain results in significant virulence attenuation in guinea pigs, rabbits and mice, underlying the universality of the attenuated phenotype associated with htrA knockout. Accordingly, htrA disruption was implemented for the development of a Sterne-derived safe live vaccine compatible with human use. The novel B. anthracis SterneΔhtrA strain secretes functional anthrax toxins but is 10-10(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. PMID:26732659

  13. Safety of Porcine Reproductive and Respiratory Syndrome Modified Live Virus (MLV) vaccine strains in a young pig infection model

    PubMed Central

    2013-01-01

    The objective of this study was to compare the safety of all modified live virus vaccines commercially available in Europe against Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) under the same experimental conditions. For this purpose, one hundred and twenty three-week-old piglets, divided into five groups, were used. On day 0 of the experiment, nine pigs per group were removed and the remaining fifteen were vaccinated with the commercial vaccines Ingelvac PRRS MLV, Amervac PRRS, Pyrsvac-183 and Porcilis PRRS by the IM route or were mock vaccinated and used as controls. On day 3, the nine unvaccinated pigs were re-introduced into their respective groups and served as sentinel pigs. Clinical signs were recorded daily and lung lesions were determined on days 7, 14 and 21, when 5 vaccinated pigs per group were euthanized. Blood samples and swabs were taken every three days and different organs were collected at necropsy to determine the presence of PRRSV. None of the vaccines studied caused detectable clinical signs in vaccinated pigs although lung lesions were found. Altogether, these results indicate that all vaccines can be considered clinically safe. However, some differences were found in virological parameters. Thus, neither Pyrsvac-183 nor Porcilis PRRS could be detected in porcine alveolar macrophage (PAM) cultures or in lung sections used to determine PRRSV by immunohistochemistry, indicating that these viruses might have lost their ability to replicate in PAM. This inability to replicate in PAM might be related to the lower transmission rate and the delay in the onset of viremia observed in these groups PMID:24308693

  14. Use of a genetically defined double mutant strain of Bordetella bronchiseptica lacking adenylate cyclase and type III secretion as a live vaccine.

    PubMed

    Mann, Paul; Goebel, Elizabeth; Barbarich, James; Pilione, Mylisa; Kennett, Mary; Harvill, Eric

    2007-07-01

    While most vaccines consisting of killed bacteria induce high serum antibody titers, they do not always confer protection as effective as that induced by infection, particularly against mucosal pathogens. Bordetella bronchiseptica is a gram-negative respiratory pathogen that is endemic in many nonhuman mammalian populations and causes substantial disease in a variety of animals. At least 14 different live attenuated vaccines against this pathogen are available for use in a variety of livestock and companion animals. However, there are few published data on the makeup or efficacy of these vaccines. Here we report the use of a genetically engineered double mutant of B. bronchiseptica, which lacks adenylate cyclase and type III secretion, as a vaccine candidate. This strain is safe at high doses, even for highly immunocompromised animals, and induces immune responses that are protective against highly divergent B. bronchiseptica strains, preventing colonization in the lower respiratory tract and decreasing the bacterial burden in the upper respiratory tract. This novel B. bronchiseptica vaccine candidate induces strong local immunity while eliminating damage caused by the two predominant cytotoxic mechanisms. PMID:17452472

  15. An integrated, multistudy analysis of the safety of Ann Arbor strain live attenuated influenza vaccine in children aged 2–17 years

    PubMed Central

    Ambrose, Christopher S; Yi, Tingting; Falloon, Judith

    2011-01-01

    Background Trivalent, Ann Arbor strain, live attenuated influenza vaccine (LAIV) is approved in several countries for use in eligible children aged ≥2 years. Objective To describe the safety of Ann Arbor strain LAIV in children aged 2–17 years. Methods An integrated analysis of randomized, controlled trials of LAIV. Results A total of 4245 and 10 693 children received ≥1 dose of LAIV in year 1 of 6 trivalent inactivated influenza vaccine (TIV)-controlled and 14 placebo-controlled studies, respectively; 3212 children were revaccinated in year 2 of 4 placebo-controlled studies. Compared with placebo for days 0–10 post-vaccination, LAIV recipients exhibited increased runny/stuffy nose (+7%), headache (+7%), and tiredness/decreased activity (+2%) after dose 1; and a higher rate of decreased appetite (+4%) after year 2 revaccination. Compared with TIV, only runny/stuffy nose was increased (dose 1, +12%; dose 2, +4%). Compared with initial vaccination, LAIV reactogenicity was lower after dose 2 in year 1 and revaccination in year 2. Unsolicited adverse events (AEs) increased with LAIV in some comparisons were headache, nasal congestion/rhinorrhea, rhinitis, and pyrexia; ear pain and lower respiratory illness were decreased. There was no evidence of an increase in any potential vaccine-related serious AE in LAIV recipients. Among children aged 2–17 years and specifically aged 24–35 months, there was no evidence that lower respiratory illness or wheezing illness occurred at a higher rate in LAIV recipients. Conclusion This analysis supports the safety of Ann Arbor strain LAIV in children aged 2–17 years and provides a consensus assessment of events expected after vaccination. PMID:21668683

  16. Use of a current varicella vaccine as a live polyvalent vaccine vector.

    PubMed

    Murakami, Kouki; Mori, Yasuko

    2016-01-01

    Varicella-zoster virus (VZV) is the causative agent of varicella and zoster. The varicella vaccine was developed to control VZV infection in children. The currently available Oka vaccine strain is the only live varicella vaccine approved by the World Health Organization. We previously cloned the complete genome of the Oka vaccine strain into a bacterial artificial chromosome vector and then successfully reconstituted the virus. We then used this system to generate a recombinant Oka vaccine virus expressing mumps virus gene(s). The new recombinant vaccine may be an effective polyvalent live vaccine that provides protection against both varicella and mumps viruses. In this review, we discussed about possibility of polyvalent live vaccine(s) using varicella vaccine based on our recent studies. PMID:25444800

  17. Serologic response of roosters to gradient dosage levels of a commercially available live F strain-derived Mycoplasma gallisepticum vaccine over time

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spray application is a commonly used time- and labor-efficient means to deliver live Mycoplasma gallisepticum (MG) vaccine to laying hens in commercial production facilities. The dosage of vaccine received by spray vaccinated birds can vary due to variation in the spray plume and vaccine suspension...

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  20. Subclinical Chlamydial Infection of the Female Mouse Genital Tract Generates a Potent Protective Immune Response: Implications for Development of Live Attenuated Chlamydial Vaccine Strains

    PubMed Central

    Su, Hua; Messer, Ronald; Whitmire, William; Hughes, Scott; Caldwell, Harlan D.

    2000-01-01

    Chlamydia trachomatis is a major cause of sexually transmitted disease (STD) for which a vaccine is needed. CD4+ T-helper type 1 (Th1) cell-mediated immunity is an important component of protective immunity against murine chlamydial genital infection. Conventional vaccine approaches have not proven effective in eliciting chlamydial-specific CD4 Th1 immunity at the genital mucosa. Thus, it is possible that the development of a highly efficacious vaccine against genital infection will depend on the generation of a live attenuated C. trachomatis vaccine. Attenuated strains of C. trachomatis do not exist, so their potential utility as vaccines cannot be tested in animal models of infection. We have developed a surrogate model to study the effect of chlamydial attenuation on infection and immunity of the female genital tract by treating mice with a subchlamydiacidal concentration of oxytetracycline following vaginal infection. Compared to untreated control mice, antibiotic-treated mice shed significantly fewer infectious organisms (3 log10) from the cervico-vagina, produced a minimal inflammatory response in urogenital tissue, and did not experience infection-related sequelae. Antibiotic-treated mice generated levels of chlamydia-specific antibody and cell-mediated immunity equivalent to those of control mice. Importantly, antibiotic-treated mice were found to be as immune as control untreated mice when rechallenged vaginally. These findings demonstrate that subclinical chlamydial infection of the murine female genital tract is sufficient to stimulate a potent protective immune response. They also present indirect evidence supporting the possible use of live attenuated chlamydial organisms in the development of vaccines against chlamydial STDs. PMID:10603387

  1. Mucosal, Cellular, and Humoral Immune Responses Induced by Different Live Infectious Bronchitis Virus Vaccination Regimes and Protection Conferred against Infectious Bronchitis Virus Q1 Strain

    PubMed Central

    Chhabra, Rajesh; Forrester, Anne; Lemiere, Stephane; Awad, Faez; Chantrey, Julian

    2015-01-01

    The objectives of the present study were to assess the mucosal, cellular, and humoral immune responses induced by two different infectious bronchitis virus (IBV) vaccination regimes and their efficacy against challenge by a variant IBV Q1. One-day-old broiler chicks were vaccinated with live H120 alone (group I) or in combination with CR88 (group II). The two groups were again vaccinated with CR88 at 14 days of age (doa). One group was kept as the control (group III). A significant increase in lachrymal IgA levels was observed at 4 doa and then peaked at 14 doa in the vaccinated groups. The IgA levels in group II were significantly higher than those in group I from 14 doa. Using immunohistochemistry to examine changes in the number of CD4+ and CD8+ cells in the trachea, it was found that overall patterns of CD8+ cells were dominant compared to those of CD4+ cells in the two vaccinated groups. CD8+ cells were significantly higher in group II than those in group I at 21 and 28 doa. All groups were challenged oculonasally with a virulent Q1 strain at 28 doa, and their protection was assessed. The two vaccinated groups gave excellent ciliary protection against Q1, although group II's histopathology lesion scores and viral RNA loads in the trachea and kidney showed greater levels of protection than those in group I. These results suggest that greater protection is achieved from the combined vaccination of H120 and CR88 of 1-day-old chicks, followed by CR88 at 14 doa. PMID:26202435

  2. Influenza Vaccine, Live Intranasal

    MedlinePlus

    ... the next 7 days, who requires a protected environment (for example, following a bone marrow transplant). Sometimes ... The National Vaccine Injury Compensation ProgramThe National Vaccine Injury Compensation Program (VICP) is a federal program that was created to compensate people who may have ...

  3. Protection from persistent infection with a bovine viral diarrhea virus (BVDV) type 1b strain by a modified-live vaccine containing BVDV types 1a and 2, infectious bovine rhinotracheitis virus, parainfluenza 3 virus and bovine respiratory syncytial virus.

    PubMed

    Xue, Wenzhi; Mattick, Debra; Smith, Linda

    2011-06-24

    Recent studies showed that BVDV-1b subgenotype is dominant in North and South American field BVDV isolates. However, nearly all commercially available BVDV-1 vaccines contain BVDV-1a strains. In order to study the efficacy of BVDV-1a vaccine against BVDV-1b infection, this study was designed to evaluate a modified-live vaccine (MLV) containing BVDV-1a and BVDV-2 strains for its efficacy in prevention of persistent infection of fetuses against BVDV-1b strain, when the heifers were vaccinated prior to breeding. Heifers were vaccinated subcutaneously with a single dose of the MLV and bred four weeks after vaccination. The pregnant heifers were challenged with a non-cytopathic BVDV-1b strain at approximately 80 days of gestation. Vaccinated heifers were protected from clinical disease and viremia caused by the BVDV-1b virus. At approximately 155 days of gestation, the fetuses were harvested and tissue samples of thymus, lungs, spleen, kidney and intestines were collected for virus isolation. BVDV was isolated from 100% of the fetuses in the non-vaccinated control group, and from only one fetus (4.3%) from the vaccinated group. Results demonstrated that the MLV containing BVDV-1a and BVDV-2 strains provided 96% protection from fetal persistent infection caused by the BVDV-1b strain. PMID:21596076

  4. 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. PMID:25692656

  5. Influenza virus vaccine live intranasal--MedImmune vaccines: CAIV-T, influenza vaccine live intranasal.

    PubMed

    2003-01-01

    MedImmune Vaccines (formerly Aviron) has developed a cold-adapted live influenza virus vaccine [FluMist] that can be administered by nasal spray. FluMist is the first live virus influenza vaccine and also the first nasally administered vaccine to be marketed in the US. The vaccine will be formulated to contain live attenuated (att) influenza virus reassortants of the strains recommended by the US Public Health Service for each 'flu season. The vaccine is termed cold-adapted (ca) because the virus has been adapted to replicate efficiently at 25 degrees C in the nasal passages, which are below normal body temperature. The strains used in the seasonal vaccine will also be made temperature sensitive (ts) so that their replication is restricted at 37 degrees C (Type B strains) and 39 degrees C (Type A strains). The combined effect of the antigenic properties and the att, ca and ts phenotypes of the influenza strains contained in the vaccine enables the viruses to replicate in the nasopharynx to produce protective immunity. The original formulation of FluMist requires freezer storage throughout distribution. Because many international markets do not have distribution channels well suited to the sale of frozen vaccines, Wyeth and MedImmune are collaborating to develop a second generation, refrigerator-stable, liquid trivalent cold-adapted influenza vaccine (CAIV-T), which is in phase III trials. Initially, the frozen formulation will only be available in the US. For the 2003-2004 season, FluMist will contain A/New Caledonia/20/99 (H1N1), A/Panama/2007/99 (H3N2) (A/Moscow/10/99-like) and B/Hong Kong/330/2001. Aviron was acquired by MedImmune on 15 January 2002. Aviron is now a wholly-owned subsidiary of MedImmune and is called MedImmune Vaccines. Aviron acquired FluMist in March 1995 through a Co-operative Research and Development Agreement (CRADA) with the US NIAID, and a licensing agreement with the University of Michigan, Ann Arbor, USA. In June 2000, the CRADA was

  6. Live attenuated influenza vaccine strains elicit a greater innate immune response than antigenically-matched seasonal influenza viruses during infection of human nasal epithelial cell cultures.

    PubMed

    Fischer, William A; Chason, Kelly D; Brighton, Missy; Jaspers, Ilona

    2014-03-26

    Influenza viruses are global pathogens that infect approximately 10-20% of the world's population each year. Vaccines, including the live attenuated influenza vaccine (LAIV), are the best defense against influenza infections. The LAIV is a novel vaccine that actively replicates in the human nasal epithelium and elicits both mucosal and systemic protective immune responses. The differences in replication and innate immune responses following infection of human nasal epithelium with influenza seasonal wild type (WT) and LAIV viruses remain unknown. Using a model of primary differentiated human nasal epithelial cell (hNECs) cultures, we compared influenza WT and antigenically-matched cold adapted (CA) LAIV virus replication and the subsequent innate immune response including host cellular pattern recognition protein expression, host innate immune gene expression, secreted pro-inflammatory cytokine production, and intracellular viral RNA levels. Growth curves comparing virus replication between WT and LAIV strains revealed significantly less infectious virus production during LAIV compared with WT infection. Despite this disparity in infectious virus production the LAIV strains elicited a more robust innate immune response with increased expression of RIG-I, TLR-3, IFNβ, STAT-1, IRF-7, MxA, and IP-10. There were no differences in cytotoxicity between hNEC cultures infected with WT and LAIV strains as measured by basolateral levels of LDH. Elevated levels of intracellular viral RNA during LAIV as compared with WT virus infection of hNEC cultures at 33°C may explain the augmented innate immune response via the up-regulation of pattern recognition receptors and down-stream type I IFN expression. Taken together our results suggest that the decreased replication of LAIV strains in human nasal epithelial cells is associated with a robust innate immune response that differs from infection with seasonal influenza viruses, limits LAIV shedding and plays a role in the silent

  7. Viable Newcastle Disease Vaccine Strains in a Pharmaceutical Dump

    PubMed Central

    Bianchi, Silvia; Canuti, Marta; Zappa, Alessandra; Zanoni, Giovanna; Koncan, Raffaella; Tanzi, Elisabetta; Cornaglia, Giuseppe; Zanetti, Alessandro Remo; Tridente, Giuseppe

    2007-01-01

    To assess the viability of discarded and buried vaccine strains, we examined vaccines that had been buried for >20 years in an industrial waste dump in the city of Milan, Italy. Viability results showed potential biological risk associated with uncontrolled burial of pharmaceutical industry waste, including some live vaccines. PMID:18258042

  8. Evaluation of immune responses by live infectious bursal disease vaccines to avoid vaccination failures.

    PubMed

    Jakka, P; Reddy, Y K; Kirubaharan, J J; Chandran, N D J

    2014-06-01

    Infectious Bursal Disease (IBD) is a viral, contagious immunosuppressive disease posing an important threat to the commercial poultry industry. Evolution of highly virulent strains of IBD virus warranted the need for detailed characterization of the immune responses offered by the currently available vaccines. Two extensively used live vaccines of varied attenuation levels - intermediate and intermediate plus - strains were analyzed for the induction of immune responses. Both the vaccines induced protective antibody titers with the onset, quicker and higher with the intermediate plus vaccine. The intermediate plus strain vaccinate was observed to induce higher levels of IFN-γ in the birds. These results were supported by immunophenotype analyses with an increase in CD8+ and simultaneous decrease in CD4+ cell population. Both vaccine strains conferred protective immunity against virulent challenge. The study warrants the use of intermediate plus vaccines in disease endemic regions and intermediate vaccines in non-endemic regions to prevent IBD infection. PMID:24883198

  9. A stable live bacterial vaccine.

    PubMed

    Kunda, Nitesh K; Wafula, Denis; Tram, Meilinn; Wu, Terry H; Muttil, Pavan

    2016-06-01

    Formulating vaccines into a dry form enhances its thermal stability. This is critical to prevent administering damaged and ineffective vaccines, and to reduce its final cost. A number of vaccines in the market as well as those being evaluated in the clinical setting are in a dry solid state; yet none of these vaccines have achieved long-term stability at high temperatures. We used spray-drying to formulate a recombinant live attenuated Listeria monocytogenes (Lm; expressing Francisella tularensis immune protective antigen pathogenicity island protein IglC) bacterial vaccine into a thermostable dry powder using various sugars and an amino acid. Lm powder vaccine showed minimal loss in viability when stored for more than a year at ambient room temperature (∼23°C) or for 180days at 40°C. High temperature viability was achieved by maintaining an inert atmosphere in the storage container and removing oxygen free radicals that damage bacterial membranes. Further, in vitro antigenicity was confirmed by infecting a dendritic cell line with cultures derived from spray dried Lm and detection of an intracellularly expressed protective antigen. A combination of stabilizing excipients, a cost effective one-step drying process, and appropriate storage conditions could provide a viable option for producing, storing and transporting heat-sensitive vaccines, especially in regions of the world that require them the most. PMID:27020530

  10. In vitro and in vivo characterization of chimeric duck Tembusu virus based on Japanese encephalitis live vaccine strain SA14-14-2.

    PubMed

    Wang, Hong-Jiang; Liu, Long; Li, Xiao-Feng; Ye, Qing; Deng, Yong-Qiang; Qin, E-De; Qin, Cheng-Feng

    2016-07-01

    Duck Tembusu virus (DTMUV), a newly identified flavivirus, has rapidly spread to China, Malaysia and Thailand. The potential threats to public health have been well-highlighted; however its virulence and pathogenesis remain largely unknown. Here, by using reverse genetics, a recombinant chimeric DTMUV based on Japanese encephalitis live vaccine strain SA14-14-2 was obtained by substituting the corresponding prM and E genes (named ChinDTMUV). In vitro characterization demonstrated that ChinDTMUV replicated efficiently in mammalian cells with small-plaque phenotype in comparison with its parental viruses. Mouse tests showed ChinDTMUV exhibited avirulent phenotype in terms of neuroinvasiveness, while it retained neurovirulence from its parental virus DTMUV. Furthermore, immunization with ChinDTMUV was evidenced to elicit robust IgG and neutralizing antibody responses in mice. Overall, we successfully developed a viable chimeric DTMUV, and these results provide a useful platform for further investigation of the pathogenesis of DTMUV and development of a live attenuated DTMUV vaccine candidate. PMID:27100268

  11. Improvement of the live vaccine strain Salmonella enterica serovar Typhi Ty21a for antigen delivery via the hemolysin secretion system of Escherichia coli.

    PubMed

    Hotz, Christian; Fensterle, Joachim; Goebel, Werner; Meyer, Susanne R; Kirchgraber, Gabriel; Heisig, Martin; Fürer, Andreas; Dietrich, Guido; Rapp, Ulf R; Gentschev, Ivaylo

    2009-02-01

    The attenuated Salmonella enterica serovar Typhi strain Ty21a (Ty21a) is the only attenuated live oral vaccine against typhoid fever. Ty21a is also an attractive carrier for the delivery of heterologous antigens. We have used Ty21a for antigen delivery via the hemolysin (HlyA) secretion system of Escherichia coli, the prototype of the type I secretion system (T1SS). In this study, we identified by genetic complementation that the specific mutation of rpoS correlated with the hemolysin production of strain Ty21a. We furthermore showed that complementation with a plasmid encoding rfaH, which is described to be a downstream target of rpoS, led to increased expression and secretion of hemolysin. Finally, we demonstrated a significant enhancement of antibody responses against the heterologous HlyA antigen of Ty21a after immunization of mice with rfaH complemented S. typhi strain secreting HlyA compared with the same strain without rfaH plasmid. PMID:18706861

  12. Comparison of molecular and biological characteristics of a modified live porcine reproductive and respiratory syndrome virus (PRRSV) vaccine (ingelvac PRRS MLV), the parent strain of the vaccine (ATCC VR2332), ATCC VR2385, and two recent field isolates of PRRSV.

    PubMed

    Opriessnig, T; Halbur, P G; Yoon, K-J; Pogranichniy, R M; Harmon, K M; Evans, R; Key, K F; Pallares, F J; Thomas, P; Meng, X J

    2002-12-01

    The objectives of this study were to compare the molecular and biological characteristics of recent porcine reproductive and respiratory syndrome virus (PRRSV) field isolates to those of a modified live virus (MLV) PRRS vaccine and its parent strain. One hundred seventeen, 4-week-old pigs were randomly assigned to six groups. Group 1 (n = 20) served as sham-inoculated negative controls, group 2 (n = 19) was inoculated with Ingelvac PRRS MLV vaccine, group 3 (n = 20) was inoculated with the parent strain of the vaccine (ATCC VR2332), group 4 (n = 19) was inoculated with vaccine-like PRRSV field isolate 98-38803, group 5 (n = 19) was inoculated with PRRSV field isolate 98-37120, and group 6 (n = 20) was inoculated with known high-virulence PRRSV isolate ATCC VR2385. The levels of severity of gross lung lesions (0 to 100%) among the groups were significantly different at both 10 (P < 0.0001) and 28 days postinoculation (p.i.) (P = 0.002). At 10 days p.i., VR2332 (26.5% +/- 4.64%) and VR2385 (36.4% +/- 6.51%) induced gross lesions of significantly greater severity than 98-38803 (0.0% +/- 0.0%), 98-37120 (0.8% +/- 0.42%), Ingelvac PRRS MLV (0.9% +/- 0.46%), and negative controls (2.3% +/- 1.26%). At 28 days p.i., 98-37120 (17.2% +/- 6.51%) induced gross lesions of significantly greater severity than any of the other viruses. Analyses of the microscopic-interstitial-pneumonia-lesion scores (0 to 6) revealed that VR2332 (2.9 +/- 0.23) and VR2385 (3.1 +/- 0.35) induced significantly more severe lesions at 10 days p.i. At 28 days p.i., VR2385 (2.5 +/- 0.27), VR2332 (2.3 +/- 0.21), 98-38803 (2.6 +/- 0.29), and 98-37120 (3.0 +/- 0.41) induced significantly more severe lesions than Ingelvac PRRS MLV (0.7 +/- 0.17) and controls (0.7 +/- 0.15). The molecular analyses and biological characterizations suggest that the vaccine-like isolate 98-38803 (99.5% amino acid homology based on the ORF5 gene) induces microscopic pneumonia lesions similar in type to, but different in severity

  13. Enhancement of Vaccine Efficacy by Expression of a TLR5 Ligand in the Defined Live Attenuated Francisella tularensis subsp. novicida Strain U112▲iglB::fljB

    PubMed Central

    Cunningham, Aimee L.; Dang, Kim Minh; Yu, Jieh-Juen; Guentzel, M. Neal; Heidner, Hans; Klose, Karl E.; Arulanandam, Bernard P.

    2014-01-01

    Oral vaccination with the defined live attenuated Francisella novicida vaccine strain U112▲iglB has been demonstrated to induce protective immunity against pulmonary challenge with the highly human virulent F. tularensis strain SCHU S4. However, this vaccination regimen requires a booster dose in mice and exhibits 50% protective efficacy in the Fischer 344 rat model. To enhance the efficacy of this vaccine strain, we engineered U112▲iglB to express the Salmonella typhimurium FljB flagellin D1 domain, a TLR5 agonist. The U112▲iglB::fljB strain was highly attenuated for intracellular macrophage replication, and although the FljB protein was expressed within the cytosol, it exhibited TLR5 activation in a TLR5-expressing HEK cell line. Additionally, infection of splenocytes and lymphocytes with U112▲iglB::fljB induced significantly greater TNF-α production than infection with U112▲iglB. Oral vaccination with U112▲iglB::fljB also induced significantly greater protection than U112ΔiglB against pulmonary SCHU S4 challenge in rats. The enhanced protection was accompanied by higher IgG2a production and serum-mediated reduction of Francisella infectivity. Thus, the U112▲iglB::fljB strain may serve as a potential vaccine candidate against pneumonic tularemia. PMID:25050972

  14. "R"-living vaccine against colibacillosis. Communication I.

    PubMed

    Parnas, J; Dam, A; Jorgensen, J B

    1977-04-01

    After our estimation of the LD100 of enteropathogenic E. coli 0149 and 0138 (and their toxins) in rabbits and mice (intravenously and subcutaneously or intraperitoneally, respectively), rabbits and mice were vaccinated subcutaneously by the living "R" 0149 vaccine. All animals showed resistance against the LD100 of both E. coli serotypes; this state of resistance lasted 1-5 months in rabbits, and 1-3 months in mice. Sera of vaccinated rabbits showed bactericidal activity against both E. coli serotypes. The R-E-system of rabbits which were immunized by the endotoxin of "R" 0149 living vaccine, showed mobilization of immunocytes. The vaccine seems to be harmless to newborn piglets after oral vaccination; 2 colostrum deprived piglets, despite vaccination at once after birth, did not survive the big chalenge with 100 ml of broth culture of E. coli 0149 "S" (anapylactic shock). But in comparison to 1 not vaccinated control piglet, the two piglests showed only few E. coli colonies in the intestines, while the intestine of the control animal was very massively colonized by the virulent strain. As the immunizing potency of the "R" 0149 living vaccine was clearly shown in rabbits and mice, further investigations on piglets (newborns, weaning epriod, and after weaning) are needed, to state whether the value of this vaccine corresponds with the immunizing potency shown in our preliminary experiments. The "R"-vaccine seems to open some perspective in colibacillosis prevention of children and animals, and therefore it deserves our attention. PMID:325952

  15. Reduction in faecal excretion of Salmonella typhimurium strain F98 in chickens vaccinated with live and killed S. typhimurium organisms.

    PubMed Central

    Barrow, P. A.; Hassan, J. O.; Berchieri, A.

    1990-01-01

    Chickens given orally at 4 days of age a smooth spectinomycin resistant mutant (Spcr) of Salmonella typhimurium strain F98 excreted the organism in their faeces for approximately 4 weeks. Following oral administration of a nalidixic acid resistant (Nalr) mutant of the same strain 4 weeks later when the chickens had virtually cleared themselves of the first infection, these chickens excreted far fewer salmonella organisms and for a shorter time than did a previously uninfected control group of chickens which were infected at the same time with the Nalr mutant. Chickens inoculated intramuscularly at 4 days developed a similar immunity to challenge and also excreted the immunizing strain in their faeces. In contrast intramuscular inoculation or incorporation into the food of formalin-killed S. typhimurium organisms had little lasting effect on the faecal excretion of the challenge strain. Two attenuated mutants of strain F98 Nalr were produced: one was a rough strain produced by lytic bacteriophage and the other was an aro A auxotrophic mutant which had been cured of the 85 kilobase-pair virulence-associated plasmid. These mutants were avirulent for chickens, mice, calves and man and when ingested by human volunteers did not persist in the faeces. When inoculated intramuscularly into chickens they produced an early reduction in faecal excretion of the challenge strain (Spcr) which was not maintained. Oral administration of both strains produced reductions in faecal excretion of the challenge strain. This was much more noticeable with the rough strain which was itself excreted for a much longer period than the parent strain. PMID:2189743

  16. Live Vaccination Tactics: Possible Approaches for Controlling Visceral Leishmaniasis

    PubMed Central

    Saljoughian, Noushin; Taheri, Tahareh; Rafati, Sima

    2014-01-01

    Vaccination with durable immunity is the main goal and fundamental to control leishmaniasis. To stimulate the immune response, small numbers of parasites are necessary to be presented in the mammalian host. Similar to natural course of infection, strategy using live vaccine is more attractive when compared to other approaches. Live vaccines present the whole spectrum of antigens to the host immune system in the absence of any adjuvant. Leishmanization was the first effort for live vaccination and currently used in a few countries against cutaneous leishmaniasis, in spite of their obstacle and safety. Then, live attenuated vaccines developed with similar promotion of creating long-term immunity in the host with lower side effect. Different examples of attenuated strains are generated through long-term in vitro culturing, culturing under drug pressure, temperature sensitivity, and chemical mutagenesis, but none is safe enough and their revision to virulent form is possible. Attenuation through genetic manipulation and disruption of virulence factors or essential enzymes for intracellular survival are among other approaches that are intensively under study. Other designs to develop live vaccines for visceral form of leishmaniasis are utilization of live avirulent microorganisms such as Lactococcus lactis, Salmonella enterica, and Leishmania tarentolae called as vectored vaccine. Apparently, these vaccines are intrinsically safer and can harbor the candidate antigens in their genome through different genetic manipulation and create more potential to control Leishmania parasite as an intracellular pathogen. PMID:24744757

  17. Live attenuated influenza vaccine tetravalent: a clinical review.

    PubMed

    Bandell, Allyn R; Simões, Eric A F

    2015-07-01

    Live attenuated influenza vaccine (LAIV) has been available as a trivalent formulation in the EU since 2012. Influenza B strains from two lineages have co-circulated outside Asia in Europe, Israel and North America since the early 2000s. The trivalent vaccine contained a single influenza B lineage virus chosen primarily on the basis of the previous year's circulating lineage. Failure to align the vaccine virus with the circulating virus leaves even vaccinated patients, particularly children, at risk for infection with B viruses from the other lineage. Recently, a tetravalent formulation was approved and use will begin during the 2014-2015 influenza season. Approval of LAIV Tetra was based on the established efficacy and safety of trivalent LAIV and studies demonstrating similar immunogenicity between the trivalent and tetravalent vaccines. Addition of a fourth strain to the vaccine will address the issue of co-circulation of influenza B viruses and provide a broader range of protection. PMID:25864428

  18. Genetic engineering of live rabies vaccines.

    PubMed

    Morimoto, K; McGettigan, J P; Foley, H D; Hooper, D C; Dietzschold, B; Schnell, M J

    2001-05-14

    Rabies virus is not a single entity but consists of a wide array of variants that are each associated with different host species. These viruses differ greatly in the antigenic makeup of their G proteins, the primary determinant of pathogenicity and major inducer of protective immunity. Due to this diversity, existing rabies vaccines have largely been targeted to individual animal species. In this report, a novel approach to the development of rabies vaccines using genetically modified, reverse-engineered live attenuated rabies viruses is described. This approach entails the engineering of vaccine rabies virus containing G proteins from virulent strains and modification of the G protein to further reduce pathogenicity. Strategies employed included exchange of the arginine at position 333 for glutamine and modification of the cytoplasmic domain. The recombinant viruses obtained were non-neuroinvasive when administered via a peripheral route. The ability to confer protective immunity depended largely upon conservation of the G protein antigenic structure between the vaccine and challenge virus, as well as on the route of immunization. PMID:11348722

  19. Temporal Transcriptional Response during Infection of Type II Alveolar Epithelial Cells with Francisella tularensis Live Vaccine Strain (LVS) Supports a General Host Suppression and Bacterial Uptake by Macropinocytosis*

    PubMed Central

    Bradburne, Christopher E.; Verhoeven, Anne B.; Manyam, Ganiraju C.; Chaudhry, Saira A.; Chang, Eddie L.; Thach, Dzung C.; Bailey, Charles L.; van Hoek, Monique L.

    2013-01-01

    Pneumonic tularemia is caused by inhalation of Francisella tularensis, one of the most infectious microbes known. We wanted to study the kinetics of the initial and early interactions between bacterium and host cells in the lung. To do this, we examined the infection of A549 airway epithelial cells with the live vaccine strain (LVS) of F. tularensis. A549 cells were infected and analyzed for global transcriptional response at multiple time points up to 16 h following infection. At 15 min and 2 h, a strong transcriptional response was observed including cytoskeletal rearrangement, intracellular transport, and interferon signaling. However, at later time points (6 and 16 h), very little differential gene expression was observed, indicating a general suppression of the host response consistent with other reported cell lines and murine tissues. Genes for macropinocytosis and actin/cytoskeleton rearrangement were highly up-regulated and common to the 15 min and 2 h time points, suggesting the use of this method for bacterial entry into cells. We demonstrate macropinocytosis through the uptake of FITC-dextran and amiloride inhibition of Francisella LVS uptake. Our results suggest that macropinocytosis is a potential mechanism of intracellular entry by LVS and that the host cell response is suppressed during the first 2–6 h of infection. These results suggest that the attenuated Francisella LVS induces significant host cell signaling at very early time points after the bacteria's interaction with the cell. PMID:23322778

  20. 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. PMID:25902362

  1. Influenza vaccination with live-attenuated and inactivated virus-vaccines during an outbreak of disease.

    PubMed Central

    Rocchi, G.; Ragona, G.; Piga, C.; Pelosio, A.; Volpi, A.; Vella, S.; Legniti, N.; de Felici, A.

    1979-01-01

    Immunization procedures with live attenuated and inactivated vaccines were carried out on a group of young recruits at the beginning of an outbreak of infection due to an A/Victoria/3/75-related virus strain, which occurred in February 1977 in a military camp. A retrospective investigation on protection from clinical influenza was then performed in order to investigate whether immunization with live virus vaccines, administered at the beginning of an epidemic, could provide early protection from the disease. In the course of the two weeks following vaccination, laboratory-confirmed clinical influenza cases occurred in 4 subjects among the 110 volunteers of the control group which received placebo, and in 8, 7 and 4 subjects respectively of the 3 groups of about 125 individuals, each of which received one of the following vaccine preparations: (a), live attenuated A/Victoria/3/75 influenza virus oral vaccine, grown on chick embryo kidney culture; (b), live attenuated nasal vaccine, a recombinant of A/Puerto Rico/8/34 with A/Victoria/3/75 virus; and (c), inactivated A/Victoria/3/75 virus intramuscular vaccine. These data do not support the hypothesis that, during an epidemic of infection, early protection from clinical influenza can be achieved through immunization with live attenuated or inactivated influenza virus vaccines, in spite of the high immunizing capability of the vaccine preparations. PMID:512351

  2. Reproducible and Quantitative Model of Infection of Dermacentor variabilis with the Live Vaccine Strain of Francisella tularensis

    PubMed Central

    Coburn, Jenifer; Maier, Tamara; Casey, Monika; Padmore, Lavinia; Sato, Hiromi

    2014-01-01

    Pathogen life cycles in mammalian hosts have been studied extensively, but studies with arthropod vectors represent considerable challenges. In part this is due to the difficulty of delivering a reproducible dose of bacteria to follow arthropod-associated replication. We have established reproducible techniques to introduce known numbers of Francisella tularensis strain LVS from mice into Dermacentor variabilis nymphs. Using this model infection system, we performed dose-response infection experiments and followed bacterial replication through the molt to adults and at later time points. During development to adults, bacteria replicate to high numbers and can be found associated with the gut tissues, salivary glands, and hemolymph of adult ticks. Further, we can transmit a mutant of LVS (LVS ΔpurMCD) that cannot replicate in macrophages in vitro or in mice to nymphs. Our data show that the LVS ΔpurMCD mutant cannot be transstadially transmitted from nymphs to adult ticks. We then show that a plasmid-complemented strain of this mutant is recoverable in adult ticks and necessary for bacterial replication during the molt. In a mixed-infection assay (ΔpurMCD mutant versus ΔpurMCD complement), 98% of the recovered bacteria retained the plasmid marker. These data suggest that the ΔpurMCD mutation cannot be rescued by the presence a complemented strain in a mixed infection. Importantly, our infection model provides a platform to test specific mutants for their replication in ticks, perform competition studies, and use other genetic techniques to identify F. tularensis genes that are expressed or required in this unique environment. PMID:25362054

  3. Oral immunization with an attenuated Salmonella Gallinarum mutant as a fowl typhoid vaccine with a live adjuvant strain secreting the B subunit of Escherichia coli heat-labile enterotoxin

    PubMed Central

    2013-01-01

    Background The Salmonella Gallinarum (SG) lon/cpxR deletion mutant JOL916 was developed as a live vaccine candidate for fowl typhoid (FT), and a SG mutant secreting an Escherichia coli heat-labile enterotoxin B subunit (LTB), designated JOL1229, was recently constructed as an adjuvant strain for oral vaccination against FT. In this study, we evaluated the immunogenicity and protective properties of the SG mutant JOL916 and the LTB adjuvant strain JOL1229 in order to establish a prime and boost immunization strategy for each strain. In addition, we compared the increase in body weight, the immunogenicity, the egg production rates, and the bacteriological egg contamination of these strains with those of SG 9R, a widely used commercial vaccine. Results Plasma IgG, intestinal secretory IgA (sIgA), and cell-mediated responses were significantly induced after a boost inoculation with a mixture of JOL916 and JOL1229, and significant reductions in the mortality of chickens challenged with a wild-type SG strain were observed in the immunized groups. There were no significant differences in increases in body weight, cell-mediated immune responses, or systemic IgG responses between our vaccine mixture and the SG 9R vaccine groups. However, there was a significant elevation in intestinal sIgA in chickens immunized with our mixture at 3 weeks post-prime-immunization and at 3 weeks post-boost-immunization, while sIgA levels in SG 9R-immunized chickens were not significantly elevated compared to the control. In addition, the SG strain was not detected in the eggs of chickens immunized with our mixture. Conclusion Our results suggest that immunization with the LTB-adjuvant strain JOL1229 can significantly increase the immune response, and provide efficient protection against FT with no side effects on body weight, egg production, or egg contamination. PMID:23647814

  4. 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

  5. Hereditary Hemochromatosis Restores the Virulence of Plague Vaccine Strains

    PubMed Central

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

    2012-01-01

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

  6. Safety and immunogenicity of single-dose live oral cholera vaccine strain CVD 103-HgR, prepared from new master and working cell banks.

    PubMed

    Chen, Wilbur H; Greenberg, Richard N; Pasetti, Marcela F; Livio, Sofie; Lock, Michael; Gurwith, Marc; Levine, Myron M

    2014-01-01

    Currently, no cholera vaccine is available for persons traveling from the United States to areas of high cholera transmission and who for reasons of occupation or host factors are at increased risk for development of the disease. A single-dose oral cholera vaccine with a rapid onset of protection would be particularly useful for such travelers and might also be an adjunct control measure for cholera outbreaks. The attenuated Vibrio cholerae O1 vaccine strain CVD 103-HgR harbors a 94% deletion of the cholera toxin A subunit gene (ctxA) and has a mercury resistance gene inserted in the gene encoding hemolysin A. We undertook a phase I randomized placebo-controlled two-site trial to assess the safety and immunogenicity of a preliminary formulation of CVD 103-HgR prepared from new master and working cell banks. Healthy young adults were randomized (5:1 vaccinees to placebo recipients) to receive a single oral dose of ∼4.4 × 10(8) CFU of vaccine or a placebo. Blood serum vibriocidal and cholera toxin-specific IgG antibodies were measured before and 10, 14, and 28 days following vaccination or placebo. Excretion of the vaccine strain in the stool was assessed during the first week postvaccination. A total of 66 subjects were enrolled, comprising 55 vaccinees and 11 placebo recipients. The vaccine was well tolerated. The overall vibriocidal and anti-cholera toxin seroconversion rates were 89% and 57%, respectively. CVD 103-HgR is undergoing renewed manufacture for licensure in the United States under the auspices of PaxVax. Our data mimic those from previous commercial formulations that elicited vibriocidal antibody seroconversion (a correlate of protection) in ∼90% of vaccinees. (This study has been registered at ClinicalTrials.gov under registration no. NCT01585181.). PMID:24173028

  7. Immune Responses to Circulating and Vaccine Viral Strains in HIV-Infected and Uninfected Children and Youth Who Received the 2013/2014 Quadrivalent Live-Attenuated Influenza Vaccine

    PubMed Central

    Weinberg, Adriana; Curtis, Donna; Ning, Mariangeli Freitas; Claypool, David Jeremy; Jalbert, Emilie; Patterson, Julie; Frank, Daniel N.; Ir, Diana; Armon, Carl

    2016-01-01

    The live-attenuated influenza vaccine (LAIV) has generally been more efficacious than the inactivated vaccine in children. However, LAIV is not recommended for HIV-infected children because of insufficient data. We compared cellular, humoral, and mucosal immune responses to the 2013–2014 LAIV quadrivalent (LAIV4) in HIV-infected and uninfected children 2–25 years of age (yoa). We analyzed the responses to the vaccine H1N1 (H1N1-09), to the circulating H1N1 (H1N1-14), which had significant mutations compared to H1N1-09 and to B Yamagata (BY), which had the highest effectiveness in 2013–2014. Forty-six HIV-infected and 56 uninfected participants with prior influenza immunization had blood and nasal swabs collected before and after LAIV4 for IFNγ T and IgG/IgA memory B-cell responses (ELISPOT), plasma antibodies [hemagglutination inhibition (HAI) and microneutralization (MN)], and mucosal IgA (ELISA). The HIV-infected participants had median CD4+ T cells = 645 cells/μL and plasma HIV RNA = 20 copies/mL. Eighty-four percent were on combination anti-retroviral therapy. Regardless of HIV status, significant increases in T-cell responses were observed against BY, but not against H1N1-09. H1N1-09 T-cell immunity was higher than H1N1-14 both before and after vaccination. LAIV4 significantly increased memory IgG B-cell immunity against H1N1-14 and BY in uninfected, but not in HIV-infected participants. Regardless of HIV status, H1N1-09 memory IgG B-cell immunity was higher than H1N1-14 and lower than BY. There were significant HAI titer increases after vaccination in all groups and against all viruses. However, H1N1-14 MN titers were significantly lower than H1N1-09 before and after vaccination overall and in HIV-uninfected vaccinees. Regardless of HIV status, LAIV4 increased nasal IgA concentrations against all viruses. The fold-increase in H1N1-09 IgA was lower than BY. Overall, participants <9 yoa had decreased BY-specific HAI and nasal IgA responses

  8. Transgenic Neospora caninum strains constitutively expressing the bradyzoite NcSAG4 protein proved to be safe and conferred significant levels of protection against vertical transmission when used as live vaccines in mice.

    PubMed

    Marugán-Hernández, V; Ortega-Mora, L M; Aguado-Martínez, A; Jiménez-Ruíz, E; Alvarez-García, G

    2011-10-13

    At present, there is no effective treatment or vaccine to prevent vertical transmission or abortion associated with Neospora caninum infection in cattle. Different vaccine formulations have been assayed, and live vaccines have shown the most promising results in terms of protection. Previously, transgenic N. caninum tachyzoites expressing the bradyzoite stage-specific NcSAG4 antigen in a constitutive manner (Nc-1 SAG4(c)) were obtained and showed a reduced persistence of parasite in inoculated mice. Thus, the present study evaluates the Nc-1 SAG4(c)1.1 and Nc-1 SAG4(c)2.1 transgenic strains and the Nc-1 wild-type (WT) strain to determine their protective efficacy against vertical transmission and cerebral neosporosis in mice. Consequently, dams were immunized twice with 5 × 10(5) tachyzoites of each strain and challenged with 2 × 10(6) tachyzoites of a heterologous and virulent isolate at 7-10 days of gestation. The Nc-1 SAG4(c)1.1 strain offered less protection than the other transgenic strain (Nc-1 SAG4(c)2.1) or their ancestor (Nc-1 WT). Indeed, 40%, 7% and 5.6% of the postnatal deaths corresponded to pups from dams vaccinated with Nc-1 SAG4(c)1.1, Nc-1 SAG4(c)2.1 and Nc-1 (WT) strains, respectively. In comparison, the non-immunized challenge group had a 100% mortality rate. In addition, mice were protected against congenital transmission; vertical transmission rates were 45%, 11.1% and 10.8% in the Nc-1 SAG4(c)1.1, Nc-1 SAG4(c)2.1 and Nc-1 WT immunized groups, respectively, vs. 94.9% in the non-vaccinated infected group. However, this protection against the postnatal mortality and the vertical transmission was not associated with a consistent Th1 or Th2-type immune response. Nonetheless, the Nc-1 SAG4(c)2.1 strain appears to be the best candidate for use as a live vaccine, as evidenced by results demonstrating its high levels of protection against vertical transmission and its lower persistence in mice, making this transgenic strain safer than Nc-1 WT. PMID

  9. Efficacy of a modified live porcine reproductive and respiratory syndrome virus (PRRSV) vaccine in pigs naturally exposed to a heterologous European (Italian cluster) field strain: Clinical protection and cell-mediated immunity.

    PubMed

    Martelli, Paolo; Gozio, Stefano; Ferrari, Luca; Rosina, Stefano; De Angelis, Elena; Quintavalla, Cecilia; Bottarelli, Ezio; Borghetti, Paolo

    2009-06-01

    The purpose of this study was to assess clinical protection in pigs vaccinated with a commercially available attenuated porcine reproductive and respiratory syndrome virus (PRRSV) vaccine (Porcilis) PRRS) and then naturally exposed under field conditions to a heterologous (Italian cluster) strain of virulent PRRSV. A total of 30, 4-week-old pigs seronegative for PRRSV were allocated to 1 of 3 groups (IM, ID, and C groups). At 5 weeks of age, pigs of groups IM (n=10 pigs) and ID (n=10 pigs) were vaccinated intramuscularly and intradermally, respectively, with modified live PRRSV-1 vaccine (Porcilis) PRRS). Pigs of group C (n=10 pigs) were kept as non-vaccinated controls. At post-vaccination (PV) days 0, 7, 14, 28, and 45, blood samples were collected for detection of vaccine virus (PCR) and antibody response (ELISA), identification of changes in lymphocyte subpopulations by cytometry, and IFN-gamma PRRSV-specific secreting cells (SC) by ELISpot. At PV day 45, pigs of A, B, and C groups were moved to a site 3 conventional finishing herd with a history of respiratory disease caused by PRRSV and the most common bacteria to be exposed to a natural challenge. The PRRSV field strain, belonging to the Italian cluster of the PRRSV-1, demonstrated a 84% identity with the vaccine virus (DV strain) at ORF5 sequencing. At 0 (exposure day=45 days PV), 4, 7, 11, 14, 19, 21, 28, and 34 days post-exposure (PE) blood samples were collected for detection and titration of PRRSV and antibody, as well as for lymphocyte and IFN-gamma measurement as described above. Throughout the post-exposure period, all pigs were observed daily for clinical signs. The overall clinical signs were reduced by 68 and 72%, respectively in the intramuscularly and intradermally vaccinated pigs compared to controls. Respiratory signs were reduced by 72 and 80%, respectively in the IM and ID groups. Clinical protection was associated with marked activation of cell-mediated immune response. The highest levels of

  10. Biological safety concepts of genetically modified live bacterial vaccines.

    PubMed

    Frey, Joachim

    2007-07-26

    Live vaccines possess the advantage of having access to induce cell-mediated and antibody-mediated immunity; thus in certain cases they are able to prevent infection, and not only disease. Furthermore, live vaccines, particularly bacterial live vaccines, are relatively cheap to produce and easy to apply. Hence they are suitable to immunize large communities or herds. The induction of both cell-mediated immunity as well as antibody-mediated immunity, which is particularly beneficial in inducing mucosal immune responses, is obtained by the vaccine-strain's ability to colonize and multiply in the host without causing disease. For this reason, live vaccines require attenuation of virulence of the bacterium to which immunity must be induced. Traditionally attenuation was achieved simply by multiple passages of the microorganism on growth medium, in animals, eggs or cell cultures or by chemical or physical mutagenesis, which resulted in random mutations that lead to attenuation. In contrast, novel molecular methods enable the development of genetically modified organisms (GMOs) targeted to specific genes that are particularly suited to induce attenuation or to reduce undesirable effects in the tissue in which the vaccine strains can multiply and survive. Since live vaccine strains (attenuated by natural selection or genetic engineering) are potentially released into the environment by the vaccinees, safety issues concerning the medical as well as environmental aspects must be considered. These involve (i) changes in cell, tissue and host tropism, (ii) virulence of the carrier through the incorporation of foreign genes, (iii) reversion to virulence by acquisition of complementation genes, (iv) exchange of genetic information with other vaccine or wild-type strains of the carrier organism and (v) spread of undesired genes such as antibiotic resistance genes. Before live vaccines are applied, the safety issues must be thoroughly evaluated case-by-case. Safety assessment

  11. Influenza (Flu) vaccine (Live, Intranasal): What you need to know

    MedlinePlus

    ... is taken in its entirety from the CDC Influenza Live, Intranasal Flu Vaccine Information Statement (VIS): www.cdc.gov/vaccines/ ... flulive.html . CDC review information for Live, Intranasal Influenza VIS: Vaccine Information Statement Influenza Page last reviewed: ...

  12. Oral administration of a live attenuated Salmonella vaccine strain expressing the VapA protein induces protection against infection by Rhodococcus equi.

    PubMed

    Oliveira, Aline F; Ferraz, Luciana C; Brocchi, Marcelo; Roque-Barreira, Maria-Cristina

    2007-03-01

    Rhodococcus equi remains one of the most important pathogens of foals and vaccination strategies to prevent rhodococcosis are under increasing investigation. Attenuated Salmonella strains carrying heterologous antigens offer an advantageous alternative to conventional vaccines, especially because they induce mucosal and systemic immunity. In this work, we expressed the VapA antigen from R. equi in a Salmonella enterica Typhimurium strain, which was able to colonize and persist in the lymphoid tissue of BALB/c mice. Two days after being challenged, oral immunized mice presented a 3- to 7-fold increase in R. equi clearance. This was progressively enhanced during infection and, on the 10th day, a CFU value 50-fold lower than that recovered from non-immunized mice was attained. The number of hepatic granulomas was 2 times lower, and leukocyte infiltration was transiently detected in immunized mice, contrasting with the severe inflammation and necrosis presented by non-immunized mice. Infection with 1 x 10(7)R. equi CFU caused 100% mortality in the control groups, while all immunized mice survived. This protection was associated with the detection of high levels of anti-VapA IgG in the serum of the vaccinated mice, predominantly the IgG2a isotype. Our results suggest that attenuated Salmonella encoding VapA may be used in foals to prevent rhodococcosis. PMID:17307012

  13. Immune responses to modified live virus vaccines developed from classical or highly pathogenic PRRSV following challenge with a highly pathogenic PRRSV strain.

    PubMed

    Wang, Gang; Yu, Ying; Zhang, Chong; Tu, Yabin; Tong, Jie; Liu, Yonggang; Chang, Yafei; Jiang, Chenggang; Wang, Shujie; Zhou, En-Min; Cai, Xuehui

    2016-09-01

    Modified live virus vaccines (MLVs) are used on swine farms to control porcine reproductive and respiratory syndrome virus (PRRSV). MLVs from classical PRRSV (C-PRRSV) provide some protection against emergent highly pathogenic PRRSV (HP-PRRSV). This study characterized the protective efficacy and immune response to MLVs from C-PRRSV (CH-1R) or HP-PRRSV (HuN4-F112) in a challenge using HP-PRRSV (HuN4). The outcomes were clinical signs of disease, pathological changes in the thymus and lungs, viremia, and humoral and cellular immune responses. CH-1R provided some protection against challenge with HuN4, while HuN4-F112 was protective in the HuN4 challenge. Compared to unvaccinated piglets, the vaccinated piglets had milder symptoms and fewer pathological changes in the lung and thymus. Piglets vaccinated with HuN4-F112 had higher antibody titers and lower viral loads than piglets vaccinated with CH-1R post challenge. The differences in outcome between the MLVs suggested that underlying differences in the immune responses might warrant further study. PMID:27119981

  14. 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

  15. Characterization of a multicomponent live, attenuated Shigella flexneri vaccine.

    PubMed

    DeLaine, BreOnna C; Wu, Tao; Grassel, Christen L; Shimanovich, Avital; Pasetti, Marcela F; Levine, Myron M; Barry, Eileen M

    2016-07-01

    Shigella flexneri is a leading cause of diarrheal disease in children under five in developing countries. There is currently no licensed vaccine and broad spectrum protection requires coverage of multiple serotypes. The live attenuated vaccines CVD 1213 and CVD 1215 were derived from two prominent S. flexneri serotypes: S. flexneri 3a and S. flexneri 6. To provide broad-spectrum immunity, they could be combined with CVD 1208S, a S. flexneri 2a strain that demonstrated promising results in phase I and II clinical trials. Each strain contains a mutation in the guaBA operon. These vaccine candidates were tested in vitro and in vivo and were found to be auxotrophic for guanine and defective in intracellular replication, but capable of inducing cytokine production from both epithelial cells and macrophages. Both strains were attenuated for virulence in the guinea pig Serény test and induced robust serotype-specific antibody responses following immunization. Each strain induced homologous serotype protection against challenge and a mixed inoculum of the three S. flexneri vaccines conferred protection against all three virulent wild-type strains. These data support the use of CVD 1213, CVD 1215 and CVD 1208S in a multivalent vaccine to confer broad protection against disease caused by Shigella flexneri. PMID:27106253

  16. Live bacterial vaccines – a review and identification of potential hazards

    PubMed Central

    Detmer, Ann; Glenting, Jacob

    2006-01-01

    The use of live bacteria to induce an immune response to itself or to a carried vaccine component is an attractive vaccine strategy. Advantages of live bacterial vaccines include their mimicry of a natural infection, intrinsic adjuvant properties and their possibility to be administered orally. Derivatives of pathogenic and non-pathogenic food related bacteria are currently being evaluated as live vaccines. However, pathogenic bacteria demands for attenuation to weaken its virulence. The use of bacteria as vaccine delivery vehicles implies construction of recombinant strains that contain the gene cassette encoding the antigen. With the increased knowledge of mucosal immunity and the availability of genetic tools for heterologous gene expression the concept of live vaccine vehicles gains renewed interest. However, administration of live bacterial vaccines poses some risks. In addition, vaccination using recombinant bacteria results in the release of live recombinant organisms into nature. This places these vaccines in the debate on application of genetically modified organisms. In this review we give an overview of live bacterial vaccines on the market and describe the development of new live vaccines with a focus on attenuated bacteria and food-related lactic acid bacteria. Furthermore, we outline the safety concerns and identify the hazards associated with live bacterial vaccines and try to give some suggestions of what to consider during their development. PMID:16796731

  17. Rational Considerations about Development of Live Attenuated Y. pestis Vaccines

    PubMed Central

    Sun, Wei; Curtiss, Roy

    2014-01-01

    The risk of plague as a bioweapon has prompted increasing research efforts to develop plague vaccines due to its extreme virulence and the ease of its transmission. Subunit vaccines that contain F1 and LcrV antigens of Y. pestis have been tested for safety and immunogenicity, but doubts have been raised about whether subunit vaccines that engender antibody responses will protect against pneumonic plague, which requires both humeral and cellular immune responses for protection. The live, attenuated vaccine EV76, a pgm locus deficient Y. pestis strain, has been used for a long time in the Former Soviet Union and some Asian countries, but is not commercially available in the US and Europe due to safety concerns. However, the live attenuated Y. pestis vaccines are still considered to be the most effective way to prevent plague. In this review, we present our opinions about rationally creating live, safe and immunogenic Y. pestis vaccines with potential use for human based on established researches. PMID:24372254

  18. Construction, expression, and immunogenicity of the Schistosoma mansoni P28 glutathione S-transferase as a genetic fusion to tetanus toxin fragment C in a live Aro attenuated vaccine strain of Salmonella.

    PubMed Central

    Khan, C M; Villarreal-Ramos, B; Pierce, R J; Riveau, G; Demarco de Hormaeche, R; McNeill, H; Ali, T; Fairweather, N; Chatfield, S; Capron, A

    1994-01-01

    A vector has been constructed to allow genetic fusions of guest antigens via a hinge domain to the C terminus of the highly immunogenic C fragment of tetanus toxin. A fusion has been constructed with the gene encoding the protective 28-kDa glutathione S-transferase (EC 2.5.1.18) from Schistosoma mansoni. The recombinant vector has been electroporated into the nonvirulent Salmonella typhimurium aroA live vaccine strain SL3261. The corresponding chimeric protein is stably expressed in a soluble form in Salmonella as evaluated by Western blotting with fragment C and glutathione S-transferase antisera. Mice immunized intravenously with a single dose of the live recombinant bacteria elicit antibodies to both fragment C and glutathione S-transferase as detected by enzyme-linked immunosorbent assays. Furthermore, all of the mice were solidly protected when challenged with lethal doses of either tetanus toxin or the virulent Salmonella typhimurium strain C5. Mice have also elicited antibodies to fragment C and glutathione S-transferase after oral immunization. It may be that a live trivalent vaccine against typhoid, tetanus, and schistosomiasis is feasible. Images PMID:7972044

  19. Development of a live, attenuated, potential vaccine strain of R. equi expressing vapA and the virR operon, and virulence assessment in the mouse.

    PubMed

    Whitehead, Ashley E; Parreira, Valeria R; Hewson, Joanne; Watson, Johanna L; Prescott, John F

    2012-01-15

    Pneumonia caused by Rhodococcus equi remains a significant problem in foals. The objective of this study was to develop a safe and efficacious attenuated strain of R. equi for eventual use in oral immunization of foals. The approach involved expression of vapA in a live, virulence plasmid-negative, strain of R. equi (strain 103-). PCR-amplified fragments of the vapA gene, with and without the upstream genes virR, orf5, vapH, orf7 and orf8 (orf4-8), were cloned into a shuttle vector pNBV1. These plasmids, named pAW48A and pAWVapA respectively, were electroporated into strain 103-. The presence of the recombinant vectors in the attenuated strain (103-) and the integrity of the inserted genes were confirmed, and both constructs expressed VapA. The virulence of the two strains was compared to that of wild type R. equi 103+ and negative controls by their intravenous inoculation into mice, followed by examination of liver clearance 4 days later. Mice inoculated with R. equi 103-, 103-/pAWVapA and 103-/pNBV1 completely cleared infection, whereas strain 103-/pAW48A persisted in 47% of mice. PMID:22088674

  20. Capripox disease in Ethiopia: Genetic differences between field isolates and vaccine strain, and implications for vaccination failure.

    PubMed

    Gelaye, Esayas; Belay, Alebachew; Ayelet, Gelagay; Jenberie, Shiferaw; Yami, Martha; Loitsch, Angelika; Tuppurainen, Eeva; Grabherr, Reingard; Diallo, Adama; Lamien, Charles Euloge

    2015-07-01

    Sheeppox virus (SPPV), goatpox virus (GTPV) and lumpy skin disease virus (LSDV) of the genus Capripoxvirus (CaPV) cause capripox disease in sheep, goats and cattle, respectively. These viruses are not strictly host-specific and their geographical distribution is complex. In Ethiopia, where sheep, goats and cattle are all affected, a live attenuated vaccine strain (KS1-O180) is used for immunization of both small ruminants and cattle. Although occurrences of the disease in vaccinated cattle are frequently reported, information on the circulating isolates and their relation to the vaccine strain in use are still missing. The present study addressed the parameters associated with vaccination failure in Ethiopia. Retrospective outbreak data were compiled and isolates collected from thirteen outbreaks in small ruminants and cattle at various geographical locations and years were analyzed and compared to the vaccine strain. Isolates of GTPV and LSDV genotypes were responsible for the capripox outbreaks in small ruminants and cattle, respectively, while SPPV was absent. Pathogenic isolates collected from vaccinated cattle were identical to those from the non-vaccinated ones. The vaccine strain, genetically distinct from the outbreak isolates, was not responsible for these outbreaks. This study shows capripox to be highly significant in Ethiopia due to low performance of the local vaccine and insufficient vaccination coverage. The development of new, more efficient vaccine strains, a GTPV strain for small ruminants and a LSDV for cattle, is needed to promote the acceptance by farmers, thus contribute to better control of CaPVs in Ethiopia. PMID:25907637

  1. Oral Typhoid Vaccination With Live-Attenuated Salmonella Typhi Strain Ty21a Generates Ty21a-Responsive and Heterologous Influenza Virus–Responsive CD4+ and CD8+ T Cells at the Human Intestinal Mucosa

    PubMed Central

    Pennington, Shaun H.; Thompson, Ameeka L.; Wright, Adam K. A.; Ferreira, Daniela M.; Jambo, Kondwani C.; Wright, Angela D.; Faragher, Brian; Gilmour, Jill W.; Gordon, Stephen B.; Gordon, Melita A.

    2016-01-01

    Background. Oral vaccination with live-attenuated Salmonella Typhi strain Ty21a is modestly efficacious, but the mechanisms of protection are currently unknown. While humoral and cellular immune responses are well described in peripheral blood, the cellular response at the intestinal mucosa has never been directly assessed. Methods. We vaccinated healthy adults with Ty21a and assessed humoral and cellular immunity in vaccinated volunteers and controls after 18 days. Immunoglobulin levels were assessed in peripheral blood by an enzyme-linked immunosorbent assay. Cellular responses were assessed in peripheral blood and at the duodenal and colonic mucosa by flow cytometry. Results. We demonstrate the generation of Ty21a-responsive and heterologous influenza virus–responsive CD4+ and CD8+ T cells at the duodenal mucosa. All duodenal responses were consistently correlated, and no responses were observed at the colonic mucosa. Peripheral anti-lipopolysaccharide immunoglobulin G and immunoglobulin A responses were significantly correlated with duodenal responses. The assessment of integrin β7 expression intensity among peripheral and duodenal T-cell subsets revealed varied capacities for mucosal homing and residence. Conclusions. The breadth of duodenal cellular responses was not reflected peripherally. The direct evaluation of mucosal immune defense may yield functional correlates of protection and could provide insight into mechanisms that may be manipulated to enhance vaccine immunogenicity. PMID:26810369

  2. Brucellosis: The Case for Live, Attenuated Vaccines

    PubMed Central

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

    2009-01-01

    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 a 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. PMID:19837284

  3. In-Depth Characterization of Live Vaccines Used in Europe for Oral Rabies Vaccination of Wildlife.

    PubMed

    Cliquet, Florence; Picard-Meyer, Evelyne; Mojzis, Miroslav; Dirbakova, Zuzana; Muizniece, Zita; Jaceviciene, Ingrida; Mutinelli, Franco; Matulova, Marta; Frolichova, Jitka; Rychlik, Ivan; Celer, Vladimir

    2015-01-01

    Although rabies incidence has fallen sharply over the past decades in Europe, the disease is still present in Eastern Europe. Oral rabies immunization of wild animal rabies has been shown to be the most effective method for the control and elimination of rabies. All rabies vaccines used in Europe are modified live virus vaccines based on the Street Alabama Dufferin (SAD) strain isolated from a naturally-infected dog in 1935. Because of the potential safety risk of a live virus which could revert to virulence, the genetic composition of three commercial attenuated live rabies vaccines was investigated in two independent laboratories using next genome sequencing. This study is the first one reporting on the diversity of variants in oral rabies vaccines as well as the presence of a mix of at least two different variants in all tested batches. The results demonstrate the need for vaccine producers to use new robust methodologies in the context of their routine vaccine quality controls prior to market release. PMID:26509266

  4. In-Depth Characterization of Live Vaccines Used in Europe for Oral Rabies Vaccination of Wildlife

    PubMed Central

    Cliquet, Florence; Picard-Meyer, Evelyne; Mojzis, Miroslav; Dirbakova, Zuzana; Muizniece, Zita; Jaceviciene, Ingrida; Mutinelli, Franco; Matulova, Marta; Frolichova, Jitka; Rychlik, Ivan; Celer, Vladimir

    2015-01-01

    Although rabies incidence has fallen sharply over the past decades in Europe, the disease is still present in Eastern Europe. Oral rabies immunization of wild animal rabies has been shown to be the most effective method for the control and elimination of rabies. All rabies vaccines used in Europe are modified live virus vaccines based on the Street Alabama Dufferin (SAD) strain isolated from a naturally-infected dog in 1935. Because of the potential safety risk of a live virus which could revert to virulence, the genetic composition of three commercial attenuated live rabies vaccines was investigated in two independent laboratories using next genome sequencing. This study is the first one reporting on the diversity of variants in oral rabies vaccines as well as the presence of a mix of at least two different variants in all tested batches. The results demonstrate the need for vaccine producers to use new robust methodologies in the context of their routine vaccine quality controls prior to market release. PMID:26509266

  5. New approaches to the development of live attenuated rabies vaccines.

    PubMed

    Dietzschold, Bernhard; Schnell, Matthias J

    2002-04-01

    In the United States, extensive reservoirs of the rabies virus exist in many diverse wild animal species, which continue to pose a serious risk of lethal infection of humans and cause an economic burden exceeding $1 billion annually. Previous experience with rabies control in foxes in Europe has clearly demonstrated that oral immunization with live vaccines is the only practical approach to eradicate rabies in free-ranging animals. However, unlike Europe where vulpine rabies was the only major reservoir, the Americas harbor a variety of species including raccoons, skunks, coyotes, and bats that serve as the primary reservoirs of rabies. Each of these animal reservoirs carries an antigenically distinct virus variant. The currently available modified-live rabies virus vaccines have either safety problems or do not induce sufficient protective immunity in particular wildlife species. Therefore, there is a need for the development of new live rabies virus vaccines that are very safe and highly effective in particular wildlife species. Based on previous observations indicating that the potency of a vaccine is significantly increased if the G protein of the vaccine strain is identical to that of the target virus, we have used a reverse genetics approach to engineer viruses that contain G proteins from virus strains associated with relevant wildlife species. Furthermore, because our recent data also indicate that the pathogenicity of a particular rabies virus strain is inversely proportional to its ability to induce apoptosis and that low-level apoptosis-inducing ability is associated with low anti-viral immune responses, we inserted genes encoding pro-apoptotic proteins to stimulate immunity or otherwise interfere with viral pathogenesis into these recombinant viruses to enhance their efficacy and safety. PMID:12031103

  6. Efficacy of combined killed-in-oil emulsion and live Newcastle disease vaccines in chickens.

    PubMed

    Folitse, R; Halvorson, D A; Sivanandan, V

    1998-01-01

    Following the introduction of routine vaccination regimes with different types of Newcastle disease (ND) vaccines, the incidence of velogenic viscerotropic Newcastle disease (VVND) in commercial poultry worldwide has declined dramatically. Unfortunately, these vaccination regimes are not feasible in free-range and backyard systems of poultry production practiced in many developing countries. In this study, we sought to develop a single vaccination regime in chickens with ND vaccines to elicit a long-lasting high level of ND virus (NDV) antibodies adequate to protect chickens against ND. The level of antibody response, as measured by the hemagglutination-inhibition (HI) test, and the degree of protection against the virulent strain of NDV were studied in chickens immunized with different vaccines. The vaccines used were: killed-in-oil emulsion (subcutaneous; s.c.) plus live virus (oculanasal; o.n.), given concurrently; experimental vaccine (s.c.) plus live virus (o.n.), given concurrently; killed-in-oil (s.c.); experimental vaccine prepared by homogenizing commercial live vaccine and oil emulsion (s.c.); and live virus (o.n.). The results obtained in this study indicate that concurrent administration of oil emulsion and live NDV vaccines induced the best antibody response, but there was no significant difference in protection among the vaccinated groups. PMID:9533096

  7. [The effect of coccidiostats on the growth capacity and the survival ability of Salmonella live vaccine agents].

    PubMed

    Martin, G; Meyer, H

    1994-11-01

    Anticoccidial agents are obligatory feed additives during several rearing periods of poultry. The success of an oral immunization of young chicken with Salmonella live vaccines depends on the insensitivity of the vaccine strain against such anticoccidial agents because the vaccination success depends on the survival of the vaccine strain in the gut of the chick and the temporary colonization of lymphatic tissue. We investigated the in vitro sensitivity of the vaccine strain in the S. typhimurium live vaccine "Zoosaloral H" registered for the vaccination of poultry in Germany in connection with often used anticoccidial agents (Diclazuril, Monensin, Narasin and Salinomycin). No differences in growth and survival between the samples containing and lacking anticoccidial agents were found even by using double amounts of the permitted concentration of the anticoccidial agents. No negative effects of the tested anticoccidial agents on Salmonella being used as oral live vaccines in poultry should be expected. PMID:7872948

  8. A rapid real-time quantitative PCR assay to determine the minimal inhibitory extracellular concentration of antibiotics against an intracellular Francisella tularensis Live Vaccine Strain

    PubMed Central

    Aloni-Grinstein, Ronit; Shifman, Ohad; Lazar, Shlomi; Steinberger-Levy, Ida; Maoz, Sharon; Ber, Raphael

    2015-01-01

    Francisella tularensis is a highly virulent facultative intracellular bacterium. The lack of a safe and efficient vaccine makes antibiotics the preferred treatment. F. tularensis antibiotic susceptibility tests are based on the in vitro standard CLSI-approved microdilution method for determining the MIC. However, limited data are available regarding the minimal inhibitory extracellular concentration (MIEC) needed to eradicate intracellular bacteria. Here, we evaluated the MIEC values of various WHO-recommended antibiotics and compared the MIEC values to the established MICs. We describe a rapid 3-h quantitative PCR (qPCR) intracellular antibiogram assay, which yields comparable MIEC values to those obtained by the classical 72-h cfu assay. This rapid qPCR assay is highly advantageous in light of the slow growth rates of F. tularensis. Our results showed that the MIECs obtained for doxycycline, chloramphenicol and ciprofloxacin were indicative of intracellular activity. Gentamicin was not effective against intracellular bacteria for at least 32 h post treatment, raising the question of whether slow-penetrating gentamicin should be used for certain stages of the disease. We suggest that the qPCR intracellular antibiogram assay may be used to screen for potentially active antibiotics against intracellular F. tularensis as well as to detect strains with acquired resistance to recommended antibiotics. PMID:26579112

  9. Efficacy of Brucella abortus vaccine strain RB51 compared to the reference vaccine Brucella abortus strain 19 in water buffalo.

    PubMed

    Caporale, Vincenzo; Bonfini, Barbara; Di Giannatale, Elisabetta; Di Provvido, Andrea; Forcella, Simona; Giovannini, Armando; Tittarelli, Manuela; Scacchia, Massimo

    2010-01-01

    Approximately 250,000 water buffalo (Bubalus bubalis) live in the Campania region of southern Italy where the breeding of this species is very popular. Of these animals, almost 150,000 are concentrated in the Caserta province where the prevalence of Brucella abortus in this species represents approximately 20% at herd level. The Italian brucellosis eradication programme provides a slaughter and vaccination strategy for this province. B. abortus strain RB51 (RB51) has become the official vaccine for the prevention of brucellosis in cattle in several countries. The aim of this study was to evaluate the efficacy of RB51 in water buffalo compared to the B. abortus S19 vaccine (S19). The study was performed in accordance with a protocol described in mice. Female buffalo aged five months were inoculated. Five received a RB51 dosage on two occasions that was three times greater than that approved for use in cattle and a booster after one month, five received B. abortus S19 vaccine at the standard dosage and three controls received a phosphate buffer solution. Buffalo were then challenged with a virulent B. abortus strain 544 thirty days post vaccination. Antibodies that developed in the five animals vaccinated with RB51 were not detected by the Rose Bengal test or complement fixation test (CFT) and were also tested by CFT prepared with RB51 antigen. After culling, B. abortus was cultured from the spleen, retropharyngeal and supra-mammary lymph nodes. A statistical evaluation was performed to assess the immunogenicity values obtained in buffalo vaccinated with S19, compared to those obtained in buffalo vaccinated with the RB51 vaccine and in the unvaccinated control group. PMID:20391363

  10. Permissive growth of human adenovirus type 4 vaccine strain-based vector in porcine cell lines.

    PubMed

    Gao, Dong-Sheng; Li, Xiao-Jing; Wan, Wen-Yan; Li, Hong-Jie; Wang, Xiao-Xue; Yang, Xia; Li, Yong-Tao; Chang, Hong-Tao; Chen, Lu; Wang, Chuan-Qing; Zhao, Jun

    2016-02-01

    In recent years, there has been considerable interest in using adenoviruses as live vectors to develop recombinant vaccines. Previous studies have demonstrated the safety and effectiveness of HIV/SIV and influenza vaccine candidates based on human adenovirus type 4 (Ad4) replication-competent vectors in rhesus macaque and human model. To explore the possibility of human Ad4 vaccine strain used as a vector in developing porcine vaccines, the growth properties of replication-competent human Ad4 vaccine strain recombinant encoding EGFP in different porcine cell lines were investigated. All tested cell lines are permissive for Ad4 vaccine strain vector with varied replication efficiency. Thus, human Ad4 based vectors would be promising supplement to adenovirus vectors as a delivery vehicle for recombinant vaccines in swine industry. PMID:26850542

  11. Development of Streptococcus pneumoniae Vaccines Using Live Vectors

    PubMed Central

    Wang, Shifeng; Curtiss, Roy

    2014-01-01

    Streptococcus pneumoniae still causes severe morbidity and mortality worldwide, especially in young children and the elderly. Much effort has been dedicated to developing protein-based universal vaccines to conquer the current shortcomings of capsular vaccines and capsular conjugate vaccines, such as serotype replacement, limited coverage and high costs. A recombinant live vector vaccine delivering protective antigens is a promising way to achieve this goal. In this review, we discuss the researches using live recombinant vaccines, mainly live attenuated Salmonella and lactic acid bacteria, to deliver pneumococcal antigens. We also discuss both the limitations and the future of these vaccines. PMID:25309747

  12. Stabilization of live Mycoplasma gallisepticum vaccines during vaccination with second generation Spray-Vac® vaccine stabilizer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dilutions and application of live Mycoplasma gallisepticum vaccines without the use of vaccine stabilizing compounds may lead to significant loss of vaccine viability and loss of vaccine efficacy. Vaccine viability may decreases due to osmotic lysis of the mycoplasma as well as the presence of chlo...

  13. 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.

  14. Principles underlying rational design of live attenuated influenza vaccines

    PubMed Central

    Jang, Yo Han

    2012-01-01

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

  15. Photopolymerized hydrogel carriers for live vaccine ballistic delivery.

    PubMed

    Christie, R J; Findley, D J; Dunfee, M; Hansen, R D; Olsen, S C; Grainger, D W

    2006-02-27

    Photopolymerized poly(ethylene glycol) (PEG)-crosslinked hydrogels were assessed for their ability to serve as a payload vehicle to deliver a viable bacterial vaccine (Brucella abortus strain RB51 (RB51) to bison in Yellowstone National Park) ballistically using thermoplastic degradable Biobullets. PEG modified with degradable glycolide or lactide oligomers capped with photopolymerizable methacrylate groups served to crosslink the hydrogel vaccine carrier inside commercial hydroxypropylcellulose Biobullets. Release of 1 microm diameter model fluorescent particles from hydrogels followed known degradation trends for glycolide- and lactide-modified PEG hydrogels. All particles were released from PEG-co-glycolide hydrogels after approximately 10 days and PEG-co-lactide hydrogels after approximately 45 days following gel degradation. Minimal particle release was observed from pure PEG dimethacrylate hydrogels over 40 days. P. aeruginosa (strain PAO1) and RB51 live vaccines exhibit excellent viability following exposure to photopolymerization encapsulation within these gel matrices. Hydrogels photopolymerized into the payload chamber of Biobullets exhibit similar ballistic properties to commercially available Biobullets and penetrate and remain intact when fired intramuscularly into live elk for release of their gel payload in the host. PMID:16246467

  16. Protective efficacy afforded by live Pasteurella multocida vaccines in chickens is independent of lipopolysaccharide outer core structure.

    PubMed

    Harper, Marina; John, Marietta; Edmunds, Mark; Wright, Amy; Ford, Mark; Turni, Conny; Blackall, P J; Cox, Andrew; Adler, Ben; Boyce, John D

    2016-03-29

    Pasteurella multocida is a major animal pathogen that causes a range of diseases including fowl cholera. P. multocida infections result in considerable losses to layer and breeder flocks in poultry industries worldwide. Both killed whole-cell and live-attenuated vaccines are available; these vaccines vary in their protective efficacy, particularly against heterologous strains. Moreover, until recently there was no knowledge of P. multocida LPS genetics and structure to determine precisely how LPS structure affects the protective capacity of these vaccines. In this study we show that defined lipopolysaccharide (LPS) mutants presented as killed whole-cell vaccines elicited solid protective immunity only against P. multocida challenge strains expressing highly similar or identical LPS structures. This finding indicates that vaccination of commercial flocks with P. multocida killed cell formulations will not protect against strains producing an LPS structure different to that produced by strains included in the vaccine formulation. Conversely, protective immunity conferred by vaccination with live P. multocida strains was found to be largely independent of LPS structure. Birds vaccinated with a range of live mutants belonging to the L1 and L3 LPS genotypes, each expressing a specific truncated LPS structure, were protected against challenge with the parent strain. Moreover, birds vaccinated with any of the five LPS mutants belonging to the L1 LPS genotype were also protected against challenge with an unrelated strain and two of the five groups vaccinated with live LPS mutants belonging to the L3 genotype were protected against challenge with an unrelated strain. In summary, vaccination with live P. multocida aroA mutants producing full-length L1 or L3 LPS or vaccination with live strains producing shortened L1 LPS elicited strong protective immunity against both homologous and heterologous challenge. PMID:26892738

  17. Genetic stability of vaccine strain Salmonella Typhi Ty21a over 25 years.

    PubMed

    Kopecko, Dennis J; Sieber, Heike; Ures, Jose A; Fürer, Andreas; Schlup, Jacqueline; Knof, Ulrich; Collioud, Andre; Xu, Deqi; Colburn, Kevin; Dietrich, Guido

    2009-04-01

    The attenuated live bacterial vaccine strain Salmonella enterica Serovar Typhi Ty21a is the main constituent of Vivotif, the only licensed oral vaccine against typhoid fever. The strain was developed in the 1970s by chemical mutagenesis. In the course of this mutagenesis, a number of mutations were introduced into the vaccine strain. Characterisation of the vaccine strain during development as well as release of master- and working seed lots (MSL and WSL) and commercial batches is based on phenotypic assays assessing microbiological and biochemical characteristics of Ty21a. In the current study, we have analysed by DNA sequencing the specific mutations originally correlated with the attenuation of strain Ty21a. These data demonstrate the stability of these mutations for MSLs and WSLs of Ty21a produced between 1980 and 2005. Finally, we have confirmed the correlation of these genetic mutations with the expected phenotypic attenuations for the seed lots used in vaccine manufacture over 25 years. PMID:19121604

  18. The serological response of young dogs to the Flury LEP strain of rabies virus vaccine.

    PubMed

    Aghomo, H O; Oduye, O O; Rupprecht, C E

    1990-01-01

    The serological response of puppies from Nigeria to live Flury low egg passage (LEP) rabies vaccine was determined. Two sets of puppies were used: one set from rabies-vaccinated bitches and another set from non-vaccinated bitches. Puppies were vaccinated intramuscularly with Flury LEP strain rabies vaccine and serially bled from the 4th week to the 30th week. Serum rabies virus neutralizing antibodies (VNA) were measured by a modified rapid fluorescent focus inhibition test (RFFIT). Puppies from non-vaccinated bitches responded well to vaccination after the 4th week and through to the 10th week of age, showing a progressive increase in VNA. In contrast, puppies from vaccinated bitches responded well to rabies vaccination only at 10 weeks of age, although detectable maternal rabies VNA and rabies anti-ribonucleoprotein (RNP) antibodies had decreased by 6 weeks post partum. PMID:2247948

  19. Live bacterial vaccine vectors: An overview

    PubMed Central

    da Silva, Adilson José; Zangirolami, Teresa Cristina; Novo-Mansur, Maria Teresa Marques; Giordano, Roberto de Campos; Martins, Elizabeth Angélica Leme

    2014-01-01

    Genetically attenuated microorganisms, pathogens, and some commensal bacteria can be engineered to deliver recombinant heterologous antigens to stimulate the host immune system, while still offering good levels of safety. A key feature of these live vectors is their capacity to stimulate mucosal as well as humoral and/or cellular systemic immunity. This enables the use of different forms of vaccination to prevent pathogen colonization of mucosal tissues, the front door for many infectious agents. Furthermore, delivery of DNA vaccines and immune system stimulatory molecules, such as cytokines, can be achieved using these special carriers, whose adjuvant properties and, sometimes, invasive capacities enhance the immune response. More recently, the unique features and versatility of these vectors have also been exploited to develop anti-cancer vaccines, where tumor-associated antigens, cytokines, and DNA or RNA molecules are delivered. Different strategies and genetic tools are constantly being developed, increasing the antigenic potential of agents delivered by these systems, opening fresh perspectives for the deployment of vehicles for new purposes. Here we summarize the main characteristics of the different types of live bacterial vectors and discuss new applications of these delivery systems in the field of vaccinology. PMID:25763014

  20. Efficacy of a live Cryptobia salmositica vaccine, and the mechanism of protection in vaccinated rainbow trout, Oncorhynchus mykiss, against cryptobiosis.

    PubMed

    Li, S; Woo, P T

    1995-10-01

    An attenuated strain of Cryptobia salmositica was used as a live vaccine to protect rainbow trout, Oncorhynchus mykiss, against cryptobiosis. Fish immunized with 1.0 x 10(4) or 5.5 x 10(4) attenuated C. salmositica per fish were protected 3 weeks after immunization; however, this period was reduced to 2 weeks if fish were vaccinated with 1.0 x 10(5) attenuated parasites per fish. Fish were still protected at 6, 12 and 24 months after vaccination. Complement fixing antibodies in the blood of immunized fish lysed C. salmositica under in vitro conditions. The titre of complement fixing antibodies in vaccinated fish increased rapidly 1-2 weeks post-challenge. In vitro phagocytosis was enhanced by antiserum and by activated macrophages from vaccinated fish. There was also evidence of antibody independent and antibody dependent cell-mediated cytotoxicity in vaccinated fish. PMID:8578692

  1. Vaccination against Anthrax with Attenuated Recombinant Strains of Bacillus anthracis That Produce Protective Antigen

    PubMed Central

    Barnard, John P.; Friedlander, Arthur M.

    1999-01-01

    The protective efficacy of several live, recombinant anthrax vaccines given in a single-dose regimen was assessed with Hartley guinea pigs. These live vaccines were created by transforming ΔANR and ΔSterne, two nonencapsulated, nontoxinogenic strains of Bacillus anthracis, with four different recombinant plasmids that express the anthrax protective antigen (PA) protein to various degrees. This enabled us to assess the effect of the chromosomal background of the strain, as well as the amount of PA produced, on protective efficacy. There were no significant strain-related effects on PA production in vitro, plasmid stability in vivo, survival of the immunizing strain in the host, or protective efficacy of the immunizing infection. The protective efficacy of the live, recombinant anthrax vaccine strains correlated with the anti-PA antibody titers they elicited in vivo and the level of PA they produced in vitro. PMID:9916059

  2. Bovine herpesvirus-1: comparison and differentiation of vaccine and field strains based on genomic sequence variation.

    PubMed

    Fulton, R W; d'Offay, J M; Eberle, R

    2013-03-01

    Bovine herpesvirus-1 (BoHV-1) causes significant disease in cattle including respiratory, fetal diseases, and reproductive tract infections. Control programs usually include vaccination with a modified live viral (MLV) vaccine. On occasion BoHV-1 strains are isolated from diseased animals or fetuses postvaccination. Currently there are no markers for differentiating MLV strains from field strains of BoHV-1. In this study several BoHV-1 strains were sequenced using whole-genome sequencing technologies and the data analyzed to identify single nucleotide polymorphisms (SNPs). Strains sequenced included the reference BoHV-1 Cooper strain (GenBank Accession JX898220), eight commercial MLV vaccine strains, and 14 field strains from cases presented for diagnosis. Based on SNP analyses, the viruses could be classified into groups having similar SNP patterns. The eight MLV strains could be differentiated from one another although some were closely related to each other. A number of field strains isolated from animals with a history of prior vaccination had SNP patterns similar to specific MLV viruses, while other field isolates were very distinct from all vaccine strains. The results indicate that some BoHV-1 isolates from clinically ill cattle/fetuses can be associated with a prior MLV vaccination history, but more information is needed on the rate of BoHV-1 genome sequence change before irrefutable associations can be drawn. PMID:23333211

  3. Detection of Novel Rotavirus Strain by Vaccine Postlicensure Surveillance

    PubMed Central

    Teel, Elizabeth N.; Mijatovic-Rustempasic, Slavica; Payne, Daniel C.; Roy, Sunando; Foytich, Kimberly; Parashar, Umesh D.; Gentsch, Jon R.; Bowen, Michael D.

    2013-01-01

    Surveillance for rotavirus-associated diarrhea after implementation of rotavirus vaccination can assess vaccine effectiveness and identify disease-associated genotypes. During active vaccine postlicensure surveillance in the United States, we found a novel rotavirus genotype, G14P[24], in a stool sample from a child who had diarrhea. Unusual rotavirus strains may become more prevalent after vaccine implementation. PMID:23876297

  4. 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

  5. Effect of Dosage and Vaccination Route on Transmission of a Live Attenuated Mycoplasma gallesepticum Vaccine: A Broiler Model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mycoplasma gallisepticum (MG) is an economically significant pathogen of poultry species and among the table egg sector of the poultry industry, live attenuated strains of MG are commonly utilized to limit production losses associated with MG-induced disease. The vaccine, however, may be problemati...

  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. PMID:27055100

  7. Rescue of a vaccine strain of peste des petits ruminants virus: In vivo evaluation and comparison with standard vaccine

    PubMed Central

    Muniraju, Murali; Mahapatra, Mana; Buczkowski, Hubert; Batten, Carrie; Banyard, Ashley C.; Parida, Satya

    2015-01-01

    Across the developing world peste des petits ruminants virus places a huge disease burden on agriculture, primarily affecting the production of small ruminant. The disease is most effectively controlled by vaccinating sheep and goats with live attenuated vaccines that provide lifelong immunity. However, the current vaccines and serological tests are unable to enable Differentiation between naturally Infected and Vaccinated Animals (DIVA). This factor precludes meaningful assessment of vaccine coverage and epidemiological surveillance based on serology, in turn reducing the efficiency of control programmes. The availability of a recombinant PPRV vaccine with a proven functionality is a prerequisite for the development of novel vaccines that may enable the development of DIVA tools for PPRV diagnostics. In this study, we have established an efficient reverse genetics system for PPRV Nigeria 75/1 vaccine strain and, further rescued a version of PPRV Nigeria 75/1 vaccine strain that expresses eGFP as a novel transcription cassette and a version of PPRV Nigeria 75/1 vaccine strain with mutations in the haemagglutinin (H) gene to enable DIVA through disruption of binding to H by the C77 monoclonal antibody used in the competitive (c) H-ELISA. All three rescued viruses showed similar growth characteristics in vitro in comparison to parent vaccine strain and, following in vivo assessment the H mutant provided full protection in goats. Although the C77 monoclonal antibody used in the cH-ELISA was unable to bind to the mutated form of H in vitro, the mutation was not sufficient to enable DIVA in vivo. PMID:25444790

  8. Rescue of a vaccine strain of peste des petits ruminants virus: In vivo evaluation and comparison with standard vaccine.

    PubMed

    Muniraju, Murali; Mahapatra, Mana; Buczkowski, Hubert; Batten, Carrie; Banyard, Ashley C; Parida, Satya

    2015-01-01

    Across the developing world peste des petits ruminants virus places a huge disease burden on agriculture, primarily affecting the production of small ruminant. The disease is most effectively controlled by vaccinating sheep and goats with live attenuated vaccines that provide lifelong immunity. However, the current vaccines and serological tests are unable to enable Differentiation between naturally Infected and Vaccinated Animals (DIVA). This factor precludes meaningful assessment of vaccine coverage and epidemiological surveillance based on serology, in turn reducing the efficiency of control programmes. The availability of a recombinant PPRV vaccine with a proven functionality is a prerequisite for the development of novel vaccines that may enable the development of DIVA tools for PPRV diagnostics. In this study, we have established an efficient reverse genetics system for PPRV Nigeria 75/1 vaccine strain and, further rescued a version of PPRV Nigeria 75/1 vaccine strain that expresses eGFP as a novel transcription cassette and a version of PPRV Nigeria 75/1 vaccine strain with mutations in the haemagglutinin (H) gene to enable DIVA through disruption of binding to H by the C77 monoclonal antibody used in the competitive (c) H-ELISA. All three rescued viruses showed similar growth characteristics in vitro in comparison to parent vaccine strain and, following in vivo assessment the H mutant provided full protection in goats. Although the C77 monoclonal antibody used in the cH-ELISA was unable to bind to the mutated form of H in vitro, the mutation was not sufficient to enable DIVA in vivo. PMID:25444790

  9. [Standardization of the seeding material in producing live anthrax vaccine].

    PubMed

    Gladus, M A; Nikolaenko, Iu P; Lazareva, E S; Fatkhinurova, T I; Mashilova, G M

    1978-09-01

    Technology of obtaining dry concentrated seeding material of the anthrax bacillus STI-1 vaccine strain was worked out. The use of dry seeding material for making dry anthrax vaccine rendered the preparations obtained more standard, reduced the time required for their production, led to increase of AKM-SH productivity, and to greater profitability of the vaccine production. The vaccine preparations obtained with the use of dry seeding material did not differ from control by immunogenicity. PMID:106609

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  11. 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

    2015-01-01

    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. PMID:26159607

  12. Antibiotic sensitivity and molecular analyses demonstrate a lack of IncA/C plasmid in modified live Edwardsiella ictaluri vaccine strain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plasmid mediated antibiotic resistance was first discovered in Edwardsiella ictaluri in the early 1990’s and in 2007, an E. ictaluri strain harboring an IncA/C plasmid was isolated from a moribund channel catfish infected with the bacterium. Due to the recent identification of IncA/C plasmids in aqu...

  13. 76 FR 3075 - Availability of an Environmental Assessment for Field Testing Feline Leukemia Vaccine, Live...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-19

    ... Feline Leukemia Vaccine, Live Canarypox Vector AGENCY: Animal and Plant Health Inspection Service, USDA... testing, and then to field test, an unlicensed Feline Leukemia Vaccine, Live Canarypox Vector. The.... Product: Feline Leukemia Vaccine, Live Canarypox Vector. Field Test Locations: Alabama,...

  14. Heterologous protection in pigs induced by a plasmid-cured and crp gene-deleted Salmonella choleraesuis live vaccine.

    PubMed

    Chu, Chun-Yen; Wang, Shiang-Yiu; Chen, Zeng-Weng; Chien, Maw-Sheng; Huang, Ji-Ping; Chen, Jen-Jin; Hong, Li-Shian; Shiau, Ai-Li; Tsai, Jeng-Liang; Wu, Chao-Liang

    2007-10-10

    In this study, we exploited a crp (cAMP receptor protein) gene-deleted, virulence plasmid-cured Salmonella choleraesuis mutant with decreased carbon source utilization, designated S.C.-Deltacrp/vpl(-), as a live vaccine strain. Normal weight gain with no clinical signs was observed in pigs immunized with high doses of S.C.-Deltacrp/vpl(-) live vaccine. Vaccination in pregnant sows induced high maternal antibodies, which could prevent piglets from Salmonella infection. Moreover, serial transmission of the vaccine strain in piglets produced no evidence of reversion to virulence. Furthermore, the peripheral blood mononuclear cells from immunized piglets also developed Salmonella specific T-cell proliferative response in vitro. Our results indicate that immunogenic antigens in S.C.-Deltacrp/vpl(-) can induce adequate immunity to protect pigs against challenge with a heterologous virulent strain. Thus, this mutant holds promise for the development of a new live S. choleraesuis vaccine. PMID:17825957

  15. The second Geneva Consensus: Recommendations for novel live TB vaccines.

    PubMed

    Walker, K B; Brennan, M J; Ho, M M; Eskola, J; Thiry, G; Sadoff, J; Dobbelaer, R; Grode, L; Liu, M A; Fruth, U; Lambert, P H

    2010-03-01

    Infection with Mycobacterium tuberculosis continues to be a major public health burden in most developing parts of the world and efforts to develop effective strategies for containing the disease remain a priority. It has long been evident that effective mass vaccination programmes are a cost effective and efficient approach to controlling communicable diseases in a public health setting and tuberculosis (TB) continues to be a major target. One approach with increasing acceptance is based upon on live mycobacterial vaccines, either as recombinant BCG or rationally attenuated M. tuberculosis, thus generating a new live TB vaccine. The Geneva Consensus published in March 2005 set out the opinion on priorities and requirements for developing live mycobacterial vaccines for Phase I trials. In the intervening period much progress has been made in both preclinical and clinical development of new TB vaccines and has provided the impetus for organising the second Geneva Consensus (held at WHO headquarters, April 2009) to discuss issues, including: i. Explore the regulatory requirements for live TB vaccines to enter Phase I trials, in particular those based on attenuated M. tuberculosis. Particular attention was paid to the characterisation and safety package likely to be required, including issues of attenuation, the presence of antibiotic resistance markers in live vaccines and the nature of any attenuated vaccine phenotype. ii. To identify the general criteria for further clinical development from Phase I through to Phase III. iii. Obtain a perspective of the regulatory landscape of developing countries where Phase II and III trials are to be held. iv. Review manufacturing considerations for live TB vaccines and relevance of the WHO and European Pharmacopeia guidelines and requirements for BCG vaccine. v. Consider requirements and associated issues related to the use of these new vaccines within an existing BCG vaccination programme. PMID:20074686

  16. Complete Genome Sequence of Mycoplasma mycoides subsp. mycoides T1/44, a Vaccine Strain against Contagious Bovine Pleuropneumonia.

    PubMed

    Gourgues, Géraldine; Barré, Aurélien; Beaudoing, Emmanuel; Weber, Johann; Magdelenat, Ghislaine; Barbe, Valérie; Schieck, Elise; Jores, Joerg; Vashee, Sanjay; Blanchard, Alain; Lartigue, Carole; Sirand-Pugnet, Pascal

    2016-01-01

    Mycoplasma mycoidessubsp.mycoidesis the etiologic agent of contagious bovine pleuropneumonia. We report here the complete genome sequence of the strain T1/44, which is widely used as a live vaccine in Africa. PMID:27081135

  17. Complete Genome Sequence of Mycoplasma mycoides subsp. mycoides T1/44, a Vaccine Strain against Contagious Bovine Pleuropneumonia

    PubMed Central

    Gourgues, Géraldine; Barré, Aurélien; Beaudoing, Emmanuel; Weber, Johann; Magdelenat, Ghislaine; Barbe, Valérie; Schieck, Elise; Jores, Joerg; Vashee, Sanjay; Blanchard, Alain; Lartigue, Carole

    2016-01-01

    Mycoplasma mycoides subsp. mycoides is the etiologic agent of contagious bovine pleuropneumonia. We report here the complete genome sequence of the strain T1/44, which is widely used as a live vaccine in Africa. PMID:27081135

  18. Α1-giardin based live heterologous vaccine protects against Giardia lamblia infection in a murine model.

    PubMed

    Jenikova, Gabriela; Hruz, Petr; Andersson, Mattias K; Tejman-Yarden, Noa; Ferreira, Patricia C D; Andersen, Yolanda S; Davids, Barbara J; Gillin, Frances D; Svärd, Staffan G; Curtiss, Roy; Eckmann, Lars

    2011-11-28

    Giardia lamblia is a leading protozoan cause of diarrheal disease worldwide, yet preventive medical strategies are not available. A crude veterinary vaccine has been licensed for cats and dogs, but no defined human vaccine is available. We tested the vaccine potential of three conserved antigens previously identified in human and murine giardiasis, α1-giardin, α-enolase, and ornithine carbamoyl transferase, in a murine model of G. lamblia infection. Live recombinant attenuated Salmonella enterica Serovar Typhimurium vaccine strains were constructed that stably expressed each antigen, maintained colonization capacity, and sustained total attenuation in the host. Oral administration of the vaccine strains induced antigen-specific serum IgG, particularly IgG(2A), and mucosal IgA for α1-giardin and α-enolase, but not for ornithine carbamoyl transferase. Immunization with the α1-giardin vaccine induced significant protection against subsequent G. lamblia challenge, which was further enhanced by boosting with cholera toxin or sublingual α1-giardin administration. The α-enolase vaccine afforded no protection. Analysis of α1-giardin from divergent assemblage A and B isolates of G. lamblia revealed >97% amino acid sequence conservation and immunological cross-reactivity, further supporting the potential utility of this antigen in vaccine development. Together. These results indicate that α1-giardin is a suitable candidate antigen for a vaccine against giardiasis. PMID:22001876

  19. Live RB51 vaccine lyophilized hydrogel formulations with increased shelf life for practical ballistic delivery.

    PubMed

    Falconer, Jonathan L; Christie, R James; Pollard, Emily J; Olsen, Steven C; Grainger, David W

    2016-02-10

    Ballistic delivery capability is essential to delivering vaccines and other therapeutics effectively to both livestock and wildlife in many global scenarios. Here, lyophilized poly(ethylene glycol) (PEG)-glycolide dimethacrylate crosslinked but degradable hydrogels were assessed as payload vehicles to protect and deliver a viable bacterial vaccine, Brucella abortus strain RB51 (RB51), ballistically using commercial thermoplastic cellulosic degradable biobullets. Degradable PEG hydrogel rods loaded with ∼10(10) live RB51 bacteria (CFUs) were fabricated using three different polymerization methods, cut into fixed-sized payload segments, and lyophilized. Resulting dense, glassy RB51 vaccine-loaded monoliths were inserted into thermoplastic biobullet 100-μL payload chambers. Viability studies of lyophilized formulations assessed as a function of time and storage temperature supported the abilities of several conditions to produce acceptable vaccine shelf-lives. Fired from specifically designed air rifles, gel-loaded biobullets exhibit down-range ballistic properties (i.e., kinetic energy, trajectory, accuracy) similar to unloaded biobullets. Delivered to bovine tissue, these hydrogels rehydrate rapidly by swelling in tissue fluids, with complete hydration observed after 5h in serum. Live RB51 vaccine exhibited excellent viability following carrier polymerization, lyophilization, and storage, at levels sufficient for vaccine dosing to wild range bison, the intended target. These data validate lyophilized degradable PEG hydrogel rods as useful drug carriers for remote delivery of both live vaccines and other therapeutics to livestock, wildlife, or other free-range targets using ballistic technologies. PMID:26705151

  20. Bovine herpesvirus-1: evaluation of genetic diversity of subtypes derived from field strains of varied clinical syndromes and their relationship to vaccine strains.

    PubMed

    Fulton, R W; d'Offay, J M; Eberle, R; Moeller, R B; Campen, H Van; O'Toole, D; Chase, C; Miller, M M; Sprowls, R; Nydam, D V

    2015-01-15

    Bovine herpesvirus-1 (BoHV-1) causes significant disease in cattle. Control programs in North America incorporate vaccination with modified live viral (MLV) or killed (KV) vaccine. BoHV-1 strains are isolated from diseased animals or fetuses after vaccination. There are markers for differentiating MLV from field strains using whole-genome sequencing and analysis identifying single nucleotide polymorphisms (SNPs). Using multiple primer sets and sequencing of products permits association of BoHV-1 isolates with vaccines. To determine association between vaccine virus and strains isolated from clinical cases following vaccination, we analyzed 12 BoHV-1 isolates from animals with various clinical syndromes; 9 corresponded to BoHV-1.1 respiratory group. The remaining three corresponded to BoHV-1.2b, typically found in genital tracts of cattle. Four BoHV-1 isolates were identical to a vaccine strain; three were from post-vaccination abortion episodes with typical herpetic lesions whose dams had received MLV vaccine during pregnancy, and one from a heifer given a related MLV vaccine; Sequences of two respiratory isolates perfectly matched mutations characterizing RLB106 strain, a temperature sensitive mutant used in intranasal and parenteral vaccines. The last three respiratory strains clearly appeared related to a group of MLV vaccines. Previously the MLV vaccines were grouped into four groups based on SNPs patterns. In contrast with above-mentioned isolates that closely matched SNP patterns of their respective MLV vaccine virus, these 3 strains both lacked some and possessed a number of additional mutations compared to a group of MLV vaccine viral genome. Finding BoHV-1.2b in respiratory cases indicates focus should be given BoHV-1.2b as an emerging virus or a virus not recognized nor fully characterized in BRD. PMID:25454086

  1. Live porcine reproductive and respiratory syndrome virus vaccines: Current status and future direction.

    PubMed

    Renukaradhya, Gourapura J; Meng, Xiang-Jin; Calvert, Jay G; Roof, Michael; Lager, Kelly M

    2015-08-01

    Porcine reproductive and respiratory syndrome (PRRS) caused by PRRS virus (PRRSV) was reported in the late 1980s. PRRS still is a huge economic concern to the global pig industry with a current annual loss estimated at one billion US dollars in North America alone. It has been 20 years since the first modified live-attenuated PRRSV vaccine (PRRSV-MLV) became commercially available. PRRSV-MLVs provide homologous protection and help in reducing shedding of heterologous viruses, but they do not completely protect pigs against heterologous field strains. There have been many advances in understanding the biology and ecology of PRRSV; however, the complexities of virus-host interaction and PRRSV vaccinology are not yet completely understood leaving a significant gap for improving breadth of immunity against diverse PRRS isolates. This review provides insights on immunization efforts using infectious PRRSV-based vaccines since the 1990s, beginning with live PRRSV immunization, development and commercialization of PRRSV-MLV, and strategies to overcome the deficiencies of PRRSV-MLV through use of replicating viral vectors expressing multiple PRRSV membrane proteins. Finally, powerful reverse genetics systems (infectious cDNA clones) generated from more than 20 PRRSV isolates of both genotypes 1 and 2 viruses have provided a great resource for exploring many innovative strategies to improve the safety and cross-protective efficacy of live PRRSV vaccines. Examples include vaccines with diminished ability to down-regulate the immune system, positive and negative marker vaccines, multivalent vaccines incorporating antigens from other porcine pathogens, vaccines that carry their own cytokine adjuvants, and chimeric vaccine viruses with the potential for broad cross-protection against heterologous strains. To combat this devastating pig disease in the future, evaluation and commercialization of such improved live PRRSV vaccines is a shared goal among PRRSV researchers, pork

  2. The impact of deposition site on vaccination efficiency of a live bacterial poultry vaccine.

    PubMed

    Evans, J D; Leigh, S A; Purswell, J L; Collier, S D; Kim, E J; Boykin, D L; Branton, S L

    2015-08-01

    Vaccines are utilized within the poultry industry to minimize disease-associated losses and spray vaccination is a commonly utilized means for the mass application of poultry vaccines. During this process, vaccine-laden particles are deposited upon target areas (e.g., eyes, nares, and oral cavity) resulting in the direct internalization of the vaccine. However, particles are also deposited on nontarget areas such as the exterior of the subject and its surrounding environment. To better determine the fate of particles deposited upon nontarget areas and the impact of deposition site on the efficiency of vaccine application, a live bacterial poultry vaccine (AviPro(®) MG F) was applied via spray using a spray cabinet with a slotted partition allowing for head-only, body-only, and whole-bird spray application. At 11 wk age, Hy-Line(®) W-36 pullets (n = 280) were allocated equally among 7 treatments including: nonvaccinated controls, pullets spray-vaccinated at the manufacturer's recommended dose (1X) in a site-specific manner (head-only, body-only, and whole-bird), pullets spray-vaccinated at 5X the recommended level (body-only), pullets vaccinated by manual eye-drop application (1X), and pullets eye-drop vaccinated at a level approximating that achieved during the spray vaccination process (1/700X). At 6 to 7 wk postvaccination, vaccination efficiency was assessed via serological-based assays [serum plate agglutination (SPA) and ELISA] and the detection of vaccine-derived in vivo populations. Results indicate an additive contribution of the vaccine deposited on the body to the overall vaccination efficiency of this live bacterial live poultry vaccine. PMID:26049801

  3. Live Attenuated Borrelia burgdorferi Targeted Mutants in an Infectious Strain Background Protect Mice from Challenge Infection.

    PubMed

    Hahn, Beth L; Padmore, Lavinia J; Ristow, Laura C; Curtis, Michael W; Coburn, Jenifer

    2016-08-01

    Borrelia burgdorferi, B. garinii, and B. afzelii are all agents of Lyme disease in different geographic locations. If left untreated, Lyme disease can cause significant and long-term morbidity, which may continue after appropriate antibiotic therapy has been administered and live bacteria are no longer detectable. The increasing incidence and geographic spread of Lyme disease are renewing interest in the vaccination of at-risk populations. We took the approach of vaccinating mice with two targeted mutant strains of B. burgdorferi that, unlike the parental strain, are avirulent in mice. Mice vaccinated with both strains were protected against a challenge with the parental strain and a heterologous B. burgdorferi strain by either needle inoculation or tick bite. In ticks, the homologous strain was eliminated but the heterologous strain was not, suggesting that the vaccines generated a response to antigens that are produced by the bacteria both early in mammalian infection and in the tick. Partial protection against B. garinii infection was also conferred. Protection was antibody mediated, and reactivity to a variety of proteins was observed. These experiments suggest that live attenuated B. burgdorferi strains may be informative regarding the identification of protective antigens produced by the bacteria and recognized by the mouse immune system in vivo Further work may illuminate new candidates that are effective and safe for the development of Lyme disease vaccines. PMID:27335385

  4. Efficacy of Brucella suis strain 2 vaccine against Brucella ovis in rams.

    PubMed

    Blasco, J M; Marín, C; Jiménez de Bagüés, M P; Barberán, M

    1993-10-01

    The protective efficacy against Brucella ovis of live vaccine Brucella suis strain 2 (S2) and Brucella melitensis strain Rev 1 has been evaluated in rams. Fourteen 4-month-old Brucella-free Aragonesa rams were vaccinated conjunctivally with 2 x 10(9) c.f.u. S2. Sixteen rams of the same breed, condition and age were conjunctivally vaccinated the same day with 1.6 x 10(9) Rev 1. Thirteen rams were unvaccinated controls. Eight months after vaccination all rams were challenged with 6 x 10(9) c.f.u. B. ovis and slaughtered 2 months thereafter for bacteriological and pathological studies. The percentage of infection in the group vaccinated with Rev 1 (43.7%) was significantly lower (p < 0.05) than that of the S2-vaccinated animals (78.6%) and unvaccinated controls (84.6%). No significant differences were found when comparing the percentages of infection corresponding to S2-vaccinated and control groups. The degree of infection (percentage of necropsy samples infected) was significantly lower in Rev 1-vaccinated (13%) than in S2-vaccinated (36.9%) or control groups (47.4%) (p < 0.001). However, no significant differences were found when comparing S2-vaccinated and control groups. PMID:8296481

  5. Development of a stable liquid formulation of live attenuated influenza vaccine.

    PubMed

    White, Jessica A; Estrada, Marcus; Flood, E Alexander; Mahmood, Kutub; Dhere, Rajeev; Chen, Dexiang

    2016-07-12

    Vaccination is the most effective means of preventing influenza. However, the cost of producing annual seasonal influenza vaccines puts them out of reach for most developing countries. While live attenuated influenza vaccines are among the most efficacious and can be manufactured at low cost, they may require lyophilization to be stable enough for developing-country use, which adds a significant cost burden. The development of a liquid live attenuated seasonal influenza vaccine that is stable for around a year-the duration of an annual influenza season-would significantly improve not only the production output but also the use and accessibility of influenza vaccines in low-resource settings. In this study, potential stabilizing excipients were screened and optimized using the least stable influenza vaccine strain presently known, H1N1 (A/California/07/2009), as a model. The stability-conferring properties of the lead formulations were also tested with a Type B strain of influenza virus (B/Brisbane/60/2008). Stability was also evaluated with higher titers of influenza virus and exposure to agitation and freeze-thaw stresses to further confirm the stability of the lead formulations. Through this process, we identified a liquid formulation consisting of sucrose phosphate glutamate buffer with 1% arginine and 0.5% recombinant human serum albumin that provided storage stability of one year at 2-8°C for the influenza A and B strains tested. PMID:27155495

  6. [PERSPECTIVES OF DEVELOPMENT OF LIVE RECOMBINANT ANTHRAX VACCINES BASED ON OPPORTUNISTIC AND APATHOGENIC MICROORGANISMS].

    PubMed

    Popova, P Yu; Mikshis, N I

    2016-01-01

    Live genetic engineering anthrax vaccines on the platform of avirulent and probiotic micro-organisms are a safe and adequate alternative to preparations based on attenuated Bacillus anthracis strains. Mucosal application results in a direct contact of the vaccine preparations with mucous membranes in those organs arid tissues of the macro-organisms, that are exposed to the pathogen in the first place, resulting in a development of local and systemic immune response. Live recombinant anthrax vaccines could be used both separately as well as in a prime-boost immunization scheme. The review focuses on immunogenic and protective properties of experimental live genetic engineering prearations, created based on members of geni of Salmonella, Lactobacillus and adenoviruses. PMID:27029122

  7. A Live Oral Fowl Typhoid Vaccine with Reversible O-Antigen Production.

    PubMed

    Mitra, Arindam; Łaniewski, Paweł; Curtiss, Roy; Roland, Kenneth L

    2015-03-01

    Salmonella enterica serovar Gallinarum causes fowl typhoid, recognized worldwide as an economically important disease. The current vaccine, 9R, lacks a complete O antigen, which is a Salmonella virulence factor, and, in addition, has a number of other less well characterized chromosomal mutations. For optimal efficacy, 9R is administered by injection. In an effort to develop a vaccine suitable for oral administration, we constructed Salmonella Gallinarum strains with a reversible O-antigen phenotype. In this scenario, the vaccine strain produces full-length O antigen at the time it is administered to birds. After the vaccine has had time to colonize internal lymphoid tissues, the O-antigen is gradually lost, resulting in an attenuated strain. We found that strains carrying single mutations conferring this phenotype, Apmi and arabinose-regulated rfc, retained virulence. However, a mutant strain carrying both of these mutations was completely attenuated and immunogenic in chickens. This work demonstrates a novel approach for developing live Salmonella vaccines for poultry. PMID:26292534

  8. Reversion of a live porcine reproductive and respiratory syndrome virus vaccine investigated by parallel mutations.

    PubMed

    Nielsen, H S; Oleksiewicz, M B; Forsberg, R; Stadejek, T; Bøtner, A; Storgaard, T

    2001-06-01

    A live attenuated porcine reproductive and respiratory syndrome (PRRS) vaccine virus has been shown to revert to virulence under field conditions. In order to identify genetic virulence determinants, ORF1 from the attenuated vaccine virus and three Danish vaccine-derived field isolates was sequenced and compared with the parental strain of the vaccine virus (VR2332). This revealed five mutations that had occurred independently in all three vaccine-derived field isolates, indicating strong parallel selective pressure on these positions in the vaccine virus when used in swine herds. Two of these parallel mutations were direct reversions to the parental VR2332 sequence and were situated in a papain-like cysteine protease domain and in the helicase domain. The remaining parallel mutations might be seen as second-site compensatory mutations for one or more of the mutations that accumulated in the vaccine virus sequence during cell-culture adaptation. Evaluation of the remaining mutations in the ORF1 sequence revealed stronger selective pressure for amino acid conservation during spread in pigs than during vaccine production. Furthermore, it was found that the selective pressure did not change during the time period studied. The implications of these findings for PRRS vaccine attenuation and reversion are discussed. PMID:11369869

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

    PubMed Central

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

    2014-01-01

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

  10. Safety of classical swine fever virus vaccine strain LOM in pregnant sows and their offspring.

    PubMed

    Lim, Seong-In; Song, Jae-Young; Kim, Jaejo; Hyun, Bang-Hun; Kim, Ha-Young; Cho, In-Soo; Kim, Byounghan; Woo, Gye-Hyeong; Lee, Jung-Bok; An, Dong-Jun

    2016-04-12

    The present study aimed to evaluate the safety of the classical swine fever virus (CSFV) vaccine strain LOM in pregnant sows. Pregnant sows with free CSFV antibody were inoculated with a commercial LOM vaccine during early pregnancy (day 38; n=3) or mid-pregnancy (days 49-59; n=11). In pregnant sows vaccinated during the early stages of gestation, abortion (day 109) was observed in one case, with two stillbirths and seven mummified fetuses. The viability of live-born piglets was 34.9% in sows vaccinated during mid-pregnancy compared with 81.8% in the control group. Post-mortem examination of the organs of the sows and piglets did not reveal any pathological lesions caused by CSFV; however, CSFV RNA was detected in the organs of several vaccinated sows and their litters. The LOM strain was transmitted from sows with free CSFV antibody to their fetus, but did not appear to induce immune tolerance in the offspring from vaccinated pregnant sows. Side effects were not observed in pregnant sows with antibody to the LOM strain: transmission from sow to their litters and stillbirth or mummified fetuses. The LOM strain may induce sterile immunity and provide rapid, long-lasting, and complete protection against CSFV; however, it should be contraindicated in pregnant sows due to potential adverse effects in pregnant sows with free CSFV antibody. PMID:26947495

  11. Protection of Monkeys Against Experimental Shigellosis with a Living Attenuated Oral Polyvalent Dysentery Vaccine

    PubMed Central

    Formal, Samuel B.; Kent, T. H.; May, H. C.; Palmer, A.; Falkow, S.; LaBrec, E. H.

    1966-01-01

    Formal, Samuel B. (Walter Reed Army Institute of Research, Washington, D.C.), T. H. Kent, H. C. May, A. Palmer, and E. H. LaBrec. Protection of monkeys against experimental challenge with a living attenuated oral polyvalent dysentery vaccine. J. Bacteriol. 91:17–22. 1966.—Virulent strains of Shigella flexneri 1b, S. flexneri 3, and S. sonnei I were mated with an Hfr strain of Escherichia coli K-12, and hybrids were selected for the xylose marker. One hybrid strain of each of the serotypes was chosen for study of their biological characteristics. Their capacity to cause a fatal enteric infection in starved guinea pigs was reduced, they failed to cause dysentery when fed to monkeys, they caused keratoconjunctivitis in the guinea pig eye, and they penetrated HeLa cells. Two doses of a polyvalent oral vaccine composed of S. flexneri 1b, 2a, and 3, and S. sonnei I hybrid strains were fed to groups of monkeys at an interval of 4 to 7 days, and they, together with controls, were challenged 10 days after the last dose with one or another of the virulent parent dysentery strains. A significant degree of protection was afforded in all vaccinated groups with the exception of one group challenged with S. flexneri 6, a component not included in the vaccine. When animals were challenged with virulent S. flexneri 2a 1 month after oral vaccination, they were also protected. The vaccine produced a rise in serum antibody, but we were not able to detect coproantibody in saline extracts of feces from animals which received the vaccine. PMID:4957431

  12. Mycoplasma gallisepticum transmission: Comparison of commercial F-strain vaccine versus layer complex-derived field strains in a tunnel ventilated house

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two simultaneous trials were conducted using a commercially available, live, F strain Mycoplasma gallisepticum (FMG) vaccine [Trial 1] or two inocula of layer complex-derived MG strains (LCD-MG) [Trial 2]. In each of the two trials, four commercial turkeys were housed in each of two adjoining pens ...

  13. Symptomatic Infection and Detection of Vaccine and Vaccine-Reassortant Rotavirus Strains in 5 Children: A Case Series

    PubMed Central

    Boom, Julie A.; Sahni, Leila C.; Payne, Daniel C.; Gautam, Rashi; Lyde, Freda; Mijatovic-Rustempasic, Slavica; Bowen, Michael D.; Tate, Jacqueline E.; Rench, Marcia A.; Gentsch, Jon R.; Parashar, Umesh D.; Baker, Carol J.

    2015-01-01

    Vaccine or vaccine-reassortant rotavirus strains were detected in fecal specimens from 5 of 106 (4.7%) immunocompetent children who required treatment for rotavirus gastroenteritis at a large pediatric hospital in Texas in 2009–2010. Four strains were related to pentavalent rotavirus vaccine, whereas one was related to monovalent rotavirus vaccine. The contribution of these strains to each patient’s illness was unclear given that 2 patients had prominent respiratory symptoms and 2 were concurrently infected with another pathogen (group F adenovirus and norovirus). Continued monitoring is necessary to assess the role of vaccine strains and vaccine-reassortant strains in pediatric rotavirus infections. PMID:22872730

  14. 9 CFR 113.71 - Chlamydia Psittaci Vaccine (Feline Pneumonitis), Live Chlamydia.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Chlamydia Psittaci Vaccine (Feline... VECTORS STANDARD REQUIREMENTS Live Bacterial Vaccines § 113.71 Chlamydia Psittaci Vaccine (Feline Pneumonitis), Live Chlamydia. Chlamydia Psittaci Vaccine (Feline Pneumonitis), Live Chlamydia, shall...

  15. 9 CFR 113.71 - Chlamydia Psittaci Vaccine (Feline Pneumonitis), Live Chlamydia.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Chlamydia Psittaci Vaccine (Feline... VECTORS STANDARD REQUIREMENTS Live Bacterial Vaccines § 113.71 Chlamydia Psittaci Vaccine (Feline Pneumonitis), Live Chlamydia. Chlamydia Psittaci Vaccine (Feline Pneumonitis), Live Chlamydia, shall...

  16. The ERA strain of rabies vaccine.

    PubMed

    Lawson, K F; Crawley, J F

    1972-10-01

    An antigenic extinction trial in cats showed that the ERA rabies vaccine had superior antigenic properties over Flury H.E.P. C.E.O. and killed tissue culture rabies vaccine. Dogs and cats on a duration of immunity study of ERA rabies vaccine were challenged with fox salivary gland "street" rabies virus. The results of this challenge show a duration of immunity of five years in dogs and four years in cats. Vaccination of dams in late pregnancy with ERA rabies vaccine resulted in transference of maternal antibody to the newborn, in both cattle and dogs. This maternally derived antibody interfered with the successful active immunization of the young calf. Calves free of antibodies for rabies could be successfully vaccinated as early as 17 days of age and were able to withstand a challenge with virulent "street" rabies virus two years later. PMID:4263912

  17. The ERA Strain of Rabies Vaccine

    PubMed Central

    Lawson, K. F.; Crawley, J. F.

    1972-01-01

    An antigenic extinction trial in cats showed that the ERA rabies vaccine had superior antigenic properties over Flury H.E.P. C.E.O. and killed tissue culture rabies vaccine. Dogs and cats on a duration of immunity study of ERA rabies vaccine were challenged with fox salivary gland “street” rabies virus. The results of this challenge show a duration of immunity of five years in dogs and four years in cats. Vaccination of dams in late pregnancy with ERA rabies vaccine resulted in transference of maternal antibody to the newborn, in both cattle and dogs. This maternally derived antibody interfered with the successful active immunization of the young calf. Calves free of antibodies for rabies could be successfully vaccinated as early as 17 days of age and were able to withstand a challenge with virulent “street” rabies virus two years later. PMID:4263912

  18. Development of a highly immunogenic Newcastle disease virus chicken vaccine strain of duck origin.

    PubMed

    Kim, J Y; Kye, S J; Lee, H J; Gaikwad, S; Lee, H S; Jung, S C; Choi, K S

    2016-04-01

    Newcastle disease virus (NDV) strain NDRL0901 was developed as a live vaccine candidate for control of Newcastle disease. NDV isolate KR/duck/13/07 (DK1307) of duck origin was used as the selected vaccine strain. DK1307 was passaged 6 times in chickens. Then a single clone from the chicken-adapted virus (DK1307C) was finally selected, and the vaccine strain was named NDRL0901. DK1307C and the clone NDRL0901 viruses showed enhanced immunogenicity compared to the DK1307 virus. Principal component analysis based on fusion and hemagglutinin-neuraminidase genes revealed the codon usage pattern in the dataset is distinct separating duck viral sequences and avian sequences, and passage of the duck origin virus into the chicken host causes deviation in the codon usage pattern. The NDRL0901 virus was avirulent and did not acquire viral virulence even after 7 back passages in chickens. When day-old chicks were vaccinated with the NDRL0901 virus via spray, eye drops, and drinking water, the vaccinated birds showed no clinical signs and had significant protection efficacy (>80%) against very virulent NDV (Kr005 strain) infection regardless of the administration route employed. The results indicate that the NDRL0901 strain is safe in chickens and can offer protective immunity. PMID:26769266

  19. Live Attenuated Tularemia Vaccines: Recent Developments and Future Goals

    PubMed Central

    Marohn, Mark E.; Barry, Eileen M.

    2013-01-01

    In the aftermath of the 2001 anthrax attacks in the U.S., numerous efforts were made to increase the level of preparedness against a biological attack both in the US and worldwide. As a result, there has been an increase in research interest in the development of vaccines and other countermeasures against a number of agents with the potential to be used as biological weapons. One such agent, Francisella tularensis, has been the subject of a surge in the level of research being performed, leading to a substantial increase in knowledge of the pathogenic mechanisms of the organism and the induced immune responses. This information has facilitated the development of multiple new Francisella vaccine candidates. Herein we review the latest live attenuated F. tularensis vaccine efforts. Historically, live attenuated vaccines have demonstrated the greatest degree of success in protection against tularemia and the greatest promise in recent efforts to develop of a fully protective vaccine. This review summarizes recent live attenuated Francisella vaccine candidates and the lessons learned from those studies, with the goal of collating known characteristics associated with successful attenuation, immunogenicity, and protection. PMID:23764535

  20. [CONSTRUCTION AND PROPERTIES OF THE FRANCISELLA TULARENSIS VACCINE STRAIN WITHOUT ONE COPY OF THE IGLC GENE AND WITHOUT RECA GENE].

    PubMed

    Mokrievich, A N; Vakhrameeva, G M; Titareva, G M; Bakhteeva, I V; Mironova, R I; Kombarova, T I; Kravchenko, T B; Dyatlov, I A; Pavlov, V M

    2015-01-01

    The live vaccine based on the Francisella tularensis subsp. holarctica vaccine strain 15 NIIEG line is used in Russia against tularemia. This vaccine is highly effective, but fairly unstable. Therefore, development of stable live tularemia vaccine with minimal side effect is rather urgent. The method of allel removal in the F. tularensis vaccine strain was used to remove one copy of the iglC gene, which is required to provide intracellular production of the vaccine strain, as well as removal of the recA gene. The latter is crucial for homological recombination. pGM5 suicide vector based on pHV33 bireplicon plasmid was constructed to provide replacement of intact F. tularensis chromosome segments by modified segments. Modified chromosome segments contain F. Tularensis DNA fragment without iglC structural gene segment 545 p. b. (in pGMΔiglC plasmid), as well as DNA fragment containing no recA structural gene segment 1060 p.b. (pGMΔrecA plasmid). The constructed 15/23-1ΔrecA mutant, in contrast to the vaccine strain 15, was capable of reproducing in the macrophage-like cells J774A.1 line, whereas the efficiency of the reproduction was 8-10 times less. BALB/c mouse responded to immunization by the 15/23-1ΔrecA strain by smaller weight decrease (-2%) as compared to the strain 15 (-14%). Bacteria of the 15/23-1ΔrecA strain were virtually incapable of germinating from the BALB/c murine spleen 14 days after invasion, whereas bacteria of the strain 15 were found in the murine organs even after 21 days. The F. tularensis 15/23-1ΔrecA strain having smaller reaction ability can be used as a basis for construction of stable live safe tularemia vaccine. PMID:26665740

  1. Novel methods for expression of foreign antigens in live vector vaccines

    PubMed Central

    Wang, Jin Yuan; Harley, Regina H.; Galen, James E.

    2013-01-01

    Bacterial live vector vaccines represent a vaccine development strategy that offers exceptional flexibility. In this approach, genes encoding protective antigens of unrelated bacterial, viral or parasitic pathogens are expressed in an attenuated bacterial vaccine strain that delivers these foreign antigens to the immune system, thereby eliciting relevant immune responses. Rather than expressing these antigens using low copy expression plasmids, here we pursue expression of foreign proteins from the live vector chromosome. Our strategy is designed to compensate for the inherent disadvantage of loss of gene dosage (vs. plasmid-based expression) by integrating antigen-encoding gene cassettes into multiple chromosomal sites already inactivated in an attenuated Salmonella enterica serovar Typhi vaccine candidate. We tested expression of a cassette encoding the green fluorescent protein (GFPuv) integrated separately into native guaBA, htrA or clyA chromosomal loci. Using single integrations, we show that expression levels of GFPuv are significantly affected by the site of integration, regardless of the inclusion of additional strong promoters within the incoming cassette. Using cassettes integrated into both guaBA and htrA, we observe cumulative synthesis levels from two integration sites superior to single integrations. Most importantly, we observe that GFPuv expression increases in a growth phase-dependent manner, suggesting that foreign antigen synthesis may be “tuned” to the physiology of the live vaccine. We expect this novel platform expression technology to prove invaluable in the development of a wide variety of multivalent live vector vaccines, capable of expressing multiple antigens from both chromosomal and plasmid-based expression systems within a single strain. PMID:23406777

  2. [Local Immune response in rabbits following enteral immunization with live attenuated bacterial Enterobacteriaceae vaccines].

    PubMed

    Dentschev, W; Marinova, S; Sumerska, T; Nenkov, P; Koitschev, T; Trifonowa, A

    1980-01-01

    Streptomycin-dependent and inactivated Shigella flexneri 2a and Shigella sonnei strains were intra-intestinally applied to rabbits for immunisation. Rosette and plaque tests and well as indirect haemagglutination gave short-time secretion of low titres of specific copro-antibody, following monovaccines and bivaccines. High titres of secretory antibody were induced, depending on doses, by re-immunisation. No antigen competition was established. The localised immune response caused by Shigella live vaccines was found to be much stronger than that induced by inactivated vaccines PMID:6998404

  3. Mismatching between circulating strains and vaccine strains of influenza: Effect on Hajj pilgrims from both hemispheres.

    PubMed

    Alfelali, Mohammad; Khandaker, Gulam; Booy, Robert; Rashid, Harunor

    2016-03-01

    The trivalent seasonal influenza vaccine is expected to provide optimum protection if the vaccine strains match the circulating strains. The effect of worldwide mismatch between the vaccine strains and extant strains on travelers attending Hajj pilgrimage is not known. Annually 2-3 million Muslims coming from north and south hemispheres congregate at Hajj in Mecca, Saudi Arabia, where intense congestion amplifies the risk of respiratory infection up to eight fold. In order to estimate, to what extent mismatching increases the risk of vaccine failure in Hajj pilgrims, we have examined the global data on influenza epidemiology since 2003, in light of the available data from Hajj. These data demonstrate that globally mismatching between circulating and vaccine strains has occurred frequently over the last 12 years, and the mismatch seems to have affected the Hajj pilgrims, however, influenza virus characteristics were studied only in a limited number of Hajj seasons. When the vaccines are different, dual vaccination of travelers by vaccines for southern and northern hemispheres should be considered for Hajj pilgrims whenever logistically feasible. Consideration should also be given to the use of vaccines with broader coverage, i.e., quadrivalent, or higher immunogenicity. Continuous surveillance of influenza at Hajj is important. PMID:26317639

  4. Use of Arthrobacter davidanieli as a live vaccine against Renibacterium salmoninarum and Piscirickettsia salmonis in salmonids.

    PubMed

    Salonius, K; Siderakis, C; MacKinnon, A M; Griffiths, S G

    2005-01-01

    Arthrobacter davidanieli (proposed species nomenclature) is a non-pathogenic Gram-variable bacterium related to, but taxonomically distinct from, Renibacterium salmoninarum, the aetiological agent of bacterial kidney disease (BKD). We have demonstrated that vaccination with live A. davidanieli is effective against BKD in Atlantic salmon (Salmo salar) showing above 80 relative percent survival in experimental challenge trials. Good protection was also demonstrated in long-term field trials where Atlantic salmon were naturally exposed to R. salmoninarum challenge until 23 months after vaccination. The same vaccine, which is licensed in Canada against BKD has also proved effective in reducing mortality from experimental challenge of coho salmon (Oncorhynchus kisutch) with Piscirickettsia salmonis, the causative agent of piscirickettsiosis. Under field conditions in Chile, use of the vaccine led to a significant reduction in piscirickettsiosis mortality in coho salmon over 10 months following sea transfer. The vaccine strain is unique in that it is the first live organism to be licensed as a vaccine for use in aquaculture. Potential mechanisms of protection against the two taxonomically disparate pathogens are discussed. PMID:15962482

  5. 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

  6. Quantitative Determination of Lethal Toxin Proteins in Culture Supernatant of Human Live Anthrax Vaccine Bacillus anthracis A16R.

    PubMed

    Zai, Xiaodong; Zhang, Jun; Liu, Ju; Liu, Jie; Li, Liangliang; Yin, Ying; Fu, Ling; Xu, Junjie; Chen, Wei

    2016-03-01

    Bacillus anthracis (B. anthracis) is the etiological agent of anthrax affecting both humans and animals. Anthrax toxin (AT) plays a major role in pathogenesis. It includes lethal toxin (LT) and edema toxin (ET), which are formed by the combination of protective antigen (PA) and lethal factor (LF) or edema factor (EF), respectively. The currently used human anthrax vaccine in China utilizes live-attenuated B. anthracis spores (A16R; pXO1+, pXO2-) that produce anthrax toxin but cannot produce the capsule. Anthrax toxins, especially LT, have key effects on both the immunogenicity and toxicity of human anthrax vaccines. Thus, determining quantities and biological activities of LT proteins expressed by the A16R strain is meaningful. Here, we explored LT expression patterns of the A16R strain in culture conditions using another vaccine strain Sterne as a control. We developed a sandwich ELISA and cytotoxicity-based method for quantitative detection of PA and LF. Expression and degradation of LT proteins were observed in culture supernatants over time. Additionally, LT proteins expressed by the A16R and Sterne strains were found to be monomeric and showed cytotoxic activity, which may be the main reason for side effects of live anthrax vaccines. Our work facilitates the characterization of anthrax vaccines components and establishment of a quality control standard for vaccine production which may ultimately help to ensure the efficacy and safety of the human anthrax vaccine A16R. PMID:26927174

  7. Quantitative Determination of Lethal Toxin Proteins in Culture Supernatant of Human Live Anthrax Vaccine Bacillus anthracis A16R

    PubMed Central

    Zai, Xiaodong; Zhang, Jun; Liu, Ju; Liu, Jie; Li, Liangliang; Yin, Ying; Fu, Ling; Xu, Junjie; Chen, Wei

    2016-01-01

    Bacillus anthracis (B. anthracis) is the etiological agent of anthrax affecting both humans and animals. Anthrax toxin (AT) plays a major role in pathogenesis. It includes lethal toxin (LT) and edema toxin (ET), which are formed by the combination of protective antigen (PA) and lethal factor (LF) or edema factor (EF), respectively. The currently used human anthrax vaccine in China utilizes live-attenuated B. anthracis spores (A16R; pXO1+, pXO2−) that produce anthrax toxin but cannot produce the capsule. Anthrax toxins, especially LT, have key effects on both the immunogenicity and toxicity of human anthrax vaccines. Thus, determining quantities and biological activities of LT proteins expressed by the A16R strain is meaningful. Here, we explored LT expression patterns of the A16R strain in culture conditions using another vaccine strain Sterne as a control. We developed a sandwich ELISA and cytotoxicity-based method for quantitative detection of PA and LF. Expression and degradation of LT proteins were observed in culture supernatants over time. Additionally, LT proteins expressed by the A16R and Sterne strains were found to be monomeric and showed cytotoxic activity, which may be the main reason for side effects of live anthrax vaccines. Our work facilitates the characterization of anthrax vaccines components and establishment of a quality control standard for vaccine production which may ultimately help to ensure the efficacy and safety of the human anthrax vaccine A16R. PMID:26927174

  8. Modified live Edwardsiella ictaluri vaccine, AQUAVAC-ESC, lacks multidrug resistance plasmids.

    PubMed

    Lafrentz, Benjamin R; Welch, Timothy J; Shoemaker, Craig A; Drennan, John D; Klesius, Phillip H

    2011-12-01

    Plasmid-mediated antibiotic resistance was first discovered in Edwardsiella ictaluri in the early 1990s, and in 2007 an E. ictaluri isolate harboring an IncA/C plasmid was recovered from a moribund channel catfish Ictalurus punctatus infected with the bacterium. Due to the identification of multidrug resistance plasmids in aquaculture and their potential clinical importance, we sought to determine whether the modified live E. ictaluri vaccine strain in AQUAVAC-ESC harbors such plasmids, so that the use of this vaccine will not directly contribute to the pool of bacteria carrying plasmid-borne resistance. Antimicrobial sensitivity testing of the E. ictaluri parent isolate and vaccine strain demonstrated that both were sensitive to 15 of the 16 antimicrobials tested. Total DNA from each isolate was analyzed by polymerase chain reaction (PCR) using a set of 13 primer pairs specific for conserved regions of the IncA/C plasmid backbone, and no specific products were obtained. PCR-based replicon typing of the parent isolate and vaccine strain demonstrated the absence of the 18 commonly occurring plasmid incompatibility groups. These results demonstrate that the vaccine strain does not carry resistance to commonly used antimicrobials and provide strong support for the absence of IncA/C and other commonly occurring plasmid incompatibility groups. Therefore, its use should not directly contribute to the pool of bacteria carrying plasmid-borne resistance. This work highlights the importance of thoroughly investigating potential vaccine strains for the presence of plasmids or other transmissible elements that may encode resistance to antibiotics. PMID:22372247

  9. On strain and stress in living cells

    NASA Astrophysics Data System (ADS)

    Cox, Brian N.; Smith, David W.

    2014-11-01

    Recent theoretical simulations of amelogenesis and network formation and new, simple analyses of the basic multicellular unit (BMU) allow estimation of the order of magnitude of the strain energy density in populations of living cells in their natural environment. A similar simple calculation translates recent measurements of the force-displacement relation for contacting cells (cell-cell adhesion energy) into equivalent volume energy densities, which are formed by averaging the changes in contact energy caused by a cell's migration over the cell's volume. The rates of change of these mechanical energy densities (energy density rates) are then compared to the order of magnitude of the metabolic activity of a cell, expressed as a rate of production of metabolic energy per unit volume. The mechanical energy density rates are 4-5 orders of magnitude smaller than the metabolic energy density rate in amelogenesis or bone remodeling in the BMU, which involve modest cell migration velocities, and 2-3 orders of magnitude smaller for innervation of the gut or angiogenesis, where migration rates are among the highest for all cell types. For representative cell-cell adhesion gradients, the mechanical energy density rate is 6 orders of magnitude smaller than the metabolic energy density rate. The results call into question the validity of using simple constitutive laws to represent living cells. They also imply that cells need not migrate as inanimate objects of gradients in an energy field, but are better regarded as self-powered automata that may elect to be guided by such gradients or move otherwise. Thus Ġel=d/dt 1/2 >[(C11+C12)ɛ02+2μγ02]=(C11+C12)ɛ0ɛ˙0+2μγ0γ˙0 or Ġel=ηEɛ0ɛ˙0+η‧Eγ0γ˙0 with 1.4≤η≤3.4 and 0.7≤η‧≤0.8 for Poisson's ratio in the range 0.2≤ν≤0.4 and η=1.95 and η‧=0.75 for ν=0.3. The spatial distribution of shear strains arising within an individual cell as cells slide past one another during amelogenesis is not known

  10. DeltaznuADeltapurE Brucella abortus 2308 mutant as a live vaccine candidate.

    PubMed

    Yang, Xinghong; Thornburg, Theresa; Walters, Nancy; Pascual, David W

    2010-01-22

    To create a new, safe brucellosis live vaccine, a double mutant strain was constructed from Brucella abortus 2308. Using the DeltaznuA B. abortus 2308 mutant, a second mutation was introduced by deleting purE gene. The DeltaznuA DeltapurE B. abortus 2308 strain was less capable of surviving in macrophages. When evaluated in vivo, it was cleared within 8 weeks (wks) from mice, causing significantly less inflammation than spleens obtained from wild-type B. abortus 2308-infected mice. Furthermore, two doses of DeltaznuA DeltapurE B. abortus 2308 conferred 0.79 log protection, similar to S19 as did a single dose of DeltaznuA B. abortus 2308. Thus, this study shows the DeltaznuA DeltapurE B. abortus 2308 strain to be a potential livestock vaccine candidate. PMID:19914192

  11. Detection and differentiation of wild-type and a vaccine strain of Streptococcus equi ssp. equi using pyrosequencing.

    PubMed

    Livengood, Julia L; Lanka, Saraswathi; Maddox, Carol; Tewari, Deepanker

    2016-07-25

    Streptococcus equi subspecies equi (S. equi), the causative agent of strangles, is an important equine pathogen. Strangles is a highly contagious disease and a commercial modified live vaccine (MLV) is used for protection, which although effective, may also result in clinical signs of the disease. A rapid means to differentiate between the MLV and wild-type infection is crucial for quarantine release and limiting the disease spread. This study describes the use of a pyrosequencing assay targeting a single nucleotide deletion upstream of the SzPSe gene to distinguish between the wild-type and vaccine strains. A set of 96 characterized clinical specimens and isolates were tested using the assay. The assay was successful in differentiating between wild-type S. equi and the vaccine strains and in discriminating S. equi from other Streptococci. The vaccine strain was identified in 61.7% (29/47) of the strangles cases in horses with a history of MLV vaccination. PMID:27317457

  12. Live vaccines for human metapneumovirus designed by reverse genetics.

    PubMed

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

    2006-10-01

    Human metapneumovirus (HMPV) was first described in 2001 and has quickly become recognized as an important cause of respiratory tract disease worldwide, especially in the pediatric population. A vaccine against HMPV is required to prevent severe disease associated with infection in infancy. The primary strategy is to develop a live-attenuated virus for intranasal immunization, which is particularly well suited against a respiratory virus. Reverse genetics provides a means of developing highly characterized 'designer' attenuated vaccine candidates. To date, several promising vaccine candidates have been developed, each using a different mode of attenuation. One candidate involves deletion of the G glycoprotein, providing attenuation that is probably based on reduced efficiency of attachment. A second candidate involves deletion of the M2-2 protein, which participates in regulating RNA synthesis and whose deletion has the advantageous property of upregulating transcription and increasing antigen synthesis. A third candidate involves replacing the P protein gene of HMPV with its counterpart from the related avian metapneumovirus, thereby introducing attenuation owing to its chimeric nature and host range restriction. Another live vaccine strategy involves using an attenuated parainfluenza virus as a vector to express HMPV protective antigens, providing a bivalent pediatric vaccine. Additional modifications to provide improved vaccines will also be discussed. PMID:17181442

  13. Effectiveness of live or killed plague vaccines in man

    PubMed Central

    Meyer, K. F.

    1970-01-01

    While the safety of the available live plague vaccine EV 76 (Paris) continues to be the subject of further study, the USP formol-killed, virulent Pasteurella pestis (Yersinia pestis) suspension capable of protecting 60% of non-human primates, particularly Hanuman langurs (Presbytis entellus), warrants further clinical tests and field trials. Inoculated in a dosage of 2×109 killed plague bacilli (1 ml), followed by a booster of 400 million organisms (0.2 ml) in 1-3 months, this vaccine stimulates the appearance of passive mouse-protection antibodies (below an index of 10) and passive haemagglutinins in 60%-65% of human subjects. Recent experiences in Viet-Nam demonstrate that personnel vaccinated with the USP vaccine, although frequently exposed, enjoy almost complete freedom from the disease. One of the 4 known and confirmed cases of bubonic plague in North Americans occurred in an unvaccinated individual. Among individuals inoculated with the USP vaccine, 2 confirmed cases of pneumonic plague and 1 case of asymptomatic pharyngeal plague have been recorded. The incidence of plague in the Republic of Viet-Nam during the past 3 years is estimated at 13 263 cases in a population in part vaccinated with a live plague which exhibited inadequate immunogenic efficacy in experimental tests. PMID:4988692

  14. 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

  15. Efficacy of live adjuvanted mesogenic Newcastle disease vaccine in chickens.

    PubMed

    Roy, P; Venugopalan, A T; Koteeswaran, A

    1999-06-01

    120 white leghorn chickens primed with a lentogenic Newcastle disease (ND) live vaccine at 7 days of age were divided into three equal groups of 8 weeks of age and vaccinated with a live mesogenic ND vaccine (NDV). One group received only Newcastle disease mesogenic vaccine (RDVK) in normal saline, the second group received RDVK with groundnut oil as adjuvant and the third group received RDVK with liquid paraffin as adjuvant. Sera were collected at different time points for the assessment of antibody level against ND virus (NDV) by the haemagglutination inhibition (HI) test. The commonly used non-adjuvanted RDVK could not evince 100% protective HI titre beyond 11 weeks of age but in both the adjuvanted groups 100% protective HI titre was evident up to 20 weeks of age. On challenge at 20 weeks of age both the adjuvanted groups withstood challenge but in the non-adjuvanted group 80% of chickens withstood the challenge. A significant difference in immune response between the adjuvanted and non-adjuvanted groups was seen but not between both the adjuvanted groups. The advantage of vegetable oil (groundnut oil) as an adjuvant for live mesogenic ND vaccine has been discussed. PMID:10418918

  16. The Sabin live poliovirus vaccination trials in the USSR, 1959.

    PubMed Central

    Horstmann, D. M.

    1991-01-01

    Widespread use of the Sabin live attenuated poliovirus vaccine has had tremendous impact on the disease worldwide, virtually eliminating it from a number of countries, including the United States. Early proof of its safety and effectiveness was presented in 1959 by Russian investigators, who had staged massive trials in the USSR, involving millions of children. Their positive results were at first viewed in the United States and elsewhere with some skepticism, but the World Health Organization favored proceeding with large-scale trials, and responded to the claims made by Russian scientists by sending a representative to the USSR to review in detail the design and execution of the vaccine programs and the reliability of their results. The report that followed was a positive endorsement of the findings and contributed to the acceptance of the Sabin vaccine in the United States, where it has been the polio vaccine of choice since the mid-1960s. PMID:1814062

  17. HPV Vaccine Awareness and Knowledge Among Women Living with HIV.

    PubMed

    Wigfall, L T; Bynum, S A; Brandt, H M; Hébert, J R

    2016-03-01

    Cervical cancer risk is increased among women living with HIV (WLH). Human papillomavirus (HPV) vaccination has been shown to be safe and immunogenic among WLH. We examined HPV vaccine awareness and HPV knowledge among WLH. This cross-sectional study collected data from 145 WLH between March 2011 and April 2012. An interviewer-administered survey assessed HPV vaccine awareness and knowledge. Stata/IC 13 was used to perform chi-square tests and multivariate logistic regression analyses. Our sample was 90 % non-Hispanic black and 64 % earned <$10,000/year. Few (38 %) had heard of the HPV vaccine. Half (50 %) knew that HPV caused cervical cancer. HPV vaccine awareness was ten times higher among WLH who knew HPV caused cervical cancer (OR = 10.17; 95 % CI 3.82-27.06). HPV vaccine awareness is low among WLH. Cancer prevention efforts aimed at raising awareness about the HPV vaccine and increasing knowledge about HPV are necessary first steps in reducing cervical cancer disparities among WLH. PMID:26561426

  18. Global antibody response to Staphylococcus aureus live-cell vaccination.

    PubMed

    Selle, Martina; Hertlein, Tobias; Oesterreich, Babett; Klemm, Theresa; Kloppot, Peggy; Müller, Elke; Ehricht, Ralf; Stentzel, Sebastian; Bröker, Barbara M; Engelmann, Susanne; Ohlsen, Knut

    2016-01-01

    The pathogen Staphylococcus aureus causes a broad range of severe diseases and is feared for its ability to rapidly develop resistance to antibiotic substances. The increasing number of highly resistant S. aureus infections has accelerated the search for alternative treatment options to close the widening gap in anti-S. aureus therapy. This study analyses the humoral immune response to vaccination of Balb/c mice with sublethal doses of live S. aureus. The elicited antibody pattern in the sera of intravenously and intramuscularly vaccinated mice was determined using of a recently developed protein array. We observed a specific antibody response against a broad set of S. aureus antigens which was stronger following i.v. than i.m. vaccination. Intravenous but not intramuscular vaccination protected mice against an intramuscular challenge infection with a high bacterial dose. Vaccine protection was correlated with the strength of the anti-S. aureus antibody response. This study identified novel vaccine candidates by using protein microarrays as an effective tool and showed that successful vaccination against S. aureus relies on the optimal route of administration. PMID:27103319

  19. Global antibody response to Staphylococcus aureus live-cell vaccination

    PubMed Central

    Selle, Martina; Hertlein, Tobias; Oesterreich, Babett; Klemm, Theresa; Kloppot, Peggy; Müller, Elke; Ehricht, Ralf; Stentzel, Sebastian; Bröker, Barbara M.; Engelmann, Susanne; Ohlsen, Knut

    2016-01-01

    The pathogen Staphylococcus aureus causes a broad range of severe diseases and is feared for its ability to rapidly develop resistance to antibiotic substances. The increasing number of highly resistant S. aureus infections has accelerated the search for alternative treatment options to close the widening gap in anti-S. aureus therapy. This study analyses the humoral immune response to vaccination of Balb/c mice with sublethal doses of live S. aureus. The elicited antibody pattern in the sera of intravenously and intramuscularly vaccinated mice was determined using of a recently developed protein array. We observed a specific antibody response against a broad set of S. aureus antigens which was stronger following i.v. than i.m. vaccination. Intravenous but not intramuscular vaccination protected mice against an intramuscular challenge infection with a high bacterial dose. Vaccine protection was correlated with the strength of the anti-S. aureus antibody response. This study identified novel vaccine candidates by using protein microarrays as an effective tool and showed that successful vaccination against S. aureus relies on the optimal route of administration. PMID:27103319

  20. Protection Induced in Broiler Chickens following Drinking-Water Delivery of Live Infectious Laryngotracheitis Vaccines against Subsequent Challenge with Recombinant Field Virus

    PubMed Central

    Korsa, Mesula G.; Browning, Glenn F.; Coppo, Mauricio J. C.; Legione, Alistair R.; Gilkerson, James R.; Noormohammadi, Amir H.; Vaz, Paola K.; Lee, Sang-Won

    2015-01-01

    Infectious laryngotracheitis virus (ILTV) causes acute upper respiratory tract disease in chickens. Attenuated live ILTV vaccines are often used to help control disease, but these vaccines have well documented limitations, including retention of residual virulence, incomplete protection, transmission of vaccine virus to unvaccinated birds and reversion to high levels of virulence following bird-to-bird passage. Recently, two novel ILTV field strains (class 8 and 9 ILTV viruses) emerged in Australia due to natural recombination between two genotypically distinct commercial ILTV vaccines. These recombinant field strains became dominant field strains in important poultry producing areas. In Victoria, Australia, the recombinant class 9 virus largely displaced the previously predominant class 2 ILTV strain. The ability of ILTV vaccines to protect against challenge with the novel class 9 ILTV strain has not been studied. Here, the protection induced by direct (drinking-water) and indirect (contact) exposure to four different ILTV vaccines against challenge with class 9 ILTV in commercial broilers was studied. The vaccines significantly reduced, but did not prevent, challenge virus replication in vaccinated chickens. Only one vaccine significantly reduced the severity of tracheal pathology after direct drinking-water vaccination. The results indicate that the current vaccines can be used to help control class 9 ILTV, but also indicate that these vaccines have limitations that should be considered when designing and implementing disease control programs. PMID:26366738

  1. Protection Induced in Broiler Chickens following Drinking-Water Delivery of Live Infectious Laryngotracheitis Vaccines against Subsequent Challenge with Recombinant Field Virus.

    PubMed

    Korsa, Mesula G; Browning, Glenn F; Coppo, Mauricio J C; Legione, Alistair R; Gilkerson, James R; Noormohammadi, Amir H; Vaz, Paola K; Lee, Sang-Won; Devlin, Joanne M; Hartley, Carol A

    2015-01-01

    Infectious laryngotracheitis virus (ILTV) causes acute upper respiratory tract disease in chickens. Attenuated live ILTV vaccines are often used to help control disease, but these vaccines have well documented limitations, including retention of residual virulence, incomplete protection, transmission of vaccine virus to unvaccinated birds and reversion to high levels of virulence following bird-to-bird passage. Recently, two novel ILTV field strains (class 8 and 9 ILTV viruses) emerged in Australia due to natural recombination between two genotypically distinct commercial ILTV vaccines. These recombinant field strains became dominant field strains in important poultry producing areas. In Victoria, Australia, the recombinant class 9 virus largely displaced the previously predominant class 2 ILTV strain. The ability of ILTV vaccines to protect against challenge with the novel class 9 ILTV strain has not been studied. Here, the protection induced by direct (drinking-water) and indirect (contact) exposure to four different ILTV vaccines against challenge with class 9 ILTV in commercial broilers was studied. The vaccines significantly reduced, but did not prevent, challenge virus replication in vaccinated chickens. Only one vaccine significantly reduced the severity of tracheal pathology after direct drinking-water vaccination. The results indicate that the current vaccines can be used to help control class 9 ILTV, but also indicate that these vaccines have limitations that should be considered when designing and implementing disease control programs. PMID:26366738

  2. Efficacy of a modified live Flavobacterium columnare vaccine in fish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flavobacterium columnare is an aquatic bacterium that is responsible for columnaris disease. This aquatic pathogen has a worldwide distribution and is highly infectious to both warm and cold water fish. A modified live F. columnare vaccine was developed through repeated passage of a virulent strai...

  3. Effect of different adjuvant formulations on the immunogenicity and protective effect of a live Mycoplasma hyopneumoniae vaccine after intramuscular inoculation.

    PubMed

    Xiong, Qiyan; Wei, Yanna; Xie, Haidong; Feng, Zhixin; Gan, Yuan; Wang, Chunlai; Liu, Maojun; Bai, Fangfang; Xie, Fang; Shao, Guoqing

    2014-06-01

    Mycoplasma hyopneumoniae (M. hyopneumoniae) vaccine strain 168 is an intrapulmonically injected attenuated live vaccine that is available in the Chinese market. The aim of this study was to develop suitable adjuvants for this live vaccine to provide effective protection after intramuscular inoculation. Several adjuvant components were screened to assess their toxicity for the live vaccine, and various adjuvant formulations were then designed and prepared. Vaccines supplemented with these adjuvants were used to immunize mice intramuscularly to assess the capacity of the adjuvants to induce a specific immune response. The screened formulations were then evaluated in pigs. Seven of the eight adjuvant components did not affect the viability of the live vaccine, and seven different adjuvant formulations were then designed. In mice, the ISCOM-matrix adjuvant and the levamisole-chitosan mixture adjuvant significantly enhanced serum IgG responses against M. hyopneumoniae, while lymphocyte proliferation was enhanced by the ISCOM-matrix adjuvant, the carbomer-astragalus polysaccharide mixture adjuvant and an oil-in-water emulsion adjuvant. These four adjuvants were evaluated in pigs. Enhancement of specific lymphocyte proliferation responses was observed in the groups vaccinated with the ISCOM-matrix adjuvant and the carbomer-astragalus polysaccharide mixture adjuvant. Significant enhancement of serum IgG antibody production was observed before challenge in pigs vaccinated with the carbomer-astragalus polysaccharide mixture adjuvant and the levamisole-chitosan mixture adjuvant, while after challenge, all of the animals that received vaccines containing adjuvants had higher antibody concentrations against M. hyopneumoniae than unvaccinated animals. Animals inoculated with a vaccine containing the ISCOM-matrix adjuvant (median score 3.57) or the carbomer-astragalus polysaccharide mixture adjuvant (median score 5.28) had reduced lesion scores compared to unvaccinated animals

  4. 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

  5. Brucella suis strain 2 vaccine is safe and protective against heterologous Brucella spp. infections.

    PubMed

    Zhu, Liangquan; Feng, Yu; Zhang, Ge; Jiang, Hui; Zhang, Zhen; Wang, Nan; Ding, Jiabo; Suo, Xun

    2016-01-12

    Brucellosis is a wide spread zoonotic disease that causes abortion and infertility in mammals and leads to debilitating, febrile illness in humans. Brucella abortus, Brucella melitensis and Brucella suis are the major pathogenic species to humans. Vaccination with live attenuated B. suis strain 2 (S2) vaccine is an essential and critical component in the control of brucellosis in China. The S2 vaccine is very effective in preventing brucellosis in goats, sheep, cattle and swine. However, there are still debates outside of China whether the S2 vaccine is able to provide protection against heterologous virulent Brucella species. We investigated the residual virulence, immunogenicity and protective efficacy of the S2 vaccine in BALB/c mice by determining bacteria persistence in spleen, serum antibody response, cellular immune response and protection against a heterologous virulent challenge. The S2 vaccine was of low virulence as there were no bacteria recovered in spleen four weeks post vaccination. The vaccinated mice developed Brucella-specific IgG in 2-3 weeks, and a burst production of IFN-γ at one week as well as a two-fold increase in TNF-α production. The S2 vaccine protected mice from a virulent challenge by B. melitensis M28, B. abortus 2308 and B. suis S1330, and the S2 vaccinated mice did not develop any clinical signs or tissue damage. Our study demonstrated that the S2 vaccine is of low virulence, stimulates good humoral and cellular immunity and protects animals against infection by heterologous, virulent Brucella species. PMID:26626213

  6. Nonreplicating, Cyst-Defective Type II Toxoplasma gondii Vaccine Strains Stimulate Protective Immunity against Acute and Chronic Infection

    PubMed Central

    2015-01-01

    Live attenuated vaccine strains, such as type I nonreplicating uracil auxotroph mutants, are highly effective in eliciting lifelong immunity to virulent acute infection by Toxoplasma gondii. However, it is currently unknown whether vaccine-elicited immunity can provide protection against acute infection and also prevent chronic infection. To address this problem, we developed nonreverting, nonreplicating, live attenuated uracil auxotroph vaccine strains in the type II Δku80 genetic background by targeting the deletion of the orotidine 5′-monophosphate decarboxylase (OMPDC) and uridine phosphorylase (UP) genes. Deletion of OMPDC induced a severe uracil auxotrophy with loss of replication, loss of virulence in mice, and loss of the ability to develop cysts and chronic infection. Vaccination of mice using type II Δku80 Δompdc mutants stimulated a fully protective CD8+ T cell-dependent immunity that prevented acute infection by type I and type II strains of T. gondii, and this vaccination also severely reduced or prevented cyst formation after type II challenge infection. Nonreverting, nonreplicating, and non-cyst-forming Δompdc mutants provide new tools to examine protective immune responses elicited by vaccination with a live attenuated type II vaccine. PMID:25776745

  7. Nonreplicating, cyst-defective type II Toxoplasma gondii vaccine strains stimulate protective immunity against acute and chronic infection.

    PubMed

    Fox, Barbara A; Bzik, David J

    2015-05-01

    Live attenuated vaccine strains, such as type I nonreplicating uracil auxotroph mutants, are highly effective in eliciting lifelong immunity to virulent acute infection by Toxoplasma gondii. However, it is currently unknown whether vaccine-elicited immunity can provide protection against acute infection and also prevent chronic infection. To address this problem, we developed nonreverting, nonreplicating, live attenuated uracil auxotroph vaccine strains in the type II Δku80 genetic background by targeting the deletion of the orotidine 5'-monophosphate decarboxylase (OMPDC) and uridine phosphorylase (UP) genes. Deletion of OMPDC induced a severe uracil auxotrophy with loss of replication, loss of virulence in mice, and loss of the ability to develop cysts and chronic infection. Vaccination of mice using type II Δku80 Δompdc mutants stimulated a fully protective CD8(+) T cell-dependent immunity that prevented acute infection by type I and type II strains of T. gondii, and this vaccination also severely reduced or prevented cyst formation after type II challenge infection. Nonreverting, nonreplicating, and non-cyst-forming Δompdc mutants provide new tools to examine protective immune responses elicited by vaccination with a live attenuated type II vaccine. PMID:25776745

  8. Persistence and spreading of field and vaccine strains of infectious laryngotracheitis virus (ILTV) in vaccinated and unvaccinated geographic regions, in Brazil.

    PubMed

    Chacón, Jorge Luis; Núñez, Luis Fabian Naranjo; Vejarano, Maria Pilar; Parra, Silvana Hipatia Santander; Astolfi-Ferreira, Claudete Serrano; Ferreira, Antonio José Piantino

    2015-08-01

    Infectious laryngotracheitis (ILT) is a highly infectious respiratory disease that causes morbidity and mortality in commercial chickens. Despite the use of attenuated vaccines, ILT outbreaks have been described in broiler and long-lived birds. Molecular approaches, including polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing, are used to characterize ILT viruses (ILTVs) detected in vaccinated and unvaccinated geographical regions. As part of an ILT control program implemented in a region of commercial layer production, samples of conjunctiva, trachea, and trigeminal ganglia were collected from chickens in a vaccinated and quarantined region over a period of 8 years after initiation of vaccination. To determine the origin of new ILT outbreaks in unvaccinated regions, samples collected from ill chickens were also analyzed. Chicken embryo origin (CEO) vaccine viruses and the Bastos field strain were detected circulating in healthy chickens in the vaccinated region. CEO strains and field viruses molecularly related to the Bastos strain were also detected outside of the quarantined region in chickens showing clinical signs of ILT. This study reveals the persistence and circulation of a wild field strain, despite the intensive use of tissue culture origin (TCO) and CEO vaccines in a quarantined region. Spreading of CEO viruses to unvaccinated regions and the capacity of this virus to establish latent infections and cause severe outbreaks were also observed. PMID:25904510

  9. Recombinant canine distemper virus serves as bivalent live vaccine against rabies and canine distemper.

    PubMed

    Wang, Xijun; Feng, Na; Ge, Jinying; Shuai, Lei; Peng, Liyan; Gao, Yuwei; Yang, Songtao; Xia, Xianzhu; Bu, Zhigao

    2012-07-20

    Effective, safe, and affordable rabies vaccines are still being sought. Attenuated live vaccine has been widely used to protect carnivores from canine distemper. In this study, we generated a recombinant canine distemper virus (CDV) vaccine strain, rCDV-RVG, expressing the rabies virus glycoprotein (RVG) by using reverse genetics. The recombinant virus rCDV-RVG retained growth properties similar to those of vector CDV in Vero cell culture. Animal studies demonstrated that rCDV-RVG was safe in mice and dogs. Mice inoculated intracerebrally or intramuscularly with rCDV-RVG showed no apparent signs of disease and developed a strong rabies virus (RABV) neutralizing antibody response, which completely protected mice from challenge with a lethal dose of street virus. Canine studies showed that vaccination with rCDV-RVG induced strong and long-lasting virus neutralizing antibody responses to RABV and CDV. This is the first study demonstrating that recombinant CDV has the potential to serve as bivalent live vaccine against rabies and canine distemper in animals. PMID:22698451

  10. Effects of live and killed vaccines against Mycoplasma gallisepticum on the performance characteristics of commercial layer chickens.

    PubMed

    Jacob, R; Branton, S L; Evans, J D; Leigh, S A; Peebles, E D

    2014-06-01

    Different vaccine strains of Mycoplasma gallisepticum have been used on multiple-age commercial layer farms in an effort to protect birds against virulent field-strain infections. Use of the F-strain of M. gallisepticum (FMG), as an overlay vaccine during lay, may be necessary because of the lower level of protection afforded by M. gallisepticum vaccines of low virulence given before lay. Two replicate trials were conducted to investigate effects of live and killed M. gallisepticum vaccines administered individually and in combination before lay, in conjunction with an FMG vaccine overlay after peak egg production (EP), on the performance characteristics of commercial layers. The following treatments were utilized at 10 wk of age (woa): 1) control (no vaccinations); 2) ts11 strain M. gallisepticum (ts11MG) vaccine; 3) M. gallisepticum-Bacterin vaccine (MG-Bacterin); and 4) ts11MG and MG-Bacterin vaccines combination. At 45 woa, half of the birds were overlaid with an FMG vaccine. Hen mortality, BW, egg weight, percentage hen-day EP, egg blood spots, and egg meat spots were determined at various time periods between 18 and 52 woa. The data from each trial were pooled. Treatment did not affect performance in interval I (23 to 45 woa). However, during interval II (46 to 52 woa), the EP of control and MG-Bacterin-vaccinated birds that later received an FMG vaccine overlay was lower than that in the other treatment groups. Furthermore, treatment application reduced bird BW during interval II. Despite the effects on BW and EP, no differences were observed for egg blood or meat spots among the various treatments. It is suggested that the vaccination of commercial layers before lay with ts11MG, but not MG-Bacterin, may reduce the negative impacts of an FMG overlay vaccination given during lay. These results establish that the vaccination of pullets with ts11MG in combination with the vaccination of hens with an FMG overlay, for continual protection against field-strain M

  11. ChimeriVax-West Nile Virus Live-Attenuated Vaccine: Preclinical Evaluation of Safety, Immunogenicity, and Efficacy

    PubMed Central

    Arroyo, Juan; Miller, Chuck; Catalan, John; Myers, Gwendolyn A.; Ratterree, Marion S.; Trent, Dennis W.; Monath, Thomas P.

    2004-01-01

    The availability of ChimeriVax vaccine technology for delivery of flavivirus protective antigens at the time West Nile (WN) virus was first detected in North America in 1999 contributed to the rapid development of the vaccine candidate against WN virus described here. ChimeriVax-Japanese encephalitis (JE), the first live- attenuated vaccine developed with this technology has successfully undergone phase I and II clinical trials. The ChimeriVax technology utilizes yellow fever virus (YF) 17D vaccine strain capsid and nonstructural genes to deliver the envelope gene of other flaviviruses as live-attenuated chimeric viruses. Amino acid sequence homology between the envelope protein (E) of JE and WN viruses facilitated targeting attenuating mutation sites to develop the WN vaccine. Here we discuss preclinical studies with the ChimeriVax-WN virus in mice and macaques. ChimeriVax-WN virus vaccine is less neurovirulent than the commercial YF 17D vaccine in mice and nonhuman primates. Attenuation of the virus is determined by the chimeric nature of the construct containing attenuating mutations in the YF 17D virus backbone and three point mutations introduced to alter residues 107, 316, and 440 in the WN virus E protein gene. The safety, immunogenicity, and efficacy of the ChimeriVax-WN02 vaccine in the macaque model indicate the vaccine candidate is expected to be safe and immunogenic for humans. PMID:15507637

  12. Systemic, nasal and oral live vaccines against Pseudomonas aeruginosa: a clinical trial of immunogenicity in lower airways of human volunteers.

    PubMed

    Bumann, Dirk; Behre, Christoph; Behre, Katharina; Herz, Steffen; Gewecke, Britta; Gessner, J Engelbert; von Specht, Bernd Ulrich; Baumann, Ulrich

    2010-01-01

    Vaccination against Pseudomonas aeruginosa is a desirable, yet challenging strategy for prevention of airway infection in patients with cystic fibrosis. We compared the formation of antibodies in lower airways induced by systemic and mucosal vaccination strategies. We immunised 48 volunteers in six vaccination groups with either a systemic, a nasal, or four newly constructed oral live vaccines based on attenuated live Salmonella (strains CVD908 and Ty21a), followed by a systemic booster vaccination. All vaccines were based on a recombinant fusion protein of the highly conserved P. aeruginosa outer membrane proteins OprF and OprI as antigen. While systemic and mucosal vaccines induced a comparable rise of serum antibody titers, a significant rise of IgA and IgG antibodies in the lower airways was noted only after nasal and oral vaccinations. We conclude that nasal and oral OprF-OprI vaccines are promising candidates for development of antipseudomonal immunisation through inducing a specific antibody response in the lung. PMID:19887136

  13. An avian live attenuated master backbone for potential use in epidemic and pandemic influenza vaccines

    PubMed Central

    Hickman, Danielle; Hossain, Md Jaber; Song, Haichen; Araya, Yonas; Solórzano, Alicia; Perez, Daniel R.

    2008-01-01

    The unprecedented emergence in Asia of multiple avian influenza virus (AIV) subtypes with a broad host range poses a major challenge in the design of vaccination strategies that are both effective and available in a timely manner. The present study focused on the protective effects of a genetically modified AIV as a source for the preparation of vaccines for epidemic and pandemic influenza. It has previously been demonstrated that a live attenuated AIV based on the internal backbone of influenza A/Guinea fowl/Hong Kong/WF10/99 (H9N2), called WF10att, is effective at protecting poultry species against low- and high-pathogenicity influenza strains. More importantly, this live attenuated virus provided effective protection when administered in ovo. In order to characterize the WF10att backbone further for use in epidemic and pandemic influenza vaccines, this study evaluated its protective effects in mice. Intranasal inoculation of modified attenuated viruses in mice provided adequate protective immunity against homologous lethal challenges with both the wild-type influenza A/WSN/33 (H1N1) and A/Vietnam/1203/04 (H5N1) viruses. Adequate heterotypic immunity was also observed in mice vaccinated with modified attenuated viruses carrying H7N2 surface proteins. The results presented in this report suggest that the internal genes of a genetically modified AIV confer similar protection in a mouse model and thus could be used as a master donor strain for the generation of live attenuated vaccines for epidemic and pandemic influenza. PMID:18931063

  14. 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

  15. Infection and transmission of live recombinant Newcastle disease virus vaccines in Rock Pigeons, European House Sparrows, and Japanese Quail

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In China and Mexico, engineered recombinant Newcastle disease virus (rNDV) strains are used as live vaccines for the control of Newcastle disease and as vectors to express the avian influenza virus hemagglutinin (HA) gene to control avian influenza in poultry. In this study, non-target species wer...

  16. Oral vaccination with microencapsuled strain 19 vaccine confers enhanced protection against Brucella abortus strain 2308 challenge in red deer (Cervus elaphus elaphus).

    PubMed

    Arenas-Gamboa, Angela M; Ficht, Thomas A; Davis, Donald S; Elzer, Philip H; Kahl-McDonagh, Melissa; Wong-Gonzalez, Alfredo; Rice-Ficht, Allison C

    2009-10-01

    Bison (Bison bison) and elk (Cervus elaphus nelsoni) in the Greater Yellowstone Area (GYA), USA, are infected with Brucella abortus, the causative agent of bovine brucellosis, and they serve as a wildlife reservoir for the disease. Bovine brucellosis recently has been transmitted from infected elk to cattle in Montana, Wyoming, and Idaho and has resulted in their loss of brucellosis-free status. An efficacious Brucella vaccine with a delivery system suitable for wildlife would be a valuable tool in a disease prevention and control program. We evaluated Strain 19 (S19) in a sustained release vehicle consisting of alginate microspheres containing live vaccine. In a challenge study using red deer (Cervus elaphus elaphus) as a model for elk, alginate, a naturally occurring polymer combined with a protein of Fasciola hepatica vitelline protein B was used to microencapsulate S19. Red deer were orally or subcutaneously immunized with 1.5 x 10(10) colony-forming units (CFUs) using microencapsulated S19. Humoral and cellular profiles were analyzed bimonthly throughout the study. The vaccinated red deer and nonvaccinated controls were challenged 1 yr postimmunization conjunctivally with 1 x 10(9) CFUs of B. abortus strain 2308. Red deer vaccinated with oral microencapsulated S19 had a statistically significant lower bacterial tissue load compared with controls. These data indicate for the first time that protection against Brucella-challenge can be achieved by combining a commonly used vaccine with a novel oral delivery system such as alginate-vitelline protein B microencapsulation. This system is a potential improvement for efficacious Brucella-vaccine delivery to wildlife in the GYA. PMID:19901378

  17. Chinese border disease virus strain JSLS12-01 infects piglets and down-regulates the antibody responses of classical swine fever virus C strain vaccination.

    PubMed

    Mao, Li; Li, Wenliang; Liu, Xia; Hao, Fei; Yang, Leilei; Deng, Jiawu; Zhang, Wenwen; Wei, Jianzhong; Jiang, Jieyuan

    2015-07-31

    During 2012 and 2013, several border disease virus (BDV) strains were identified from Chinese goat and sheep herds. At the same time, pigs from the same areas were found to be seropositive to BDV by ELISA, without showing clinical signs (unpublished data). To examine the susceptibility of pigs to the Chinese BDV strains, BDV isolate JSLS12-01, isolated from naturally infected sheep, was used to infect pigs. Antibody responses, viremia, clinical signs and pathological changes of the infected animals were examined. It confirmed that the current BDV strain could infect the domestic pigs, the animals showed viremia during 4 to 14 days post infection (dpi) and sero-conversion from 14dpi; no clinical and pathological changes were observed. In addition, CSFV maternal antibody did not influence BDV infection. Subsequently, pigs were infected with the BDV isolate and vaccinated with Hog cholera lapinized virus (HCLV) 21 days later to determine the effect of BDV infection on antibody induction of CSFV vaccination. The specific CSFV antibody and neutralizing antibody titers of the BDV infected group remained negative after the primary vaccination. Even after the boost vaccination, they were still significantly lower than those of the uninfected groups (p<0.05). These results indicated that BDV infection could down-regulate the antibody responses of CSFV C-strain vaccination. It should be paid attention that BDV prevalence in pig herds and in live vaccines might hamper the vaccination of CSF. PMID:26117151

  18. [Testing of apathogenic influenza virus H5N3 as a poultry live vaccine].

    PubMed

    Boravleva, E Y; Chvala, I A; Lomakina, N F; Repin, P I; Mudrak, N S; Rudenko, L G; Gambaryan, A S; Drygin, V V

    2015-01-01

    Four H5N2 experimental vaccine strains and the apathogenic wild duck H5N3 influenza virus A/duck/ Moscow/4182/2010 (dk/4182) were tested as a live poultry vaccine. Experimental strains had the hemagglutinin of the A/Vietnam/1203/04 strain lacking the polybasic HA cleavage site or the hemagglutinin from attenuated virus (Ku/ at) that was derived from the highly pathogenic influenza virus A/chicken/Kurgan/3/2005 (H5N1). The hemagglutinin of the Ku-at has the amino acid substitutions Asp54/Asn and Lys222/Thr in HA1 and Val48/Ile and Lys131/Thr in HA2, while maintaining the polybasic HA cleavage site at an invariable level. The other genes of these experimental strains were from the H2N2 cold-adapted master strain A/Leningrad/134/17/57 (VN-Len and Ku-Len) or from the apathogenic H6N2 virus A/gull/Moscow/3100/2006 (VN-Gull and Ku-Gull). A single immunization of mice with all tested strains elicited a high level of serum antibodies and provided complete protection against the challenge with the lethal dose of A/chicken/Kurgan/3/05. The pathogenicity indexes of the Ku-at and the other strains for chicken were virtually zero, whereas the index of the parent H5N1 virus A/chicken/Kurgan/3/2005 was 2.98. Intravenous, intranasal, and aerosol routes of vaccination were compared. It was shown that the strain dk/4182 was totally apathogenic for one-day-old chicken and provided complete protection against the highly pathogenic H5N1 virus. PMID:26665435

  19. A diagnostic protocol to identify water buffaloes (Bubalus bubalis) vaccinated with Brucella abortus strain RB51 vaccine.

    PubMed

    Tittarelli, Manuela; Atzeni, Marcello; Calistri, Paolo; Di Giannatale, Elisabetta; Ferri, Nicola; Marchi, Enrico; Martucciello, Alessandra; De Massis, Fabrizio

    2015-01-01

    The use of live vaccine strain RB51 for vaccination of domestic water buffaloes (Bubalus bubalis) at risk of infection with Brucella abortus is permitted notwithstanding the plans for the eradication and only under strict veterinary control. The antibodies induced by RB51 vaccination are not detectable using conventional diagnostic techniques; therefore, it is necessary to have a specific diagnostic tool able to discriminate vaccinated from unvaccinated animals. The combination of a complement fixation test (CFT) with specific RB51 antigen (RB51-CFT) and a brucellin skin test has been demonstrated to be a reliable diagnostic system to identify single cattle (Bos taurus) vaccinated with RB51. So far, no data are available in the international scientific literature regarding the use of this test association in water buffalo. For this reason the suitability of this test combination has been evaluated in a water buffalo herd. One hundred twenty-seven animals farmed in a herd of Salerno province (Campania, Southern Italy), in the context of a presumptive unauthorized use of RB51 vaccine were chosen for this study. All tested animals resulted negative to Rose Bengal test (RBT) and complement fixation test (CFT) used for the detection of specific antibodies against Brucella field strains. Seventy-one animals (56%) developed RB51 antigen-specific CFT (RB51-CFT) antibodies against RB51 vaccine in a first sampling, while 104 animals (82%) gave positive result to a second serum sampling conducted 11 days after the intradermal inoculation of the RB51 brucellin. One hundred and seven animals (84%) showed a positive reaction to the RB51-CFT in at least 1 sampling, while 111 animals (87%) resulted positive to the RB51 brucellin skin test. Thus, analysing the results of the 3 testing in parallel, 119 animals (94%) were positive to at least 1 of the performed tests. The results suggest that the use in parallel of the RB51 brucellin skin test with RB51-CFT may represent a reliable

  20. Immunogenic and antigenic activity of an experimental oral rabies vaccine prepared from the strain Vnukovo-32/107.

    PubMed

    Svrcek, S; Durove, A; Ondrejka, R; Závadová, J; Süliová, J; Benísek, Z; Vrtiak, O J; Feketeová, J; Mad'ar, M

    1995-03-01

    The immunogenic and antigenic activity of an experimental live oral rabies vaccine prepared from the strain Vnukovo-32/107 was evaluated on the basis of results obtained in 3 sets of experiments. These were carried out as model experiments on white mice, then on target animals--red foxes (Vulpes vulpes) and a related species--farm-bred polar foxes (Alopex lagopus). For quantitative determination of the immunogenic activity of the orally or subcutaneously administered rabies vaccines in model experiments on mice a method was used that had been developed in our laboratory. Antibodies were detected and quantified by an ELISA kit that had also been developed in our lab. Tenacity of the experimental vaccine (infectious tissue culture medium after yolk addition) was verified at different temperatures; the effects of storage temperature upon virus titre and immunogenic activity were investigated. An important part of the experiments--evaluation of the antigenic and immunogenic activity of the live vaccine at oral vaccination (vaccination baits, conditions simulating field vaccination) was carried out in foxes. The immunogenic activity (challenge experiments with a street virus on day 180 and 360 after vaccination) was evaluated in common foxes (Vulpes vulpes). The results document a high immunogenic and antigenic activity of the experimental live oral rabies vaccine. The strain Vnukovo-32/107 is suitable for the industrial manufacturing of vaccination baits. In the target species--common foxes challenged on day 180 after primovaccination an 83% protection was observed. Challenge on day 180 after revaccination (or day 360 after primovaccination), the orally immunized foxes proved to be 100% protected. For parallel evaluation of the immunogenic activity of an oral vaccine and for antibody titration it is recommended to employ the quantitative mice test and an ELISA technique, respectively. PMID:7762124

  1. Demystifying FluMist, a new intranasal, live influenza vaccine.

    PubMed

    Mossad, Sherif B

    2003-09-01

    FluMist--a cold-adapted, live-attenuated, trivalent, intranasal influenza virus vaccine approved by the US Food and Drug Administration on June 17, 2003--has been shown to be safe and effective, but its role in the general prevention of influenza is yet to be defined. Intranasal administration is expected to be more acceptable than parenteral, particularly in children, but the potential for the shedding of live virus may pose a risk to anyone with a compromised immune system. PMID:14518575

  2. Immune responses of infants to infection with respiratory viruses and live attenuated respiratory virus candidate vaccines.

    PubMed

    Crowe, J E

    1998-01-01

    Respiratory viruses such as respiratory syncytial virus (RSV), the parainfluenza viruses (PIV), and the influenza viruses cause severe lower respiratory tract diseases in infants and children throughout the world. Experimental live attenuated vaccines for each of these viruses are being developed for intranasal administration in the first weeks or months of life. A variety of promising RSV, PIV-3, and influenza virus vaccine strains have been developed by classical biological methods, evaluated extensively in preclinical and clinical studies, and shown to be attenuated and genetically stable. The ongoing clinical evaluation of these vaccine candidates, coupled with recent major advances in the ability to develop genetically engineered viruses with specified mutations, may allow the rapid development of respiratory virus strains that possess ideal levels of replicative capacity and genetic stability in vivo. A major remaining obstacle to successful immunization of infants against respiratory virus associated disease may be the relatively poor immune response of very young infants to primary virus infection. This paper reviews the immune correlates of protection against disease caused by these viruses, immune responses of infants to naturally-acquired infection, and immune responses of infants to experimental infection with candidate vaccine viruses. PMID:9711783

  3. A Novel Live Vector Group A Streptococcal emm Type 9 Vaccine Delivered Intranasally Protects Mice against Challenge Infection with emm Type 9 Group A Streptococci

    PubMed Central

    García, Patricia; Geoffroy, Enrique A.; Aguirre, Daniel B.; González, Samantha A.; Sarno, Victoria A.; Dale, James B.; Salazar-Echegarai, Francisco J.; Vera, Andrea; Bueno, Susan M.; Kalergis, Alexis M.

    2014-01-01

    The availability of a protective vaccine against Streptococcus pyogenes (group A Streptococcus [GAS]) is a priority for public health worldwide. Here, we have generated six live vaccine strains, each engineered to express an N-terminal M protein peptide from one of six of the most prevalent emm types of GAS (M1, M2, M4, M9, M12, and M28). The vaccine strains are based on a food-grade Lactococcus lactis strain and do not bear any antibiotic resistance. Mice immunized with the vaccine strain expressing the M9 peptide (termed here the L. lactis M9 strain) showed high titers of serum antibodies when delivered intranasally. Mice immunized with the L. lactis M9 strain were protected against infection after intranasal challenge with type 9 streptococci. Several parameters of disease, such as weight loss, body temperature, colony counts in mouth washes, and lung histology, were significantly improved in immunized mice compared to naive control mice. Our results indicate that intranasal delivery of the L. lactis M9 strain live bacterial vaccine induced GAS-specific IgG titers, prevented pharyngeal colonization of GAS, and protected mice from disease upon challenge. The design of this vaccine prototype may provide a lower cost alternative to vaccines comprised of purified recombinant proteins. PMID:25056362

  4. Safety tests with Flury HEP strain 675 in wild-living European mammals.

    PubMed

    Wachendörfer, G; Kiefert, C; Frost, J W

    1982-01-01

    For the evaluation of residual pathogenicity of Flury HEP strain 675, the vaccinal virus was orally administered to 207 animals belonging to 15 wild-living and 1 domestic species. Rabies virus antigen could be demonstrated by FA method in 20 animals. Reisolation of the virus was possible from 23 animals within the first two weeks after application, the titres being very low. During the observation period of 100 days no symptoms of rabies could be observed in the animals tested. PMID:7128066

  5. 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

  6. Live-attenuated influenza A virus vaccines using a B virus backbone

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The currently FDA-licensed live attenuated influenza virus vaccine contains a trivalent mixture of types A (H1N1 and H3N2) and B vaccine viruses. The two A virus vaccines have the backbone of a cold-adapted influenza A virus and the B virus vaccine has the six backbone segments derived from a cold-...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  8. Vector Development for the Expression of Foreign Proteins in the Vaccine Strain Brucella abortus S19

    PubMed Central

    Comerci, Diego J.; Pollevick, Guido D.; Vigliocco, Ana M.; Frasch, Alberto C. C.; Ugalde, Rodolfo A.

    1998-01-01

    A vector for the expression of foreign antigens in the vaccine strain Brucella abortus S19 was developed by using a DNA fragment containing the regulatory sequences and the signal peptide of the Brucella bcsp31 gene. This fragment was cloned in broad-host-range plasmid pBBR4MCS, resulting in plasmid pBEV. As a reporter protein, a repetitive antigen of Trypanosoma cruzi was used. The recombinant fusion protein is stably expressed and secreted into the Brucella periplasmic space, inducing a good antibody response against the T. cruzi antigen. The expression of the repetitive antigen in Brucella neither altered its growth pattern nor generated a toxic or lethal effect during experimental infection. The application of this strategy for the generation of live recombinant vaccines and the tagging of B. abortus S19 vaccine is discussed. This is the first time that a recombinant protein has been expressed in the periplasm of brucellae. PMID:9673273

  9. Maternal outcomes among pregnant women receiving live attenuated influenza vaccine

    PubMed Central

    Toback, Seth L.; Beigi, Richard; Tennis, Patricia; Sifakis, Frangiscos; Calingaert, Brian; Ambrose, Christopher S.

    2011-01-01

    Please cite this paper as: Toback et al. (2012) Maternal outcomes among pregnant women receiving live attenuated influenza accine. Influenza and Other Respiratory Viruses 6(1), 44–51. Background  Although the live attenuated influenza vaccine (LAIV) prescribing information contains warnings/precautions against use during pregnancy, administration of LAIV to pregnant women does occur. Data regarding maternal outcomes after LAIV administration during pregnancy are limited. Objectives  Maternal outcomes after LAIV vaccination during pregnancy were examined. Methods  Data from a health insurance claims database that covers approximately 50 million individuals were analyzed for the six influenza seasons from 2003–2004 through 2008–2009. Emergency department (ED) visits and hospitalizations occurring within 42 days of vaccination were analyzed by primary diagnosis; outcomes were categorized as cardiopulmonary, obstetric, and other. Cohort characteristics were analyzed using descriptive statistics. Results  Of 834 999 pregnancies identified, 138 (0·017%) were among women who received LAIV vaccinations. Of the 138 pregnant women, 13% were ≤19 years, 67% were 20–34 years, and 20% were ≥35 years of age. Eight events occurred within 42 days of vaccination: one ED visit for bronchitis, two hospitalizations for hyperemesis gravidarum and premature labor, and five ED visits/hospitalizations for common medical conditions. All outcomes identified after LAIV exposure occurred at rates similar to rates in unvaccinated pregnant women reported in the medical literature. Conclusions  Administration of LAIV to pregnant women is rare; the rate has remained constant since 2004–2005. In this cohort, there was no evidence of significant maternal adverse outcomes after receipt of LAIV. These data may offer some reassurance to providers and pregnant women in the event of inadvertent LAIV administration, but do not support the routine use of LAIV in

  10. 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

  11. 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

  12. 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

  13. H5N1 Vaccine-Specific B Cell Responses in Ferrets Primed with Live Attenuated Seasonal Influenza Vaccines

    PubMed Central

    Xu, Qi; Zhou, Helen; Kulkarni, Deepali; Subbarao, Kanta; Kemble, George; Jin, Hong

    2009-01-01

    Background Live attenuated influenza H5N1 vaccines have been produced and evaluated in mice and ferrets that were never exposed to influenza A virus infection (Suguitan et al., Plos Medicine, e360:1541, 2006). However, the preexisting influenza heterosubtypic immunity on live attenuated H5N1 vaccine induced immune response has not been evaluated. Methodology and Principal Findings Primary and recall B cell responses to live attenuated H5N1 vaccine viruses were examined using a sensitive antigen-specific B cell ELISpot assay to investigate the effect of preexisting heterosubtypic influenza immunity on the development of H5N1-specific B cell immune responses in ferrets. Live attenuated H5N1 A/Hong Kong/213/03 and A/Vietnam/1203/04 vaccine viruses induced measurable H5-specific IgM and IgG secreting B cells after intranasal vaccination. However, H5-specific IgG secreting cells were detected significantly earlier and at a greater frequency after H5N1 inoculation in ferrets previously primed with trivalent live attenuated influenza (H1N1, H3N2 and B) vaccine. Priming studies further revealed that the more rapid B cell responses to H5 resulted from cross-reactive B cell immunity to the hemagglutinin H1 protein. Moreover, vaccination with the H1N1 vaccine virus was able to induce protective responses capable of limiting replication of the H5N1 vaccine virus to a level comparable with prior vaccination with the H5N1 vaccine virus without affecting H5N1 vaccine virus induced antibody response. Conclusion The findings indicate that previous vaccination with seasonal influenza vaccine may accelerate onset of immunity by an H5N1 ca vaccine and the heterosubtypic immunity may be beneficial for pandemic preparedness. PMID:19209231

  14. Protection by novel vaccine candidates, Mycobacterium tuberculosis ΔmosR and ΔechA7, against challenge with a Mycobacterium tuberculosis Beijing strain.

    PubMed

    Marcus, Sarah A; Steinberg, Howard; Talaat, Adel M

    2015-10-13

    Mycobacterium tuberculosis, the etiological agent of tuberculosis (TB), infects over two billion people, claiming around 1.5 million lives annually. The only vaccine approved for clinical use against this disease is the Bacillus Calmette-Guérin (BCG) vaccine. Unfortunately, BCG has limited efficacy against the adult, pulmonary form of tuberculosis. This vaccine was developed from M. bovis with antigen expression and host specificity that differ from M. tuberculosis. To address these problems, we have designed two novel, live attenuated vaccine (LAV) candidates on an M. tuberculosis background: ΔmosR and ΔechA7. These targeted genes are important to M. tuberculosis pathogenicity during infection. To examine the efficacy of these strains, C57BL/6 mice were vaccinated subcutaneously with either LAV, BCG, or PBS. Both LAV strains persisted up to 16 weeks in the spleens or lungs of vaccinated mice, while eliciting minimal pathology prior to challenge. Following challenge with a selected, high virulence M. tuberculosis Beijing strain, protection was notably greater for both groups of LAV vaccinated animals as compared to BCG at both 30 and 60 days post-challenge. Additionally, vaccination with either ΔmosR or ΔechA7 elicited an immune response similar to BCG. Although these strains require further development to meet safety standards, this first evidence of protection by these two new, live attenuated vaccine candidates shows promise. PMID:26363381

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

    PubMed

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

    2013-12-01

    Nontyphoidal Salmonella (NTS) serovars are a common cause of acute food-borne gastroenteritis worldwide and can cause invasive systemic disease in young infants, the elderly, and immunocompromised hosts, accompanied by high case fatality. Vaccination against invasive NTS disease is warranted where the disease incidence and mortality are high and multidrug resistance is prevalent, as in sub-Saharan Africa. Live-attenuated vaccines that mimic natural infection constitute one strategy to elicit protection. However, they must particularly be shown to be adequately attenuated for consideration of immunocompromised subjects. Accordingly, we examined the safety and tolerability of an oral live attenuated Salmonella typhimurium vaccine candidate, CVD 1921, in an established chronic simian immunodeficiency virus (SIV)-infected rhesus macaque model. We evaluated clinical parameters, histopathology, and measured differences in mucosal permeability to wild-type and vaccine strains. Compared to the wild-type S. typhimurium strain I77 in both SIV-infected and SIV-uninfected nonhuman primate hosts, this live-attenuated vaccine shows reduced shedding and systemic spread, exhibits limited pathological disease manifestations in the digestive tract, and induces low levels of cellular infiltration in tissues. Furthermore, wild-type S. typhimurium induces increased intestinal epithelial damage and permeability, with infiltration of neutrophils and macrophages in both SIV-infected and SIV-uninfected nonhuman primates compared to the vaccine strain. Based on shedding, systemic spread, and histopathology, the live-attenuated S. typhimurium strain CVD 1921 appears to be safe and well-tolerated in the nonhuman primate model, including chronically SIV-infected rhesus macaques. PMID:24099872

  16. Differential Immune Responses and Protective Effects in Avirulent Mycobacterial Strains Vaccinated BALB/c Mice.

    PubMed

    Liu, Laicheng; Fu, Ruiling; Yuan, Xuefeng; Shi, Chunwei; Wang, Shuling; Lu, Xianyu; Ma, Zhao; Zhang, Xiaoming; Qin, Weiyan; Fan, Xionglin

    2015-07-01

    Screening live mycobacterial vaccine candidates is the important strategy to develop new vaccines against adult tuberculosis (TB). In this study, the immunogenicity and protective efficacy of several avirulent mycobacterial strains including Mycobacterium smegmatis, M. vaccae, M. terrae, M. phlei, M. trivial, and M. tuberculosis H37Ra were compared with M. bovis BCG in BALB/c mice. Our results demonstrated that differential immune responses were induced in different mycobacterial species vaccinated mice. As BCG-vaccinated mice did, M. terrae immunization resulted in Th1-type responses in the lung, as well as splenocytes secreting IFN-γ against a highly conserved mycobacterial antigen Ag85A. M. smegmatis also induced the same splenocytes secreting IFN-γ as BCG and M. terrae did. In addition, M. terrae and M. smegmatis-immunized mice predominantly increased expression of IL-10 and TGF-β in the lung. Most importantly, mice vaccinated with H37Ra and M. vaccae could provide the same protection in the lung against virulent M. tuberculosis challenge as BCG. The result may have important implications in developing adult TB vaccine. PMID:25995039

  17. Novel BVDV-2 mutants as new candidates for modified-live vaccines.

    PubMed

    Zemke, Johanna; König, Patricia; Mischkale, Katrin; Reimann, Ilona; Beer, Martin

    2010-04-21

    Protection against Bovine viral diarrhea virus (BVDV) type 2 infection of commercially available vaccines is often limited due to marked genetic and antigenic differences between BVDV types 1 (BVDV-1) and 2 (BVDV-2). Therefore, the immunogenicity of selected BVDV-1 and BVDV-2 mutants derived from infectious full-length cDNA clones and their use as modified-live vaccine candidates against challenge infection with a virulent heterologous BVDV-2 field isolate were investigated. Deletion mutants of BVDV-1 and BVDV-2 lacking a part of the N(pro) gene (BVDV-1DeltaN(pro)/BVDV-2DeltaN(pro)) were used as well as a packaged replicon with a deletion in the structural core protein encoding region (BVDV-2DeltaC-pseudovirions). The 25 calves used in this vaccination/challenge trial were allocated in five groups (n=5/group). One group received BVDV-1DeltaN(pro) (1 shot), one group BVDV-2DeltaN(pro) (1 shot), one group received both, BVDV-1DeltaN(pro) and BVDV-2DeltaN(pro) (1 shot), and one group was immunised with the BVDV-2DeltaC-pseudovirions (2 shots). The fifth group served as non-vaccinated control group. All groups were challenged intranasally with the BVDV-2 strain HI916 and monitored for signs of clinical disease, virus shedding and viremia. All tested BVDV vaccine candidates markedly reduced the outcome of the heterologous virulent BVDV-2 challenge infection showing graduated protective effects. The BVDV-2DeltaN(pro) mutant was able to induce complete protection and a "sterile immunity" upon challenge. Thus it represents a promising candidate for an efficacious future live vaccine. PMID:19875253

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

    PubMed

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

    2001-08-01

    By combining molecular-biological techniques with our increased understanding of the effect of gene sequence modification on viral function, yellow fever 17D, a positive-strand RNA virus vaccine, has been manipulated to induce a protective immune response against viruses of the same family (e.g. Japanese encephalitis and dengue viruses). Triggered by the emergence of West Nile virus infections in the New World afflicting humans, horses and birds, the success of this recombinant technology has prompted the rapid development of a live-virus attenuated candidate vaccine against West Nile virus. PMID:11516995

  19. On the Efficacy and Safety of Vaccination with Live Tachyzoites of Neospora caninum for Prevention of Neospora-Associated Fetal Loss in Cattle

    PubMed Central

    Jackson, James A.; Sobecki, Brian; Choromanski, Les; Olsen, Mary; Meinert, Todd; Frank, Rodney; Reichel, Michael P.; Ellis, John T.

    2013-01-01

    Infection of cattle with Neospora caninum may result in abortion or the birth of a congenitally infected calf. Vaccination with live N. caninum protects against experimental infection of cattle and mice, and the naturally attenuated Nc-Nowra strain of N. caninum is of particular interest as a potential vaccine candidate. Vaccination of heifers prior to breeding with live Nc-Nowra tachyzoites by either the subcutaneous or the intravenous route reduced the rate of abortion and the presence of the parasite in calves as determined by PCR and serology after infection of cows with a virulent isolate. Protected fractions were 55.6% to 85.2% depending on the route of vaccination and growth conditions of the vaccine strain, with cryopreserved Nc-Nowra tachyzoites being less effective, with a 25.9% protected fraction. Vaccination appeared to reduce the rate of pregnancy after artificial insemination in some groups compared to nonvaccinated, nonchallenged controls. One animal that was vaccinated but not challenged experienced an abortion, but Nc-Nowra could not be detected in any of the cows in this group or their progeny. This study confirms that live vaccination can be an effective method of preventing neosporosis in cattle and yet highlights the technical hurdle of preservation of live parasites that must be overcome for a vaccine to be commercially successful. PMID:23175289

  20. Propagation of the Israeli vaccine strain of Anaplasma centrale in tick cell lines.

    PubMed

    Bell-Sakyi, Lesley; Palomar, Ana M; Bradford, Emma L; Shkap, Varda

    2015-09-30

    Anaplasma centrale has been used in cattle as a live blood vaccine against the more pathogenic Anaplasma marginale for over 100 years. While A. marginale can be propagated in vitro in tick cell lines, facilitating studies on antigen production, immunisation and vector-pathogen interaction, to date there has been no in vitro culture system for A. centrale. In the present study, 25 cell lines derived from 13 ixodid tick species were inoculated with the Israeli vaccine strain of A. centrale and monitored for at least 12 weeks by microscopic examination of Giemsa-stained cytocentrifuge smears. Infection of 19 tick cell lines was subsequently attempted by transfer of cell-free supernate from vaccine-inoculated tick cells. In two separate experiments, rickettsial inclusions were detected in cultures of the Rhipicephalus appendiculatus cell line RAE25 28-32 days following inoculation with the vaccine. Presence of A. centrale in the RAE25 cells was confirmed by PCR assays targeting the 16S rRNA, groEL and msp4 genes; sequenced PCR products were 100% identical to published sequences of the respective genes in the Israeli vaccine strain of A. centrale. A. centrale was taken through three subcultures in RAE25 cells over a 30 week period. In a single experiment, the Dermacentor variabilis cell line DVE1 was also detectably infected with A. centrale 11 weeks after inoculation with the vaccine. Availability of an in vitro culture system for A. centrale in tick cells opens up the possibility of generating a safer and more ethical vaccine for bovine anaplasmosis. PMID:26210950

  1. Propagation of the Israeli vaccine strain of Anaplasma centrale in tick cell lines

    PubMed Central

    Bell-Sakyi, Lesley; Palomar, Ana M.; Bradford, Emma L.; Shkap, Varda

    2015-01-01

    Anaplasma centrale has been used in cattle as a live blood vaccine against the more pathogenic Anaplasma marginale for over 100 years. While A. marginale can be propagated in vitro in tick cell lines, facilitating studies on antigen production, immunisation and vector-pathogen interaction, to date there has been no in vitro culture system for A. centrale. In the present study, 25 cell lines derived from 13 ixodid tick species were inoculated with the Israeli vaccine strain of A. centrale and monitored for at least 12 weeks by microscopic examination of Giemsa-stained cytocentrifuge smears. Infection of 19 tick cell lines was subsequently attempted by transfer of cell-free supernate from vaccine-inoculated tick cells. In two separate experiments, rickettsial inclusions were detected in cultures of the Rhipicephalus appendiculatus cell line RAE25 28–32 days following inoculation with the vaccine. Presence of A. centrale in the RAE25 cells was confirmed by PCR assays targeting the 16S rRNA, groEL and msp4 genes; sequenced PCR products were 100% identical to published sequences of the respective genes in the Israeli vaccine strain of A. centrale. A. centrale was taken through three subcultures in RAE25 cells over a 30 week period. In a single experiment, the Dermacentor variabilis cell line DVE1 was also detectably infected with A. centrale 11 weeks after inoculation with the vaccine. Availability of an in vitro culture system for A. centrale in tick cells opens up the possibility of generating a safer and more ethical vaccine for bovine anaplasmosis. PMID:26210950

  2. Live attenuated simian immunodeficiency virus vaccination confers superinfection resistance against macrophage-tropic and neurovirulent wild-type SIV challenge

    PubMed Central

    Ham, Claire; Alden, Jack; Clarke, Sean; Stebbings, Richard; Stott, Jim; Ferguson, Deborah; Almond, Neil

    2015-01-01

    Vaccination with live attenuated simian immunodeficiency virus (SIV) in non-human primate species provides a means of characterizing the protective processes of retroviral superinfection and may lead to novel advances of human immunodeficiency virus (HIV)/AIDS vaccine design. The minimally attenuated SIVmacC8 vaccine has been demonstrated to elicit early potent protection against pathogenic rechallenge with genetically diverse viral isolates in cynomolgus macaques (Macaca fascicularis). In this study, we have characterized further the biological breadth of this vaccine protection by assessing the ability of both the nef-disrupted SIVmacC8 and its nef-intact counterpart SIVmacJ5 viruses to prevent superinfection with the macrophage/neurotropic SIVmac239/17E-Fr (SIVmac17E-Fr) isolate. Inoculation with either SIVmacC8 or SIVmacJ5 and subsequent detailed characterization of the viral replication kinetics revealed a wide range of virus–host outcomes. Both nef-disrupted and nef-intact immunizing viruses were able to prevent establishment of SIVmac17E-Fr in peripheral blood and secondary lymphoid tissues. Differences in virus kinetics, indicative of an active process, identified uncontrolled replication in one macaque which although able to prevent SIVmac17E-Fr superinfection led to extensive neuropathological complications. The ability to prevent a biologically heterologous, CD4-independent/CCR5+ viral isolate and the macrophage-tropic SIVmac316 strain from establishing infection supports the hypothesis that direct target cell blocking is unlikely to be a central feature of live lentivirus vaccination. These data provide further evidence to demonstrate that inoculation of a live retroviral vaccine can deliver broad spectrum protection against both macrophage-tropic as well as lymphocytotropic viruses. These data add to our knowledge of live attenuated SIV vaccines but further highlight potential safety concerns of vaccinating with a live retrovirus. PMID:25834093

  3. Development of a multivalent live vaccine active against a wide range of Enterobacteriaceae.

    PubMed

    Levi, B; Witz, I; Malkinson, M; Singer, N; Wiseman, Y; Ron, E Z

    1980-01-01

    We have constructed a deletion mutant of E. coli which lacks O-antigen - "deep rough". Living bacteria of this strain were injected repeatedly in high numbers into mice and chicks and in all cases were found to be completely harmless. In C3HeB mice, protection was obtained against a wide variety of enteric bacteria and was accompanied by an appreciable increase in titer of antibodies which cross react with LPS extracted from these bacteria. Preliminary experiments indicate that the vaccine provides protection against avian coli pathogens. PMID:7010371

  4. Combination of competitive exclusion and immunisation with a live Salmonella vaccine in newly hatched chickens: Immunological and microbiological effects.

    PubMed

    Braukmann, M; Barrow, P A; Berndt, A; Methner, U

    2016-08-01

    In addition to evaluating the efficacy potential of a combined use of vaccination and competitive exclusion (CE) against Salmonella exposure in chicks at 3-days of age, a live Salmonella Enteritidis vaccine (SE-LV) and a CE culture were tested for their ability to induce parameters of the innate immunity. Whereas the invasive SE-LV induced an influx of granulocytes and macrophages as well as an increased transcription of several cytokines in the caecal mucosa, the CE culture did not demonstrate any differences in these parameters compared to controls. It is therefore highly probable that the effects observed with CE cultures are not due to the rapid stimulation of the immune system. The combined use of both preparations did not result in an additive intestinal exclusion effect of the challenge strain more pronounced than that after single administration of the CE culture. The combined use of the Salmonella live vaccine and the CE culture resulted in an additive protective effect and prevented completely the systemic dissemination of the Salmonella challenge strain. To exploit the potential of combined use of CE and vaccination further and most effectively, live Salmonella vaccines are needed that are despite their attenuation in virulence still capable to induce both intestinal colonisation- and invasion-inhibition effects against Salmonella exposure. PMID:27473972

  5. Antibody response of cattle to vaccination with commercial modified live rabies vaccines in Guatemala.

    PubMed

    Gilbert, Amy; Greenberg, Lauren; Moran, David; Alvarez, Danilo; Alvarado, Marlon; Garcia, Daniel L; Peruski, Leonard

    2015-01-01

    Vampire bat rabies is a public and animal health concern throughout Latin America. As part of an ecological study of vampire bat depredation on cattle in southern Guatemala, we conducted a vaccine seroconversion study among three dairy farms. The main objectives of this cross sectional and cohort study were to understand factors associated with bat bites among cattle, to determine whether unvaccinated cattle had evidence of rabies virus exposure and evaluate whether exposure was related to bat bite prevalence, and to assess whether cattle demonstrate adequate seroconversion to two commercial vaccines used in Guatemala. In 2012, baseline blood samples were collected immediately prior to intramuscular inoculation of cattle with one of two modified live rabies vaccines. Post vaccination blood samples were collected 13 and 393 days later. Sera were tested for rabies virus neutralizing antibodies (rVNA) by the rapid fluorescent focus inhibition test (RFFIT). Across two years of study, 36% (254/702) of inspected cattle presented gross evidence of vampire bat bites. Individual cattle with a bat bite in 2012 were more likely have a bat bite in 2013. Prior to vaccination, 12% (42/350) of cattle sera demonstrated rVNA, but bite status in 2012 was not associated with presence of rVNA. Vaccine brand was the only factor associated with adequate rVNA response of cattle by day 13. However, vaccine brand and rVNA status at day 13 were associated with an adequate rVNA titer on day 393, with animals demonstrating an adequate titer at day 13 more likely to have an adequate titer at day 393. Our findings support stable levels of vampire bat depredation and evidence of rVNA in unvaccinated cattle. Brand of vaccine may be an important consideration impacting adequate rVNA response and long-term maintenance of rVNA in cattle. Further, the results demonstrate that initial response to vaccination is associated with rVNA status over one year following vaccination. PMID:25466762

  6. Genome sequence comparison of two United States live attenuated vaccines of infectious laryngotracheitis virus (ILTV).

    PubMed

    Chandra, Yohanna Gita; Lee, Jeongyoon; Kong, Byung-Whi

    2012-06-01

    This study was conducted to identify unique nucleotide differences in two U.S. chicken embryo origin (CEO) vaccines [LT Blen (GenBank accession: JQ083493) designated as vaccine 1; Laryngo-Vac(®) (GenBank accession: JQ083494) designated as vaccine 2] of infectious laryngotracheitis virus (ILTV) genomes compared to an Australian Serva vaccine reference ILTV genome sequence [Gallid herpesvirus 1 (GaHV-1); GenBank accession number: HQ630064]. Genomes of the two vaccine ILTV strains were sequenced using Illumina Genome Analyzer 2X of 36 cycles of single-end reads. Results revealed that few nucleotide differences (23 in vaccine 1; 31 in vaccine 2) were found and indicate that the US CEO strains are practically identical to the Australian Serva CEO strain, which is a European-origin vaccine. The sequence differences demonstrated the spectrum of variability among vaccine strains. Only eight amino acid differences were found in ILTV proteins including UL54, UL27, UL28, UL20, UL1, ICP4, and US8 in vaccine 1. Similarly, in vaccine 2, eight amino acid differences were found in UL54, UL27, UL28, UL36, UL1, ICP4, US10, and US8. Further comparison of US CEO vaccines to several ILTV genome sequences revealed that US CEO vaccines are genetically close to both the Serva vaccine and 63140/C/08/BR (GenBank accession: HM188407) and are distinct from the two Australian-origin CEO vaccines, SA2 (GenBank accession: JN596962) and A20 (GenBank accession: JN596963), which showed close similarity to each other. These data demonstrate the potential of high-throughput sequencing technology to yield insight into the sequence variation of different ILTV strains. This information can be used to discriminate between vaccine ILTV strains and further, to identify newly emerging mutant strains of field isolates. PMID:22382591

  7. Comparative efficacy and toxicity of a ribosomal vaccine, acetone-killed cells, lipopolysaccharide, and a live cell vaccine prepared from Salmonella typhhimurium.

    PubMed Central

    Angerman, C R; Eisenstein, T K

    1978-01-01

    The protective and toxic properties of a ribosomal vaccine prepared from Salmonella typhimurium W118-2 were systematicaly compared with those of an acetone-killed whole cell vaccine, purified lipopolysaccharide, and living cells in CD-1 mice. Tests of graded immunizing doses of each vaccine against several challenge doses of live strain W118-2 showed that, although the protection given by ribosomes approached the levels of protection conferred by living organisms, acetone-killed cells administered in appropriate dosages provided levels of protection comparable to that of ribosomes. Lipopolysaccharide was found to be significantly less protective than the other vaccines. On a dry-weight basis, ribosomes were the least toxic with a 50% toxic dose (TD50) of 5,000 microgram; acetone-killed cells had an intermediate TD50 of 1,400 microgram; and lipolysaccharide was the most toxic, with a TD50 of 320 microgram. The dose of each vaccine that protected 50% of the mice against a challenge of 1,00 times the 50% lethal dose was determined and divided by the TD50 to give the therapeutic index. This ratio also indicated that the ribosomes and acetone-killed cells were equally effective, whereas lipopolysaccharide was markedly inferior. PMID:344216

  8. Use of quadrivalent human papillomavirus vaccine and the prevalence of antibodies to vaccine-targeted strains among female service members before and after vaccination.

    PubMed

    Hurt, Lee; Nsouli-Maktabi, Hala; Rohrbeck, Patricia; Clark, Leslie L

    2016-02-01

    The quadrivalent human papillomavirus vaccine (HPV4) has been shown to generate a robust immune response among fully vaccinated individuals; however, among U.S. service members, HPV vaccine completion rates are low. This study compared the immunogenicity of HPV4 vaccine among partially and fully vaccinated service members at 4-6 years post-vaccination. A random sample was obtained of 2,091 female service members, aged 17-26 years, who received 1-3 HPV4 doses during 2006-2012, stratified by number of doses (one, two, or three). Pre- and post-immunization sera from these service members were tested for antibodies to the HPV strains covered by the vaccine. Prior to immunization 42% were seropositive for HPV strain 6; 34% for strain 11; 29% for strain 16; and 16% for strain 18. Among those naive to all four strains prior to immunization, there was 100% seroconversion after one, two, or three doses. The results indicate that many service members had already been exposed to strains of HPV prior to receiving the vaccine; however, seropositivity prevalence was lower for the oncogenic HPV strains 16 and 18. The data demonstrate sustained immunogenicity after a single dose of vaccine, with modest improvement with successive doses for all strains except 18. PMID:26930146

  9. Live Eimeria vaccination success in the face of artificial non-uniform vaccine administration in conventionally reared pullets.

    PubMed

    Price, Kayla R; Hafeez, Mian A; Bulfon, Julia; Barta, John R

    2016-01-01

    Live Eimeria vaccines against coccidiosis in poultry initiate immunity using a vaccine dose containing few oocysts; protection is enhanced through subsequent faecal-oral transmission ("cycling") of parasites in the poultry house. Spray-administered Eimeria vaccines can permit wide variations in doses ingested by individual chicks; some chicks may receive no primary vaccination at all. Consequently, protective immunity for the entire flock depends on successful environmental cycling of vaccine progeny. Pullets missing primary vaccination at day of age can become protected from coccidial challenge through cycling of vaccine progeny oocysts from vaccinated (V) cage mates. This study tested whether 40% cage floor coverage (CFC) with a durable material could improve protection against challenge in these "contact-vaccinated" (CV) or successfully V pullets. The six treatment groups tested were CV, V or sham-vaccinated pullets cage-reared on either 0% or 40% CFC. Oocyst output was measured separately for each group for 30 days following vaccine administration. Lesion scores, body weights and total oocyst outputs were measured to quantify protection at 30 days of age against single or mixed Eimeria species challenge infections. Use of 40% CFC to promote low-level oocyst cycling impacted the flock in two ways: (1) more uniform flock immunity was achieved in the 40% CFC (CV similar to V pullets) compared with 0% CFC and (2) protection was enhanced in the 40% CFC compared with the 0% CFC. The use of CFC is an easily adopted means of improving live Eimeria vaccination of caged pullets. PMID:26743571

  10. Immune responses of bison and efficacy after booster vaccination with Brucella abortus strain RB51

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thirty-one bison heifers were randomly assigned to saline (control; n=7) or single vaccination (n=24) with 1010 CFU of B. abortus strain RB51 (RB51). Some vaccinated bison were randomly selected for booster vaccination with 10**10 CFU of RB51 at 11 months after initial vaccination (n=16). When comp...

  11. Protective immunity induced by immunization with a live, cultured Anaplasma marginale strain

    PubMed Central

    Hammac, G. Kenitra; Ku, Pei-Shin; Galletti, Maria F.; Noh, Susan M.; Scoles, Glen A.; Palmer, Guy H.; Brayton, Kelly A.

    2014-01-01

    Despite significant economic losses resulting from infection with Anaplasma marginale, a tick-transmitted rickettsial pathogen of cattle, available vaccines provide, at best, only partial protection against clinical disease. The green-fluorescent protein expressing mutant of the A. marginale St. Maries strain is a live, marked vaccine candidate (AmStM-GFP1). To test whether AmStM-GFP is safe and provides clinical protection, a group of calves was vaccinated, and clinical parameters, including percent parasitized erythrocytes (PPE), packed cell volume (PCV) and days required to reach peak bacteremia, were measured following inoculation and following tick challenge with wild type St Maries strain (AmStM). These clinical parameters were compared to those obtained during infection with the A. marginale subsp. centrale vaccine strain (A. centrale) or wild type AmStM. AmStM-GFP resulted in similar clinical parameters to A. centrale, but had a lower maximum PPE, smaller drop in PCV and took longer to reach peak bacteremia than wild type AmStM. AmStM-GFP provided clinical protection, yielding a stable PCV and low bacteremia following challenge, whereas A. centrale only afforded partial clinical protection. PMID:23664994

  12. Burkholderia mallei CLH001 Attenuated Vaccine Strain Is Immunogenic and Protects against Acute Respiratory Glanders.

    PubMed

    Hatcher, Christopher L; Mott, Tiffany M; Muruato, Laura A; Sbrana, Elena; Torres, Alfredo G

    2016-08-01

    Burkholderia mallei is the causative agent of glanders, an incapacitating disease with high mortality rates in respiratory cases. Its endemicity and ineffective treatment options emphasize its public health threat and highlight the need for a vaccine. Live attenuated vaccines are considered the most viable vaccine strategy for Burkholderia, but single-gene-deletion mutants have not provided complete protection. In this study, we constructed the select-agent-excluded B. mallei ΔtonB Δhcp1 (CLH001) vaccine strain and investigated its ability to protect against acute respiratory glanders. Here we show that CLH001 is attenuated, safe, and effective at protecting against lethal B. mallei challenge. Intranasal administration of CLH001 to BALB/c and NOD SCID gamma (NSG) mice resulted in complete survival without detectable colonization or abnormal organ histopathology. Additionally, BALB/c mice intranasally immunized with CLH001 in a prime/boost regimen were fully protected against lethal challenge with the B. mallei lux (CSM001) wild-type strain. PMID:27271739

  13. 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

  14. Efficacy of HVT-IBD vector vaccine compared to attenuated live vaccine using in-ovo vaccination against a Korean very virulent IBDV in commercial broiler chickens.

    PubMed

    Roh, J-H; Kang, M; Wei, B; Yoon, R-H; Seo, H-S; Bahng, J-Y; Kwon, J-T; Cha, S-Y; Jang, H-K

    2016-05-01

    The production performance, efficacy, and safety of two types of vaccines for infectious bursal disease virus (IBDV) were compared with in-ovo vaccination of Cobb 500 broiler chickens for gross and microscopic examination of the bursa of Fabricius, bursa/body weight (b/B) ratio, flow cytometry, and serologic response to Newcastle disease virus (NDV) vaccination. One vaccine was a recombinant HVT-IBD vector vaccine (HVT as for herpesvirus of turkeys) and the other was an intermediate plus live IBDV vaccine. A significant difference was detected at 21 d. Eight of 10 chickens that received the IBDV live vaccine had severe bursal lesions and a relatively low b/B ratio of 0.95, and an inhibited NDV vaccine response. On the other hand, the HVT-IBD vector vaccine resulted in mild bursal lesions and a b/B ratio of 1.89. Therefore, the live vaccine had lower safety than that of the HVT-IBD vector vaccine. To determine the protective efficacy, chickens were intraocularly challenged at 24 d. Eight of 10 chickens in the IBDV live vaccination group showed gross and histological lesions characterized by hemorrhage, cyst formation, lymphocytic depletion, and a decreased b/B ratio. In contrast, the HVT-IBD vector vaccinated chickens showed mild gross and histological lesions in three of 10 chickens with a b/B ratio of 1.36, which was similar to that of the unchallenged controls. Vaccinated chickens showed a significant increase in IBDV antibody titers, regardless of the type of vaccine used. In addition, significantly better broiler flock performance was observed with the HVT-IBD vector vaccine compared to that of the live vaccine. Our results revealed that the HVT-IBD vector vaccine could be used as an alternative vaccine to increase efficacy, and to have an improved safety profile compared with the IBDV live vaccine using in-ovo vaccination against the Korean very virulent IBDV in commercial broiler chickens. PMID:26944964

  15. Live attenuated influenza vaccine provides superior protection from heterologous infection in pigs with maternal antibodies without inducing vaccine-associated enhanced respiratory disease.

    PubMed

    Vincent, Amy L; Ma, Wenjun; Lager, Kelly M; Richt, Jürgen A; Janke, Bruce H; Sandbulte, Matthew R; Gauger, Philip C; Loving, Crystal L; Webby, Richard J; García-Sastre, Adolfo

    2012-10-01

    Control of swine influenza A virus (IAV) in the United States is hindered because inactivated vaccines do not provide robust cross-protection against the multiple antigenic variants cocirculating in the field. Vaccine efficacy can be limited further for vaccines administered to young pigs that possess maternally derived immunity. We previously demonstrated that a recombinant A/sw/Texas/4199-2/1998 (TX98) (H3N2) virus expressing a truncated NS1 protein is attenuated in swine and has potential for use as an intranasal live attenuated influenza virus (LAIV) vaccine. In the present study, we compared 1 dose of intranasal LAIV with 2 intramuscular doses of TX98 whole inactivated virus (WIV) with adjuvant in weanling pigs with and without TX98-specific maternally derived antibodies (MDA). Pigs were subsequently challenged with wild-type homologous TX98 H3N2 virus or with an antigenic variant, A/sw/Colorado/23619/1999 (CO99) (H3N2). In the absence of MDA, both vaccines protected against homologous TX98 and heterologous CO99 shedding, although the LAIV elicited lower hemagglutination inhibition (HI) antibody titers in serum. The efficacy of both vaccines was reduced by the presence of MDA; however, WIV vaccination of MDA-positive pigs led to dramatically enhanced pneumonia following heterologous challenge, a phenomenon known as vaccine-associated enhanced respiratory disease (VAERD). A single dose of LAIV administered to MDA-positive pigs still provided partial protection from CO99 and may be a safer vaccine for young pigs under field conditions, where dams are routinely vaccinated and diverse IAV strains are in circulation. These results have implications not only for pigs but also for other influenza virus host species. PMID:22811541

  16. Cytokine responses in camels (Camelus bactrianus) vaccinated with Brucella abortus strain 19 vaccine.

    PubMed

    Odbileg, Raadan; Purevtseren, Byambaa; Gantsetseg, Dorj; Boldbaatar, Bazartseren; Buyannemekh, Tumurjav; Galmandakh, Zagd; Erdenebaatar, Janchivdorj; Konnai, Satoru; Onuma, Misao; Ohashi, Kazuhiko

    2008-02-01

    In the present study, we determined the levels of cytokines produced by camel (Camelus bactrianus) peripheral blood mononuclear cells (PBMCs) in response to live attenuated Brucella abortus (B. abortus) S19 vaccine. Seven camels were vaccinated with commercial B. abortus S19 vaccine, and their cytokine responses were determined using a real-time PCR assay. Cytokine responses to B. abortus S19 were examined at 6 hr, 48 hr and 1, 2 and 3 weeks post-vaccination. Serological tests were performed to further confirm these immune responses. The results revealed that IFN-gamma and IL-6 were upregulated during the first week post-vaccination. Low level expressions of IL-1alpha, IL-1beta, TNFalpha and IL-10 and no expression of IL-2 and IL-4 were observed compared with the control camels. The findings showed that B. abortus stimulates cell-mediated immunity by directly activating camel Th1 cells to secrete IFN-gamma. This quantification of cytokine expression in camels is essential for understanding of Camelidae disease development and protective immune responses. This is the first report of in vivo camel cytokine quantification after vaccination. PMID:18319583

  17. Clinical Trial of an Oral Live Shigella sonnei Vaccine Candidate, WRSS1, in Thai Adults

    PubMed Central

    Islam, Dilara; Chamnanchanunt, Supat; Ruamsap, Nattaya; Khantapura, Patchariya; Kaewkungwal, Jaranit; Kittitrakul, Chatporn; Luvira, Viravarn; Dhitavat, Jittima; Venkatesan, Malabi M.; Mason, Carl J.; Bodhidatta, Ladaporn

    2016-01-01

    Live attenuated Shigella sonnei vaccine candidate WRSS1, previously tested in U.S. and Israeli volunteers, was evaluated in a population of adult Thai volunteers in which the organism is endemic. In a randomized placebo-controlled, double-blind design, inpatient participants received a single oral dose of 1.6 × 104 CFU of WRSS1. The vaccine was generally well tolerated, with equal numbers of vaccinees and placebo controls showing mild symptoms. Only 3 of 13 vaccinees (23%) had culture-positive stools, while a total of 9 vaccinees were positive by PCR. Lack of vaccine shedding in volunteers correlated with lack of clinical symptoms and immune responses, just as the duration of fecal shedding correlated directly with stronger immune responses. Two months following immunization, 10 vaccinees and 10 newly recruited naive controls received a challenge dose of 1,670 CFU of virulent S. sonnei strain 53G. This dose had previously demonstrated a 75% attack rate for dysentery in Thai volunteers. However, in this study the attack rate for dysentery in naive controls after challenge was 20%. Based on clinical record summaries, 3 vaccinees and 5 naive controls experienced clinically relevant illness (diarrhea/dysentery/fever/shigellosis), and a 40% vaccine efficacy was calculated. When these data are compared to those for the performance of this vaccine candidate in more naive populations, it is clear that a single oral dose of WRSS1 at 104 CFU failed to achieve its full potential in a population in which the organism is endemic. Higher doses and/or repeated immunizations may contribute to improved vaccine shedding and consequent elevation of protective immune responses in a population in which the organism is endemic. (The study has been registered at ClinicalTrials.gov under registration no. NCT01080716.) PMID:27146000

  18. Clinical Trial of an Oral Live Shigella sonnei Vaccine Candidate, WRSS1, in Thai Adults.

    PubMed

    Pitisuttithum, Punnee; Islam, Dilara; Chamnanchanunt, Supat; Ruamsap, Nattaya; Khantapura, Patchariya; Kaewkungwal, Jaranit; Kittitrakul, Chatporn; Luvira, Viravarn; Dhitavat, Jittima; Venkatesan, Malabi M; Mason, Carl J; Bodhidatta, Ladaporn

    2016-07-01

    Live attenuated Shigella sonnei vaccine candidate WRSS1, previously tested in U.S. and Israeli volunteers, was evaluated in a population of adult Thai volunteers in which the organism is endemic. In a randomized placebo-controlled, double-blind design, inpatient participants received a single oral dose of 1.6 × 10(4) CFU of WRSS1. The vaccine was generally well tolerated, with equal numbers of vaccinees and placebo controls showing mild symptoms. Only 3 of 13 vaccinees (23%) had culture-positive stools, while a total of 9 vaccinees were positive by PCR. Lack of vaccine shedding in volunteers correlated with lack of clinical symptoms and immune responses, just as the duration of fecal shedding correlated directly with stronger immune responses. Two months following immunization, 10 vaccinees and 10 newly recruited naive controls received a challenge dose of 1,670 CFU of virulent S. sonnei strain 53G. This dose had previously demonstrated a 75% attack rate for dysentery in Thai volunteers. However, in this study the attack rate for dysentery in naive controls after challenge was 20%. Based on clinical record summaries, 3 vaccinees and 5 naive controls experienced clinically relevant illness (diarrhea/dysentery/fever/shigellosis), and a 40% vaccine efficacy was calculated. When these data are compared to those for the performance of this vaccine candidate in more naive populations, it is clear that a single oral dose of WRSS1 at 10(4) CFU failed to achieve its full potential in a population in which the organism is endemic. Higher doses and/or repeated immunizations may contribute to improved vaccine shedding and consequent elevation of protective immune responses in a population in which the organism is endemic. (The study has been registered at ClinicalTrials.gov under registration no. NCT01080716.). PMID:27146000

  19. A Wide Extent of Inter-Strain Diversity in Virulent and Vaccine Strains of Alphaherpesviruses

    PubMed Central

    Szpara, Moriah L.; Tafuri, Yolanda R.; Parsons, Lance; Shamim, S. Rafi; Verstrepen, Kevin J.; Legendre, Matthieu; Enquist, L. W.

    2011-01-01

    Alphaherpesviruses are widespread in the human population, and include herpes simplex virus 1 (HSV-1) and 2, and varicella zoster virus (VZV). These viral pathogens cause epithelial lesions, and then infect the nervous system to cause lifelong latency, reactivation, and spread. A related veterinary herpesvirus, pseudorabies (PRV), causes similar disease in livestock that result in significant economic losses. Vaccines developed for VZV and PRV serve as useful models for the development of an HSV-1 vaccine. We present full genome sequence comparisons of the PRV vaccine strain Bartha, and two virulent PRV isolates, Kaplan and Becker. These genome sequences were determined by high-throughput sequencing and assembly, and present new insights into the attenuation of a mammalian alphaherpesvirus vaccine strain. We find many previously unknown coding differences between PRV Bartha and the virulent strains, including changes to the fusion proteins gH and gB, and over forty other viral proteins. Inter-strain variation in PRV protein sequences is much closer to levels previously observed for HSV-1 than for the highly stable VZV proteome. Almost 20% of the PRV genome contains tandem short sequence repeats (SSRs), a class of nucleic acids motifs whose length-variation has been associated with changes in DNA binding site efficiency, transcriptional regulation, and protein interactions. We find SSRs throughout the herpesvirus family, and provide the first global characterization of SSRs in viruses, both within and between strains. We find SSR length variation between different isolates of PRV and HSV-1, which may provide a new mechanism for phenotypic variation between strains. Finally, we detected a small number of polymorphic bases within each plaque-purified PRV strain, and we characterize the effect of passage and plaque-purification on these polymorphisms. These data add to growing evidence that even plaque-purified stocks of stable DNA viruses exhibit limited sequence

  20. Lactic acid bacteria--20 years exploring their potential as live vectors for mucosal vaccination.

    PubMed

    Wyszyńska, Agnieszka; Kobierecka, Patrycja; Bardowski, Jacek; Jagusztyn-Krynicka, Elżbieta Katarzyna

    2015-04-01

    Lactic acid bacteria (LAB) are a diverse group of Gram-positive, nonsporulating, low G + C content bacteria. Many of them have been given generally regarded as safe status. Over the past two decades, intensive genetic and molecular research carried out on LAB, mainly Lactococcus lactis and some species of the Lactobacillus genus, has revealed new, potential biomedical LAB applications, including the use of LAB as adjuvants, immunostimulators, or therapeutic drug delivery systems, or as factories to produce therapeutic molecules. LAB enable immunization via the mucosal route, which increases effectiveness against pathogens that use the mucosa as the major route of entry into the human body. In this review, we concentrate on the encouraging application of Lactococcus and Lactobacillus genera for the development of live mucosal vaccines. First, we present the progress that has recently been made in the field of developing tools for LAB genetic manipulations, which has resulted in the successful expression of many bacterial, parasitic, and viral antigens in LAB strains. Next, we discuss the factors influencing the efficacy of the constructed vaccine prototypes that have been tested in various animal models. Apart from the research focused on an application of live LABs as carriers of foreign antigens, a lot of work has been recently done on the potential usage of nonliving, nonrecombinant L. lactis designated as Gram-positive enhancer matrix (GEM), as a delivery system for mucosal vaccination. The advantages and disadvantages of both strategies are also presented. PMID:25750046

  1. Safety and vaccine efficacy of a glycoprotein G deficient strain of infectious laryngotracheitis virus delivered in ovo.

    PubMed

    Legione, Alistair R; Coppo, Mauricio J C; Lee, Sang-Won; Noormohammadi, Amir H; Hartley, Carol A; Browning, Glenn F; Gilkerson, James R; O'Rourke, Denise; Devlin, Joanne M

    2012-11-26

    Infectious laryngotracheitis virus (ILTV), an alphaherpesvirus, causes respiratory disease in chickens and is commonly controlled by vaccination with conventionally attenuated vaccines. Glycoprotein G (gG) is a virulence factor in ILTV and a gG deficient strain of ILTV (ΔgG-ILTV) has shown potential for use as a vaccine. In the poultry industry vaccination via drinking water is common, but technology is now available to allow quicker and more accurate in ovo vaccination of embryos at 18 days of incubation. In this study ΔgG-ILTV was delivered to chicken embryos at three different doses (10(2), 10(3) and 10(4) plaque forming units per egg) using manual in ovo vaccination. At 20 days after hatching, birds were challenged intra-tracheally with wild type ILTV and protection was measured. In ovo vaccination was shown to be safe, as there were no developmental differences between birds from hatching up to 20 days of age, as measured by weight gain. The highest dose of vaccine was the most efficacious, resulting in a weight gain not significantly different from unvaccinated/unchallenged birds seven days after challenge. In contrast, birds vaccinated with the lowest dose showed weight gains not significantly different from unvaccinated/challenged birds. Gross pathology and histopathology of the trachea reflected these observations, with birds vaccinated with the highest dose having less severe lesions. However, qPCR results suggested the vaccine did not prevent the challenge virus replicating in the trachea. This study is the first to assess in ovo delivery of a live attenuated ILTV vaccine and shows that in ovo vaccination with ΔgG-ILTV can be both safe and efficacious. PMID:23084851

  2. Bovine herpesvirus-1: Genetic diversity of field strains from cattle with respiratory disease, genital, fetal disease and systemic neonatal disease and their relationship to vaccine strains.

    PubMed

    Fulton, R W; d'Offay, J M; Dubovi, E J; Eberle, R

    2016-09-01

    Bovine herpesvirus-1 (BoHV-1) causes disease in cattle with varied clinical forms. In the U.S. there are two BoHV1 subtypes, BoHV-1.1 and BoHV-1.2b. Control programs in North America incorporate modified live (MLV) or killed (KV) viral vaccines. However, BoHV-1 strains continue to be isolated from diseased animals or fetuses after vaccination. It is possible to differentiate BoHV-1 wild-type from MLV vaccine strains by determining their single nucleotide polymorphism (SNP) patterns through either whole-genome sequencing or PCR sequencing of genomic regions containing vaccine-defining SNPs. To determine the BoHV-1 subtype in clinical isolates and their relationship to MLV strains, 8 isolates from varied clinical disease at three different laboratories in the U.S. were sequenced and phylogenetically analyzed. Five samples were isolated within the past 5 years from New York and 3 were archived samples recovered 35 years prior from Oklahoma and Louisiana. Based on phylogenetic analysis, four of the cases appeared to be due to an MLV vaccine: 3 cases of aborted fetuses and one neonate with systemic BoHV-1 disease. One aborted fetus was from a herd with no reported history of MLV vaccination in two years. The remaining four isolates did not group with any MLV vaccines: two were associated with bovine respiratory disease, one with vulvovaginitis, and a fourth was determined to be a BoHV-1.2b respiratory isolate. Recovery of BoHV-1.1 that is very closely related to an MLV vaccine virus from a herd not receiving vaccines in an extended period prior to its isolation suggests that MLV viruses may remain latent or circulate within herds for long periods. PMID:27374060

  3. Use of antigenic cartography in vaccine seed strain selection.

    PubMed

    Fouchier, Ron A M; Smith, Derek J

    2010-03-01

    Human influenza A viruses are classic examples of antigenically variable pathogens that have a seemingly endless capacity to evade the host's immune response. The viral hemagglutinin (HA) and neuraminidase (NA) proteins are the main targets of our antibody response to combat infections. HA and NA continuously change to escape from humoral immunity, a process known as antigenic drift. As a result of antigenic drift, the human influenza vaccine is updated frequently. The World Health Organization (WHO) coordinates a global influenza surveillance network that, by the hemagglutination inhibition (HI) assay, routinely characterizes the antigenic properties of circulating strains in order to select new seed viruses for such vaccine updates. To facilitate a quantitative interpretation and easy visualization of HI data, a new computational technique called "antigenic cartography" was developed. Since its development, antigenic cartography has been applied routinely to assist the WHO with influenza surveillance activities. Until recently, antigenic variation was not considered a serious issue with influenza vaccines for poultry. However, because of the diversification of the Asian H5N1 lineage since 1996 into multiple genetic clades and subclades, and because of the long-term use of poultry vaccines against H5 in some parts of the world, this issue needs to be re-addressed. The antigenic properties of panels of avian H5N1 viruses were characterized by HI assay, using mammalian or avian antisera, and analyzed using antigenic cartography methods. These analyses revealed antigenic differences between circulating H5N1 viruses and the H5 viruses used in poultry vaccines. Considerable antigenic variation was also observed within and between H5N1 clades. These observations have important implications for the efficacy and long-term use of poultry vaccines. PMID:20521635

  4. In ovo vaccination of commercial broilers with a glycoprotein J gene-deleted strain of infectious laryngotracheitis virus.

    PubMed

    Mashchenko, Anna; Riblet, Sylva M; Zavala, Guillermo; García, Maricarmen

    2013-06-01

    Conventional live attenuated vaccines have been used as the main tool worldwide for the control of infectious laryngotracheitis. However, their suboptimal attenuation combined with poor mass administration practices allowed chicken embryo origin vaccine-derived isolates to circulate in the field, regain virulence, and be the cause of continuous outbreaks of the disease. Previous studies indicated that stable attenuation of infectious laryngotracheitis virus (ILTV) can be achieved by the deletion of individual viral genes that are not essential for viral replication in vitro. One of these genes is the glycoprotein J (gJ) gene. Its deletion provided significant attenuation to virulent ILTV strains from Europe and the United States. The objective of this study was to construct an attenuated gJ-deleted ILTV strain and evaluate its safety and efficacy for in ovo (IO) administration of commercial broilers. A novel gJ-deleted virus (N(delta)gJ) was constructed, and a 10(3) median tissue culture infective dose administered at 18 days of embryo age was considered safe because it did not affect hatchability or survivability of chickens during the first week posthatch. Broilers vaccinated IO and IO + eye drop at 14 days of age presented a significant reduction in clinical signs and reduction of virus loads after challenge, as compared with the nonvaccinated challenged group of chickens. Therefore, this study presents initial proof that the N(delta)gJ strain is a potential ILTV live-attenuated vaccine candidate suitable for IO vaccination of commercial broilers. PMID:23901771

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

    PubMed Central

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

    2014-01-01

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

  6. Recombinant infectious bronchitis virus (IBV) H120 vaccine strain expressing the hemagglutinin-neuraminidase (HN) protein of Newcastle disease virus (NDV) protects chickens against IBV and NDV challenge.

    PubMed

    Yang, Xin; Zhou, Yingshun; Li, Jianan; Fu, Li; Ji, Gaosheng; Zeng, Fanya; Zhou, Long; Gao, Wenqian; Wang, Hongning

    2016-05-01

    Infectious bronchitis (IB) and Newcastle disease (ND) are common viral diseases of chickens, which are caused by infectious bronchitis virus (IBV) and Newcastle disease virus (NDV), respectively. Vaccination with live attenuated strains of IBV-H120 and NDV-LaSota are important for the control of IB and ND. However, conventional live attenuated vaccines are expensive and result in the inability to differentiate between infected and vaccinated chickens. Therefore, there is an urgent need to develop new efficacious vaccines. In this study, using a previously established reverse genetics system, we generated a recombinant IBV virus based on the IBV H120 vaccine strain expressing the haemagglutinin-neuraminidase (HN) protein of NDV. The recombinant virus, R-H120-HN/5a, exhibited growth dynamics, pathogenicity and viral titers that were similar to those of the parental IBV H120, but it had acquired hemagglutination activity from NDV. Vaccination of SPF chickens with the R-H120-HN/5a virus induced a humoral response at a level comparable to that of the LaSota/H120 commercial bivalent vaccine and provided significant protection against challenge with virulent IBV and NDV. In summary, the results of this study indicate that the IBV H120 strain could serve as an effective tool for designing vaccines against IB and other infectious diseases, and the generation of IBV R-H120-HN/5a provides a solid foundation for the development of an effective bivalent vaccine against IBV and NDV. PMID:26873815

  7. Association of serum antibody levels following vaccination with a modified live BVDV vaccine and protection from clinical disease upon challenge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    : Measurements of antigen specific serum antibodies following vaccination of cattle with a modified live vaccine (MLV) were conducted to examine the range of responses elicited against bovine viral diarrhea virus type 2 (BVDV2). Cattle averaging 130 weeks of age were housed in a commercial setting ...

  8. Avian pathogenic Escherichia coli ΔtonB mutants are safe and protective live-attenuated vaccine candidates.

    PubMed

    Holden, Karen M; Browning, Glenn F; Noormohammadi, Amir H; Markham, Philip; Marenda, Marc S

    2014-10-10

    Avian pathogenic Escherichia coli (APEC) cause colibacillosis, a serious respiratory disease in poultry. Most APEC strains possess TonB-dependent outer membrane transporters for the siderophores salmochelin and aerobactin, which both contribute to their capacity to cause disease. To assess the potential of iron transport deficient mutants as vaccine candidates, the tonB gene was deleted in the APEC wild type strain E956 and a Δfur (ferric uptake repressor) mutant of E956. The growth of the ΔtonB and ΔtonB/Δfur mutants was impaired in iron-restricted conditions, but not in iron-replete media. Day old chicks were exposed to aerosols of the mutants to assess their efficacy as live attenuated vaccines. At day 18, the birds were challenged with aerosols of the virulent parent strain E956. Both mutants conferred protection against colibacillosis; weight gains and lesion scores were significantly different between the vaccinated groups and an unvaccinated challenged control group. Thus mutation of iron uptake systems can be used as a platform technology to generate protective live attenuated vaccines against extraintestinal E. coli infections, and potentially a range of Gram negative pathogens of importance in veterinary medicine. PMID:25205199

  9. Refined Live Attenuated Salmonella enterica Serovar Typhimurium and Enteritidis Vaccines Mediate Homologous and Heterologous Serogroup Protection in Mice

    PubMed Central

    Schmidlein, Patrick; Simon, Raphael; Pasetti, Marcela F.; Galen, James E.; Levine, Myron M.

    2015-01-01

    Invasive nontyphoidal Salmonella (NTS) infections constitute a major health problem among infants and toddlers in sub-Saharan Africa; these infections also occur in infants and the elderly in developed countries. We genetically engineered a Salmonella enterica serovar Typhimurium strain of multilocus sequence type 313, the predominant genotype circulating in sub-Saharan Africa. We evaluated the capacities of S. Typhimurium and Salmonella enterica serovar Enteritidis ΔguaBA ΔclpX live oral vaccines to protect mice against a highly lethal challenge dose of the homologous serovar and determined protection against other group B and D serovars circulating in sub-Saharan Africa. The vaccines S. Typhimurium CVD 1931 and S. Enteritidis CVD 1944 were immunogenic and protected BALB/c mice against 10,000 50% lethal doses (LD50) of S. Typhimurium or S. Enteritidis, respectively. S. Typhimurium CVD 1931 protected mice against the group B serovar Salmonella enterica serovar Stanleyville (91% vaccine efficacy), and S. Enteritidis CVD 1944 protected mice against the group D serovar Salmonella enterica serovar Dublin (85% vaccine efficacy). High rates of survival were observed when mice were infected 12 weeks postimmunization, indicating that the vaccines elicited long-lived protective immunity. Whereas CVD 1931 did not protect against S. Enteritidis R11, CVD 1944 did mediate protection against S. Typhimurium D65 (81% efficacy). These findings suggest that a bivalent (S. Typhimurium and S. Enteritidis) vaccine would provide broad protection against the majority of invasive NTS infections in sub-Saharan Africa. PMID:26351285

  10. Refined live attenuated Salmonella enterica serovar Typhimurium and Enteritidis vaccines mediate homologous and heterologous serogroup protection in mice.

    PubMed

    Tennant, Sharon M; Schmidlein, Patrick; Simon, Raphael; Pasetti, Marcela F; Galen, James E; Levine, Myron M

    2015-12-01

    Invasive nontyphoidal Salmonella (NTS) infections constitute a major health problem among infants and toddlers in sub-Saharan Africa; these infections also occur in infants and the elderly in developed countries. We genetically engineered a Salmonella enterica serovar Typhimurium strain of multilocus sequence type 313, the predominant genotype circulating in sub-Saharan Africa. We evaluated the capacities of S. Typhimurium and Salmonella enterica serovar Enteritidis ΔguaBA ΔclpX live oral vaccines to protect mice against a highly lethal challenge dose of the homologous serovar and determined protection against other group B and D serovars circulating in sub-Saharan Africa. The vaccines S. Typhimurium CVD 1931 and S. Enteritidis CVD 1944 were immunogenic and protected BALB/c mice against 10,000 50% lethal doses (LD50) of S. Typhimurium or S. Enteritidis, respectively. S. Typhimurium CVD 1931 protected mice against the group B serovar Salmonella enterica serovar Stanleyville (91% vaccine efficacy), and S. Enteritidis CVD 1944 protected mice against the group D serovar Salmonella enterica serovar Dublin (85% vaccine efficacy). High rates of survival were observed when mice were infected 12 weeks postimmunization, indicating that the vaccines elicited long-lived protective immunity. Whereas CVD 1931 did not protect against S. Enteritidis R11, CVD 1944 did mediate protection against S. Typhimurium D65 (81% efficacy). These findings suggest that a bivalent (S. Typhimurium and S. Enteritidis) vaccine would provide broad protection against the majority of invasive NTS infections in sub-Saharan Africa. PMID:26351285

  11. Arenavirus Genome Rearrangement for the Development of Live Attenuated Vaccines

    PubMed Central

    Cheng, Benson Yee Hin; Ortiz-Riaño, Emilio

    2015-01-01

    ABSTRACT Several members of the Arenaviridae family cause hemorrhagic fever disease in humans and pose serious public health problems in their geographic regions of endemicity as well as a credible biodefense threat. To date, there have been no FDA-approved arenavirus vaccines, and current antiarenaviral therapy is limited to an off-label use of ribavirin that is only partially effective. Arenaviruses are enveloped viruses with a bisegmented negative-stranded RNA genome. Each genome segment uses an ambisense coding strategy to direct the synthesis of two viral polypeptides in opposite orientations, separated by a noncoding intergenic region. Here we have used minigenome-based approaches to evaluate expression levels of reporter genes from the nucleoprotein (NP) and glycoprotein precursor (GPC) loci within the S segment of the prototypic arenavirus lymphocytic choriomeningitis virus (LCMV). We found that reporter genes are expressed to higher levels from the NP than from the GPC locus. Differences in reporter gene expression levels from the NP and GPC loci were confirmed with recombinant trisegmented LCM viruses. We then used reverse genetics to rescue a recombinant LCMV (rLCMV) containing a translocated viral S segment (rLCMV/TransS), where the viral NP and GPC open reading frames replaced one another. The rLCMV/TransS showed slower growth kinetics in cultured cells and was highly attenuated in vivo in a mouse model of lethal LCMV infection, but immunization with rLCMV/TransS conferred complete protection against a lethal challenge with wild-type LCMV. Attenuation of rLCMV/TransS was associated with reduced NP expression levels. These results open a new avenue for the development of arenavirus live attenuated vaccines based on rearrangement of their viral genome. IMPORTANCE Several arenaviruses cause severe hemorrhagic fever in humans and also pose a credible bioterrorism threat. Currently, no FDA-licensed vaccines are available to combat arenavirus infections and

  12. Comparative safety, immunogenicity, and efficacy of several anti‐H5N1 influenza experimental vaccines in a mouse and chicken models (Testing of killed and live H5 vaccine)

    PubMed Central

    Gambaryan, Alexandra S.; Lomakina, Natalia F.; Boravleva, Elizaveta Y.; Kropotkina, Ekaterina A.; Mashin, Vadim V.; Krasilnikov, Igor V.; Klimov, Alexander I.; Rudenko, Larisa G.

    2011-01-01

    Please cite this paper as: Gambaryan et al. (2011) Comparative safety, immunogenicity, and efficacy of several anti‐H5N1 influenza experimental vaccines in a mouse and chicken models. Parallel testing of killed and live H5 vaccine. Influenza and Other Respiratory Viruses 6(3), 188–195. Objective  Parallel testing of inactivated (split and whole virion) and live vaccine was conducted to compare the immunogenicity and protective efficacy against homologous and heterosubtypic challenge by H5N1 highly pathogenic avian influenza virus. Method  Four experimental live vaccines based on two H5N1 influenza virus strains were tested; two of them had hemagglutinin (HA) of A/Vietnam/1203/04 strain lacking the polybasic HA cleavage site, and two others had hemagglutinins from attenuated H5N1 virus A/Chicken/Kurgan/3/05, with amino acid substitutions of Asp54/Asn and Lys222/Thr in HA1 and Val48/Ile and Lys131/Thr in HA2 while maintaining the polybasic HA cleavage site. The neuraminidase and non‐glycoprotein genes of the experimental live vaccines were from H2N2 cold‐adapted master strain A/Leningrad/134/17/57 (VN‐Len and Ku‐Len) or from the apathogenic H6N2 virus A/Gull/Moscow/3100/2006 (VN‐Gull and Ku‐Gull). Inactivated H5N1 and H1N1 and live H1N1 vaccine were used for comparison. All vaccines were applied in a single dose. Safety, immunogenicity, and protectivity against the challenge with HPAI H5N1 virus A/Chicken/Kurgan/3/05 were estimated. Results  All experimental live H5 vaccines tested were apathogenic as determined by weight loss and conferred more than 90% protection against lethal challenge with A/Chicken/Kurgan/3/05 infection. Inactivated H1N1 vaccine in mice offered no protection against challenge with H5N1 virus, while live cold‐adapted H1N1 vaccine reduced the mortality near to zero level. Conclusions  The high yield, safety, and protectivity of VN‐Len and Ku‐Len made them promising strains for the production of inactivated and live

  13. Innocuity of a commercial live attenuated vaccine for epizootic hemorrhagic disease virus serotype 2 in late-term pregnant cows.

    PubMed

    Spedicato, Massimo; Carmine, Irene; Teodori, Liana; Leone, Alessandra; Portanti, Ottavio; Marini, Valeria; Pisciella, Maura; Lorusso, Alessio; Savini, Giovanni

    2016-03-14

    Epizootic hemorrhagic disease (EHD) is an arthropod-borne infectious viral disease sustained by the epizootic hemorrhagic disease virus (EHDV). The only commercially available and currently used vaccines are manufactured for EHDV-2 in Japan, either live or inactivated vaccines. In this study we tested the innocuity for fetuses of the live attenuated EHDV-2 vaccine in five late-term pregnant cows. Whole blood and serum samples were collected from dams and screened for the presence of EHDV-2 RNA, infectious virus and antibodies. After calving, whole blood and serum samples collected from calves, before and after colostrum intake, were also tested for antibodies and for virus detection. In dams, neither fever nor clinical signs were observed. All of them seroconverted and a strong humoral response was detected throughout the sampling period. All blood samples tested negative for EHDV-2 except for one sample collected from a dam 11 days post-vaccination which tested positive at virus isolation at the third cell passage following two rounds of blind passages. Although they had free access to colostrum, calves tested serologically negative for EHDV-2 during the entire course of the experiment. Overall, the tested live attenuated vaccine can be safely administered to late-term pregnant cows as it was not demonstrated to cross the placental barrier. The safety of the live-attenuated vaccine is further confirmed by the emergence of Ibaraki virus in 2013 in Japan which is apparently not related to the spread of the vaccine strain currently used in Japan. PMID:26876438

  14. Evolutionary and bioinformatic analysis of the spike glycoprotein gene of H120 vaccine strain protectotype of infectious bronchitis virus from India.

    PubMed

    Kamble, Nitin Machindra; Pillai, Aravind S; Gaikwad, Satish S; Shukla, Sanjeev Kumar; Khulape, Sagar Aashok; Dey, Sohini; Mohan, C Madhan

    2016-01-01

    The infectious bronchitis virus is a causative agent of avian infectious bronchitis (AIB), and is is an important disease that produces severe economic losses to the poultry industry worldwide. Recent AIB outbreaks in India have been associated with poor growth in broilers, drop in egg production, and thin egg shells in layers. The complete spike gene of Indian AIB vaccine strain was amplified and sequenced using a conventional reverse transcription polymerase chain reaction and is submitted to the GenBank (accession no KF188436). Phylogenetic analysis revealed that the vaccine strain currently used belongs to H120 genotype, an attenuated strain of Massachusetts (Mass) serotype. Nucleotide and amino acid sequence comparisons have shown that the reported spike gene from Indian isolates have 71.8%-99% and 71.4%-96.9% genetic similarity with the sequenced H120 strain. The study identifies live attenuated IBV vaccine strain, which is routinely used for vaccination, for the first time. Based on nucleotide and amino acid relatedness studies of the vaccine strain with reported IBV sequences from India, it is shown that the current vaccine strain is efficient in controlling the IBV infection. Continuous monitoring of IBV outbreaks by sequencing for genotyping and in vivo cross protection studies for serotyping is not only important for epidemiological investigation but also for evaluation of efficacy of the current vaccine. PMID:25311758

  15. Rapid Strategy for Screening by Pyrosequencing of Influenza Virus Reassortants - Candidates for Live Attenuated Vaccines

    PubMed Central

    Shcherbik, Svetlana V.; Pearce, Nicholas C.; Levine, Marnie L.; Klimov, Alexander I.; Villanueva, Julie M.; Bousse, Tatiana L.

    2014-01-01

    Background Live attenuated influenza vaccine viruses (LAIVs) can be generated by classical reassortment of gene segments between a cold adapted, temperature sensitive and attenuated Master Donor Virus (MDV) and a seasonal wild-type (wt) virus. The vaccine candidates contain hemagglutinin (HA) and neuraminidase (NA) genes derived from the circulating wt viruses and the remaining six genes derived from the MDV strains. Rapid, efficient selection of the viruses with 6∶2 genome compositions from the large number of genetically different viruses generated during reassortment is essential for the biannual production schedule of vaccine viruses. Methodology/Principal Findings This manuscript describes a new approach for the genotypic analysis of LAIV reassortant virus clones based on pyrosequencing. LAIV candidate viruses were created by classical reassortment of seasonal influenza A (H3N2) (A/Victoria/361/2011, A/Ohio/02/2012, A/Texas/50/2012) or influenza A (H7N9) (A/Anhui/1/2013) wt viruses with the MDV A/Leningrad/134/17/57(H2N2). Using strain-specific pyrosequencing assays, mixed gene variations were detected in the allantoic progenies during the cloning procedure. The pyrosequencing analysis also allowed for estimation of the relative abundance of segment variants in mixed populations. This semi-quantitative approach was used for selecting specific clones for the subsequent cloning procedures. Conclusions/Significance The present study demonstrates that pyrosequencing analysis is a useful technique for rapid and reliable genotyping of reassortants and intermediate clones during the preparation of LAIV candidates, and can expedite the selection of vaccine virus candidates. PMID:24647786

  16. Strain-Specific Protective Effect of the Immunity Induced by Live Malarial Sporozoites under Chloroquine Cover

    PubMed Central

    Wijayalath, Wathsala; Cheesman, Sandra; Tanabe, Kazuyuki; Handunnetti, Shiroma; Carter, Richard; Pathirana, Sisira

    2012-01-01

    The efficacy of a whole-sporozoite malaria vaccine would partly be determined by the strain-specificity of the protective responses against malarial sporozoites and liver-stage parasites. Evidence from previous reports were inconsistent, where some studies have shown that the protective immunity induced by irradiated or live sporozoites in rodents or humans were cross-protective and in others strain-specific. In the present work, we have studied the strain-specificity of live sporozoite-induced immunity using two genetically and immunologically different strains of Plasmodium cynomolgi, Pc746 and PcCeylon, in toque monkeys. Two groups of monkeys were immunized against live sporozoites of either the Pc746 (n = 5), or the PcCeylon (n = 4) strain, by the bites of 2–4 sporozoite-infected Anopheles tessellates mosquitoes per monkey under concurrent treatments with chloroquine and primaquine to abrogate detectable blood infections. Subsequently, a group of non-immunized monkeys (n = 4), and the two groups of immunized monkeys were challenged with a mixture of sporozoites of the two strains by the bites of 2–5 infective mosquitoes from each strain per monkey. In order to determine the strain-specificity of the protective immunity, the proportions of parasites of the two strains in the challenge infections were quantified using an allele quantification assay, Pyrosequencing™, based on a single nucleotide polymorphism (SNP) in the parasites’ circumsporozoite protein gene. The Pyrosequencing™ data showed that a significant reduction of parasites of the immunizing strain in each group of strain-specifically immunized monkeys had occurred, indicating a stronger killing effect on parasites of the immunizing strain. Thus, the protective immunity developed following a single, live sporozoite/chloroquine immunization, acted specifically against the immunizing strain and was, therefore, strain-specific. As our experiment does not allow us to determine the

  17. Comparative analysis of the immunologic response induced by the Sterne 34F2 live spore Bacillus anthracis vaccine in a ruminant model.

    PubMed

    Ndumnego, Okechukwu C; Köhler, Susanne M; Crafford, Jannie; van Heerden, Henriette; Beyer, Wolfgang

    2016-10-01

    The Sterne 34F2 live spore vaccine (SLSV) developed in 1937 is the most widely used veterinary vaccine against anthrax. However, literature on the immunogenicity of this vaccine in a target ruminant host is scarce. In this study, we evaluated the humoral response to the Bacillus anthracis protective antigen (rPA), a recombinant bacillus collagen-like protein of anthracis (rBclA), formaldehyde inactivated spores (FIS) prepared from strain 34F2 and a vegetative antigen formulation prepared from a capsule and toxin deficient strain (CDC 1014) in Boer goats. The toxin neutralizing ability of induced antibodies was evaluated using an in vitro toxin neutralization assay. The protection afforded by the vaccine was also assessed in vaccinates. Anti-rPA, anti-FIS and lethal toxin neutralizing titres were superior after booster vaccinations, compared to single vaccinations. Qualitative analysis of humoral responses to rPA, rBclA and FIS antigens revealed a preponderance of anti-FIS IgG titres following either single or double vaccinations with the SLSV. Antibodies against FIS and rPA both increased by 350 and 300-fold following revaccinations respectively. There was no response to rBclA following vaccinations with the SLSV. Toxin neutralizing titres increased by 80-fold after single vaccination and 700-fold following a double vaccination. Lethal challenge studies in naïve goats indicated a minimum infective dose of 36 B. anthracis spores. Single and double vaccination with the SLSV protected 4/5 and 3/3 of goats challenged with>800 spores respectively. An early booster vaccination following the first immunization is suggested in order to achieve a robust immunity. Results from this study indicate that this crucial second vaccination can be administered as early as 3 months after the initial vaccination. PMID:27496738

  18. 9 CFR 113.27 - Detection of extraneous viable bacteria and fungi in live vaccines.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... bacteria and fungi in live vaccines. 113.27 Section 113.27 Animals and Animal Products ANIMAL AND PLANT... bacteria and fungi in live vaccines. Unless otherwise specified by the Administrator or elsewhere exempted... Seed Bacteria shall be tested for extraneous viable bacteria and fungi as prescribed in this section....

  19. 9 CFR 113.27 - Detection of extraneous viable bacteria and fungi in live vaccines.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... bacteria and fungi in live vaccines. 113.27 Section 113.27 Animals and Animal Products ANIMAL AND PLANT... bacteria and fungi in live vaccines. Unless otherwise specified by the Administrator or elsewhere exempted... Seed Bacteria shall be tested for extraneous viable bacteria and fungi as prescribed in this section....

  20. 9 CFR 113.27 - Detection of extraneous viable bacteria and fungi in live vaccines.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... bacteria and fungi in live vaccines. 113.27 Section 113.27 Animals and Animal Products ANIMAL AND PLANT... bacteria and fungi in live vaccines. Unless otherwise specified by the Administrator or elsewhere exempted... Seed Bacteria shall be tested for extraneous viable bacteria and fungi as prescribed in this section....

  1. 9 CFR 113.27 - Detection of extraneous viable bacteria and fungi in live vaccines.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... bacteria and fungi in live vaccines. 113.27 Section 113.27 Animals and Animal Products ANIMAL AND PLANT... bacteria and fungi in live vaccines. Unless otherwise specified by the Administrator or elsewhere exempted... Seed Bacteria shall be tested for extraneous viable bacteria and fungi as prescribed in this section....

  2. 9 CFR 113.27 - Detection of extraneous viable bacteria and fungi in live vaccines.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... bacteria and fungi in live vaccines. 113.27 Section 113.27 Animals and Animal Products ANIMAL AND PLANT... bacteria and fungi in live vaccines. Unless otherwise specified by the Administrator or elsewhere exempted... Seed Bacteria shall be tested for extraneous viable bacteria and fungi as prescribed in this section....

  3. Identification of the Immunogenic Spore and Vegetative Proteins of Bacillus anthracis Vaccine Strain A16R

    PubMed Central

    Feng, Erling; Wang, Xuefang; Zhu, Li; Wang, Hengliang

    2013-01-01

    Immunoproteomics was used to screen the immunogenic spore and vegetative proteins of Bacillus anthracis vaccine strain A16R. The spore and vegetative proteins were separated by 2D gel electrophoresis and transferred to polyvinylidene difluoride membranes, and then western blotting was performed with rabbit immune serum against B.anthracis live spores. Immunogenic spots were cut and digested by trypsin. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry was performed to identify the proteins. As a result, 11 and 45 immunogenic proteins were identified in the spores and vegetative cells, respectively; 26 of which have not been reported previously. To verify their immunogenicity, 12 of the identified proteins were selected to be expressed, and the immune sera from the mice vaccinated by the 12 expressed proteins, except BA0887, had a specific western blot band with the A16R whole cellular lytic proteins. Some of these immunogenic proteins might be used as novel vaccine candidates themselves or for enhancing the protective efficacy of a protective-antigen-based vaccine. PMID:23516421

  4. A Web-Based Platform for Designing Vaccines against Existing and Emerging Strains of Mycobacterium tuberculosis

    PubMed Central

    Dhanda, Sandeep Kumar; Vir, Pooja; Singla, Deepak; Gupta, Sudheer; Kumar, Shailesh

    2016-01-01

    Development of an effective vaccine against drug-resistant Mycobacterium tuberculosis (Mtb) is crucial for saving millions of premature deaths every year due to tuberculosis. This paper describes a web portal developed for assisting researchers in designing vaccines against emerging Mtb strains using traditional and modern approaches. Firstly, we annotated 59 genomes of Mycobacterium species to understand similarity/dissimilarity between tuberculoid, non-tuberculoid and vaccine strains at genome level. Secondly, antigen-based vaccine candidates have been predicted in each Mtb strain. Thirdly, epitopes-based vaccine candidates were predicted/discovered in above antigen-based vaccine candidates that can stimulate all arms of immune system. Finally, a database of predicted vaccine candidates at epitopes as well at antigen level has been developed for above strains. In order to design vaccine against a newly sequenced genome of Mtb strain, server integrates three modules for identification of strain-, antigen-, epitope-specific vaccine candidates. We observed that 103522 unique peptides (9mers) had the potential to induce an antibody response and/or promiscuous binder to MHC alleles and/or have the capability to stimulate T lymphocytes. In summary, this web-portal will be useful for researchers working on designing vaccines against Mtb including drug-resistant strains. Availability: The database is available freely at http://crdd.osdd.net/raghava/mtbveb/. PMID:27096425

  5. Comparative Safety and Immunogenicity of Two Attenuated Enterotoxigenic Escherichia coli Vaccine Strains in Healthy Adults

    PubMed Central

    McKenzie, Robin; Bourgeois, A. Louis; Engstrom, Fayette; Hall, Eric; Chang, H. Sunny; Gomes, Joseph G.; Kyle, Jennifer L.; Cassels, Fred; Turner, Arthur K.; Randall, Roger; Darsley, Michael; Lee, Cynthia; Bedford, Philip; Shimko, Janet; Sack, David A.

    2006-01-01

    A vaccine against enterotoxigenic Escherichia coli (ETEC) is needed to prevent diarrheal illness among children in developing countries and at-risk travelers. Two live attenuated ETEC strains, PTL002 and PTL003, which express the ETEC colonization factor CFA/II, were evaluated for safety and immunogenicity. In a randomized, double-blind, placebo-controlled trial, 19 subjects ingested one dose, and 21 subjects ingested two doses (days 0 and 10) of PTL-002 or PTL-003 at 2 × 109 CFU/dose. Anti-CFA/II mucosal immune responses were determined from the number of antibody-secreting cells (ASC) in blood measured by enzyme-linked immunospot assay, the antibody in lymphocyte supernatants (ALS) measured by enzyme-linked immunosorbent assay (ELISA), and fecal immunoglobulin A (IgA) levels determined by ELISA. Time-resolved fluorescence (TRF) ELISA was more sensitive than standard colorimetric ELISA for measuring serum antibody responses to CFA/II and its components, CS1 and CS3. Both constructs were well tolerated. Mild diarrhea occurred after 2 of 31 doses (6%) of PTL-003. PTL-003 produced more sustained intestinal colonization than PTL-002 and better IgA response rates: 90% versus 55% (P = 0.01) for anti-CFA/II IgA-ASCs, 55% versus 30% (P = 0.11) for serum anti-CS1 IgA by TRF, and 65% versus 25% (P = 0.03) for serum anti-CS3 IgA by TRF. Serum IgG response rates to CS1 or CS3 were 55% in PTL-003 recipients and 15% in PTL-002 recipients (P = 0.02). Two doses of either strain were not significantly more immunogenic than one. Based on its superior immunogenicity, which was comparable to that of a virulent ETEC strain and other ETEC vaccine candidates, PTL-003 will be developed further as a component of a live, oral attenuated ETEC vaccine. PMID:16428745

  6. Shedding of live Eimeria vaccine progeny is delayed in chicks with delayed access to feed after vaccination.

    PubMed

    Price, Kayla R; Freeman, Megan; Van-Heerden, Kobus; Barta, John R

    2015-03-15

    Hatching, processing and transportation result in inevitable delays before chicks are placed into brooding and receive their first feed and drinking water after hatching. To determine if delayed access to feed for different durations following live Eimeria vaccination affected initial shedding of vaccine progeny, replacement layer chicks (480, Lohmann-LSL Lite) aged approximately 6h after hatch were administered a commercial live Eimeria vaccine. Vaccinated chicks were divided randomly into groups and were provided access to feed immediately (0 h) or after a delay of 6, 12, or 24 h (4 treatments × 6 replicates per treatment × 20 pullets per replicate). All pullets were provided drinking water immediately following vaccination. Fecal oocysts shed per gram of feces for each cage replicate was determined daily from 4 to 9 days post inoculation. Chicks provided feed immediately had peak oocyst shedding at 5 days post-inoculation but delayed access to feed for 24h was associated with a 2 days delay in peak oocyst shedding to 7 days post-inoculation. Chicks with delays in access to feed of intermediate duration (i.e. 6 or 12h) had peak oocyst shedding at 6 days post-inoculation. Overall oocyst shedding was not affected. Live Eimeria vaccination success may be measured by evaluating initial shedding of oocysts at some pre-established time after vaccine application, usually by a single fecal collection conducted at 5, 6 or 7 days post-inoculation. Recognizing that withholding feed following live Eimeria vaccination shifts the time of the resultant peak oocyst shedding complicates the assessment of vaccine application; if delayed access to feed is not taken into account, it is possible that false conclusions could be drawn regarding the relative success of vaccine administration. PMID:25638718

  7. Genetic stability of Brucella abortus S19 and RB51 vaccine strains by multiple locus variable number tandem repeat analysis (MLVA16).

    PubMed

    Dorneles, Elaine Maria Seles; de Faria, Ana Paula Paiva; Pauletti, Rebeca Barbosa; Santana, Jordana Almeida; Caldeira, George Afonso Vítor; Heinemann, Marcos Bryan; Titze-de-Almeida, Ricardo; Lage, Andrey Pereira

    2013-10-01

    The aims of the present study were (i) to assess the in vitro genetic stability of S19 and RB51 Brucella abortus vaccines strains and (ii) to evaluate the ability of multiple-locus variable-number tandem repeat (VNTR) analysis (MLVA) as a tool to be used in the quality control of live vaccines against brucellosis. Sixty-three batches of commercial S19 (n=53) and RB51 (n=10) vaccines, produced between 2006 and 2009, were used in this study. S19 and RB51 vaccines were obtained from, respectively, seven and two different manufacturers. Ten in vitro serial passages were performed on reference strains and on selected batches of commercial vaccines. All batches, reference strains and strains of serial passages were typed by the MLVA16. The results demonstrated that B. abortus S19 and RB51 vaccine strains are genetically stable and very homogeneous in their respective groups. Anyway, batches of S19 from one manufacturer and batches of RB51 from another presented genotypes distincts from the reference vaccine strains. In both cases, differences were found on locus Bruce07, which had addition of one repeat unit in the case of S19 batches and the deletion of one repeat unit in the case of RB51 batches. In summary, MLVA16 proved to be a molecular tool capable of discriminating small genomic variations and should be included in in vitro official tests. PMID:23933375

  8. Vaccination of pigs against Aujeszky's disease by the intradermal route using live attenuated and inactivated virus vaccines.

    PubMed

    Vannier, P; Cariolet, R

    1989-09-01

    A study was undertaken of the protection induced by inactivated and live Aujeszky's disease virus vaccines. The vaccines were administered using a special device which, without the use of a needle, delivered the preparation intradermally. The trials were performed on 88 pigs which were vaccinated at the beginning of the fattening period both in experimental conditions and in pig herds. All the pigs were challenged at the end of the fattening period in isolation units. The results obtained were compared with those obtained using the same vaccines injected intramuscularly. It was shown that vaccination via the intradermal route induced good protection in the vaccinated animals and was similar to that conferred by live virus vaccine injected intramuscularly. The results, with the inactivated virus vaccine, were not so good when it was injected via the intradermal route. Studies with intradermal vaccination showed no local lesion or very small nodules strictly localized to the dermis. The results also confirmed that the effects of challenge exposure depended on the health status of animals prior to infection and show the necessity to use a synthetic value (delta G) to interpret the data and mainly to compare the results objectively. In fattening pigs this vaccination procedure is attractive because (i) less animal constraint is needed than would be for intramuscular injections, (ii) injection can be checked by the presence of a visible papula at the site of inoculation and, (iii) pigs can be vaccinated in the ham while they are feeding. Injection without a needle also contributes to avoiding bacterial contamination under practical farm conditions of vaccination. PMID:2554623

  9. Protection of Cattle against Rinderpest by Vaccination with Wild-Type but Not Attenuated Strains of Peste des Petits Ruminants Virus

    PubMed Central

    Holzer, Barbara; Hodgson, Sophia; Logan, Nicola; Willett, Brian

    2016-01-01

    ABSTRACT Although rinderpest virus (RPV) has been eradicated in the wild, efforts are still continuing to restrict the extent to which live virus is distributed in facilities around the world and to prepare for any reappearance of the disease, whether through deliberate or accidental release. In an effort to find an alternative vaccine which could be used in place of the traditional live attenuated RPV strains, we have determined whether cattle can be protected from rinderpest by inoculation with vaccine strains of the related morbillivirus, peste des petits ruminants virus (PPRV). Cattle were vaccinated with wild-type PPRV or either of two established PPRV vaccine strains, Nigeria/75/1 or Sungri/96. All animals developed antibody and T cell immune responses to the inoculated PPRV. However, only the animals given wild-type PPRV were protected from RPV challenge. Animals given PPRV/Sungri/96 were only partially protected, and animals given PPRV/Nigeria/75/1 showed no protection against RPV challenge. While sera from animals vaccinated with the vaccine strain of RPV showed cross-neutralizing ability against PPRV, none of the sera from animals vaccinated with any strain of PPRV was able to neutralize RPV although sera from animals inoculated with wild-type PPRV were able to neutralize RPV-pseudotyped vesicular stomatitis virus. IMPORTANCE Rinderpest virus has been eradicated, and it is only the second virus for which this is so. Significant efforts are still required to ensure preparedness for a possible escape of RPV from a laboratory or its deliberate release. Since RPV vaccine protects sheep and goats from PPRV, it is important to determine if the reverse is true as this would provide a non-RPV vaccine for dealing with suspected RPV outbreaks. This is probably the last in vivo study with live RPV that will be approved. PMID:26984722

  10. Humoral response to calicivirus in captive tigers given a dual-strain vaccine.

    PubMed

    Harrison, Tara M; Harrison, Scott H; Sikarskie, James G; Armstrong, Douglas

    2014-03-01

    The current feline vaccine with a single strain of calicivirus has been used for captive tigers, yet it may not protect against virulent systemic calicivirus infections. A cross-institutional study investigated the humoral response to a new dual-strain, killed-virus calicivirus vaccine for nine captive tigers. The subspecies of these tigers were Amur (Panthera tigris altaica), Bengal (Panthera tigris tigris), and Malayan (Panthera tigris jacksoni). Serum neutralization titers for virulent feline calicivirus strain FCV-DD1 were higher following dual-strain vaccine administration. There were no reports of adverse vaccine reactions. Dual-strain vaccination may afford broadened cross-protection against different calicivirus strains and is desirable to reduce the risk of virulent systemic calicivirus disease in tigers. PMID:24712158

  11. Live attenuated and inactivated viral vaccine formulation and nasal delivery: potential and challenges.

    PubMed

    Tlaxca, José L; Ellis, Scott; Remmele, Richard L

    2015-10-01

    Vaccines are cost-effective for the prevention of infectious diseases and have significantly reduced mortality and morbidity. Novel approaches are needed to develop safe and effective vaccines against disease. Major challenges in vaccine development include stability in a suitable dosage form and effective modes of delivery. Many live attenuated vaccines are capable of eliciting both humoral and cell mediated immune responses if physicochemically stable in an appropriate delivery vehicle. Knowing primary stresses that impart instability provides a general rationale for formulation development and mode of delivery. Since most pathogens enter the body through the mucosal route, live-attenuated vaccines have the advantage of mimicking natural immunization via non-invasive delivery. This presentation will examine aspects of formulation design, types of robust dosage forms to consider, effective routes of delivery (invasive and noninvasive), and distinctions between live attenuated or inactivated vaccines. PMID:25312673

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  13. A live attenuated H9N2 influenza vaccine is well tolerated and immunogenic in healthy adults.

    PubMed

    Karron, Ruth A; Callahan, Karen; Luke, Catherine; Thumar, Bhagvanji; McAuliffe, Josephine; Schappell, Elizabeth; Joseph, Tomy; Coelingh, Kathleen; Jin, Hong; Kemble, George; Murphy, Brian R; Subbarao, Kanta

    2009-03-01

    Development of live attenuated influenza vaccines (LAIV) against avian strains with pandemic potential is an important public-health strategy. Either 1 or 2 10(7)-TCID(50) doses of H9N2 LAIV A/chicken/Hong Kong/G9/97 were administered intranasally to 50 adults in isolation; 41 participants were H9N2 seronegative, 24 of whom received 2 doses. The vaccine was well tolerated; vaccine shedding was minimal. After 2 doses, 92% of H9-seronegative participants had > or = 4-fold increases in hemagglutination-inhibition antibody, and 79% had > or = 4-fold increases in neutralizing antibody; 100% had responses detected by at least 1 assay. Although replication of the H9N2 LAIV was restricted, 2 doses were immunogenic in H9N2-seronegative adults. Trial registration. ClinicalTrials.gov identifier: NCT00110279 . PMID:19210163

  14. Comparative analysis of pentavalent rotavirus vaccine strains and G8 rotaviruses identified during vaccine trial in Africa

    PubMed Central

    Heylen, Elisabeth; Zeller, Mark; Ciarlet, Max; Lawrence, Jody; Steele, Duncan; Van Ranst, Marc; Matthijnssens, Jelle

    2015-01-01

    RotaTeqTM is a pentavalent rotavirus vaccine based on a bovine rotavirus genetic backbone in vitro reassorted with human outer capsid genes. During clinical trials of RotaTeqTM in Sub-Saharan Africa, the vaccine efficacy over a 2-year follow-up was lower against the genotypes contained in the vaccine than against the heterotypic G8P[6] and G8P[1] rotavirus strains of which the former is highly prevalent in Africa. Complete genome analyses of 43 complete rotavirus genomes collected during phase III clinical trials of RotaTeqTM in Sub-Saharan Africa, were conducted to gain insight into the high level of cross-protection afforded by RotaTeqTM against these G8 strains. Phylogenetic analysis revealed the presence of a high number of bovine rotavirus gene segments in these human G8 strains. In addition, we performed an in depth analysis on the individual amino acid level which showed that G8 rotaviruses were more similar to the RotaTeqTM vaccine than non-G8 strains. Because RotaTeqTM possesses a bovine genetic backbone, the high vaccine efficacy against G8 strains might be partially explained by the fact that all these strains contain a complete or partial bovine-like backbone. Altogether, this study supports the hypothesis that gene segments other than VP7 and VP4 play a role in vaccine-induced immunity. PMID:26440913

  15. Classical swine fever virus Strain 'C'. How long is it detectable after oral vaccination?

    PubMed

    Kaden, V; Lange, E; Riebe, R; Lange, B

    2004-08-01

    To determine the persistence period of C-strain vaccine virus in immunized animals, domestic pigs and wild boars were vaccinated orally and killed on different days post vaccinationem (dpv). Tissue samples were taken at necropsy from both species for detection of C-strain virus. From domestic pigs nasal swabs and faeces were also collected. During the investigation period (2-12 dpv) vaccine virus could never be detected in nasal secretions and in faeces of vaccinated domestic pigs. In contrast, C-strain virus was found in organs until day 8 pv in domestic pigs and until day 9 pv in wild boars. Whereas in domestic pigs virus was detected in tonsils, Ln. mandibularis or in spleen, in wild boar it only was found in tonsils. We conclude that C-strain vaccine virus is not detectable in wild boars longer than 10-12 days after intake of the vaccine baits. PMID:15458487

  16. Assessment of attenuated Salmonella vaccine strains in controlling experimental Salmonella Typhimurium infection in chickens

    PubMed Central

    Pei, Yanlong; Parreira, Valeria R.; Roland, Kenneth L.; Curtiss, Roy; Prescott, John F.

    2014-01-01

    Salmonella hold considerable promise as vaccine delivery vectors for heterologous antigens in chickens. Such vaccines have the potential additional benefit of also controlling Salmonella infection in immunized birds. As a way of selecting attenuated strains with optimal immunogenic potential as antigen delivery vectors, this study screened 20 novel Salmonella Typhimurium vaccine strains, differing in mutations associated with delayed antigen synthesis and delayed attenuation, for their efficacy in controlling colonization by virulent Salmonella Typhimurium, as well as for their persistence in the intestine and the spleen. Marked differences were observed between strains in these characteristics, which provide the basis for selection for further study as vaccine vectors. PMID:24396177

  17. Assessment of attenuated Salmonella vaccine strains in controlling experimental Salmonella Typhimurium infection in chickens.

    PubMed

    Pei, Yanlong; Parreira, Valeria R; Roland, Kenneth L; Curtiss, Roy; Prescott, John F

    2014-01-01

    Salmonella hold considerable promise as vaccine delivery vectors for heterologous antigens in chickens. Such vaccines have the potential additional benefit of also controlling Salmonella infection in immunized birds. As a way of selecting attenuated strains with optimal immunogenic potential as antigen delivery vectors, this study screened 20 novel Salmonella Typhimurium vaccine strains, differing in mutations associated with delayed antigen synthesis and delayed attenuation, for their efficacy in controlling colonization by virulent Salmonella Typhimurium, as well as for their persistence in the intestine and the spleen. Marked differences were observed between strains in these characteristics, which provide the basis for selection for further study as vaccine vectors. PMID:24396177

  18. 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

    2016-06-01

    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

  19. Development of a novel live vaccine delivering enterotoxigenic Escherichia coli fimbrial antigens to prevent post-weaning diarrhea in piglets.

    PubMed

    Hur, Jin; Lee, John Hwa

    2012-05-15

    The efficacy of a novel, live delivery vaccine was examined for protection against post-weaning diarrhea in pigs. An expression/secretion plasmid harboring genes encoding enterotoxigenic Escherichia coli K88ab, K88ac, FedA and FedF fimbriae was constructed and harbored in an attenuated Salmonella, which was used as the vaccine candidate. Groups A (n=3) and B (n=3) sows were orally immunized with the candidate vaccine and PBS as a control, respectively, at 8 and 11 weeks of pregnancy. All group piglets were challenged with two challenge strains at 5-week-old. All immunized sows had significantly increased IgG and IgA levels in both serum and colostrum to individual adhesins compared to the control (p ≤ 0.05). Immune response in Group A piglets were significantly increased (p ≤ 0.05). Furthermore, no clinical signs were observed in Group A piglets after the challenge and no challenge strains were detected in rectal swabs, while diarrhea was observed in 47.8% control piglets and challenge strains were isolated from all the diarrheic piglets. These results show that immune response of sucking piglets can maintain at higher levels through the milk of the immunized sows and vaccination of sows with the candidate may protect colibacillosis in weaned piglets. PMID:22417986

  20. Influence of antibiotics used as feed additives on the immune effect of erysipelas live vaccine in swine.

    PubMed

    Yamamoto, K; Takagi, M; Endoh, Y S; Kijima, M; Takahashi, T

    2000-08-01

    To investigate the influence of antibiotics used as feed additives on the immune response to erysipelas live vaccine, the pig inoculation test was applied. Avilamycin, oxytetracycline quaternary salt, enramycin, virginiamycin and tylosin phosphate were selected as test antibiotics. Five experimental feeds containing each antibiotic at the highest concentration permitted for feed additives in Japan, and the basal diet lacking antibiotics were examined. Twenty-nine pigs were divided into six groups. At first all the groups were fed with the antibiotic-free basal diet for 7 days, and then each group received the experimental feeds. On the 14th day after feeding with test feeds all the pigs, except for one control pig in each group, were immunized with the vaccine and all the pigs were then challenge-exposed to a virulent strain of Erysipelothrix rhusiopathiae 14 days after vaccination. The clinical response was observed every day for 14 days. In all the groups, most of the vaccinated pigs did not develop any clinical signs of acute erysipelas after the challenge exposure, whereas non-vaccinated control pigs died or showed severe generalized erythema with profound depression and anorexia. No differences in the protection against the challenge exposure were observed among the groups. Therefore, the present results suggest that these selected antibiotics would not interfere with the immune effect of the vaccine if given at the usual concentrations used for feed additives. PMID:11014067

  1. Assessment of inactivated human rabies vaccines: biochemical characterization and genetic identification of virus strains.

    PubMed

    Finke, Stefan; Karger, Axel; Freuling, Conrad; Müller, Thomas

    2012-05-21

    The World Health Organization (WHO) recommends the periodic evaluation of the purity of the cell lines used in the production of rabies vaccines, as well as the antigenic identity of the virus strains. Here, we analyzed seventeen marketed inactivated human rabies virus vaccines for viral and non-viral proteins by SDS-PAGE and Coomassie/silver staining. Mass spectrometric analysis of an abundant 60-70 kDa signal indicated that in most vaccines serum albumin of human origin (HSA) was the major component. Quantification of HSA in the vaccines revealed a mean concentration of 22 mg HSA/dose in all tested PVRV (purified vero cell rabies vaccine), HDCV (human diploid cell rabies vaccine) and PHK (primary hamster kidney) vaccines. In contrast, 1000-fold lower HSA levels and no HSA were detected in PCECV (purified chick embryo cell-culture vaccine) and PDEV (duck embryo rabies vaccine), respectively. Western blot analyses further confirmed a high bias in the HSA content, whereas the virus protein levels were rather similar in all tested vaccines. In addition, the vaccine viruses were sequenced within the N- and G-genes to identify the strain. In the majority of sequenced vaccines, the declared vaccine strain was confirmed. However, some discrepancies in the genetic identification were observed, supporting WHO's recommendation for the molecular characterization of vaccine seed strains. This research highlights the variation in purity found between different human rabies virus vaccines, and suggests that further research is needed to establish the impact non-active components have on the potency of such vaccines. PMID:22469862

  2. Comparative Full Length Sequence Analysis of Oncogenic and Vaccine (Rispens) Strains of Marek's Disease Virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The complete DNA sequence of the Marek’s disease virus serotype 1 vaccine strain CVI988 was determined and consists of 178,311 bp with an overall gene organization identical to that of the oncogenic strains. In examining open reading frames (ORFs), nine ORFs differ between vaccine and oncogenic stra...

  3. Effectiveness of Meningococcal B Vaccine against Endemic Hypervirulent Neisseria meningitidis W Strain, England.

    PubMed

    Ladhani, Shamez N; Giuliani, Marzia Monica; Biolchi, Alessia; Pizza, Mariagrazia; Beebeejaun, Kazim; Lucidarme, Jay; Findlow, Jamie; Ramsay, Mary E; Borrow, Ray

    2016-02-01

    Serum samples from children immunized with a meningococcal serogroup B vaccine demonstrated potent serum bactericidal antibody activity against the hypervirulent Neisseria meningitidis serogroup W strain circulating in England. The recent introduction of this vaccine into the United Kingdom national immunization program should also help protect infants against this endemic strain. PMID:26811872

  4. Effectiveness of Meningococcal B Vaccine against Endemic Hypervirulent Neisseria meningitidis W Strain, England

    PubMed Central

    Giuliani, Marzia Monica; Biolchi, Alessia; Pizza, Mariagrazia; Beebeejaun, Kazim; Lucidarme, Jay; Findlow, Jamie; Ramsay, Mary E.; Borrow, Ray

    2016-01-01

    Serum samples from children immunized with a meningococcal serogroup B vaccine demonstrated potent serum bactericidal antibody activity against the hypervirulent Neisseria meningitidis serogroup W strain circulating in England. The recent introduction of this vaccine into the United Kingdom national immunization program should also help protect infants against this endemic strain. PMID:26811872

  5. Novel polyvalent live vaccine against varicella-zoster and mumps virus infections.

    PubMed

    Matsuura, Masaaki; Somboonthum, Pranee; Murakami, Kouki; Ota, Megumi; Shoji, Masaki; Kawabata, Kenji; Mizuguchi, Hiroyuki; Gomi, Yasuyuki; Yamanishi, Koichi; Mori, Yasuko

    2013-10-01

    The varicella-zoster virus (VZV) Oka vaccine strain (vOka) is a highly immunogenic and safe live vaccine that has long been used worldwide. Because its genome is large, making it suitable for inserting foreign genes, vOka is considered a candidate vector for novel polyvalent vaccines. Previously, a recombinant vOka, rvOka-HN, that expresses mumps virus (MuV) hemagglutinin-neuraminidase (HN) was generated by the present team. rvOka-HN induces production of neutralizing antibodies against MuV in guinea pigs. MuV also expresses fusion (F) protein, which is important for inducing neutralizing antibodies, in its viral envelope. To induce a more robust immune response against MuV than that obtained with rvOka-HN, here an rvOka expressing both HN and F (rvOka-HN-F) was generated. However, co-expression of HN and F caused the infected cells to form syncytia, which reduced virus titers. To reduce the amount of cell fusion, an rvOka expressing HN and a mutant F, F(S195Y) were generated. Almost no syncytia formed among the rvOka-HN-F(S195Y)-infected cells and the growth of rvOka-HN-F(S195Y) was similar to that of the original vOka clone. Moreover, replacement of serine 195 with tyrosine had no effect on the immunogenicity of F in mice and guinea pigs. Although obvious augmentation of neutralizing antibody production was not observed after adding F protein to vOka-HN, the anti-F antibodies did have neutralizing activity. These data suggest that F protein contributes to induction of immune protection against MuV. Therefore this recombinant virus is a promising candidate vaccine for polyvalent protection against both VZV and MuV. PMID:23905963

  6. 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

  7. Oral Fluids as a Live-Animal Sample Source for Evaluating Cross-Reactivity and Cross-Protection following Intranasal Influenza A Virus Vaccination in Pigs

    PubMed Central

    Hughes, Holly R.; Vincent, Amy L.; Brockmeier, Susan L.; Gauger, Phillip C.; Pena, Lindomar; Santos, Jefferson; Braucher, Douglas R.; Perez, Daniel R.

    2015-01-01

    In North American swine, there are numerous antigenically distinct H1 influenza A virus (IAV) variants currently circulating, making vaccine development difficult due to the inability to formulate a vaccine that provides broad cross-protection. Experimentally, live-attenuated influenza virus (LAIV) vaccines demonstrate increased cross-protection compared to inactivated vaccines. However, there is no standardized assay to predict cross-protection following LAIV vaccination. Hemagglutination-inhibiting (HI) antibody in serum is the gold standard correlate of protection following IAV vaccination. LAIV vaccination does not induce a robust serum HI antibody titer; however, a local mucosal antibody response is elicited. Thus, a live-animal sample source that could be used to evaluate LAIV immunogenicity and cross-protection is needed. Here, we evaluated the use of oral fluids (OF) and nasal wash (NW) collected after IAV inoculation as a live-animal sample source in an enzyme-linked immunosorbent assay (ELISA) to predict cross-protection in comparison to traditional serology. Both live-virus exposure and LAIV vaccination provided heterologous protection, though protection was greatest against more closely phylogenetically related viruses. IAV-specific IgA was detected in NW and OF samples and was cross-reactive to representative IAV from each H1 cluster. Endpoint titers of cross-reactive IgA in OF from pigs exposed to live virus was associated with heterologous protection. While LAIV vaccination provided significant protection, LAIV immunogenicity was reduced compared to live-virus exposure. These data suggest that OF from pigs inoculated with wild-type IAV, with surface genes that match the LAIV seed strain, could be used in an ELISA to assess cross-protection and the antigenic relatedness of circulating and emerging IAV in swine. PMID:26291090

  8. Efficacy of live attenuated influenza vaccine in children 6 months to 17 years of age

    PubMed Central

    Belshe, Robert B.; Toback, Seth L.; Yi, Tingting; Ambrose, Christopher S.

    2010-01-01

    Please cite this paper as: Belshe et al. (2010). Efficacy of live attenuated influenza vaccine in children 6 months to 17 years of age. Influenza and Other Respiratory Viruses 4(3), 141–145. Background  It has been suggested that live attenuated influenza vaccine (LAIV) may be less effective in older individuals because of prior wild‐type influenza infections. LAIV is currently approved in the United States, South Korea and Hong Kong for individuals 2–49 years of age. Objective  To examine data from previously published pediatric studies to determine the efficacy of LAIV in various age groups. Methods  Four studies in which the subject age range exceeded 36 months were identified: one 2‐year study comparing LAIV with placebo and three 1‐year studies comparing LAIV with trivalent inactivated influenza vaccine (TIV). Efficacy against any strain regardless of antigenic similarity to vaccine was analyzed by age; age groups were based on the study design and sample size. A logistic regression model was used to assess whether age, as a continuous variable, was an effect modifier on LAIV efficacy. Results  The efficacy of LAIV did not vary with age in children aged 15–84 months compared with placebo or in children aged 6 months to 17 years compared with TIV. Conclusions  The available data from prospective, randomized studies in children does not support the concept that prior repeated exposure to influenza, either through wild‐type infection or vaccination with live, attenuated or inactivated vaccines, reduces the efficacy of LAIV compared with placebo or TIV. The decreased immunologic responses to LAIV reported in older individuals or those with pre‐existing immunity do not appear to translate into reduced protection from influenza in children. PMID:20409210

  9. Demonstration of Complement Fixing Antibody in the Sera of Cattle Vaccinated with Combined Living Blackleg-anthrax Vaccine

    PubMed Central

    Cho, H. J.

    1971-01-01

    Complement fixing antibodies could be detected in the sera of cattle vaccinated with combined living blackleg-anthrax vaccine by modified complement fixation tests. Conventional direct complement fixation tests with bovine antibody-antigen systems often caused false negative reactions; however, in the modified test, when guinea pig complement was supplemented with fresh unheated normal rabbit serum, positive reactions were obtained and the sensitivity of the test was increased without loss of specificity. PMID:17647601

  10. Characterization of Erysipelothrix Species Isolates from Clinically Affected Pigs, Environmental Samples, and Vaccine Strains from Six Recent Swine Erysipelas Outbreaks in the United States ▿

    PubMed Central

    Bender, J. S.; Shen, H. G.; Irwin, C. K.; Schwartz, K. J.; Opriessnig, T.

    2010-01-01

    The aim of this study was to characterize Erysipelothrix sp. isolates from clinically affected pigs and their environment and compare them to the Erysipelothrix sp. vaccines used at the sites. Samples were collected during swine erysipelas outbreaks in vaccinated pigs in six Midwest United States swine operations from 2007 to 2009. Pig tissue samples were collected from 1 to 3 pigs from each site. Environmental samples (manure, feed, central-line water, oral fluids, and swabs collected from walls, feed lines, air inlets, exhaust fans, and nipple drinkers) and live vaccine samples were collected following the isolation of Erysipelothrix spp. from clinically affected pigs. All Erysipelothrix sp. isolates obtained were further characterized by serotyping. Selected isolates were further characterized by PCR assays for genotype (E. rhusiopathiae, E. tonsillarum, Erysipelothrix sp. strain 1, and Erysipelothrix sp. strain 2) and surface protective antigen (spa) type (A, B1, B2, and C). All 26 isolates obtained from affected pigs were E. rhusiopathiae, specifically, serotypes 1a, 1b, 2, and 21. From environmental samples, 56 isolates were obtained and 52/56 were E. rhusiopathiae (serotypes 1a, 1b, 2, 6, 9, 12, and 21), 3/56 were Erysipelothrix sp. strain 1 (serotypes 13 and untypeable), and one was a novel species designated Erysipelothrix sp. strain 3 (serotype untypeable). Four of six vaccines used at the sites were commercially available products and contained live E. rhusiopathiae serotype 1a. Of the remaining two vaccines, one was an autogenous live vaccine and contained live E. rhusiopathiae serotype 2 and one was a commercially produced inactivated vaccine and was described by the manufacturer to contain serotype 2 antigen. All E. rhusiopathiae isolates were positive for spaA. All Erysipelothrix sp. strain 1 isolates and the novel Erysipelothrix sp. strain 3 isolate were negative for all currently known spa types (A, B1, B2, and C). These results indicate that

  11. Evolutionary reversion of live viral vaccines: Can genetic engineering subdue it?

    PubMed Central

    Bull, J. J.

    2016-01-01

    Attenuated, live viral vaccines have been extraordinarily successful in protecting against many diseases. The main drawbacks in their development and use have been reliance on an unpredictable method of attenuation and the potential for evolutionary reversion to high virulence. Methods of genetic engineering now provide many safer alternatives to live vaccines, so if live vaccines are to compete with these alternatives in the future, they must either have superior immunogenicity or they must be able to overcome these former disadvantages. Several live vaccine designs that were historically inaccessible are now feasible because of advances in genome synthesis. Some of those methods are addressed here, with an emphasis on whether they enable predictable levels of attenuation and whether they are stable against evolutionary reversion. These new designs overcome many of the former drawbacks and position live vaccines to be competitive with alternatives. Not only do new methods appear to retard evolutionary reversion enough to prevent vaccine-derived epidemics, but it may even be possible to permanently attenuate live vaccines that are transmissible but cannot evolve to higher virulence under prolonged adaptation. PMID:27034780

  12. Selecting vaccine strains for H3N2 human influenza A virus

    PubMed Central

    Suzuki, Yoshiyuki

    2015-01-01

    H3N2 human influenza A virus causes epidemics of influenza mainly in the winter season in temperate regions. Since the antigenicity of this virus evolves rapidly, several attempts have been made to predict the major amino acid sequence of hemagglutinin 1 (HA1) in the target season of vaccination. However, the usefulness of predicted sequence was unclear because its relationship to the antigenicity was unknown. Here the antigenic model for estimating the degree of antigenic difference (antigenic distance) between amino acid sequences of HA1 was integrated into the process of selecting vaccine strains for H3N2 human influenza A virus. When the effectiveness of a potential vaccine strain for a target season was evaluated retrospectively using the average antigenic distance between the strain and the epidemic viruses sampled in the target season, the most effective vaccine strain was identified mostly in the season one year before the target season (pre-target season). Effectiveness of actual vaccines appeared to be lower than that of the strains randomly chosen in the pre-target season on average. It was recommended to replace the vaccine strain for every target season with the strain having the smallest average antigenic distance to the others in the pre-target season. The procedure of selecting vaccine strains for future epidemic seasons described in the present study was implemented in the influenza virus forecasting system (INFLUCAST) (http://www.nsc.nagoya-cu.ac.jp/~yossuzuk/influcast.html). PMID:25893173

  13. Genome sequence of Bacillus anthracis attenuated vaccine strain A16R used for human in China.

    PubMed

    Liu, Xiankai; Qi, Xinpeng; Zhu, Li; Wang, Dongshu; Gao, Zhiqi; Deng, Haijun; Wu, Weili; Hu, Tao; Chen, Chen; Chen, Weijun; Wang, Hengliang

    2015-09-20

    An attenuated Bacillus anthracis vaccine strain for human use, A16R, was obtained in China after ultraviolet radiation treatment and continuous subculture of the wild-type strain A16. A16R can synthesize the exotoxin, but without a capsule. We sequenced and annotated the A16R genome to encourage the use of this strain. The genome sequencing of the wild-type strain A16 is underway and the genomic comparison between the two strains will help to illustrate the attenuating mechanism of the A16R vaccine strain. PMID:26116813

  14. Laboratory investigations on "postvaccinall rabies" caused by live sheep-brain vaccine.

    PubMed

    Wojciechowski, K J

    1976-01-01

    The viral ethiology of postvaccinal complications among 30 dogs vaccinated by live antirabies vaccine (Umeno-Doi type, sheep brain vaccine) was fully confirmed. Three lots of virulent vaccine were inoculated subcutaneously into groups of "Wistar" rats according to the different schemes. Between the 1st and 12th day after the end of the vaccination there were no isolations of fixed virus in direct and blind i.c. passages of suspensions made from the thalamus area on succkling mice and rats. Also the viral antigen in the CNS of vaccinated but apparently healthy rats was undetectable. The "postvaccinal rabies" with the next isolation of fixed r.v. in the CNS was developed experimentally in rats only following the subcutaneous injection of the crude sheep-brain's and spinal cord's suspensions--composing the materials to production of antirabies vaccine. PMID:59530

  15. Comparative trial of live attenuated measles vaccine in Hong Kong by intramuscular and intradermal injection

    PubMed Central

    1967-01-01

    Between April and July 1966 a comparative trial of two live attenuated measles vaccines (Schwarz and Beckenham 31), given intramuscularly or intradermally, was conducted in Hong Kong. Some 910 non-immune children completed the trial. The Beckenham 31 vaccine caused significantly more complications than Schwarz vaccine, but it also resulted in a much higher mean antibody titre by both intramuscular and intradermal injection than did Schwarz vaccine. The seroconversion rates were satisfactory for both vaccines given intramuscularly but not for either given intradermally (at one-fifth the recognized intramuscular dose). The authors suggest that either vaccine may usefully be given for measles prophylaxis. The choice between Beckenham 31, with a higher complication rate and higher antibody levels, and Schwarz, with fewer complications but lower antibody levels, would depend on the type of community, the adequacy of the medical services, the severity of measles and an assessment of how either vaccine, with its known complications, might affect other immunization programmes. PMID:5299670

  16. 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

  17. Horizontal transmission dynamics of a glycoprotein G deficient candidate vaccine strain of infectious laryngotracheitis virus and the effect of vaccination on transmission of virulent virus.

    PubMed

    Devlin, Joanne M; Hartley, Carol A; Gilkerson, James R; Coppo, Mauricio J C; Vaz, Paola; Noormohammadi, Amir H; Wells, Ben; Rubite, Ambrosio; Dhand, Navneet K; Browning, Glenn F

    2011-08-01

    Infectious laryngotracheitis virus (ILTV) is an alphaherpesvirus that causes acute respiratory disease in chickens worldwide. The virus is horizontally transmitted and causes large outbreaks of disease. Recent studies have shown that a glycoprotein G deficient candidate vaccine strain of ILTV (ΔgG ILTV) is safe and protects birds from disease following challenge with virulent virus. This study examined the transmission dynamics of this candidate vaccine and of ILTV in field and experimental settings. The reproduction ratio (R₀, average number of secondary infectious cases from a typical infectious case) was calculated from the growth rate of disease epidemics in broiler flocks. Assuming a latent period of 2 days and an infectious period of 4 days R₀ was estimated to be 2.43 (95% CI 2.25-2.69). In experimental settings the transmission characteristics of ΔgG ILTV were similar to those of wildtype virus, and importantly ΔgG ILTV remained safe following one in vivo passage and subsequent infection via contact-exposure. There was minimal transmission of wildtype virus in vaccinated birds. The findings from this study further demonstrate the suitability of ΔgG ILTV for use as a live attenuated vaccine. Knowledge of the basic reproduction ratio of ILTV will be valuable for future studies that aim to improve disease control using vaccination programs. PMID:21689710

  18. Oral Vaccination of Channel Catfish against Enteric Septicemia of Catfish Using a Live Attenuated Edwardsiella ictaluri Isolate.

    PubMed

    Wise, David J; Greenway, Terrence E; Byars, Todd S; Griffin, Matt J; Khoo, Lester H

    2015-06-01

    Enteric septicemia of catfish (ESC), caused by Edwardsiella ictaluri, is the most problematic bacterial disease affecting catfish aquaculture in the southeastern United States. Efforts to develop an effective ESC vaccine have had limited industrial success. In commercial settings, ESC vaccines are typically administered by immersion when fry are transferred from the hatchery to rearing ponds. While this approach is a practical method of mass delivery, this strategy administers vaccines to very young fish, which lack a fully developed immune system. To circumvent this limitation, an oral vaccination strategy was evaluated as a means of immunizing catfish at the fingerling stage of production, when fish possess a more complete immune arsenal. A virulent E. ictaluri isolate (S97-773) was attenuated by successive passage on media containing increasing concentrations of rifamycin. In laboratory trials, cultured vaccine was diluted and mixed with feed (100 mL diluted vaccine/454 g feed). This mixture was then fed to Channel Catfish Ictalurus punctatus fingerlings. Two separate dilutions of cultured vaccine (1:10 and 1:100) were used to create the vaccine-feed mixture, equating to estimated doses of 5 × 10⁷ and 5 × 10⁶ CFU/g of feed, respectively. After 30 d, catfish were exposed by immersion (1 × 10⁶ CFU/mL) to the virulent parental strain of E. ictaluri. The target dose (1:100 dilution, ∼5 × 10⁶ CFU/g of feed) offered exceptional protection (relative percent survival = 82.6-100%). In addition, negligible deaths occurred in fish vaccinated at 10 times the target dose (1:10 dilution, ∼5 × 10⁷ CFU/g of feed). In pond trials, antibody production increased 18-fold in orally vaccinated fish. When compared with nonvaccinated controls, vaccination significantly improved survival, feed fed, feed conversion, biomass produced, and total harvest. This research demonstrates Channel Catfish can be successfully immunized in a commercial setting against E. ictaluri

  19. Potential drug interaction between Rho(D) immune globulin and live virus vaccine.

    PubMed

    Holmes, Amy; Wright, Debra

    2014-12-01

    Women often receive Rho(D) immune globulin as well as a live virus vaccine in the immediate postpartum period. The immune globulin product has the potential to interfere with appropriate immune response to the vaccine. Here we describe our approach to identifying and following up on this often overlooked potential drug interaction. PMID:25495973

  20. Inactivated or live-attenuated bivalent vaccines that confer protection against rabies and Ebola viruses.

    PubMed

    Blaney, Joseph E; Wirblich, Christoph; Papaneri, Amy B; Johnson, Reed F; Myers, Carey J; Juelich, Terry L; Holbrook, Michael R; Freiberg, Alexander N; Bernbaum, John G; Jahrling, Peter B; Paragas, Jason; Schnell, Matthias J

    2011-10-01

    The search for a safe and efficacious vaccine for Ebola virus continues, as no current vaccine candidate is nearing licensure. We have developed (i) replication-competent, (ii) replication-deficient, and (iii) chemically inactivated rabies virus (RABV) vaccines expressing Zaire Ebola virus (ZEBOV) glycoprotein (GP) by a reverse genetics system based on the SAD B19 RABV wildlife vaccine. ZEBOV GP is efficiently expressed by these vaccine candidates and is incorporated into virions. The vaccine candidates were avirulent after inoculation of adult mice, and viruses with a deletion in the RABV glycoprotein had greatly reduced neurovirulence after intracerebral inoculation in suckling mice. Immunization with live or inactivated RABV vaccines expressing ZEBOV GP induced humoral immunity against each virus and conferred protection from both lethal RABV and EBOV challenge in mice. The bivalent RABV/ZEBOV vaccines described here have several distinct advantages that may speed the development of inactivated vaccines for use in humans and potentially live or inactivated vaccines for use in nonhuman primates at risk of EBOV infection in endemic areas. PMID:21849459

  1. Inactivated or Live-Attenuated Bivalent Vaccines That Confer Protection against Rabies and Ebola Viruses ▿

    PubMed Central

    Blaney, Joseph E.; Wirblich, Christoph; Papaneri, Amy B.; Johnson, Reed F.; Myers, Carey J.; Juelich, Terry L.; Holbrook, Michael R.; Freiberg, Alexander N.; Bernbaum, John G.; Jahrling, Peter B.; Paragas, Jason; Schnell, Matthias J.

    2011-01-01

    The search for a safe and efficacious vaccine for Ebola virus continues, as no current vaccine candidate is nearing licensure. We have developed (i) replication-competent, (ii) replication-deficient, and (iii) chemically inactivated rabies virus (RABV) vaccines expressing Zaire Ebola virus (ZEBOV) glycoprotein (GP) by a reverse genetics system based on the SAD B19 RABV wildlife vaccine. ZEBOV GP is efficiently expressed by these vaccine candidates and is incorporated into virions. The vaccine candidates were avirulent after inoculation of adult mice, and viruses with a deletion in the RABV glycoprotein had greatly reduced neurovirulence after intracerebral inoculation in suckling mice. Immunization with live or inactivated RABV vaccines expressing ZEBOV GP induced humoral immunity against each virus and conferred protection from both lethal RABV and EBOV challenge in mice. The bivalent RABV/ZEBOV vaccines described here have several distinct advantages that may speed the development of inactivated vaccines for use in humans and potentially live or inactivated vaccines for use in nonhuman primates at risk of EBOV infection in endemic areas. PMID:21849459

  2. Effects of vaccination with F-strain Mycoplasma gallisepticum on egg production and quality parameters of commercial layer hens previously vaccinated with 6/85-strain Mycoplasma gallisepticum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An experiment was conducted to determine the effect of overlaying (revaccinating) F strain Mycoplasma gallisepticum (MG) at 22 or 45 weeks of age on commercial leghorn hens previously vaccinated with 6/85 strain MG at 10 weeks of age. The treatment groups include unvaccinated hens (group 1), hens r...

  3. Effects of two commercial European modified-live vaccines against porcine reproductive and respiratory syndrome viruses in pregnant gilts.

    PubMed

    Scortti, Mariela; Prieto, Cinta; Martínez-Lobo, Francisco J; Simarro, Isabel; Castro, José M

    2006-11-01

    The purpose of this study was to assess the effects of two currently available commercial European-type modified-live virus (MLV) vaccines against porcine reproductive and respiratory syndrome in a reproductive pig model. Sixteen 90-day pregnant gilts were divided into four groups and allocated to one of the following intranasal treatments: group A gilts served as negative controls; group B gilts were exposed to a virulent European field strain; group C gilts were exposed to vaccine strain VP046 Bis and group D gilts to vaccine strain All-183. The results indicated that MLV strains can replicate in breeding animals and have the ability to cross the placenta. In particular, viraemia was detected in all gilts in group C and 2/4 gilts in group D, at least at one time point. In addition, transplacental infection was demonstrated in 3/4 gilts in group C and 2/4 gilts in group D. However, congenital and early postnatal infection did not have a marked detrimental effect on piglet performance when compared to negative controls, and no statistically significant differences were observed in most cases. Conversely, the reproductive performance of gilts in group B was significantly worse than that of the other groups. Specifically, the number of born-alive piglets, the survival rate of piglets during lactation and the mean weight of weaned pigs were significantly lower. It was concluded that the two commercial European-type MLV vaccines tested had no marked detrimental effects in pregnant gilts, although the MLV strains can cross the placenta leading to the birth of congenitally infected piglets. PMID:16169756

  4. Real-time RT-PCR assays to differentiate wild-type group A rotavirus strains from Rotarix® and RotaTeq® vaccine strains in stool samples

    PubMed Central

    Gautam, Rashi; Esona, Mathew D; Mijatovic-Rustempasic, Slavica; Ian Tam, Ka; Gentsch, Jon R; Bowen, Michael D

    2014-01-01

    Group A rotaviruses (RVA) are the leading cause of severe diarrhea in young children worldwide. Two live-attenuated RVA vaccines, Rotarix® and RotaTeq® are recommended by World Health Organization (WHO) for routine immunization of all infants. Rotarix® and RotaTeq® vaccines have substantially reduced RVA associated mortality but occasionally have been associated with acute gastroenteritis (AGE) cases identified in vaccinees and their contacts. High-throughput assays are needed to monitor the prevalence of vaccine strains in AGE cases and emergence of new vaccine-derived strains following RVA vaccine introduction. In this study, we have developed quantitative real-time RT-PCR (qRT-PCR) assays for detection of Rotarix® and RotaTeq® vaccine components in stool samples. Real-time RT-PCR assays were designed for vaccine specific targets in the genomes of Rotarix® (NSP2, VP4) and RotaTeq® (VP6, VP3-WC3, VP3-human) and validated on sequence confirmed stool samples containing vaccine strains, wild-type RVA strains, and RVA-negative stools. For quantification, standard curves were generated using dsRNA transcripts derived from RVA gene segments. Rotarix® NSP2 and VP4 qRT-PCR assays exhibited 92–100% sensitivity, 99–100% specificity, 94–105% efficiency, and a limit of detection of 2–3 copies per reaction. RotaTeq® VP6, VP3-WC3, and VP3-human qRT-PCR assays displayed 100% sensitivity, 94–100% specificity, 91–102% efficiency and limits of detection of 1 copy, 2 copies, and 140 copies, respectively. These assays permit rapid identification of Rotarix® and RotaTeq® vaccine components in stool samples from clinical and surveillance studies and will be helpful in determining the frequency of vaccine strain-associated AGE. PMID:24342877

  5. Real-time RT-PCR assays to differentiate wild-type group A rotavirus strains from Rotarix(®) and RotaTeq(®) vaccine strains in stool samples.

    PubMed

    Gautam, Rashi; Esona, Mathew D; Mijatovic-Rustempasic, Slavica; Ian Tam, Ka; Gentsch, Jon R; Bowen, Michael D

    2014-01-01

    Group A rotaviruses (RVA) are the leading cause of severe diarrhea in young children worldwide. Two live-attenuated RVA vaccines, Rotarix(®) and RotaTeq(®) are recommended by World Health Organization (WHO) for routine immunization of all infants. Rotarix(®) and RotaTeq(®) vaccines have substantially reduced RVA associated mortality but occasionally have been associated with acute gastroenteritis (AGE) cases identified in vaccinees and their contacts. High-throughput assays are needed to monitor the prevalence of vaccine strains in AGE cases and emergence of new vaccine-derived strains following RVA vaccine introduction. In this study, we have developed quantitative real-time RT-PCR (qRT-PCR) assays for detection of Rotarix(®) and RotaTeq(®) vaccine components in stool samples. Real-time RT-PCR assays were designed for vaccine specific targets in the genomes of Rotarix(®) (NSP2, VP4) and RotaTeq(®) (VP6, VP3-WC3, VP3-human) and validated on sequence confirmed stool samples containing vaccine strains, wild-type RVA strains, and RVA-negative stools. For quantification, standard curves were generated using dsRNA transcripts derived from RVA gene segments. Rotarix(®) NSP2 and VP4 qRT-PCR assays exhibited 92-100% sensitivity, 99-100% specificity, 94-105% efficiency, and a limit of detection of 2-3 copies per reaction. RotaTeq(®) VP6, VP3-WC3, and VP3-human qRT-PCR assays displayed 100% sensitivity, 94-100% specificity, 91-102% efficiency and limits of detection of 1 copy, 2 copies, and 140 copies, respectively. These assays permit rapid identification of Rotarix(®) and RotaTeq(®) vaccine components in stool samples from clinical and surveillance studies and will be helpful in determining the frequency of vaccine strain-associated AGE. PMID:24342877

  6. Fatal, generalized bovine herpesvirus type-1 infection associated with a modified-live infectious bovine rhinotracheitis parainfluenza-3 vaccine administered to neonatal calves.

    PubMed Central

    Bryan, L A; Fenton, R A; Misra, V; Haines, D M

    1994-01-01

    Generalized bovine herpesvirus 1 (BHV-1) infection was diagnosed in six Salers calves from the same herd. The calves had received an intramuscular injection of modified-live infectious bovine rhinotracheitis parainfluenza-3 vaccine between birth and three days of age. The purpose of this study was to determine if the outbreak was associated with the vaccine strain of BHV-1. Analysis of epidemiological data and BHV-1 DNA for restriction fragment length polymorphism was undertaken. Multifocal necrosis in multiple organs was observed on pathological examination, and the presence of BHV-1 in tissues was confirmed by immunohistochemistry. Forty-three calves (aged birth to thirty days) were vaccinated over an 11-day interval. The 10 deaths recorded for vaccinated calves were clustered over a subsequent 14-day interval. Mortality in calves vaccinated between birth and three days of age was significantly higher than in nonvaccinated calves (chi-square test; p < or = 0.025), and this mortality was characterized by a greater age at death and duration of illness for vaccinated calves (t test; p < or = 0.001). The patterns of the restriction fragments, generated by six restriction endonucleases, of BHV-1 isolated from a necropsied calf and from the vaccine were identical, and different from that of a laboratory strain of BHV-1 (P8-2). These findings support the conclusion that newborn calves were susceptible to an intramuscularly injected vaccine strain of BHV-1, and that administration of an intramuscular modified-live infectious bovine rhinotracheitis parainfluenza-3 vaccine to neonatal calves may not be an innocuous procedure. Images Figure 1. Figure 3. PMID:8076277

  7. Comparative analysis of the complete genome sequences of two Australian origin live attenuated vaccines of infectious laryngotracheitis virus.

    PubMed

    Lee, Sang-Won; Devlin, Joanne M; Markham, John F; Noormohammadi, Amir H; Browning, Glenn F; Ficorilli, Nino P; Hartley, Carol A; Markham, Philip F

    2011-12-01

    Infectious laryngotracheitis virus (ILTV) is an alphaherpesvirus that causes acute respiratory disease in poultry. Live attenuated ILTV vaccines have been used extensively to help control outbreaks of disease. Two Australian-origin attenuated vaccine strains, SA2 and A20 ILTV, are commercially available and are in frequent use in Australia. Both these vaccines are of chicken embryo origin (CEO). The A20 ILTV strain was developed from the SA2 ILTV strain by sequential passage of SA2 ILTV in tissue culture in order to reduce its residual virulence. Previous studies in our laboratories have demonstrated the greater attenuation of A20 ILTV under controlled experimental conditions, but the genetic basis of the in vivo phenotypes of A20 and SA2 ILTV has not been elucidated. In this study, the genetic differences between A20 and SA2 ILTV were examined by performing complete genome sequencing and comparative analysis. The genome sequences were also compared to a reference sequence from another CEO ILTV vaccine (Serva ILTV: GenBank accession number HQ_630064) of European-origin. Additional in ovo studies to assess cell to cell spread were performed in order to allow further comparisons of the pathogenicity of SA2 and A20 ILTV. The sequencing results showed that the genome sizes of SA2 and A20 ILTV were 152,975 and 152,978bp, respectively, while Serva ILTV had a genome size of 152,630bp. The genomes of SA2 and A20 ILTV shared 99.9% nucleotide sequence identity with each other, but only 99.2% identity with Serva ILTV. In complete genome alignments between SA2 and A20 ILTV, a total of 24 single nucleotide polymorphisms (SNPs) were identified, but only two of these were non-synonymous. These were located in the ORF B and UL15 genes. Four indels were detected in non-coding regions. The findings from this study demonstrate the general genetic stability of ILTV, but also show that non-synonymous changes in the ORF B and UL15 genes have arisen following tissue culture passage of SA

  8. 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

  9. Recombinant rabies virus as potential live-viral vaccines for HIV-1

    PubMed Central

    Schnell, Matthias J.; Foley, Heather D.; Siler, Catherine A.; McGettigan, James P.; Dietzschold, Bernhard; Pomerantz, Roger J.

    2000-01-01

    Recombinant, replication-competent rabies virus (RV) vaccine strain-based vectors were developed expressing HIV type I (HIV-1) envelope glycoprotein (gp160) from both a laboratory-adapted (CXCR4-tropic) and a primary (dual-tropic) HIV-1 isolate. An additional transcription stop/start unit within the RV genome was used to express HIV-1 gp160 in addition to the other RV proteins. The HIV-1 gp160 protein was stably and functionally expressed, as indicated by fusion of human T cell lines after infection with the recombinant RVs. Inoculation of mice with the recombinant RVs expressing HIV-1 gp160 induced a strong humoral response directed against the HIV-1 envelope protein after a single boost with recombinant HIV-1 gp120 protein. Moreover, high neutralization titers up to 1:800 against HIV-1 could be detected in the mouse sera. These data indicate that a live recombinant RV, a rhabdovirus, expressing HIV-1 gp160 may serve as an effective vector for an HIV-1 vaccine. PMID:10706640

  10. Recombinant rabies virus as potential live-viral vaccines for HIV-1.

    PubMed

    Schnell, M J; Foley, H D; Siler, C A; McGettigan, J P; Dietzschold, B; Pomerantz, R J

    2000-03-28

    Recombinant, replication-competent rabies virus (RV) vaccine strain-based vectors were developed expressing HIV type I (HIV-1) envelope glycoprotein (gp160) from both a laboratory-adapted (CXCR4-tropic) and a primary (dual-tropic) HIV-1 isolate. An additional transcription stop/start unit within the RV genome was used to express HIV-1 gp160 in addition to the other RV proteins. The HIV-1 gp160 protein was stably and functionally expressed, as indicated by fusion of human T cell lines after infection with the recombinant RVs. Inoculation of mice with the recombinant RVs expressing HIV-1 gp160 induced a strong humoral response directed against the HIV-1 envelope protein after a single boost with recombinant HIV-1 gp120 protein. Moreover, high neutralization titers up to 1:800 against HIV-1 could be detected in the mouse sera. These data indicate that a live recombinant RV, a rhabdovirus, expressing HIV-1 gp160 may serve as an effective vector for an HIV-1 vaccine. PMID:10706640

  11. A systematic review of the efficacy of live attenuated influenza vaccine upon revaccination of children.

    PubMed

    Caspard, Herve; Heikkinen, Terho; Belshe, Robert B; Ambrose, Christopher S

    2016-07-01

    Four randomized, double-blind, placebo-controlled studies in 6090 children that investigated the efficacy of live attenuated influenza vaccine (LAIV) upon revaccination of children against laboratory-confirmed cases of influenza in consecutive seasons were reviewed. The efficacy in season 2 of LAIV administered over 2 consecutive seasons was 86.7% (95 % CI: 76.8%, 92.4%) against strains antigenically similar to those contained in the vaccine. The additional efficacy of LAIV administered in season 2 compared to LAIV recipients in season 1 only was 58.4% (28.3%, 75.9%). LAIV administered over 2 consecutive seasons also was more efficacious than was LAIV administered in season 2 only (relative efficacy: 53.9% [17.4%, 74.3%]). Residual efficacy of LAIV administered in season 1 only compared to placebo administered in two consecutive seasons was 56.4% (37.0%, 69.8%). This review did not find any evidence of decreasing efficacy of LAIV when administered during 2 consecutive seasons. PMID:26751513

  12. Clinical and epidemiological evaluation of a live, cold-adapted influenza vaccine for 3-14-year-olds.

    PubMed Central

    Rudenko, L. G.; Lonskaya, N. I.; Klimov, A. I.; Vasilieva, R. I.; Ramirez, A.

    1996-01-01

    Reported is a study of live, cold-adapted (CA) reassortant mono-, di-, and trivalent influenza type A and B vaccines in a series of controlled clinical and epidemiological investigations involving nearly 130 000 children aged 3-15 years. The results of clinical, immunological, and morbidity investigations of the vaccinees and a control group over 6-months' follow-up indicated that the vaccines were completely attenuated by the children. Transient febrile reactions occurred in < 1% of the children after vaccination, including double seronegative individuals with low antibody titres. The type A reisolates examined were genetically stable. The reassortants did not suppress each other after simultaneous inoculation of children and stimulated antibody response to influenza virus strains A1, A3, and B. The incidence of influenza-like diseases was approximately 30-40% lower among the vaccinated group than among the control group. The study demonstrates, for the first time, the efficacy of CA vaccine against infections caused by influenza B virus. PMID:8653819

  13. Genetic characterisation of attenuated SAD rabies virus strains used for oral vaccination of wildlife.

    PubMed

    Geue, Lutz; Schares, Susann; Schnick, Christina; Kliemt, Jeannette; Beckert, Aline; Freuling, Conrad; Conraths, Franz J; Hoffmann, Bernd; Zanoni, Reto; Marston, Denise; McElhinney, Lorraine; Johnson, Nicholas; Fooks, Anthony R; Tordo, Noel; Müller, Thomas

    2008-06-19

    The elimination of rabies from the red fox (Vulpes vulpes) in Western Europe has been achieved by the oral rabies vaccination (ORV) of wildlife with a range of attenuated rabies virus strains. With the exception of the vaccinia rabies glycoprotein recombinant vaccine (VRG), all strains were originally derived from a common ancestor; the Street Alabama Dufferin (SAD) field strain. However, after more than 30 years of ORV it is still not possible to distinguish these vaccine strains and there is little information on the genetic basis for their attenuation. We therefore sequenced and compared the full-length genome of five commercially available SAD vaccine viruses (SAD B19, SAD P5/88, SAG2, SAD VA1 and SAD Bern) and four other SAD strains (the original SAD Bern, SAD VA1, ERA and SAD 1-3670 Wistar). Nucleotide sequencing allowed identifying each vaccine strain unambiguously. Phylogenetic analysis revealed that the majority of the currently used commercial attenuated rabies virus vaccines appear to be derived from SAD B19 rather than from SAD Bern. One commercially available vaccine virus did not contain the SAD strain mentioned in the product information of the producer. Two SAD vaccine strains appeared to consist of mixed genomic sequences. Furthermore, in-del events targeting A-rich sequences (in positive strand) within the 3' non-coding regions of M and G genes were observed in SAD-derivates developed in Europe. Our data also supports the idea of a possible recombination that had occurred during the derivation of the European branch of SAD viruses. If confirmed, this recombination event would be the first one reported among RABV vaccine strains. PMID:18485548

  14. Optimization and Characterization of Candidate Strain for Coxsackievirus A16 Inactivated Vaccine

    PubMed Central

    Li, Jingliang; Liu, Guanchen; Liu, Xin; Yang, Jiaxin; Chang, Junliang; Zhang, Wenyan; Yu, Xiao-Fang

    2015-01-01

    Coxsackievirus A16 (CA16) and enterovirus 71 (EV71), both of which can cause hand, foot and mouth disease (HFMD), are responsible for large epidemics in Asian and Pacific areas. Although inactivated EV71 vaccines have completed testing in phase III clinical trials in Mainland China, CA16 vaccines are still under development. A Vero cell-based inactivated CA16 vaccine was developed by our group. Screening identified a CA16 vaccine strain (CC024) isolated from HFMD patients, which had broad cross-protective abilities and satisfied all requirements for vaccine production. Identification of the biological characteristics showed that the CA16CC024 strain had the highest titer (107.5 CCID50/mL) in Vero cells, which would benefit the development of an EV71/CA16 divalent vaccine. A potential vaccine manufacturing process was established, including the selection of optimal time for virus harvesting, membrane for diafiltration and concentration, gel-filtration chromatography for the down-stream virus purification and virus inactivation method. Altogether, the analyses suggested that the CC-16, a limiting dilution clone of the CC024 strain, with good genetic stability, high titer and broad-spectrum immunogenicity, would be the best candidate strain for a CA16 inactivated vaccine. Therefore, our study provides valuable information for the development of a Vero cell-based CA16 or EV71-CA16 divalent inactivated vaccine. PMID:26193302

  15. Optimization and Characterization of Candidate Strain for Coxsackievirus A16 Inactivated Vaccine.

    PubMed

    Li, Jingliang; Liu, Guanchen; Liu, Xin; Yang, Jiaxin; Chang, Junliang; Zhang, Wenyan; Yu, Xiao-Fang

    2015-07-01

    Coxsackievirus A16 (CA16) and enterovirus 71 (EV71), both of which can cause hand, foot and mouth disease (HFMD), are responsible for large epidemics in Asian and Pacific areas. Although inactivated EV71 vaccines have completed testing in phase III clinical trials in Mainland China, CA16 vaccines are still under development. A Vero cell-based inactivated CA16 vaccine was developed by our group. Screening identified a CA16 vaccine strain (CC024) isolated from HFMD patients, which had broad cross-protective abilities and satisfied all requirements for vaccine production. Identification of the biological characteristics showed that the CA16CC024 strain had the highest titer (107.5 CCID50/mL) in Vero cells, which would benefit the development of an EV71/CA16 divalent vaccine. A potential vaccine manufacturing process was established, including the selection of optimal time for virus harvesting, membrane for diafiltration and concentration, gel-filtration chromatography for the down-stream virus purification and virus inactivation method. Altogether, the analyses suggested that the CC-16, a limiting dilution clone of the CC024 strain, with good genetic stability, high titer and broad-spectrum immunogenicity, would be the best candidate strain for a CA16 inactivated vaccine. Therefore, our study provides valuable information for the development of a Vero cell-based CA16 or EV71-CA16 divalent inactivated vaccine. PMID:26193302

  16. Complex adenovirus-vectored vaccine protects guinea pigs from three strains of Marburg virus challenges

    SciTech Connect

    Wang Danher; Hevey, Michael; Juompan, Laure Y.; Trubey, Charles M.; Raja, Nicholas U.; Deitz, Stephen B.; Woraratanadharm, Jan; Luo Min; Yu Hong; Swain, Benjamin M.; Moore, Kevin M.; Dong, John Y. . E-mail: dongj@genphar.com

    2006-09-30

    The Marburg virus (MARV), an African filovirus closely related to the Ebola virus, causes a deadly hemorrhagic fever in humans, with up to 90% mortality. Currently, treatment of disease is only supportive, and no vaccines are available to prevent spread of MARV infections. In order to address this need, we have developed and characterized a novel recombinant vaccine that utilizes a single complex adenovirus-vectored vaccine (cAdVax) to overexpress a MARV glycoprotein (GP) fusion protein derived from the Musoke and Ci67 strains of MARV. Vaccination with the cAdVaxM(fus) vaccine led to efficient production of MARV-specific antibodies in both mice and guinea pigs. Significantly, guinea pigs vaccinated with at least 5 x 10{sup 7} pfu of cAdVaxM(fus) vaccine were 100% protected against lethal challenges by the Musoke, Ci67 and Ravn strains of MARV, making it a vaccine with trivalent protective efficacy. Therefore, the cAdVaxM(fus) vaccine serves as a promising vaccine candidate to prevent and contain multi-strain infections by MARV.

  17. Genetic stability of vaccine strains by multilocus sequence typing and pulsed-field gel electrophoresis analysis: Implications for quality control of the leptospiral vaccine

    PubMed Central

    Xu, Yinghua; Zhang, Jinlong; Cui, Shenghui; Li, Min; Zhang, Ying; Xue, Honggang; Xin, Xiaofang; Wang, Junzhi

    2015-01-01

    Quality control of vaccine strains is directly associated with the safety and efficacy of inactivated whole bacterial vaccines. The assessment of genetic stability is one of the essential elements to guarantee the quality of vaccine strains. The multiple-valence inactivated leptospiral vaccine, comprising the main circulating serogroups, has played an important role in the control of Leptospira infection in China. In the present study, to assess the genetic stability of vaccine strains and develop novel quality control tests that enhance and extend the existing procedures, 7 Chinese leptospiral vaccine strains were characterized during in vivo and in vitro passages by multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) analysis. The seven vaccine strains were found to have distinct sequence types (STs) and PFGE profiles. Further analysis showed that the ST and PFGE pattern of each vaccine strain, after in vivo or serial in vitro passages (up to 20 passages), were identical to those of the initial strain, demonstrating that these strains were genetically stable and homogeneous. Taken together, PFGE and MLST provide a reproducible and reliable means for confirming the identity and genetic stability of vaccine seeds, suggesting that these approaches can be used to evaluate the quality of leptospiral vaccine strains. PMID:25806658

  18. Salmonella abortusovis, strain Rv6, a new vaccinal vehicle for small ruminants.

    PubMed

    Bourgogne, A; Sanchis, R; Clément, J M; Pépin, M

    1998-03-31

    Salmonella abortusovis strain Rv6 (Sao Rv6) is a live attenuated vaccine used for a few years to protect ewes against abortive salmonellosis. As Salmonellae, particularly Salmonella aro mutants, have considerable potential as vehicles for the presentation of heterologous vaccine antigens, Sao Rv6 was tested in order to develop a vaccinal vehicle for small ruminants. Five vector plasmids were tested in Sao Rv6; these plasmids, which carry Maltose Binding Protein (MBP) expressed as protein, but differ in their promotors, had been previously tested in S. typhimurium strain SL3261, and were transferred into Sao Rv6. The five plasmids were stable in vitro, and the recombinant Sao Rv6 expressed MBP at various levels. Intraperitoneal infection of OF1 mice with the recombinant bacteria did not modify the characteristics of Sao Rv6; dissemination and infection levels were similar in all groups and all mice developed antibodies to Salmonella antigens as measured by ELISA. In contrast, only animals immunized with Sao Rv6 carrying the pNTE plasmid developed a serum antibody response to MBP. This plasmid was then tested in sheep; following subcutaneous immunization with Sao Rv6-pNTE, dissemination and infection levels were not modified in comparison with sheep immunized with Sao Rv6 lacking plasmid. Antibodies specific to MBP were detected in sera of sheep immunized with Sao Rv6-pNTE, purified MBP, and with S. typhimurium SL3261-pNTE as positive controls. These results demonstrate that Sao Rv6 can be used as a vehicle for heterologous antigens in sheep with pNTE as plasmid vector. PMID:9631532

  19. Protective immunity spectrum induced by immunization with a vaccine from the TBEV strain Sofjin.

    PubMed

    Chernokhaeva, L L; Rogova, Yu V; Vorovitch, M F; Romanova, L Iu; Kozlovskaya, L I; Maikova, G B; Kholodilov, I S; Karganova, G G

    2016-04-29

    Tick-borne encephalitis (TBE) circulates widely in the territory of Eurasia with up to 10,000 cases registered annually. The TBE virus (TBEV) includes three main subtypes: European, Siberian and Far-Eastern, and two new Asiatic variants, phylogenetically distant from the others. The inactivated antigen of European or Far-Eastern strains is used in commercial TBE vaccines. A set of 14 TBEV strains, isolated in 1937-2008, with different passage histories, representing all subtypes and variants, was used in this work. The chosen set covers almost all the TBE area. Sera of mice, immunized with the TBE vaccine Moscow, prepared from the TBEV strain Sofjin, were studied in a plaque neutralization test against the set of TBEV strains. The vaccine induced antibodies at a protective titer against all TBEV strains and Omsk hemorrhagic fever virus (OHFV) with Е protein amino acid distances of 0.008-0.069, but not against Powassan virus. We showed that after a course of two immunizations, factors such as the period between vaccinations (1-4 weeks), the challenging virus dose (30-1000 LD50) and terms of challenge (1-4 weeks after the last immunization) did not significantly affect the assessment of protective efficacy of the vaccine in vivo. The protective effect of the TBE vaccine Moscow against the set of TBEV strains and the OHFV was demonstrated in in vivo experiments. TBE vaccine Moscow did not protect mice against 10 LD50 of the Powassan virus. We showed that this range of Е protein amino acid distances between the vaccine strain and challenging virus do not have a decisive impact on the TBE vaccine protective effect in vitro and in vivo. Moreover, the TBE vaccine Moscow induces an immune response protective against a wide range of TBEV variants. PMID:27013433

  20. 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. PMID:24013364

  1. 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

  2. Molecular characterization of a novobiocin-resistant Aeromonas hydrophila catfish vaccine strain compared to its virulent parent strain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A total of 10 and 13 missense mutations were found in the deduced gyrB and rpoB proteins, respectively, between avirulent AH11NOVO vaccine strain and its virulent parent strain AH11P. SDS-PAGE revealed that six proteins bands were significantly over-expressed in AH11NOVO whereas five bands were sign...

  3. Molecular characterization of a novobiocin-resistant Aeromonas hydrophila catfish vaccine strain compared to its virulent parent strain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A total of 10 and 13 missense mutations were found in the deduced GyrB and RpoB proteins, respectively, between avirulent AH11NOVO vaccine strain and its virulent parent strain AH11P. SDS-PAGE revealed that six proteins bands were significantly over-expressed in AH11NOVO whereas five bands were sign...

  4. Development and introduction of inactivated poliovirus vaccines derived from Sabin strains in Japan.

    PubMed

    Shimizu, Hiroyuki

    2016-04-01

    During the endgame of global polio eradication, the universal introduction of inactivated poliovirus vaccines is urgently required to reduce the risk of vaccine-associated paralytic poliomyelitis and polio outbreaks due to wild and vaccine-derived polioviruses. In particular, the development of inactivated poliovirus vaccines (IPVs) derived from the attenuated Sabin strains is considered to be a highly favorable option for the production of novel IPV that reduce the risk of facility-acquired transmission of poliovirus to the communities. In Japan, Sabin-derived IPVs (sIPVs) have been developed and introduced for routine immunization in November 2012. They are the first licensed sIPVs in the world. Consequently, trivalent oral poliovirus vaccine was used for polio control in Japan for more than half a century but has now been removed from the list of vaccines licensed for routine immunization. This paper reviews the development, introduction, characterization, and global status of IPV derived from attenuated Sabin strains. PMID:25448090

  5. Evaluation of the field efficacy of an avirulent live Lawsonia intracellularis vaccine in foals.

    PubMed

    Nogradi, N; Slovis, N M; Gebhart, C J; Wolfsdorf, K E; McCracken, J L; Scoggin, C F; Kass, P H; Mapes, S M; Toth, B; Lundquist, M L; Pusterla, N

    2012-06-01

    Equine proliferative enteropathy caused by Lawsonia intracellularis is an emerging disease with as yet unaddressed preventative measures. The hypothesis of this study was that vaccination will prevent clinical and sub-clinical disease. Weanling Thoroughbreds (n=202) from Central Kentucky were randomly assigned into two groups (vaccinated and non-vaccinated). Vaccinated foals received 30 mL of an avirulent, live L. intracellularis vaccine intra-rectally twice, 30 days apart. Foals were monitored for clinical disease, total solids and average weight gain until yearling age. There was an overall decreased disease incidence on the farms involved in the study that did not differ significantly between the groups. This decreased disease prevalence in the study population may be associated with the ongoing vaccine trial on these farms, as disease prevalence in Central Kentucky did not change in 2009 compared to 2008. PMID:21741284

  6. Genotype Characterization of Commonly Used Newcastle Disease Virus Vaccine Strains of India

    PubMed Central

    Gaikwad, Satish; Kataria, Jag Mohan; Vakharia, Vikram N.

    2014-01-01

    Newcastle disease is an avian pathogen causing severe economic losses to the Indian poultry industry due to recurring outbreaks in vaccinated and unvaccinated flocks. India being an endemic country, advocates vaccination against the virus using lentogenic and mesogenic strains. Two virus strains which are commonly used for vaccination are strain F (a lentogenic virus) and strain R2B (a mesogenic virus). Strain F is given to 0–7 days old chicks and R2B is given to older birds which are around 6–8 weeks old. To understand the genetic makeup of these two strains, a complete genome study and phylogenetic analysis of the F, HN genes of these vaccine strains were carried out. Both the viral strains had a genome length of 15,186 nucleotides and consisted of six genes with conserved complimentary 3' leader and 5' trailer regions. The fusion protein cleavage site of strain F is GGRQGRL and strain R2B is RRQKRF. Although both the viral strains had different virulence attributes, the length of the HN protein was similar with 577 amino acids. Phylogenetic analysis of F, HN and complete genome sequences grouped these two strains in genotype II category which are considered as early genotypes and corroborated with their years of isolation. PMID:24897503

  7. Modified live virus vaccine induces a distinct immune response profile compared to inactivated influenza A virus vaccines in swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic and antigenic diversity within H1 influenza A virus (IAV) subtypes circulating in swine is increasing. The need for cross-protective influenza vaccines in swine is necessary as the virus becomes more diverse. This study compared the humoral and cell-mediated immune response of modified live ...

  8. Reproductive performance of gilts following vaccination and subsequent heterologous challenge with European strains of porcine reproductive and respiratory syndrome virus.

    PubMed

    Scortti, Mariela; Prieto, Cinta; Simarro, Isabel; Castro, José Maria

    2006-11-01

    The objective of this study was to evaluate the efficacy of two commercially available modified live virus vaccines for preventing the reproductive and early postnatal consequences of infecting (challenging) pregnant gilts with virulent porcine reproductive and respiratory syndrome virus (PRRSV). For this purpose 21 crossbred gilts were allocated to one or another of four groups (Groups A-D). Group A comprised four gilts neither vaccinated nor challenged; Group B comprised five gilts that were challenged but not vaccinated; Group C comprised seven gilts that were vaccinated (AmervacPRRS) and challenged; Group D comprised five gilts that were vaccinated (Pyrsvac-183) and challenged. Vaccination was 24 days before conception, and challenge was at 90 days of gestation. Both vaccine viruses and the challenge virus were European strains but differed in part from one another on the basis of their genetic (nucleotide) sequence. After challenge PRRSV was isolated from five (100%), four (57%), and two (40%) of the gilts of Groups B, C and D, respectively. Although vaccination failed to prevent a detectable viremia in all of the gilts of Groups C and D after they were challenged (or congenital infection of some of their pigs), it did provide a statistically significant level of protection in regard to the incidence of congenital infection, reproductive performance, and pig health and viability. Namely, for Groups C and D the numbers of liveborn pigs/litter and healthy pigs/litter throughout the early postnatal period were similar to those of Group A (nonvaccinated and nonchallenged) and far exceeded those of Group B (nonvaccinated and challenged). PMID:16806451

  9. Protection conferred by live infectious bronchitis vaccine viruses against variant Middle East IS/885/00-like and IS/1494/06-like isolates in commercial broiler chicks

    PubMed Central

    Awad, Faez; Forrester, Anne; Baylis, Matthew; Lemiere, Stephane; Ganapathy, Kannan

    2015-01-01

    The ability of the infectious bronchitis H120 (a Massachusetts strain) and CR88 (a 793B strain) live attenuated vaccine viruses to protect from two Middle East infectious bronchitis virus isolates, IS/885/00-like (IS/885) and IS/1494/06-like (IS/1494) in broiler chicks was investigated. Day-old chicks were separated into three groups, (I) vaccinated with H120 at day-old followed by CR88 at 14 days-old, (II) vaccinated with H120 and CR88 simultaneously at day-old and again with CR88 at 14 days-old, (III) control unvaccinated. At 30 days-old, each of the groups was challenged with virulent IS/885 or IS/1494. Protection was evaluated based on the clinical signs, tracheal and kidney gross lesions and tracheal ciliostasis. Results showed that administering combined live H120 and CR88 vaccines simultaneously at day-old followed by CR88 vaccine at 14 days-old gave more than 80 per cent tracheal ciliary protection from both of the Middle East isolates. In addition, this programme conferred 100 per cent protection from clinical signs and tracheal or kidney lesions. The other vaccination programme, H120 at day-old followed by CR88 at 14 days-old, the tracheal ciliary protection conferred were 60 per cent and 80 per cent from IS/885/00-like and IS/1494/06-like, respectively. PMID:26392909

  10. Effects of challenge with a virulent genotype II strain of porcine reproductive and respiratory syndrome virus on piglets vaccinated with an attenuated genotype I strain vaccine.

    PubMed

    Roca, M; Gimeno, M; Bruguera, S; Segalés, J; Díaz, I; Galindo-Cardiel, I J; Martínez, E; Darwich, L; Fang, Y; Maldonado, J; March, R; Mateu, E

    2012-07-01

    Porcine reproductive and respiratory syndrome virus (PRRSV) is endemic in most parts of Asia, where genotype I and II strains of diverse virulence may coexist. This study evaluated the outcome of infection with a highly virulent Asian genotype II PRRSV isolate in piglets vaccinated with a genotype I vaccine. Twenty-one 3-week-old piglets were divided in three groups: Pigs in group V (n=8) were vaccinated with an attenuated genotype I commercial PRRSV vaccine, while pigs in group U (n=8) and a control group (group C; n=5) were unvaccinated; 6 weeks later, pigs in groups V and U were challenged intranasally with a highly virulent strain of genotype II PRRSV (1×10(5) 50% tissue culture infectious doses/mL), while pigs in group C received a placebo. Over a period of 21 days after challenge, vaccinated pigs had significantly lower mortality (0/8 versus 2/8), fewer days of fever, a lower frequency of catarrhal bronchopneumonia, higher weight gains (13.4 versus 6.6 kg) and lower levels of viraemia compared to unvaccinated challenged pigs. Immunisation with a genotype I attenuated PRRSV vaccine provided partial protection against challenge with a highly virulent genotype II strain. PMID:22264642

  11. Immune responses of bison and efficacy after booster vaccination with Brucella abortus strain RB51.

    PubMed

    Olsen, S C; McGill, J L; Sacco, R E; Hennager, S G

    2015-04-01

    Thirty-one bison heifers were randomly assigned to receive saline or a single vaccination with 10(10) CFU of Brucella abortus strain RB51. Some vaccinated bison were randomly selected for booster vaccination with RB51 at 11 months after the initial vaccination. Mean antibody responses to RB51 were greater (P < 0.05) in vaccinated bison after initial and booster vaccination than in nonvaccinated bison. The proliferative responses by peripheral blood mononuclear cells (PBMC) from the vaccinated bison were greater (P < 0.05) than those in the nonvaccinated bison at 16 and 24 weeks after the initial vaccination but not after the booster vaccination. The relative gene expression of gamma interferon (IFN-γ) was increased (P < 0.05) in the RB51-vaccinated bison at 8, 16, and 24 weeks after the initial vaccination and at 8 weeks after the booster vaccination. The vaccinated bison had greater (P < 0.05) in vitro production of IFN-γ at all sampling times, greater interleukin-1β (IL-1β) production in various samplings after the initial and booster vaccinations, and greater IL-6 production at one sampling time after the booster vaccination. Between 170 and 180 days of gestation, the bison were intraconjunctivally challenged with approximately 1 × 10(7) CFU of B. abortus strain 2308. The incidences of abortion and infection were greater (P < 0.05) in the nonvaccinated bison after experimental challenge than in the bison receiving either vaccination treatment. Booster-vaccinated, but not single-vaccinated bison, had a reduced (P < 0.05) incidence of infection in fetal tissues and maternal tissues compared to that in the controls. Compared to the nonvaccinated bison, both vaccination treatments lowered the colonization (measured as the CFU/g of tissue) of Brucella organisms in all tissues, except in retropharyngeal and supramammary lymph nodes. Our study suggests that RB51 booster vaccination is an effective vaccination strategy for enhancing herd immunity against

  12. Malaria Vaccine Protection Short-Lived in Young Children

    MedlinePlus

    ... a situation where unvaccinated children have more natural immunity than vaccinated children, and therefore get less malaria," ... may allow a person to develop some natural immunity to the parasite, Plowe suggested. "You're basically ...

  13. Evaluation of protective immune response against fowl typhoid in chickens vaccinated with the attenuated strain Salmonella Gallinarum ΔcobSΔcbiA.

    PubMed

    Penha Filho, Rafael Antonio Casarin; Diaz, Silvia Juliana Acelas; Medina, Tiago da Silva; Chang, Yung-Fu; da Silva, João Santana; Berchieri, Angelo

    2016-08-01

    Salmonella enterica serovar Gallinarum biovar Gallinarum (SG) causes fowl typhoid in chickens, a septicemic infection which results in high mortality rates. This disease causes high economic impact to the poultry industry worldwide because of the mortality or elimination of positive flocks to control bacterial dissemination. Live vaccines are used in the fields, however the characterization of immune mechanisms important for protection are being studied to improve the efficacy of vaccination schemes. In this study, we evaluated the immune response in brown layer-hens, vaccinated or not, during the most critical period of infection. Cellular and humoral immunity were extensively evaluated until 7 days post-infection (DPI), by flow cytometry and ELISA, respectively. Furthermore, we evaluated the expression of important pro-inflammatory cytokines after infection of bone marrow derived macrophages (BMDMs) with the live attenuated SG vaccine and with the wild SG strain. The results showed an increasing production of IgG and IgM during the first week post-infection, in vaccinated layer-hens, which was absent in unvaccinated birds. The population of CD8(+)CD44(+) and CD4(+)CD44(+) T cells in spleen and cecal tonsils constantly decreased in unvaccinated birds in comparison with vaccinated layers. The expression of IFN-γ and TNF-α in BMDMs was induced by both SG strains (attenuated and wild) at similar levels (p>0.05). Vaccination with live SG vaccine reduced systemic infection by challenge strain of SG and prevented the mortality rate of 85% that occurred in unvaccinated layer-hens during 30 dpi. Furthermore, the immunization enhanced the proliferation of effector CD4(+) and CD8(+) T cells after challenge. PMID:27473999

  14. Co-transmission of the non-transmissible South African Babesia bovis S24 vaccine strain during mixed infection with a field isolate.

    PubMed

    Combrink, M P; Troskie, P C; de Klerk, D G; Pienaar, R; Latif, A A; Mans, B J

    2015-03-01

    The South African Babesia bovis live blood vaccine, originating from a field isolate attenuated by 23 serial syringe passages in splenectomized calves, has lost the ability to infect the natural vector Rhipicephalus (Boophilus) microplus. In this study, infection with mixed parasites from the vaccine strain and a field isolate, resulted in transmission of both genotype populations. Comparing the field isolate and transmitted combination indicated no significant difference in their virulence, while challenge of vaccinated cattle with these isolates showed the ability of the vaccine to protect against both. Limiting dilution of the transmitted combination, followed by infection of splenectomized cattle (n=34) yielded no single infections for the vaccine strain genotype, seven clonal lines of the field isolate and one mixture of vaccine strain and field isolate. Only one of two field isolate clonal lines selected for vector transmission study was transmitted. Showing that B. bovis isolates can contain both tick transmissible and non-transmissible subpopulations. The findings of this study also indicate the probability of vaccine co-infection transmission occurring in the field, which may result in new genotype populations of B. bovis. However, the impact of this recombination with field isolates is considered negligible since a genotypically diverse population of B. bovis is already present in South Africa. PMID:25544307

  15. A Pandemic Influenza H1N1 Live Vaccine Based on Modified Vaccinia Ankara Is Highly Immunogenic and Protects Mice in Active and Passive Immunizations

    PubMed Central

    Hessel, Annett; Schwendinger, Michael; Fritz, Daniela; Coulibaly, Sogue; Holzer, Georg W.; Sabarth, Nicolas; Kistner, Otfried; Wodal, Walter; Kerschbaum, Astrid; Savidis-Dacho, Helga; Crowe, Brian A.; Kreil, Thomas R.; Barrett, P. Noel; Falkner, Falko G.

    2010-01-01

    Background The development of novel influenza vaccines inducing a broad immune response is an important objective. The aim of this study was to evaluate live vaccines which induce both strong humoral and cell-mediated immune responses against the novel human pandemic H1N1 influenza virus, and to show protection in a lethal animal challenge model. Methodology/Principal Findings For this purpose, the hemagglutinin (HA) and neuraminidase (NA) genes of the influenza A/California/07/2009 (H1N1) strain (CA/07) were inserted into the replication-deficient modified vaccinia Ankara (MVA) virus - a safe poxviral live vector – resulting in MVA-H1-Ca and MVA-N1-Ca vectors. These live vaccines, together with an inactivated whole virus vaccine, were assessed in a lung infection model using immune competent Balb/c mice, and in a lethal challenge model using severe combined immunodeficient (SCID) mice after passive serum transfer from immunized mice. Balb/c mice vaccinated with the MVA-H1-Ca virus or the inactivated vaccine were fully protected from lung infection after challenge with the influenza H1N1 wild-type strain, while the neuraminidase virus MVA-N1-Ca induced only partial protection. The live vaccines were already protective after a single dose and induced substantial amounts of neutralizing antibodies and of interferon-γ-secreting (IFN-γ) CD4- and CD8 T-cells in lungs and spleens. In the lungs, a rapid increase of HA-specific CD4- and CD8 T cells was observed in vaccinated mice shortly after challenge with influenza swine flu virus, which probably contributes to the strong inhibition of pulmonary viral replication observed. In addition, passive transfer of antisera raised in MVA-H1-Ca vaccinated immune-competent mice protected SCID mice from lethal challenge with the CA/07 wild-type virus. Conclusions/Significance The non-replicating MVA-based H1N1 live vaccines induce a broad protective immune response and are promising vaccine candidates for pandemic influenza

  16. Improved Newcastle disease vaccine approaches using virus strains selected on antigenic composition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Virulent Newcastle disease viruses (NDV) from the 1971 to 2002 U.S. outbreaks, are the same serotype but a different genotype than current vaccine strains. It is widely recognized that an efficacious Newcastle disease (ND) vaccine made with any NDV does induce protection against morbidity and morta...

  17. Experimental studies with homologous subtype vaccines produced with multiple antigenically different seed strains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Due to the high antigenic variability of avian influenza virus, vaccines need to be continually updated to maintain adequate protection to evolving field strains. One possible approach, to mitigating the effects of antigenic change, is to use vaccines containing more than one isolate of the same su...

  18. Genome sequence of SG33 strain and recombination between wild-type and vaccine myxoma viruses.

    PubMed

    Camus-Bouclainville, Christelle; Gretillat, Magalie; Py, Robert; Gelfi, Jacqueline; Guérin, Jean Luc; Bertagnoli, Stéphane

    2011-04-01

    Myxomatosis in Europe is the result of the release of a South America strain of myxoma virus in 1952. Several attenuated strains with origins in South America or California have since been used as vaccines in the rabbit industry. We sequenced the genome of the SG33 myxoma virus vaccine strain and compared it with those of other myxoma virus strains. We show that SG33 genome carries a large deletion in its right end. Furthermore, our data strongly suggest that the virus isolate from which SG33 is derived results from an in vivo recombination between a wild-type South America (Lausanne) strain and a California MSD-derived strain. These findings raise questions about the use of insufficiently attenuated virus in vaccination. PMID:21470452

  19. Comparison of living and nonliving vaccines for Brucella abortus in BALB/c mice.

    PubMed Central

    Montaraz, J A; Winter, A J

    1986-01-01

    The BALB/c mouse was selected as a model for infection with Brucella abortus on the basis of protracted nonclinical infection produced by strain 2308, virulent for cattle, and relatively rapid clearance of strain 19, an attenuated strain used to vaccinate cattle. Protection in mice vaccinated with strain 19 was compared with that obtained with nonliving vaccines at early (1 week) and later (4 weeks) intervals after challenge with strain 2308 and assessed by enumeration of B. abortus organisms in the spleen. Mice challenged 4 weeks after vaccination with strain 19 exhibited significant protection at 1 and 4 weeks postinfection (p.i.), with an increased magnitude of protection at the later time. When challenged 6 weeks after vaccination with strain 19, the level of protection diminished between 1 and 4 weeks p.i. and at the later time was not always significantly different from controls. Mice immunized 4 weeks earlier with nonliving vaccines in mineral oil with t trehalose dimycolate (TDM) and muramyl dipeptide (MDP) demonstrated patterns of protection similar to those obtained following the 6 week vaccination-challenge interval with strain 19. Vaccination with cell envelopes derived from strain 2308 produced equivalent protection at 1 week p.i. whether administered in phosphate-buffered saline, incomplete Freund adjuvant, or the TDM and MDP adjuvant. Equivalent protection also followed vaccination with strain 2308 killed whole cells, cell envelopes, or outer membrane proteins in phosphate-buffered saline or in the TDM and MDP adjuvant. The TDM and MDP adjuvant alone induced nonspecific resistance, which peaked at 1 day p.i. and was still present at 1 week p.i., although by this time its magnitude was significantly less than the protection induced by antigen combined with the adjuvant. These data, together with the results of antibody assays and passive and adoptive transfer studies, suggested that protection at 1 week p.i. could be accounted for largely by an effect

  20. Methods to Evaluate the Preclinical Safety and Immunogenicity of Genetically Modified Live-Attenuated Leishmania Parasite Vaccines.

    PubMed

    Gannavaram, Sreenivas; Bhattacharya, Parna; Dey, Ranadhir; Ismail, Nevien; Avishek, Kumar; Salotra, Poonam; Selvapandiyan, Angamuthu; Satoskar, Abhay; Nakhasi, Hira L

    2016-01-01

    Live-attenuated parasite vaccines are being explored as potential vaccine candidates since other approaches of vaccination have not produced an effective vaccine so far. In order for live-attenuated parasite vaccines to be tested in preclinical studies and possibly in clinical studies, the safety and immunogenicity of these organisms must be rigorously evaluated. Here we describe methods to test persistence in the immunized host and immunogenicity, and to identify biomarkers of vaccine safety and efficacy with particular reference to genetically attenuated Leishmania parasites. PMID:27076157

  1. Engineering of a live Salmonella enterica serovar Choleraesuis negative-marker strain that allows serological differentiation between immunised and infected animals.

    PubMed

    Herrero-Gil, Aldara; Carrión, Javier; Orden, Jose A; de la Fuente, Ricardo; Domínguez-Bernal, Gustavo

    2016-07-01

    The usefulness of Salmonella vaccine vehicles is limited by the fact that control programmes relying on Salmonella bacteriology and serology cannot differentiate infected animals from vaccinated ones, an ability referred to as DIVA (differentiating infected from vaccinated animals). As a first step towards Salmonella-based DIVA vaccines, the ompA gene was deleted in live attenuated ΔphoP and ΔrpoS vaccine strains. The ompA gene is present in all Salmonella enterica serovars and it encodes an abundant, highly immunogenic outer membrane protein. The double mutant ΔphoP ΔompA and ΔrpoS ΔompA strains showed similar virulence attenuation, safety and immunogenicity in a mouse model of infection as the parental ΔphoP and ΔrpoS strains. Sera from mice inoculated with the double mutant strains failed to recognise OmpA in Western blots of outer membrane extracts, whereas the protein was recognised by sera from mice inoculated with wild-type Salmonella or a mixture of double mutant and parental strains. These data suggest that OmpA can be a suitable negative marker for DIVA vaccines. PMID:27240916

  2. Genomic variations associated with attenuation in Mycobacterium avium subsp. paratuberculosis vaccine strains

    PubMed Central

    2013-01-01

    Background Mycobacterium avium subspecies paratuberculosis (MAP) whole cell vaccines have been widely used tools in the control of Johne’s disease in animals despite being unable to provide complete protection. Current vaccine strains derive from stocks created many decades ago; however their genotypes, underlying mechanisms and relative degree of their attenuation are largely unknown. Results Using mouse virulence studies we confirm that MAP vaccine strains 316 F, II and 2e have diverse but clearly attenuated survival and persistence characteristics compared with wild type strains. Using a pan genomic microarray we characterise the genomic variations in a panel of vaccine strains sourced from stocks spanning over 40 years of maintenance. We describe multiple genomic variations specific for individual vaccine stocks in both deletion (26–32 Kbp) and tandem duplicated (11–40 Kbp) large variable genomic islands and insertion sequence copy numbers. We show individual differences suitable for diagnostic differentiation between vaccine and wild type genotypes and provide evidence for functionality of some of the deleted MAP-specific genes and their possible relation to attenuation. Conclusions This study shows how culture environments have influenced MAP genome diversity resulting in large tandem genomic duplications, deletions and transposable element activity. In combination with classical selective systematic subculture this has led to fixation of specific MAP genomic alterations in some vaccine strain lineages which link the resulting attenuated phenotypes with deficiencies in high reactive oxygen species handling. PMID:23339684

  3. Comparison of antibody response to a non-adjuvanted, live canarypox-vectored recombinant rabies vaccine and a killed, adjuvanted rabies vaccine in Eld's deer (Rucervus eldi thamin).

    PubMed

    Marrow, Judilee C; Padilla, Luis R; Hayek, Lee-Ann C; Bush, Mitch; Murray, Suzan

    2014-06-01

    Captive Eld's deer (Rucervus eldi thamin) were evaluated for the presence of rabies virus-neutralizing antibodies using a rapid fluorescent focus inhibition after vaccination with either a live canarypox-vectored recombinant rabies vaccine or a killed monovalent rabies vaccine. Twelve deer were vaccinated with 1.0 ml of killed, adjuvanted, monovalent rabies vaccine at 5-33 mo of age then annually thereafter, and 14 deer were vaccinated with 1.0 ml nonadjuvanted, live canarypox-vectored rabies vaccine at 3-15 mo of age then annually thereafter. Banked serum was available or collected prospectively from deer at 6 mo and 1 yr after initial vaccination, then collected annually. Rabies virus-neutralizing antibodies considered adequate (>0.5 IU/ml) were present in 20/34 samples vaccinated with canarypox-vectored rabies vaccine and in 12/14 samples vaccinated with killed adjuvanted rabies vaccine. Poor seroconversion was noted in deer less than 6 mo of age vaccinated with the canarypox-vectored rabies vaccine. PMID:25000692

  4. Uptake and impact of vaccinating school age children against influenza during a season with circulation of drifted influenza A and B strains, England, 2014/15.

    PubMed

    Pebody, Richard G; Green, Helen K; Andrews, Nick; Boddington, Nicola L; Zhao, Hongxin; Yonova, Ivelina; Ellis, Joanna; Steinberger, Sophia; Donati, Matthew; Elliot, Alex J; Hughes, Helen E; Pathirannehelage, Sameera; Mullett, David; Smith, Gillian E; de Lusignan, Simon; Zambon, Maria

    2015-01-01

    The 2014/15 influenza season was the second season of roll-out of a live attenuated influenza vaccine (LAIV) programme for healthy children in England. During this season, besides offering LAIV to all two to four year olds, several areas piloted vaccination of primary (4-11 years) and secondary (11-13 years) age children. Influenza A(H3N2) circulated, with strains genetically and antigenically distinct from the 2014/15 A(H3N2) vaccine strain, followed by a drifted B strain. We assessed the overall and indirect impact of vaccinating school age children, comparing cumulative disease incidence in targeted and non-targeted age groups in vaccine pilot to non-pilot areas. Uptake levels were 56.8% and 49.8% in primary and secondary school pilot areas respectively. In primary school age pilot areas, cumulative primary care influenza-like consultation, emergency department respiratory attendance, respiratory swab positivity, hospitalisation and excess respiratory mortality were consistently lower in targeted and non-targeted age groups, though less for adults and more severe end-points, compared with non-pilot areas. There was no significant reduction for excess all-cause mortality. Little impact was seen in secondary school age pilot only areas compared with non-pilot areas. Vaccination of healthy primary school age children resulted in population-level impact despite circulation of drifted A and B influenza strains. PMID:26537222

  5. Impact of variation in acute virulence of BVDV1 strains on design of better vaccine efficacy challenge models

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Due to antigenic differences between BVDV1 and BVDV2 strains both pestivirus species are included in U.S. vaccines. The efficacy of these vaccines in preventing acute infections is evaluated based on reduction of clinical disease. While high virulence BVDV2 strains are used in U.S. vaccine efficac...

  6. Comparison of a live attenuated Salmonella Enteritidis vaccine candidate secreting Escherichia coli heat-labile enterotoxin B subunit with a commercial vaccine for efficacy of protection against internal egg contamination by Salmonella in hens

    PubMed Central

    Nandre, Rahul M.; Eo, Seong Kug; Park, Sang Youel; Lee, John Hwa

    2015-01-01

    This study compared a new live attenuated Salmonella Enteritidis vaccine candidate secreting Escherichia coli heat-labile enterotoxin B subunit (SE-LTB) with a commercial Salmonella Enteritidis (SE) vaccine for efficacy of protection against SE infection in laying hens. Chickens were divided into 3 groups of 20 each. Group A chickens were inoculated orally with phosphate-buffered saline and served as controls, group B chickens were inoculated orally with the vaccine candidate, and group C chickens were inoculated intramuscularly with a commercial vaccine, the primary inoculation in groups B and C being at 10 wk of age and the booster at 16 wk. Groups B and C showed significantly higher titers of plasma immunoglobulin G, intestinal secretory immunoglobulin A, and egg yolk immunoglobulin Y antibodies compared with the control group, and both vaccinated groups showed a significantly elevated cellular immune response. After virulent challenge, group B had significantly lower production of thin-shelled and/or malformed eggs and a significantly lower rate of SE contamination of eggs compared with the control group. Furthermore, the challenge strain was detected significantly less in all of the examined organs of group B compared with the control group. Group C had lower gross lesion scores only in the spleen and had lower bacterial counts only in the spleen, ceca, and ovary. These findings indicate that vaccination with the SE-LTB vaccine candidate can efficiently reduce internal egg and internal organ contamination by Salmonella and has advantages over the commercial vaccine. PMID:26130857

  7. Comparison of infectious bursal disease live vaccines and a HVT-IBD vector vaccine and their effects on the immune system of commercial layer pullets.

    PubMed

    Prandini, Francesco; Simon, Birgid; Jung, Arne; Pöppel, Manfred; Lemiere, Stéphane; Rautenschlein, Silke

    2016-02-01

    Infectious bursal disease (IBD) is an economically important disease affecting poultry production worldwide. Previous experimental studies indicated that IBD live vaccination may induce transient immunosuppression, leading to suboptimal vaccine responses and therefore insufficient protection against other pathogens. Layer pullets are commonly not only vaccinated against IBD within their rearing period, but also against a variety of other pathogens. Therefore, it is of interest to investigate the effects of different IBD vaccination regimes on conventionally applied vaccines against other pathogens, and possible protection against widely spread very virulent IBD-virus (vvIBDV). A commercially available Herpesvirus of turkey vector vaccine (vHVT-IBD) expressing viral protein 2 of IBDV, and two IBD live vaccines were compared in commercial pullets for their effects on circulating B cell numbers, the ability of vaccinated birds to mount a humoral immune response against different antigens as well as their ability to induce protection against vvIBDV challenge. The results of this study demonstrate a clear immunosuppressive effect of the intermediate plus IBD live vaccine on the humoral branch of the immune system. On the other hand, no detectable effects of vHVT-IBD vaccination on these parameters were observed. All tested IBD vaccines protected against clinical IBD, although none induced sterile immunity in commercial layer pullets. vHVT-IBD-vaccinated birds showed significantly less lesions after vvIBDV challenge than IBD live-vaccinated or non-vaccinated birds (P < 0.05). Therefore, vHVT-IBD may be a suitable alternative to conventional IBD live vaccines, and may be applied even in the presence of maternally derived IBD antibodies without induction of detectable humoral immunosuppression. PMID:26743805

  8. A rapid immunization strategy with a live-attenuated tetravalent dengue vaccine elicits protective neutralizing antibody responses in non-human primates.

    PubMed

    Ambuel, Yuping; Young, Ginger; Brewoo, Joseph N; Paykel, Joanna; Weisgrau, Kim L; Rakasz, Eva G; Haller, Aurelia A; Royals, Michael; Huang, Claire Y-H; Capuano, Saverio; Stinchcomb, Dan T; Partidos, Charalambos D; Osorio, Jorge E

    2014-01-01

    Dengue viruses (DENVs) cause approximately 390 million cases of DENV infections annually and over 3 billion people worldwide are at risk of infection. No dengue vaccine is currently available nor is there an antiviral therapy for DENV infections. We have developed a tetravalent live-attenuated DENV vaccine tetravalent dengue vaccine (TDV) that consists of a molecularly characterized attenuated DENV-2 strain (TDV-2) and three chimeric viruses containing the pre-membrane and envelope genes of DENV-1, -3, and -4 expressed in the context of the TDV-2 genome. To impact dengue vaccine delivery in endemic areas and immunize travelers, a simple and rapid immunization strategy (RIS) is preferred. We investigated RIS consisting of two full vaccine doses being administered subcutaneously or intradermally on the initial vaccination visit (day 0) at two different anatomical locations with a needle-free disposable syringe jet injection delivery devices (PharmaJet) in non-human primates. This vaccination strategy resulted in efficient priming and induction of neutralizing antibody responses to all four DENV serotypes comparable to those elicited by the traditional prime and boost (2 months later) vaccination schedule. In addition, the vaccine induced CD4(+) and CD8(+) T cells producing IFN-γ, IL-2, and TNF-α, and targeting the DENV-2 NS1, NS3, and NS5 proteins. Moreover, vaccine-specific T cells were cross-reactive with the non-structural NS3 and NS5 proteins of DENV-4. When animals were challenged with DENV-2 they were protected with no detectable viremia, and exhibited sterilizing immunity (no increase of neutralizing titers post-challenge). RIS could decrease vaccination visits and provide quick immune response to all four DENV serotypes. This strategy could increase vaccination compliance and would be especially advantageous for travelers into endemic areas. PMID:24926294

  9. A potent Brucella abortus 2308 Δery live vaccine allows for the differentiation between natural and vaccinated infection.

    PubMed

    Zhang, Junbo; Yin, Shuanghong; Guo, Fei; Meng, Ren; Chen, Chuangfu; Zhang, Hui; Li, Zhiqiang; Fu, Qiang; Shi, Huijun; Hu, Shengwei; Ni, Wei; Li, Tiansen; Zhang, Ke

    2014-08-01

    Brucellosis is a globally distributed zoonotic disease that causes animal and human diseases. However, the current Brucella abortus vaccines (S19 and RB51) are deficient; they can cause abortion in pregnant animals. Moreover, when the vaccine S19 is used, tests cannot differentiate natural from vaccinated infection. Therefore, a safer and more potent vaccine is needed. A Brucella abortus 2308 ery promoter mutant (Δery) was constructed to overcome these drawbacks. The growth of the Δery mutant was significantly attenuated in macrophages and mice and induced high protective immunity in mice. Moreover, Δery induced an anti-Brucella-specific IgG (immunoglobulin G) response and stimulated the expression of interferon-gamma (INF-γ) and interleukin-4 (IL-4). Furthermore, the expression of EryA antigen allowed for the serological differentiation between natural and vaccinated infection in mice. These results indicate that the Δery mutant is a potential attenuated live vaccine candidate against virulent Brucella abortus 2308 (S2308) infection. PMID:24994009

  10. 9 CFR 113.67 - Erysipelothrix Rhusiopathiae Vaccine.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Erysipelothrix Rhusiopathiae Vaccine... REQUIREMENTS Live Bacterial Vaccines § 113.67 Erysipelothrix Rhusiopathiae Vaccine. Erysipelothrix Rhusiopathiae Vaccine shall be prepared as a desiccated live culture of an avirulent or modified strain...

  11. 9 CFR 113.67 - Erysipelothrix Rhusiopathiae Vaccine.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Erysipelothrix Rhusiopathiae Vaccine... REQUIREMENTS Live Bacterial Vaccines § 113.67 Erysipelothrix Rhusiopathiae Vaccine. Erysipelothrix Rhusiopathiae Vaccine shall be prepared as a desiccated live culture of an avirulent or modified strain...

  12. 9 CFR 113.67 - Erysipelothrix Rhusiopathiae Vaccine.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Erysipelothrix Rhusiopathiae Vaccine... REQUIREMENTS Live Bacterial Vaccines § 113.67 Erysipelothrix Rhusiopathiae Vaccine. Erysipelothrix Rhusiopathiae Vaccine shall be prepared as a desiccated live culture of an avirulent or modified strain...

  13. 9 CFR 113.67 - Erysipelothrix Rhusiopathiae Vaccine.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Erysipelothrix Rhusiopathiae Vaccine... REQUIREMENTS Live Bacterial Vaccines § 113.67 Erysipelothrix Rhusiopathiae Vaccine. Erysipelothrix Rhusiopathiae Vaccine shall be prepared as a desiccated live culture of an avirulent or modified strain...

  14. Molecular characterization of the Israeli B. bigemina vaccine strain and field isolates.

    PubMed

    Molad, T; Erster, O; Fleiderovitz, L; Roth, A; Leibovitz, B; Wolkomirsky, R; Mazuz, M L; Behar, A; Markovics, A

    2015-09-15

    The present study demonstrated the genetic character of the Israeli Babesia bigemina vaccine strain and field isolates, based on rap-1a and rap-1c gene sequences. The RAP-1a of blood-derived Israeli B. bigemina field isolates shared 100% amino acid sequence identity. However, comparison of RAP-1c from various Israeli B. bigemina field isolates revealed that the total sequence identity among the field isolates ranged from 98.2 to 100%. High identity was observed when RAP-1a sequences from the Israeli vaccine strain and field isolates were compared with RAP-1a from Egypt, Syria, Mexico and South Africa, while, the Israeli RAP-1c sequences showed the highest identity to the Mexican isolate JG-29 and to the PR isolate from Puerto-Rico. Based on sequence variations between the rap-1a of the vaccine strain and that of the field isolate, and between the rap-1c of the vaccine strain and that of the field isolates, nPCR-RFLP procedures were developed that enable, for the first time differentiation between the Israeli B. bigemina vaccine strain and field-infection isolates. These assays could serve as fast and sensitive methods for detection and differentiation between Israeli B. bigemina vaccine strains and field isolates, as well as for epidemiological investigations. PMID:26154404

  15. Comparison of alternative buffers for use with a new live oral cholera vaccine, Peru-15, in outpatient volunteers.

    PubMed

    Sack, D A; Shimko, J; Sack, R B; Gomes, J G; MacLeod, K; O'Sullivan, D; Spriggs, D

    1997-06-01

    During development of Peru-15, a new live oral vaccine for cholera, the role of buffer needed to be evaluated. Generally, oral bacterial vaccines are acid labile and need to be administered by using a formulation which protects them from gastric acid. We compared three different buffers for use with Peru-15, including a standard bicarbonate-ascorbic acid buffer, Alka-Seltzer, and a new electrolyte-rice buffer, CeraVacx. Saline served as the control. Thirty-nine healthy adult volunteers received Peru-15 (10(8) CFU) with one of the three buffers or saline in a double-masked study. The volunteers were monitored for symptoms for 7 days after the dose, serum was tested for antibody responses by vibriocidal antibody and immunoglobulin G antitoxin enzyme-linked immunosorbent assays, and stool samples were tested for excretion of the vaccine strain. Side effects were minimal in all groups. All 30 volunteers who took Peru-15 with a buffer showed significant rises in vibriocidal antibody titer. The magnitude of the rises was higher in the CeraVacx group than in the other two buffer groups. Four of nine volunteers who took the vaccine with saline also showed increased titers, but they were lower than those in any of the three buffer groups. Excretion of the vaccine strain was similar in the buffer groups, but excretion was not associated with the magnitude of the vibriocidal responses. Excretion of Peru-15 was not detected in the saline group. We conclude that buffer does amplify the serological response to Peru-15 and that CeraVacx may provide benefits not provided by other buffers. PMID:9169739

  16. Comparison of alternative buffers for use with a new live oral cholera vaccine, Peru-15, in outpatient volunteers.

    PubMed Central

    Sack, D A; Shimko, J; Sack, R B; Gomes, J G; MacLeod, K; O'Sullivan, D; Spriggs, D

    1997-01-01

    During development of Peru-15, a new live oral vaccine for cholera, the role of buffer needed to be evaluated. Generally, oral bacterial vaccines are acid labile and need to be administered by using a formulation which protects them from gastric acid. We compared three different buffers for use with Peru-15, including a standard bicarbonate-ascorbic acid buffer, Alka-Seltzer, and a new electrolyte-rice buffer, CeraVacx. Saline served as the control. Thirty-nine healthy adult volunteers received Peru-15 (10(8) CFU) with one of the three buffers or saline in a double-masked study. The volunteers were monitored for symptoms for 7 days after the dose, serum was tested for antibody responses by vibriocidal antibody and immunoglobulin G antitoxin enzyme-linked immunosorbent assays, and stool samples were tested for excretion of the vaccine strain. Side effects were minimal in all groups. All 30 volunteers who took Peru-15 with a buffer showed significant rises in vibriocidal antibody titer. The magnitude of the rises was higher in the CeraVacx group than in the other two buffer groups. Four of nine volunteers who took the vaccine with saline also showed increased titers, but they were lower than those in any of the three buffer groups. Excretion of the vaccine strain was similar in the buffer groups, but excretion was not associated with the magnitude of the vibriocidal responses. Excretion of Peru-15 was not detected in the saline group. We conclude that buffer does amplify the serological response to Peru-15 and that CeraVacx may provide benefits not provided by other buffers. PMID:9169739

  17. 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

  18. 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

  19. Oral vaccination reduces the incidence of tuberculosis in free-living brushtail possums

    PubMed Central

    Tompkins, D. M.; Ramsey, D. S. L.; Cross, M. L.; Aldwell, F. E.; de Lisle, G. W.; Buddle, B. M.

    2009-01-01

    Bovine tuberculosis (Tb) caused by Mycobacterium bovis has proved refractory to eradication from domestic livestock in countries with wildlife disease reservoirs. Vaccination of wild hosts offers a way of controlling Tb in livestock without wildlife culling. This study was conducted in a Tb-endemic region of New Zealand, where the introduced Australian brushtail possum (Trichosurus vulpecula) is the main wildlife reservoir of Tb. Possums were trapped and vaccinated using a prototype oral-delivery system to deliver the Tb vaccine bacille Calmette–Guerin. Vaccinated and control possums were matched according to age, sex and location, re-trapped bimonthly and assessed for Tb status by palpation and lesion aspiration; the site was depopulated after 2 years and post-mortem examinations were conducted to further identify clinical Tb cases and subclinical infection. Significantly fewer culture-confirmed Tb cases were recorded in vaccinated possums (1/51) compared with control animals (12/71); the transition probability from susceptible to infected was significantly reduced in both males and females by vaccination. Vaccine efficacy was estimated at 95 per cent (87–100%) for females and 96 per cent (82–99%) for males. Hence, this trial demonstrates that orally delivered live bacterial vaccines can significantly protect wildlife against natural disease exposure, indicating that wildlife vaccination, along with existing control methods, could be used to eradicate Tb from domestic animals. PMID:19493904

  20. Salmonella enterica serovar Typhi Ty21a expressing human papillomavirus type 16 L1 as a potential live vaccine against cervical cancer and typhoid fever.

    PubMed

    Fraillery, Dominique; Baud, David; Pang, Susana Yuk-Ying; Schiller, John; Bobst, Martine; Zosso, Nathalie; Ponci, Françoise; Nardelli-Haefliger, Denise

    2007-10-01

    Human papillomavirus (HPV) vaccines based on L1 virus-like particles (VLPs) can prevent HPV-induced genital neoplasias, the precursors of cervical cancer. However, most cervical cancers occur in developing countries, where the implementation of expensive vaccines requiring multiple injections will be difficult. A live Salmonella-based vaccine could be a lower-cost alternative. We previously demonstrated that high HPV type 16 (HPV16)-neutralizing titers are induced after a single oral immunization of mice with attenuated Salmonella enterica serovar Typhimurium strains expressing a codon-optimized version of HPV16 L1 (L1S). To allow the testing of this type of vaccine in women, we constructed a new L1-expressing plasmid, kanL1S, and tested kanL1S recombinants of three Salmonella enterica serovar Typhi vaccine strains shown to be safe in humans, i.e., Ty21a, the actual licensed typhoid vaccine, and two highly immunogenic typhoid vaccine candidates, Ty800 and CVD908-htrA. In an intranasal mouse model of Salmonella serovar Typhi infection, Ty21a kanL1S was unique in inducing HPV16-neutralizing antibodies in serum and genital secretions, while anti-Salmonella responses were similar to those against the parental Ty21a vaccine. Electron microscopy examination of Ty21a kanL1S lysates showed that L1 assembled in capsomers and capsomer aggregates but not well-ordered VLPs. Comparison to the neutralizing antibody response induced by purified HPV16 L1 VLP immunizations in mice suggests that Ty21a kanL1S may be an effective prophylactic HPV vaccine. Ty21a has been widely used against typhoid fever in humans with a remarkable safety record. These finds encourage clinical testing of Ty21a kanL1S as a combined typhoid fever/cervical cancer vaccine with the potential for worldwide application. PMID:17687110

  1. Immunization of pregnant sows with a novel virulence gene deleted live Salmonella vaccine and protection of their suckling piglets against salmonellosis.

    PubMed

    Hur, Jin; Lee, John Hwa

    2010-07-14

    This study was carried out to examine a novel Salmonella Typhimurium (S. Typhimurium) vaccine for protection of suckling piglets against salmonellosis by immunization of pregnant sows using various administration routes. The vaccine strain was constructed by deletion of cpxR and lon from a wild type S. Typhimurium and the S. Typhimurium Delta cpxR Delta lon Delta asd secreting the B subunit of the Escherichia coli heat-labile enterotoxin were used as a live form of mucosal adjuvant for this study. Pregnant sows were divided into 4 groups of 3 sows a piece. Sows were primed at 8 weeks of pregnancy and were boosted 11 weeks of pregnancy. Group A sows were primed intramuscularly with the formalin-inactivated vaccine and boosted orally with the live vaccine and mucosal adjuvant, group B sows were orally primed with the live vaccine and mucosal adjuvant and boosted orally with live vaccine, group C sows were orally primed with live vaccine and mucosal adjuvant and intramuscularly boosted, and group D sows were primed and boosted with phosphate-buffered saline as controls. Piglets were orally challenged with a virulent S. Typhimurium strain at day 6 after birth. Sows from group A and B had significantly increased IgG levels compared to control group sows (P<0.05), and group C sows had lower IgG levels compared to group A and B sows. Mucosal sIgA and IgG levels in group A and B sow colostrums were significantly increased as compared to those of group D sows (P<0.05). Serum IgG and IgA levels in group A and B piglets were also significantly increased as compared to those of group D piglets (P<0.001). These data suggested that systemic and mucosal immune responses were highly induced by the vaccine candidate, especially when this was administered by both routes of intramuscular-prime and oral booster, and oral prime and booster. Furthermore, clinical signs such as diarrhea and weight loss were not observed after virulent Salmonella strain challenge in group A and B suckling

  2. Mathematical model of tuberculosis transmission in a two-strain with vaccination

    NASA Astrophysics Data System (ADS)

    Nainggolan, J.; Supian, S.; Supriatna, A. K.; Anggriani, N.

    2014-02-01

    This paper deals with the mathematical analysis of the spread of tuberculosis with vaccination in a two-strain model. The vaccination reproduction ratio (Rrs) and equilibria quantities for the models are determined and stability of the solution is analyzed. We prove that if the vaccination reproduction ratio Rrs < 1 the disease free equilibrium is locally and asymptotically stable on the nonnegative orthant and if Rrs > 1 of the other equilibria is locally and asymptotically stable. At the end of this study, the numerical computation presented and it shows that vaccination and treatment capable to reduce the number of exposed and infected compartments.

  3. Implementation of new approaches for generating conventional reassortants for live attenuated influenza vaccine based on Russian master donor viruses.

    PubMed

    Shcherbik, Svetlana; Pearce, Nicholas; Kiseleva, Irina; Larionova, Natalie; Rudenko, Larisa; Xu, Xiyan; Wentworth, David E; Bousse, Tatiana

    2016-01-01

    Cold-adapted influenza strains A/Leningrad/134/17/57 (H2N2) and B/USSR/60/69, originally developed in Russia, have been reliable master donors of attenuation for preparing live attenuated influenza vaccines (LAIV). The classical strategy for generating LAIV reassortants is robust, but has some disadvantages. The generation of reassortants requires at least 3 passages under selective conditions after co-infection; each of these selective passages takes six days. Screening the reassortants for a genomic composition traditionally starts after a second limiting dilution cloning procedure, and the number of suitable reassortants is limited. We developed a new approach to shorten process of preparing LAIV seed viruses. Introducing the genotyping of reassortants by pyrosequencing and monitoring sequence integrity of surface antigens starting at the first selective passage allowed specific selection of suitable reassortants for the next cloning procedure and also eliminate one of the group selective passage in vaccine candidate generation. Homogeneity analysis confirmed that reducing the number of selective passages didn't affect the quality of LAIV seed viruses. Finally, the two-way hemagglutination inhibition test, implemented for all the final seed viruses, confirmed that any amino acid substitutions acquired by reassortants during egg propagation didn't affect antigenicity of the vaccine. Our new strategy reduces the time required to generate a vaccine and was used to generate seasonal LAIVs candidates for the 2012/2013, 2014/2015, and 2015/2016 seasons more rapidly. PMID:26519883

  4. 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. PMID:27089205

  5. Generation of an attenuated strain oral vaccine candidate using a novel double selection platform in Escherichia coli.

    PubMed

    Liu, Wenxin; Yuan, Chaowen; Bao, Jun; Guan, Weikun; Zhao, Zhiteng; Li, Xingyue; Tang, Jie; Li, Dandan; Shi, Dongfang

    2015-01-01

    Live attenuated bacteria delivered orally are interesting tools for mucosal immunization. The objective of this study was to construct a novel counter-selection platform based on an attenuated wild-type Escherichia coli (E. coli) strain and to utilize it for the delivery of LTR192G-STaA13Q fusion protein as an oral vaccine. First, a counter-selectable marker, namely, PRPL-Kil, was inserted into an attenuated wild-type E. coli strain through the use of the red and G-DOC homologous recombination systems to construct the counter-selection platform, and PRPL-Kil was subsequently replaced by the LT192-STa13 fusion gene to construct the oral vaccine O142 (yaiT::LT192-STa13) (ER-A). Subsequently, BALB/c mice were orogastrically inoculated with ER-A. Our results showed that ER-A could induce the production of specific IgA and IgG against fimbriae (F41) and enterotoxins (LT and STa), with neutralizing activity in BALB/c mice. In addition, assays of cellular immune responses showed that the stimulation index (SI) values of immunized mice were significantly higher than those of control mice (P<0.05), and revealed a marked shift toward Th2-mediated immunity. These findings suggest that ER-A is a suitable candidate for an oral vaccine strain to protect animals from enter toxigenic Escherichia coli (ETEC) infection. PMID:25301580

  6. 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. PMID:27468028

  7. Comparative Immunogenicity of Heat-Killed and Living Oral Salmonella Vaccines

    PubMed Central

    Collins, Frank M.; Carter, Philip B.

    1972-01-01

    CD-1 mice were vaccinated intragastrically or intramuscularly with one or two doses of 200 μg of heat-killed Salmonella enteritidis 5694. Control mice were vaccinated with sublethal doses of living S. enteritidis Se795. The mice were challenged intragastrically with approximately 106S. enteritidis 5694 SMR 7 to 14 days later, and the growth of the challenge population in the liver, spleen, mesenteric lymph nodes, lungs, and intestine was measured quantitatively. Mice receiving two doses of heat-killed vaccine by mouth were able to delay the systemic emergence of a gastrically introduced salmonella infection by 1 to 2 days. The corresponding liver and spleen populations were slightly lower than those seen in the normal controls. On the other hand, mice receiving the living, attenuated vaccine (either intravenously or intragastrically) developed an effective anti-salmonella immunity against subsequent reinfection. PMID:4564282

  8. A Review of OIE Country Status Recovery Using Vaccinate-to-Live Versus Vaccinate-to-Die Foot-and-Mouth Disease Response Policies I: Benefits of Higher Potency Vaccines and Associated NSP DIVA Test Systems in Post-Outbreak Surveillance.

    PubMed

    Barnett, P V; Geale, D W; Clarke, G; Davis, J; Kasari, T R

    2015-08-01

    To rapidly return to trade, countries with OIE status, FMD-free country where vaccination is not practised, have destroyed emergency vaccinated animals, raising ethical concerns with respect to social values, the environment, animal welfare and global food security. This two-part review explores whether science could support eligibility to return to previous OIE status in 3 months irrespective of vaccinate-to-live or vaccinate-to-die policies. Here, we examine the benefits of higher potency (≥ 6 PD50 ), high-purity vaccines formulated from antigen banks for emergency use, their efficacy and performance in differentiating infected from vaccinated animals (DIVA) assays for post-outbreak surveillance. From an intensive programme of research, we conclude that high-quality, higher potency vaccines are proven to reduce FMD virus (FMDV) subclinical circulation and the risk of carriers. Broader coverage than predicted by serology suggests the potential to hold a few 'key' vaccine strains improving logistics and reducing the financial burden of antigen banks. The OIE should adopt formal definitions for emergency vaccination and emergency vaccines. In terms of supportive tools, we consider that the lack of OIE recognition of DIVA tests other than those of PANAFTOSA in cattle is a shortcoming. There is need for research on maternal antibody interference with DIVA tests and on the use of such tests to establish whether greater purification of vaccines improves performance. We consider that alignment of waiting periods for vaccinate-to-live and vaccinate-to-die in OIE Code Article 8.5.9 1 b. and c. is feasible until an acceptable level of statistical certainty for surveillance or target probability of freedom is established to substantiate the absence of FMDV infection or circulation. It is surveillance intensity rather than waiting periods that establishes the risk of residual FMDV. EU Directive 2003/85/EC implicitly recognizes this, permitting derogation of the OIE waiting

  9. Effect of vaccination with a multivalent modified-live viral vaccine on reproductive performance in synchronized beef heifers.

    PubMed

    Walz, Paul H; Edmondson, Misty A; Riddell, Kay P; Braden, Timothy D; Gard, Julie A; Bayne, Jenna; Joiner, Kellye S; Galik, Patricia K; Zuidhof, Sjoert; Givens, M Daniel

    2015-03-15

    Prebreeding vaccination should provide fetal and abortive protection against bovine viral diarrhea virus (BVDV) and bovine herpesvirus 1 (BoHV-1) but not impede reproduction when administered to cattle before estrus synchronization and breeding. The objective was to assess reproductive performance when naive beef heifers were vaccinated with modified-live viral (MLV) vaccine 2 days after unsynchronized estrus, and then revaccinated with MLV vaccine at 10 or 31 days before synchronized natural breeding. Sixty beef heifers naive to BVDV and BoHV-1 were randomly assigned to one of four treatment groups. Groups A and B (n = 20 per group) were vaccinated with MLV vaccine containing BVDV and BoHV-1 at 2 days after initial detected estrus, and then revaccinated 30 days later, which corresponded to 10 days (group A) or 31 days (group B) before synchronized natural breeding. Groups C and D (n = 10 per group) served as controls and were vaccinated with an inactivated vaccine that did not contain BVDV or BoHV-1 at the same time points as groups A and B, respectively. Estrous behavior was assessed using radio frequency technology. Estrus synchronization was performed, with initiation occurring at revaccination (groups A and C) or 21 days after revaccination (groups B and D). After synchronization, heifers were submitted to a bull breeding pasture for 45 days. At the end of the breeding period, heifers were assessed for pregnancy using ultrasonography. Progesterone concentrations were evaluated at estrus and 10 days after unsynchronized and synchronized estrus, at initial pregnancy check, and at the end of the study. All pregnant heifers in groups A and B and five pregnant heifers in group C were euthanized between 44 and 62 days of gestation and ovarian and conceptus tissues were assayed for BVDV and BoHV-1. Vaccination with MLV vaccine did not result in significant negative reproductive impact based on the duration of interestrus intervals, proportion of heifers

  10. Construction, characterization and preclinical evaluation of MTBVAC, the first live-attenuated M. tuberculosis-based vaccine to enter clinical trials.

    PubMed

    Arbues, Ainhoa; Aguilo, Juan I; Gonzalo-Asensio, Jesus; Marinova, Dessislava; Uranga, Santiago; Puentes, Eugenia; Fernandez, Conchita; Parra, Alberto; Cardona, Pere Joan; Vilaplana, Cristina; Ausina, Vicente; Williams, Ann; Clark, Simon; Malaga, Wladimir; Guilhot, Christophe; Gicquel, Brigitte; Martin, Carlos

    2013-10-01

    The development of a new tuberculosis vaccine is an urgent need due to the failure of the current vaccine, BCG, to protect against the respiratory form of the disease. MTBVAC is an attenuated Mycobacterium tuberculosis vaccine candidate genetically engineered to fulfil the Geneva consensus requirements to enter human clinical trials. We selected a M. tuberculosis clinical isolate to generate two independent deletions without antibiotic-resistance markers in the genes phoP, coding for a transcription factor key for the regulation of M. tuberculosis virulence, and fadD26, essential for the synthesis of the complex lipids phthiocerol dimycocerosates (DIM), one of the major mycobacterial virulence factors. The resultant strain MTBVAC exhibits safety and biodistribution profiles similar to BCG and confers superior protection in preclinical studies. These features have enabled MTBVAC to be the first live attenuated M. tuberculosis vaccine to enter clinical evaluation. PMID:23965219

  11. An outbreak of mumps in a population partially vaccinated with the Rubini strain.

    PubMed

    Germann, D; Ströhle, A; Eggenberger, K; Steiner, C A; Matter, L

    1996-01-01

    Since 1991, 6 years after the recommendation of universal childhood triple vaccination against measles, mumps and rubella (M + M + R), Switzerland has been confronted with an increasing number of mumps cases affecting both vaccinated and unvaccinated children. The M + M + R vaccine mainly used in the Swiss population after 1986 contains the highly attenuated Rubini strain of mumps virus. We analysed an outbreak of 102 suspected mumps cases by virus isolation, determination of IgM antibodies to mumps virus in 27 acute phase sera, and verification of vaccination histories. Mumps was confirmed by virus isolation in 88 patients, of whom 72 had previously received the Rubini vaccine strain. IgM antibodies to mumps virus were detected in 24/27 acute phase serum samples. A group of 92 subjects from the same geographic area without signs of mumps virus infection served as controls. IgG antibodies to mumps virus and vaccination status were assessed in these children. The vaccination rate in these controls was 61%, with equal seropositivity for unvaccinated and Rubini-vaccinated subjects. These data support other recent reports which indicate an insufficient protective efficacy of current mumps vaccines. PMID:8863352

  12. Sequencing analysis of Mycoplasma gallisepticum wild strains in vaccinated chicken breeder flocks.

    PubMed

    Khalifa, Rabab; Eissa, Sabry; El-Hariri, Mahmoud; Refai, Mohamed

    2014-01-01

    Mycoplasma gallisepticum (MG) infection is still of continuing economic concern in commercial broiler breeder chicken flocks in Egypt. MG infection continues to emerge despite the application of vaccination programs in breeder flocks. This prompted flock surveillance including MG isolation and molecular characterization of the circulating MG strains. The present study was concerned with 15 broiler breeder flocks of different ages (5-51 weeks). Three flocks were apparently healthy and 12 flocks were diseased. The aim of the study was to characterize the MG strains recovered from tracheal swabs. Four positive MG DNA extracts identified by rt-PCR and confirmed by isolation were subjected to sequencing of the mgc2 gene and intergenic spacer region (IGSR). The current molecular study demonstrated the presence of 3 different wild-type MG strains (RabE1-08, RabE2-09 and RabE3-09) in vaccinated diseased flocks, while the fourth strain (RabE4-08), which was isolated from a nonvaccinated apparently healthy breeder flock, scored 100% of homology and similarity to the F-strain vaccine by the sequence analysis of mgc2 and IGSR. It can be assumed that the vaccine F strain, which is supposed to replace field strains not only failed to do that, but also infected nonvaccinated flocks. Accordingly, there is a need to revise the control program including vaccine strategy in parallel with biosecurity measures. PMID:24525899

  13. No Evidence of Murine Leukemia Virus-Related Viruses in Live Attenuated Human Vaccines

    PubMed Central

    Switzer, William M.; Zheng, HaoQiang; Simmons, Graham; Zhou, Yanchen; Tang, Shaohua; Shankar, Anupama; Kapusinszky, Beatrix; Delwart, Eric L.; Heneine, Walid

    2011-01-01

    Background The association of xenotropic murine leukemia virus (MLV)-related virus (XMRV) in prostate cancer and chronic fatigue syndrome reported in previous studies remains controversial as these results have been questioned by recent data. Nonetheless, concerns have been raised regarding contamination of human vaccines as a possible source of introduction of XMRV and MLV into human populations. To address this possibility, we tested eight live attenuated human vaccines using generic PCR for XMRV and MLV sequences. Viral metagenomics using deep sequencing was also done to identify the possibility of other adventitious agents. Results All eight live attenuated vaccines, including Japanese encephalitis virus (JEV) (SA-14-14-2), varicella (Varivax), measles, mumps, and rubella (MMR-II), measles (Attenuvax), rubella (Meruvax-II), rotavirus (Rotateq and Rotarix), and yellow fever virus were negative for XMRV and highly related MLV sequences. However, residual hamster DNA, but not RNA, containing novel endogenous gammaretrovirus sequences was detected in the JEV vaccine using PCR. Metagenomics analysis did not detect any adventitious viral sequences of public health concern. Intracisternal A particle sequences closest to those present in Syrian hamsters and not mice were also detected in the JEV SA-14-14-2 vaccine. Combined, these results are consistent with the production of the JEV vaccine in Syrian hamster cells. Conclusions We found no evidence of XMRV and MLV in eight live attenuated human vaccines further supporting the safety of these vaccines. Our findings suggest that vaccines are an unlikely source of XMRV and MLV exposure in humans and are consistent with the mounting evidence on the absence of these viruses in humans. PMID:22216219

  14. Full Genome Characterisation of Bluetongue Virus Serotype 6 from the Netherlands 2008 and Comparison to Other Field and Vaccine Strains

    PubMed Central

    Maan, Sushila; Maan, Narender S.; van Rijn, Piet A.; van Gennip, René G. P.; Sanders, Anna; Wright, Isabel M.; Batten, Carrie; Hoffmann, Bernd; Eschbaumer, Michael; Oura, Chris A. L.; Potgieter, Abraham C.; Nomikou, Kyriaki; Mertens, Peter P.C.

    2010-01-01

    In mid September 2008, clinical signs of bluetongue (particularly coronitis) were observed in cows on three different farms in eastern Netherlands (Luttenberg, Heeten, and Barchem), two of which had been vaccinated with an inactivated BTV-8 vaccine (during May-June 2008). Bluetongue virus (BTV) infection was also detected on a fourth farm (Oldenzaal) in the same area while testing for export. BTV RNA was subsequently identified by real time RT-PCR targeting genome-segment (Seg-) 10, in blood samples from each farm. The virus was isolated from the Heeten sample (IAH “dsRNA virus reference collection” [dsRNA-VRC] isolate number NET2008/05) and typed as BTV-6 by RT-PCR targeting Seg-2. Sequencing confirmed the virus type, showing an identical Seg-2 sequence to that of the South African BTV-6 live-vaccine-strain. Although most of the other genome segments also showed very high levels of identity to the BTV-6 vaccine (99.7 to 100%), Seg-10 showed greatest identity (98.4%) to the BTV-2 vaccine (RSAvvv2/02), indicating that NET2008/05 had acquired a different Seg-10 by reassortment. Although Seg-7 from NET2008/05 was also most closely related to the BTV-6 vaccine (99.7/100% nt/aa identity), the Seg-7 sequence derived from the blood sample of the same animal (NET2008/06) was identical to that of the Netherlands BTV-8 (NET2006/04 and NET2007/01). This indicates that the blood contained two different Seg-7 sequences, one of which (from the BTV-6 vaccine) was selected during virus isolation in cell-culture. The predominance of the BTV-8 Seg-7 in the blood sample suggests that the virus was in the process of reassorting with the northern field strain of BTV-8. Two genome segments of the virus showed significant differences from the BTV-6 vaccine, indicating that they had been acquired by reassortment event with BTV-8, and another unknown parental-strain. However, the route by which BTV-6 and BTV-8 entered northern Europe was not established. PMID:20428242

  15. Evaluation of an attenuated strain of Ehrlichia canis as a vaccine for canine monocytic ehrlichiosis.

    PubMed

    Rudoler, Nir; Baneth, Gad; Eyal, Osnat; van Straten, Michael; Harrus, Shimon

    2012-12-17

    Canine monocytic ehrlichiosis is an important tick-borne disease worldwide. No commercial vaccine for the disease is currently available and tick control is the main preventive measure against the disease. The aim of this study was to evaluate the potential of a multi-passaged attenuated strain of Ehrlichia canis to serve as a vaccine for canine monocytic ehrlichiosis, and to assess the use of azithromycin in the treatment of acute ehrlichiosis. Twelve beagle dogs were divided into 3 groups of 4 dogs. Groups 1 and 2 were inoculated (vaccinated) with an attenuated strain of E. canis (#611A) twice or once, respectively. The third group consisted of naïve dogs which served as controls. All 3 groups were challenged with a wild virulent strain of E. canis by administering infected dog-blood intravenously. Transient thrombocytopenia was the only hematological abnormality observed following inoculation of dogs with the attenuated strain. Challenge with the virulent strain resulted in severe disease in all 4 control dogs while only 3 of 8 vaccinated dogs presented mild transient fever. Furthermore, the mean blood rickettsial load was significantly higher in the control group (27-92-folds higher during days 14-19 post challenge with the wild the strain) as compared to the vaccinated dogs. The use of azithromycin was assessed as a therapeutic agent for the acute disease. Four days treatment resulted in further deterioration of the clinical condition of the dogs. Molecular comparison of 4 genes known to express immunoreactive proteins and virulence factors (p30, gp19, VirB4 and VirB9) between the attenuated strain and the challenge wild strain revealed no genetic differences between the strains. The results of this study indicate that the attenuated E. canis strain may serve as an effective and secure future vaccine for canine ehrlichiosis. PMID:23072894

  16. Understanding the host-pathogen interaction saves lives: lessons from vaccines and vaccinations.

    PubMed

    Garon, Julie R; Orenstein, Walter A

    2015-10-01

    Vaccines are one of the most successful and cost-effective public health tools employed to date, yet these benefits are only realized when the life-saving intervention reaches each and every targeted individual. Vaccine development is prioritized based on a number of factors such as health burden, feasibility, and determination of potential target populations. But only through an arduous process of pre-clinical development and progressive clinical trials does a vaccine become licensed and recommended for use. Once used in a wider and more diverse population safety issues, long-term impact and other unintended outcomes may become apparent, influencing policy modification. This commentary explores the role host-pathogen interaction plays in vaccine development and the operational and policy considerations that may impact vaccine success post-licensure. PMID:25974089

  17. Rapid real-time PCR methods to distinguish Salmonella Enteritidis wildtype field isolates from vaccine strains Salmovac SE/Gallivac SE and AviPro SALMONELLA VAC E.

    PubMed

    Maurischat, Sven; Szabo, Istvan; Baumann, Beatrice; Malorny, Burkhard

    2015-05-01

    Salmonella enterica serovar Enteritidis is a major non-typhoid Salmonella serovar causing human salmonellosis mainly associated with the consumption of poultry and products thereof. To reduce infections in poultry, S. Enteritidis live vaccine strains AviPro SALMONELLA VAC E and Salmovac SE/Gallivac SE have been licensed and used in several countries worldwide. To definitively diagnose a S. Enteritidis contamination in vaccinated herds a reliable and fast method for the differentiation between vaccine and wildtype field isolates is required. In this study, we developed and validated real-time PCR (qPCR) assays to distinguish those variants genetically. Suitable target sequences were identified by whole genome sequencing (WGS) using the Illumina MiSeq system. SNP regions in kdpA and nhaA proved to be most useful for differentiation of AviPro SALMONELLA VAC E and Salmovac SE/Gallivac SE, respectively, from wildtype strains. For each vaccine strain one TaqMan-qPCR assay and one alternative approach using High Resolution Melting (HRM) analysis was designed. All 30 Salmovac SE and 7 AviPro SALMONELLA VAC E vaccine strain reisolates tested were correctly identified by both approaches (100% inclusivity). Furthermore, all 137 (TaqMan) and 97 (HRM) Salmonella non-vaccine and related Enterobacteriaceae strains tested were excluded (100% exclusivity). The analytical detection limits were determined to be approx. 10(2) genome copies/reaction for the TaqMan and 10(4) genome copies/reaction for the HRM approach. The real-time PCR assays proved to be a reliable and fast alternative to the cultural vaccine strain identification tests helping decision makers in control measurements to take action within a shorter period of time. PMID:25794902

  18. TLR3 and TLR9 Agonists Improve Postexposure Vaccination Efficacy of Live Smallpox Vaccines

    PubMed Central

    Israely, Tomer; Erez, Noam; Politi, Boaz; Waner, Trevor; Lustig, Shlomo; Paran, Nir

    2014-01-01

    Eradication of smallpox and discontinuation of the vaccination campaign resulted in an increase in the percentage of unvaccinated individuals, highlighting the need for postexposure efficient countermeasures in case of accidental or deliberate viral release. Intranasal infection of mice with ectromelia virus (ECTV), a model for human smallpox, is curable by vaccination with a high vaccine dose given up to 3 days postexposure. To further extend this protective window and to reduce morbidity, mice were vaccinated postexposure with Vaccinia-Lister, the conventional smallpox vaccine or Modified Vaccinia Ankara, a highly attenuated vaccine in conjunction with TLR3 or TLR9 agonists. We show that co-administration of the TLR3 agonist poly(I:C) even 5 days postexposure conferred protection, avoiding the need to increase the vaccination dose. Efficacious treatments prevented death, ameliorated disease symptoms, reduced viral load and maintained tissue integrity of target organs. Protection was associated with significant elevation of serum IFNα and anti-vaccinia IgM antibodies, modulation of IFNγ response, and balanced activation of NK and T cells. TLR9 agonists (CpG ODNs) were less protective than the TLR3 agonist poly(I:C). We show that activation of type 1 IFN by poly(I:C) and protection is achievable even without co-vaccination, requiring sufficient amount of the viral antigens of the infective agent or the vaccine. This study demonstrated the therapeutic potential of postexposure immune modulation by TLR activation, allowing to alleviate the disease symptoms and to further extend the protective window of postexposure vaccination. PMID:25350003

  19. Safety and immunogenicity of a vaccine bait containing ERA strain of attenuated rabies virus.

    PubMed

    Lawson, K F; Black, J G; Charlton, K M; Johnston, D H; Rhodes, A J

    1987-10-01

    Ninety percent of foxes fed commercial ERA vaccine in a specially designed bait developed rabies serum neutralizing antibodies. The vaccine bait did not cause clinical signs of rabies when consumed by foxes, raccoons, skunks, dogs, cats, cattle and monkeys. When presented, in the laboratory, to wild rodents of the species Microtus, Mus musculus and Peromyscus, the vaccine baits caused vaccine-induced rabies only in Mus musculus. Laboratory mice of the CD-1 and CLL strain were susceptible to vaccine-induced rabies; however, studies showed that transmission of virus to other animals did not occur. These studies suggest that the vaccine bait described could be useful in a rabies control program in areas where foxes and wild dogs are the principal vectors. PMID:3330965

  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. Successful comeback of the single-dose live oral cholera vaccine CVD 103-HgR.

    PubMed

    Herzog, Christian

    2016-01-01

    Effective and easy to administer cholera vaccines are in need more than ever, for at risk populations and travellers alike. In many parts of the world cholera is still endemic, causing outbreaks and constituting repeatedly serious public health problems. The oral live cholera vaccine CVD 103-HgR (Orochol, Mutachol), the first genetically modified organism (GMO) used as vaccine, was in its time (launched 1993, Switzerland) the ideal cholera vaccine: single-dose, protective efficacy of 80-100% against moderate to severe cholera, acting within 8 days and exhibiting excellent safety, indiscernible from placebo. However, there were strong headwinds: In the 1990s the indication for cholera vaccines was generally downplayed by experts and in 1997 the European Commission called for a moratorium of GMOs which blocked the registration in the European Union. Thus, demand for this vaccine remained low and in 2003 it was taken off the market for economic reasons. After a decade in obscurity it (Vaxchora) has resurfaced again, now produced in the U.S. and equipped with a U.S. FDA license (June 10, 2016). What had happened? This commentary gives a critical account of an almost unbelievable string of misadventures, emerging adverse circumstances and man-made failures which nearly killed this single-dose live oral cholera vaccine. The good news is that patience and persistence lead to success in the end, allowing good science to prevail for the benefit of those in need. PMID:27425792

  2. Successful vaccination with a polyvalent live vector despite existing immunity to an expressed antigen.

    PubMed

    Flexner, C; Murphy, B R; Rooney, J F; Wohlenberg, C; Yuferov, V; Notkins, A L; Moss, B

    1988-09-15

    A global vaccination strategy must take into account production and delivery costs as well as efficacy and safety. A heat-stable, polyvalent vaccine that requires only one inoculation and induces a high level of humoral and cellular immunity against several diseases is therefore desirable. A new approach is to use live microorganisms such as mycobacteria, enteric bacteria, adenoviruses, herpesviruses and poxviruses as vaccine vectors. A potential limitation of live polyvalent vaccines, however, is existing immunity within the target population not only to the vector, but to any of the expressed antigens. This could restrict replication of the vector, curtail expression of antigens, and reduce the total immune response to the vaccine. Recently acquired immunity to vaccinia virus can severely limit the efficacy of a live recombinant vaccinia-based vaccine, so a strategy involving closely spaced inoculations with the same vector expressing different antigens may present difficulties. We have constructed a recombinant vaccinia virus that expresses surface proteins from two diverse pathogens, influenza A virus haemagglutinin and herpes simplex virus type 1 (HSV-1) glycoprotein D. Mice that had recently recovered from infection with either HSV-1 or influenza A virus could still be effectively immunized with the double recombinant. PMID:2842693

  3. Genome Sequence of Brucella abortus Vaccine Strain S19 Compared to Virulent Strains Yields Candidate Virulence Genes

    PubMed Central

    Crasta, Oswald R.; Folkerts, Otto; Fei, Zhangjun; Mane, Shrinivasrao P.; Evans, Clive; Martino-Catt, Susan; Bricker, Betsy; Yu, GongXin; Du, Lei; Sobral, Bruno W.

    2008-01-01

    The Brucella abortus strain S19, a spontaneously attenuated strain, has been used as a vaccine strain in vaccination of cattle against brucellosis for six decades. Despite many studies, the physiological and molecular mechanisms causing the attenuation are not known. We have applied pyrosequencing technology together with conventional sequencing to rapidly and comprehensively determine the complete genome sequence of the attenuated Brucella abortus vaccine strain S19. The main goal of this study is to identify candidate virulence genes by systematic comparative analysis of the attenuated strain with the published genome sequences of two virulent and closely related strains of B. abortus, 9–941 and 2308. The two S19 chromosomes are 2,122,487 and 1,161,449 bp in length. A total of 3062 genes were identified and annotated. Pairwise and reciprocal genome comparisons resulted in a total of 263 genes that were non-identical between the S19 genome and any of the two virulent strains. Amongst these, 45 genes were consistently different between the attenuated strain and the two virulent strains but were identical amongst the virulent strains, which included only two of the 236 genes that have been implicated as virulence factors in literature. The functional analyses of the differences have revealed a total of 24 genes that may be associated with the loss of virulence in S19. Of particular relevance are four genes with more than 60bp consistent difference in S19 compared to both the virulent strains, which, in the virulent strains, encode an outer membrane protein and three proteins involved in erythritol uptake or metabolism. PMID:18478107

  4. Genome sequence of Brucella abortus vaccine strain S19 compared to virulent strains yields candidate virulence genes.

    PubMed

    Crasta, Oswald R; Folkerts, Otto; Fei, Zhangjun; Mane, Shrinivasrao P; Evans, Clive; Martino-Catt, Susan; Bricker, Betsy; Yu, GongXin; Du, Lei; Sobral, Bruno W

    2008-01-01

    The Brucella abortus strain S19, a spontaneously attenuated strain, has been used as a vaccine strain in vaccination of cattle against brucellosis for six decades. Despite many studies, the physiological and molecular mechanisms causing the attenuation are not known. We have applied pyrosequencing technology together with conventional sequencing to rapidly and comprehensively determine the complete genome sequence of the attenuated Brucella abortus vaccine strain S19. The main goal of this study is to identify candidate virulence genes by systematic comparative analysis of the attenuated strain with the published genome sequences of two virulent and closely related strains of B. abortus, 9-941 and 2308. The two S19 chromosomes are 2,122,487 and 1,161,449 bp in length. A total of 3062 genes were identified and annotated. Pairwise and reciprocal genome comparisons resulted in a total of 263 genes that were non-identical between the S19 genome and any of the two virulent strains. Amongst these, 45 genes were consistently different between the attenuated strain and the two virulent strains but were identical amongst the virulent strains, which included only two of the 236 genes that have been implicated as virulence factors in literature. The functional analyses of the differences have revealed a total of 24 genes that may be associated with the loss of virulence in S19. Of particular relevance are four genes with more than 60 bp consistent difference in S19 compared to both the virulent strains, which, in the virulent strains, encode an outer membrane protein and three proteins involved in erythritol uptake or metabolism. PMID:18478107

  5. Efficacy of single calfhood vaccination of elk with Brucella abortus strain 19

    USGS Publications Warehouse

    Roffe, T.J.; Jones, L.C.; Coffin, K.; Drew, M.L.; Sweeney, Steven J.; Hagius, S.D.; Elzer, P.H.; Davis, D.

    2004-01-01

    Brucellosis has been eradicated from cattle in the states of Wyoming, Montana, and Idaho, USA. However, free-ranging elk (Cervus elaphus) that use feedgrounds in the Greater Yellowstone Area (GYA) and bison (Bison bison) in Yellowstone and Grand Teton national parks still have high seroprevalence to the disease and have caused loss of brucellosis-free status in Wyoming. Management tools to control or eliminate the disease are limited; however, wildlife vaccination is among the methods currently used by wildlife managers in Wyoming. We conducted a controlled challenge study of single calfhood vaccination. Elk calves, caught in January and February of 1999 and 2000 and acclimated to captivity for 3 weeks, were randomly assigned to control or vaccinate groups. The vaccinate groups received Brucetta abortus vaccine strain 19 (S19) by hand-delivered intramuscular injection. Calves were raised to adulthood and bred at either 2.5 or 3.5 years of age for 2000 and 1999 captures, respectively. Eighty-nine (44 controls, 45 vaccinates) pregnant elk entered the challenge portion of the study. We challenged elk at mid-gestation with pathogenic B. abortus strain 2308 by intraconjunctival instillation. Abortion occurred in significantly more (P = 0.002) controls (42; 93%) than vaccinates (32; 71%), and vaccine protected 25% of the vaccinate group. We used Brucella culture of fetus/calf tissues to determine the efficacy of vaccination for preventing infection, and we found that the number of infected fetuses/calves did not differ between controls and vaccinates (P = 0.14). Based on these data, single calfhood vaccination with S19 has low efficacy, will likely have only little to moderate effect on Brucella prevalence in elk, and is unlikely to eradicate the disease in wildlife of the GYA.

  6. Room temperature stabilization of oral, live attenuated Salmonella enterica serovar Typhi-vectored vaccines.

    PubMed

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

    2011-03-24

    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 1log(10)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

  7. 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

  8. Safety evaluation of adenovirus type 4 and type 7 vaccine live, oral in military recruits.

    PubMed

    Choudhry, Azhar; Mathena, Julie; Albano, Jessica D; Yacovone, Margaret; Collins, Limone

    2016-08-31

    Before the widespread adoption of vaccination, adenovirus type 4 and type 7 were long associated with respiratory illnesses among military recruits. When supplies were depleted and vaccination was suspended in 1999 for approximately a decade, respiratory illnesses due to adenovirus infections resurged. In March 2011, a new live, oral adenovirus vaccine was licensed by the US Food and Drug Administration and was first universally administered to military recruits in October 2011, leading to rapid, dramatic elimination of the disease within a few months. As part of licensure, a postmarketing study (Sentinel Surveillance Plan) was performed to detect potential safety signals within 42days after immunization of military recruits. This study retrospectively evaluated possible adverse events related to vaccination using data from the Armed Forces Health Surveillance Branch Defense Medical Surveillance System (DMSS) database. Among 100,000 recruits who received the adenovirus vaccine, no statistically significant greater risk of prespecified medical events was observed within 42days after vaccination when compared with a historical cohort of 100,000 unvaccinated recruits. In an initial statistical analysis of International Classification of Disease, 9th Revision, Clinical Modification codes, a statistically significant higher risk for 19 other (not prespecified) medical events occurring in 5 or more recruits was observed among vaccinated compared with unvaccinated groups. After case record data abstraction for attribution and validation, two events (psoriasis [21 vs 7 cases] and serum reactions [12 vs 4 cases]) occurred more frequently in the vaccinated cohort. A causal relation of these rare events with adenovirus vaccination could not be established given confounding factors in the DMSS, such as coadministration of other vaccines and incomplete or inaccurate medical information, for some recruits. Prospective surveillance assessing these uncommon, but potentially

  9. Sequence Variation and Immunologic Cross-Reactivity among Babesia bovis Merozoite Surface Antigen 1 Proteins from Vaccine Strains and Vaccine Breakthrough Isolates

    PubMed Central

    LeRoith, Tanya; Brayton, Kelly A.; Molloy, John B.; Bock, Russell E.; Hines, Stephen A.; Lew, Ala E.; McElwain, Terry F.

    2005-01-01

    The Babesia bovis merozoite surface antigen 1 (MSA-1) is an immunodominant membrane glycoprotein that is the target of invasion-blocking antibodies. While antigenic variation has been demonstrated in MSA-1 among strains from distinct geographical areas, the extent of sequence variation within a region where it is endemic and the effect of variation on immunologic cross-reactivity have not been assessed. In this study, sequencing of MSA-1 from two Australian B. bovis vaccine strains and 14 breakthrough isolates from vaccinated animals demonstrated low sequence identity in the extracellular region of the molecule, ranging from 19.8 to 46.7% between the T vaccine strain and eight T vaccine breakthrough isolates, and from 18.7 to 99% between the K vaccine strain and six K vaccine breakthrough isolates. Although MSA-1 amino acid sequence varied substantially among strains, overall predicted regions of hydrophilicity and hydrophobicity in the extracellular domain were conserved in all strains examined, suggesting a conserved functional role for MSA-1 despite sequence polymorphism. Importantly, the antigenic variation created by sequence differences resulted in a lack of immunologic cross-reactivity among outbreak strains using sera from animals infected with the B. bovis vaccine strains. Additionally, sera from cattle hyperinfected with the Mexico strain of B. bovis and shown to be clinically immune did not cross-react with MSA-1 from any other isolate tested. The results indicate that isolates of B. bovis capable of evading vaccine-induced immunity contain an msa-1 gene that is significantly different from the msa-1 of the vaccine strain, and that the difference can result in a complete lack of cross-reactivity between MSA-1 from vaccine and breakthrough strains in immunized animals. PMID:16113254

  10. Genome Sequence of Salmonella enterica Serovar Typhi Oral Vaccine Strain Ty21a.

    PubMed

    Xu, Deqi; Cisar, John O; Poly, Frédéric; Yang, Jinghua; Albanese, Jason; Dharmasena, Madushini; Wai, Tint; Guerry, Patricia; Kopecko, Dennis J

    2013-01-01

    Attenuated Salmonella enterica serovar Typhi strain Ty21a is an important vaccine for controlling typhoid fever and serves as an oral vector for delivering heterologous antigens. The key attenuating features of this randomly mutated strain remain in question. Genome sequencing has revealed 679 single nucleotide polymorphisms (SNPs), and will help define alterations contributing to Ty21a safety and immunogenicity. PMID:23969054

  11. EBOLA VACCINE. VSV-EBOV rapidly protects macaques against infection with the 2014/15 Ebola virus outbreak strain.

    PubMed

    Marzi, Andrea; Robertson, Shelly J; Haddock, Elaine; Feldmann, Friederike; Hanley, Patrick W; Scott, Dana P; Strong, James E; Kobinger, Gary; Best, Sonja M; Feldmann, Heinz

    2015-08-14

    The latest Ebola virus (EBOV) epidemic spread rapidly through Guinea, Sierra Leone, and Liberia, creating a global public health crisis and accelerating the assessment of experimental therapeutics and vaccines in clinical trials. One of those vaccines is based on recombinant vesicular stomatitis virus expressing the EBOV glycoprotein (VSV-EBOV), a live-attenuated vector with marked preclinical efficacy. Here, we provide the preclinical proof that VSV-EBOV completely protects macaques against lethal challenge with the West African EBOV-Makona strain. Complete and partial protection was achieved with a single dose given as late as 7 and 3 days before challenge, respectively. This indicates that VSV-EBOV may protect humans against EBOV infections in West Africa with relatively short time to immunity, promoting its use for immediate public health responses. PMID:26249231

  12. Replication and transmission of live attenuated infectious laryngotracheitis virus (ILTV) vaccines.

    PubMed

    Rodríguez-Avila, Andrés; Oldoni, Ivomar; Riblet, Sylva; García, Maricarmen

    2007-12-01

    The aim of this study was to evaluate the replication of live attenuated infectious laryngotracheitis virus vaccines in selected tissues and their ability to transmit to contact-exposed birds. Four-week-old specific-pathogen-free chickens were eye drop-inoculated with tissue culture origin (TCO) and chicken embryo origin (CEO) vaccines. Contact-exposed chickens were housed in direct contact with eye drop-inoculated chickens from the first day postinoculation. Virus isolation and real-time polymerase chain reaction were used to detect the presence of live virus and viral DNA, respectively, in the trachea, trigeminal ganglia, eye conjunctiva, cecal tonsils, and cloaca from eye drop-inoculated and contact-exposed birds at days 2, 4, 5 to 10, 14, 18, 21, 24, and 28 postinoculation. No differences were observed in the ability of the TCO and CEO vaccines to replicate in the examined tissues. Both vaccines presented a localized replication in the eye conjunctiva and the trachea. Both vaccines were capable of transmitting to contact-exposed birds, attaining peaks of viral DNA as elevated as those observed in inoculated birds. The CEO vaccine replicated faster and reached higher viral genome copy number than the TCO vaccine in the conjunctiva and trachea of eye drop-inoculated and contact-exposed birds. The viral DNA from both vaccines migrated to the trigeminal ganglia during early stages of infection. Although the CEO and TCO vaccines were not recovered from the cecal tonsils and the cloaca, low levels of viral DNA were detected at these sites during the peak of viral replication in the upper respiratory tract. PMID:18251401

  13. Evaluation of Brucella abortus Phosphoglucomutase (pgm) Mutant as a New Live Rough-Phenotype Vaccine

    PubMed Central

    Ugalde, Juan Esteban; Comerci, Diego José; Leguizamón, M. Susana; Ugalde, Rodolfo Augusto

    2003-01-01

    Brucella abortus S19 is the vaccine most frequently used against bovine brucellosis. Although it induces good protection levels, it cannot be administered to pregnant cattle, revaccination is not advised due to interference in the discrimination between infected and vaccinated animals during immune-screening procedures, and the vaccine is virulent for humans. Due to these reasons, there is a continuous search for new bovine vaccine candidates that may confer protection levels comparable to those conferred by S19 but without its disadvantages. A previous study characterized the phenotype associated with the phosphoglucomutase (pgm) gene disruption in Brucella abortus S2308, as well as the possible role for the smooth lipopolysaccharide (LPS) in virulence and intracellular multiplication in HeLa cells (J. E. Ugalde, C. Czibener, M. F. Feldman, and R. A. Ugalde, Infect. Immun. 68:5716-5723, 2000). In this report, we analyze the protection, proliferative response, and cytokine production induced in BALB/c mice by a Δpgm deletion strain. We show that this strain synthesizes O antigen with a size of approximately 45 kDa but is rough. This is due to the fact that the Δpgm strain is unable to assemble the O side chain in the complete LPS. Vaccination with the Δpgm strain induced protection levels comparable to those induced by S19 and generated a proliferative splenocyte response and a cytokine profile typical of a Th1 response. On the other hand, we were unable to detect a specific anti-O-antigen antibody response by using the fluorescence polarization assay. In view of these results, the possibility that the Δpgm mutant could be used as a vaccination strain is discussed. PMID:14573645

  14. Duplex PCR for differentiation of the vaccine strain Brucella suis S2 and B. suis biovar 1 from other strains of Brucella spp.

    PubMed

    Nan, Wenlong; Tan, Pengfei; Wang, Yong; Xu, Zouliang; Mao, Kairong; Peng, Daxin; Chen, Yiping

    2014-09-01

    Immunisation with attenuated Brucella spp. vaccines prevents brucellosis, but may also interfere with diagnosis. In this study, a duplex PCR was developed to distinguish Brucella suis vaccine strain S2 from field strains of B. suis biovar 1 and other Brucella spp. The PCR detected 60 fg genomic DNA of B. suis S2 or biovar 1 field strains and was able to distinguish B. suis S2 and wild-type strains of B. suis biovar 1 among 76 field isolates representing all the common species and biovars, as well as four vaccine strains, of Brucella. PMID:25011712

  15. 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. PMID:20181702

  16. Alternative Live-Attenuated Influenza Vaccines Based on Modifications in the Polymerase Genes Protect against Epidemic and Pandemic Flu▿

    PubMed Central

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

    2010-01-01

    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. PMID:20181702

  17. New technologies for influenza vaccines.

    PubMed

    Dormitzer, Philip R; Tsai, Theodore F; Del Giudice, Giuseppe

    2012-01-01

    Influenza vaccine preparations have been administered to humans since the late 1930s, and the diversity of approaches in licensed trivalent seasonal or monovalent pandemic products is unparalleled by vaccines against any other target. These approaches include inactivated whole virus vaccines, detergent or solvent "split" vaccines, subunit vaccines, live attenuated vaccines, adjuvanted vaccines, intramuscular vaccines, intradermal vaccines, intranasal vaccines, egg-produced vaccines and mammalian cell culture-produced vaccines. The challenges of influenza immunization, including multiple co-circulating strains, antigenic change over time, a broad age spectrum of disease, and the threat of pandemics, continue to drive the development of new approaches. This review describes some of the new approaches to influenza immunization that are the subjects of active research and development. PMID:22251994

  18. The effect of a live Neospora caninum tachyzoite vaccine in naturally infected pregnant dairy cows.

    PubMed

    Mazuz, M L; Fish, L; Wolkomirsky, R; Leibovich, B; Reznikov, D; Savitsky, I; Golenser, J; Shkap, V

    2015-06-15

    Neosporosis, caused by the intracellular protozoan Neospora caninum, is a major cause of abortion and reproductive failure in cattle worldwide. The principal route of transmission of neosporosis is via in utero infection of the offspring. There is no effective prophylactic treatment or vaccine available against bovine neosporosis. A N. caninum NcIs491 isolate was examined for its ability to immunize and reduce abortions in naturally infected dairy cows under field conditions. N. caninum-seropositive pregnant dams were inoculated with 10(8) live tachyzoites during mid-term pregnancy. A total of 520 N. caninum seropositive dams were included in this study, of these, 146 were immunized and 374 cows served as a non-vaccinated control group. A significantly lower incidence of abortion was observed in vaccinated compared to non-vaccinated cows, 16 and 26% respectively (P=0.01), with a vaccine efficacy of 39%. However, the number of seropositive offspring remained similar in both groups. Overall, this field trial suggests that vaccination with live N. caninum tachyzoites should be considered as an effective measure to reduce abortions caused by neosporosis in naturally infected cows. PMID:25890821

  19. Detection and characterization of viruses as field and vaccine strains in feedlot cattle with bovine respiratory disease.

    PubMed

    Fulton, R W; d'Offay, J M; Landis, C; Miles, D G; Smith, R A; Saliki, J T; Ridpath, J F; Confer, A W; Neill, J D; Eberle, R; Clement, T J; Chase, C C L; Burge, L J; Payton, M E

    2016-06-24

    This study investigated viruses in bovine respiratory disease (BRD) cases in feedlots, including bovine herpesvirus-1 (BoHV-1), bovine viral diarrhea virus (BVDV), bovine respiratory syncytial virus (BRSV), bovine coronaviruses (BoCV) and parainfluenza-3 virus (PI3V). Nasal swabs were collected from 114 cattle on initial BRD treatment. Processing included modified live virus (MLV) vaccination. Seven BRD necropsy cases were included for 121 total cases. Mean number of days on feed before first sample was 14.9 days. Swabs and tissue homogenates were tested by gel based PCR (G-PCR), quantitative-PCR (qPCR) and quantitative real time reverse transcriptase PCR (qRT-PCR) and viral culture. There were 87/114 (76.3%) swabs positive for at least one virus by at least one test. All necropsy cases were positive for at least one virus. Of 121 cases, positives included 18/121 (14.9%) BoHV-1; 19/121 (15.7%) BVDV; 76/121 (62.8%) BoCV; 11/121 (9.1%) BRSV; and 10/121 (8.3%) PI3V. For nasal swabs, G-PCR (5 viruses) detected 44/114 (38.6%); q-PCR and qRT-PCR (4 viruses) detected 81/114 (71.6%); and virus isolation detected 40/114 (35.1%). Most were positive for only one or two tests, but not all three tests. Necropsy cases had positives: 5/7 G-PCR, 5/7 q-PCR and qRT-PCR, and all were positive by cell culture. In some cases, G-PCR and both real time PCR were negative for BoHV-1, BVDV, and PI3V in samples positive by culture. PCR did not differentiate field from vaccines strains of BoHV-1, BVDV, and PI3V. However based on sequencing and analysis, field and vaccine strains of culture positive BoHV-1, BoCV, BVDV, and PI3V, 11/18 (61.1%) of BoHV-1 isolates, 6/17 (35.3%) BVDV isolates, and 1/10 (10.0%) PI3V identified as vaccine. BRSV was only identified by PCR testing. Interpretation of laboratory tests is appropriate as molecular based tests and virus isolation cannot separate field from vaccine strains. Additional testing using sequencing appears appropriate for identifying vaccine

  20. 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

  1. Delta-pgm, a new live-attenuated vaccine against Brucella suis.

    PubMed

    Czibener, Cecilia; Del Giudice, Mariela Giselda; Spera, Juan Manuel; Fulgenzi, Fabiana Rosa; Ugalde, Juan Esteban

    2016-03-18

    Brucellosis is one of the most widespread zoonosis in the world affecting many domestic and wild animals including bovines, goats, pigs and dogs. Each species of the Brucella genus has a particular tropism toward different mammals being the most relevant for human health Brucella abortus, Brucella melitensis and Brucella suis that infect bovines, goats/camelids and swine respectively. Although for B. abortus and B. melitensis there are vaccines available, there is no efficient vaccine to protect swine from B. suis infection so far. We describe here the construction of a novel vaccine strain that confers excellent protection against B. suis in a mouse model of infection. This strain is a clean deletion of the phosphoglucomutase (pgm) gene that codes for a protein that catalyzes the conversion of glucose-6-P to glucose-1-P, which is used as a precursor for the biosynthesis of many polysaccharides. The Delta-pgm strain lacks a complete lipopolysaccharide, is unable to synthesize cyclic beta glucans and is sensitive to several detergents and Polymyxin B. We show that this strain replicates in cultured cells, is completely avirulent in the mouse model of infection but protects against a challenge of the virulent strain inducing the production of pro-inflammatory cytokines. This novel strain could be an excellent candidate for the control of swine brucellosis, a disease of emerging concern in many parts of the world. PMID:26899373

  2. Strain-specific protective immunity following vaccination against experimental Trypanosoma cruzi infection.

    PubMed

    Haolla, Filipe A; Claser, Carla; de Alencar, Bruna C G; Tzelepis, Fanny; de Vasconcelos, José Ronnie; de Oliveira, Gabriel; Silvério, Jaline C; Machado, Alexandre V; Lannes-Vieira, Joseli; Bruna-Romero, Oscar; Gazzinelli, Ricardo T; dos Santos, Ricardo Ribeiro; Soares, Milena B P; Rodrigues, Mauricio M

    2009-09-18

    Immunisation with Amastigote Surface Protein 2 (asp-2) and trans-sialidase (ts) genes induces protective immunity in highly susceptible A/Sn mice, against infection with parasites of the Y strain of Trypanosoma cruzi. Based on immunological and biological strain variations in T. cruzi parasites, our goal was to validate our vaccination results using different parasite strains. Due to the importance of the CD8(+) T cells in protective immunity, we initially determined which strains expressed the immunodominant H-2K(k)-restricted epitope TEWETGQI. We tested eight strains, four of which elicited immune responses to this epitope (Y, G, Colombian and Colombia). We selected the Colombian and Colombia strains for our studies. A/Sn mice were immunised with different regimens using both T. cruzi genes (asp-2 and ts) simultaneously and subsequently challenged with blood trypomastigotes. Immune responses before the challenge were confirmed by the presence of specific antibodies and peptide-specific T cells. Genetic vaccination did not confer protective immunity against acute infection with a lethal dose of the Colombian strain. In contrast, we observed a drastic reduction in parasitemia and a significant increase in survival, following challenge with an otherwise lethal dose of the Colombia strain. In many surviving animals with late-stage chronic infection, we observed alterations in the heart's electrical conductivity, compared to naive mice. In summary, we concluded that immunity against T. cruzi antigens, similar to viruses and bacteria, may be strain-specific and have a negative impact on vaccine development. PMID:19635607

  3. 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. PMID:26588242

  4. Immunogenicity and Protective Efficacy of a Live Attenuated H5N1 Vaccine in Nonhuman Primates

    PubMed Central

    Fan, Shufang; Gao, Yuwei; Shinya, Kyoko; Li, Chris Kafai; Li, Yanbing; Shi, Jianzhong; Jiang, Yongping; Suo, Yongbing; Tong, Tiegang; Zhong, Gongxun; Song, Jiasheng; Zhang, Ying; Tian, Guobin; Guan, Yuntao; Xu, Xiao-Ning; Bu, Zhigao; Kawaoka, Yoshihiro; Chen, Hualan

    2009-01-01

    The continued spread of highly pathogenic H5N1 influenza viruses among poultry and wild birds, together with the emergence of drug-resistant variants and the possibility of human-to-human transmission, has spurred attempts to develop an effective vaccine. Inactivated subvirion or whole-virion H5N1 vaccines have shown promising immunogenicity in clinical trials, but their ability to elicit protective immunity in unprimed human populations remains unknown. A cold-adapted, live attenuated vaccine with the hemagglutinin (HA) and neuraminidase (NA) genes of an H5N1 virus A/VN/1203/2004 (clade 1) was protective against the pulmonary replication of homologous and heterologous wild-type H5N1 viruses in mice and ferrets. In this study, we used reverse genetics to produce a cold-adapted, live attenuated H5N1 vaccine (AH/AAca) that contains HA and NA genes from a recent H5N1 isolate, A/Anhui/2/05 virus (AH/05) (clade 2.3), and the backbone of the cold-adapted influenza H2N2 A/AnnArbor/6/60 virus (AAca). AH/AAca was attenuated in chickens, mice, and monkeys, and it induced robust neutralizing antibody responses as well as HA-specific CD4+ T cell immune responses in rhesus macaques immunized twice intranasally. Importantly, the vaccinated macaques were fully protected from challenge with either the homologous AH/05 virus or a heterologous H5N1 virus, A/bar-headed goose/Qinghai/3/05 (BHG/05; clade 2.2). These results demonstrate for the first time that a cold-adapted H5N1 vaccine can elicit protective immunity against highly pathogenic H5N1 virus infection in a nonhuman primate model and provide a compelling argument for further testing of double immunization with live attenuated H5N1 vaccines in human trials. PMID:19412338

  5. Vaccination of children with a live-attenuated, intranasal influenza vaccine – analysis and evaluation through a Health Technology Assessment

    PubMed Central

    Andersohn, Frank; Bornemann, Reinhard; Damm, Oliver; Frank, Martin; Mittendorf, Thomas; Theidel, Ulrike

    2014-01-01

    Background: Influenza is a worldwide prevalent infectious disease of the respiratory tract annually causing high morbidity and mortality in Germany. Influenza is preventable by vaccination and this vaccination is so far recommended by the The German Standing Committee on Vaccination (STIKO) as a standard vaccination for people from the age of 60 onwards. Up to date a parenterally administered trivalent inactivated vaccine (TIV) has been in use almost exclusively. Since 2011 however a live-attenuated vaccine (LAIV) has been approved additionally. Consecutively, since 2013 the STIKO recommends LAIV (besides TIV) for children from 2 to 17 years of age, within the scope of vaccination by specified indications. LAIV should be preferred administered in children from 2 to 6 of age. The objective of this Health Technology Assessment (HTA) is to address various research issues regarding the vaccination of children with LAIV. The analysis was performed from a medical, epidemiological and health economic perspective, as well as from an ethical, social and legal point of view. Method: An extensive systematic database research was performed to obtain relevant information. In addition a supplementary research by hand was done. Identified literature was screened in two passes by two independent reviewers using predefined inclusion and exclusion criteria. Included literature was evaluated in full-text using acknowledged standards. Studies were graded with the highest level of evidence (1++), if they met the criteria of European Medicines Agency (EMA)-Guidance: Points to consider on applications with 1. meta-analyses; 2. one pivotal study. Results: For the medical section, the age of the study participants ranges from 6 months to 17 years. Regarding study efficacy, in children aged 6 months to ≤7 years, LAIV is superior to placebo as well as to a vac-cination with TIV (Relative Risk Reduction – RRR – of laboratory confirmed influenza infection approx. 80% and 50

  6. The Brucella abortus S19 DeltavjbR live vaccine candidate is safer than S19 and confers protection against wild-type challenge in BALB/c mice when delivered in a sustained-release vehicle.

    PubMed

    Arenas-Gamboa, A M; Ficht, T A; Kahl-McDonagh, M M; Gomez, G; Rice-Ficht, A C

    2009-02-01

    Brucellosis is an important zoonotic disease of nearly worldwide distribution. Despite the availability of live vaccine strains for bovine (S19, RB51) and small ruminants (Rev-1), these vaccines have several drawbacks, including residual virulence for animals and humans. Safe and efficacious immunization systems are therefore needed to overcome these disadvantages. A vjbR knockout was generated in the S19 vaccine and investigated for its potential use as an improved vaccine candidate. Vaccination with a sustained-release vehicle to enhance vaccination efficacy was evaluated utilizing the live S19 DeltavjbR::Kan in encapsulated alginate microspheres containing a nonimmunogenic eggshell precursor protein of the parasite Fasciola hepatica (vitelline protein B). BALB/c mice were immunized intraperitoneally with either encapsulated or nonencapsulated S19 DeltavjbR::Kan at a dose of 1 x 10(5) CFU per animal to evaluate immunogenicity, safety, and protective efficacy. Humoral responses postvaccination indicate that the vaccine candidate was able to elicit an anti-Brucella-specific immunoglobulin G response even when the vaccine was administered in an encapsulated format. The safety was revealed by the absence of splenomegaly in mice that were inoculated with the mutant. Finally, a single dose with the encapsulated mutant conferred higher levels of protection compared to the nonencapsulated vaccine. These results suggest that S19 DeltavjbR::Kan is safer than S19, induces protection in mice, and should be considered as a vaccine candidate when administered in a sustained-release manner. PMID:19047401

  7. Determination of H5N1 vaccine potency using reference antisera from heterologous strains of influenza

    PubMed Central

    Vodeiko, Galina M.; Weir, Jerry P.

    2011-01-01

    Please cite this paper as: Vodeiko and Weir (2011). Determination of H5N1 vaccine potency using reference antisera from heterologous strains of influenza. Influenza and Other Respiratory Viruses 6(3), 176–187. Background  Standardization of inactivated influenza vaccines by hemagglutinin (HA) content is performed by the single radial immunodiffusion (SRID) method. Regulatory agencies prepare, calibrate, and distribute SRID reagent standards necessary for testing of seasonal influenza vaccines, and a similar process is used to produce potency reagents for candidate pandemic influenza vaccines that are manufactured for emergency stockpiles. Objectives  Because of the concerns in generating a timely strain‐specific potency antiserum for an emerging pandemic virus, we evaluated the feasibility of using heterologous potency reference antiserum as a replacement for a strain‐specific (homologous) antiserum in the SRID potency assay for stockpiled H5N1 vaccines. Results  The results indicate that a heterologous H5N1 antiserum can be used to determine the accurate potency of inactivated H5N1 influenza vaccines. Additionally, when H5N1 vaccine was subjected to an accelerated stability protocol, both homologous and heterologous antisera provided similar measurements of vaccine potency decline. Limitations to the heterologous antiserum approach to potency determination were shown by the inability of antiserum to recent seasonal H1N1 viruses to work in an SRID assay with the 2009 pandemic H1N1 A/California/07/2009 antigen. Conclusions  The data demonstrate the feasibility of using heterologous antiserum for potency determination of at least some candidate vaccines in case of a shortage or delay of homologous antiserum. Further, the results suggest the prudence of stockpiling a broad library of potency reagents including many strains of influenza viruses with pandemic potential to provide an added measure of assurance that reagent production would not be a

  8. 28 Live Strains Are Available for a Limited Time from the MMRRC Repository —

    Cancer.gov

    Last Chance to order Live Mice! The following Live colonies will soon be taken off the shelf. Once off the shelf, these strains will only be available as cryopreserved germplasm or mice from cryo recovery. Order the following strains distributed from the MMRRC by placing your order online by the dates indicated below to receive mice from the Live colonies.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  11. 9 CFR 113.71 - Chlamydia Psittaci Vaccine (Feline Pneumonitis), Live Chlamydia.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Chlamydia Psittaci Vaccine (Feline Pneumonitis), Live Chlamydia. 113.71 Section 113.71 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS STANDARD REQUIREMENTS...

  12. Strain Selection for Generation of O-Antigen-Based Glycoconjugate Vaccines against Invasive Nontyphoidal Salmonella Disease

    PubMed Central

    Saul, Allan; MacLennan, Calman A.; Micoli, Francesca; Rondini, Simona

    2015-01-01

    Nontyphoidal Salmonellae, principally S. Typhimurium and S. Enteritidis, are a major cause of invasive bloodstream infections in sub-Saharan Africa with no vaccine currently available. Conjugation of lipopolysaccharide O-antigen to a carrier protein constitutes a promising vaccination strategy. Here we describe a rational process to select the most appropriate isolates of Salmonella as source of O-antigen for developing a bivalent glycoconjugate vaccine. We screened a library of 30 S. Typhimurium and 21 S. Enteritidis in order to identify the most suitable strains for large scale O-antigen production and generation of conjugate vaccines. Initial screening was based on growth characteristics, safety profile of the isolates, O-antigen production, and O-antigen characteristics in terms of molecular size, O-acetylation and glucosylation level and position, as determined by phenol sulfuric assay, NMR, HPLC-SEC and HPAEC-PAD. Three animal isolates for each serovar were identified and used to synthesize candidate glycoconjugate vaccines, using CRM197 as carrier protein. The immunogenicity of these conjugates and the functional activity of the induced antibodies was investigated by ELISA, serum bactericidal assay and flow cytometry. S. Typhimurium O-antigen showed high structural diversity, including O-acetylation of rhamnose in a Malawian invasive strain generating a specific immunodominant epitope. S. Typhimurium conjugates provoked an anti-O-antigen response primarily against the O:5 determinant. O-antigen from S. Enteritidis was structurally more homogeneous than from S. Typhimurium, and no idiosyncratic antibody responses were detected for the S. Enteritidis conjugates. Of the three initially selected isolates, two S. Typhimurium (1418 and 2189) and two S. Enteritidis (502 and 618) strains generated glycoconjugates able to induce high specific antibody levels with high breadth of serovar-specific strain coverage, and were selected for use in vaccine production. The

  13. Strain Selection for Generation of O-Antigen-Based Glycoconjugate Vaccines against Invasive Nontyphoidal Salmonella Disease.

    PubMed

    Lanzilao, Luisa; Stefanetti, Giuseppe; Saul, Allan; MacLennan, Calman A; Micoli, Francesca; Rondini, Simona

    2015-01-01

    Nontyphoidal Salmonellae, principally S. Typhimurium and S. Enteritidis, are a major cause of invasive bloodstream infections in sub-Saharan Africa with no vaccine currently available. Conjugation of lipopolysaccharide O-antigen to a carrier protein constitutes a promising vaccination strategy. Here we describe a rational process to select the most appropriate isolates of Salmonella as source of O-antigen for developing a bivalent glycoconjugate vaccine. We screened a library of 30 S. Typhimurium and 21 S. Enteritidis in order to identify the most suitable strains for large scale O-antigen production and generation of conjugate vaccines. Initial screening was based on growth characteristics, safety profile of the isolates, O-antigen production, and O-antigen characteristics in terms of molecular size, O-acetylation and glucosylation level and position, as determined by phenol sulfuric assay, NMR, HPLC-SEC and HPAEC-PAD. Three animal isolates for each serovar were identified and used to synthesize candidate glycoconjugate vaccines, using CRM197 as carrier protein. The immunogenicity of these conjugates and the functional activity of the induced antibodies was investigated by ELISA, serum bactericidal assay and flow cytometry. S. Typhimurium O-antigen showed high structural diversity, including O-acetylation of rhamnose in a Malawian invasive strain generating a specific immunodominant epitope. S. Typhimurium conjugates provoked an anti-O-antigen response primarily against the O:5 determinant. O-antigen from S. Enteritidis was structurally more homogeneous than from S. Typhimurium, and no idiosyncratic antibody responses were detected for the S. Enteritidis conjugates. Of the three initially selected isolates, two S. Typhimurium (1418 and 2189) and two S. Enteritidis (502 and 618) strains generated glycoconjugates able to induce high specific antibody levels with high breadth of serovar-specific strain coverage, and were selected for use in vaccine production. The

  14. Exploitation of Mycobacterium tuberculosis Reporter Strains to Probe the Impact of Vaccination at Sites of Infection

    PubMed Central

    Aldridge, Bree B.; Russell, David G.

    2014-01-01

    Mycobacterium tuberculosis (Mtb) remains a major public health problem, with an effective vaccine continuing to prove elusive. Progress in vaccination strategies has been hampered by a lack of appreciation of the bacterium's response to dynamic changes in the host immune environment. Here, we utilize reporter Mtb strains that respond to specific host immune stresses such as hypoxia and nitric oxide (hspX′::GFP), and phagosomal maturation (rv2390c′::GFP), to investigate vaccine-induced alterations in the environmental niche during experimental murine infections. While vaccination undoubtedly decreased bacterial burden, we found that it also appeared to accelerate Mtb's adoption of a phenotype better equipped to survive in its host. We subsequently utilized a novel replication reporter strain of Mtb to demonstrate that, in addition to these alterations in host stress response, there is a decreased percentage of actively replicating Mtb in vaccinated hosts. This observation was supported by the differential sensitivity of recovered bacteria to the front-line drug isoniazid. Our study documents the natural history of the impact that vaccination has on Mtb's physiology and replication and highlights the value of reporter Mtb strains for probing heterogeneous Mtb populations in the context of a complex, whole animal model. PMID:25233380

  15. FMD virus isolates: the candidate strains for polyvalent vaccine development in Ethiopia.

    PubMed

    Ayelet, G; Soressa, M; Sisay, T; Belay, A; Gelaye, E; Jembere, S; Skjerve, E; Asmare, K

    2013-06-01

    The study was conducted on foot-and-mouth disease (FMD) viruses with the aim of selecting appropriate vaccinal strain to control of FMD in Ethiopia. The study was conducted in two-dimensional virus neutralization assay to determine the antigenic relationship 'r' value between the candidate vaccine strains and field isolates. A total of 21 serotype O, 7 serotype A, and 8 serotype SAT 2 FMD viruses, which were isolated from cattle and swine. A couple of isolates from each serotype were identified as vaccine candidates in the trial (O-ETH/38/2005, O-ETH/58/2008, A-ETH/7/2008, A-ETH/6/2000, SAT2-ETH/76/2009 and SAT2-ETH/64/2009). The finding revealed all the vaccine candidate depicted high antigenic similarity, above the mean "r" value, to their own serotypes in the studied serotype population except for one serotype A field isolate, A-ETH/13/1981, with "r" value=0.14 and 0.25) which is significantly lower than the minimum requirement. In general, the result indicated that these candidate vaccinal strains can be used for polyvalent vaccine production in the country. PMID:23416124

  16. 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

  17. Presenting a foreign antigen on live attenuated Edwardsiella tarda using twin-arginine translocation signal peptide as a multivalent vaccine.

    PubMed

    Wang, Yamin; Yang, Weizheng; Wang, Qiyao; Qu, Jiangbo; Zhang, Yuanxing

    2013-12-01

    The twin-arginine translocation (Tat) system is a major pathway for transmembrane translocation of fully folded proteins. In this study, a multivalent vaccine to present foreign antigens on live attenuated vaccine Edwardsiella tarda WED using screened Tat signal peptide was constructed. Because the Tat system increases the yields of folded antigens in periplasmic space or extracellular milieu, it is expected to contribute to the production of conformational epitope-derived specific antibodies. E. tarda Tat signal peptides fused with the green fluorescent protein (GFP) was constructed under the control of an in vivo inducible dps promoter. The resulting plasmids were electroporated into WED and the subcellular localizations of GFP were analyzed with Western blotting. Eight signal peptides with optimized GFP translocation efficiency were further fused to a protective antigen glyceraldehyde-3-phosphate dehydrogenase (GapA) from a fish pathogen Aeromonas hydrophila. Signal peptides of DmsA, NapA, and SufI displayed high efficiency for GapA translocation. The relative percent survival (RPS) of turbot was measured with a co-infection of E. tarda and A. hydrophila, and the strain with DmsA signal peptide showed the maximal protection. This study demonstrated a new platform to construct multivalent vaccines using optimized Tat signal peptide in E. tarda. PMID:23994481

  18. Variable Virulence and Efficacy of BCG Vaccine Strains in Mice and Correlation With Genome Polymorphisms.

    PubMed

    Zhang, Lu; Ru, Huan-wei; Chen, Fu-zeng; Jin, Chun-yan; Sun, Rui-feng; Fan, Xiao-yong; Guo, Ming; Mai, Jun-tao; Xu, Wen-xi; Lin, Qing-xia; Liu, Jun

    2016-02-01

    Bacille Calmette-Guérin (BCG), an attenuated strain of Mycobacterium bovis, is the only vaccine available for tuberculosis (TB) control. However, BCG is not an ideal vaccine and has two major limitations: BCG exhibits highly variable effectiveness against the development of TB both in pediatric and adult populations and can cause disseminated BCG disease in immunocompromised individuals. BCG comprises a number of substrains that are genetically distinct. Whether and how these genetic differences affect BCG efficacy remains largely unknown. In this study, we performed comparative analyses of the virulence and efficacy of 13 BCG strains, representing different genetic lineages, in SCID and BALB/c mice. Our results show that BCG strains of the DU2 group IV (BCG-Phipps, BCG-Frappier, BCG-Pasteur, and BCG-Tice) exhibit the highest levels of virulence, and BCG strains of the DU2 group II (BCG-Sweden, BCG-Birkhaug) are among the least virulent group. These distinct levels of virulence may be explained by strain-specific duplications and deletions of genomic DNA. There appears to be a general trend that more virulent BCG strains are also more effective in protection against Mycobacterium tuberculosis challenge. Our findings have important implications for current BCG vaccine programs and for future TB vaccine development. PMID:26643797

  19. Development of a genotype specific live Newcastle disease vaccine by replacing the fusion (F) and hemagglutinin-neuramindase (HN) genes into a LaSota vaccine backbone

    Technology Transfer Automated Retrieval System (TEKTRAN)

    All Newcastle disease viruses (NDVs) are part of a single serotype; however, current vaccine strains display between 15 and 18% amino acid differences at the F and HN protein compared with current virulent viruses. Previous studies have shown that increased amino acid similarity between NDV vaccine...

  20. Protection of gruntlings against classical swine fever virus-infection after oral vaccination of sows with C-strain vaccine.

    PubMed

    Kaden, V; Lange, E; Müller, T; Teuffert, J; Teifke, J P; Riebe, R

    2006-12-01

    The objective of this study was to investigate the maternal protection of gruntlings derived from wild sows vaccinated orally against classical swine fever (CSF) using C-strain vaccine. Three vaccinated sows and one unvaccinated control sow were included. Challenge infection of the progeny was carried out either intranasally or by contact at the beginning of the third month of life (61-65 days post-natum). Whereas, two of three litters had maternal antibodies, the progeny of one vaccinated sow was seronegative at challenge. The progeny of the control sow, which was challenged by contact infection, developed moderate clinical signs except for one animal which became ill and died. Two gruntlings derived from the vaccinated sows also died of CSF, although one of them had a relatively high maternal antibody titre (128 ND(50)). The transient infection and partial virus shedding observed in a small number of gruntlings with maternal antibodies and the fact that one animal with maternal antibodies became ill and died confirm the incomplete maternal protection at this age. The reason for this incomplete protection is discussed. As none of the surviving gruntlings could be shown to carry CSFV or viral RNA at the end of the experiment (36 or 70 d.p.i.), it may be concluded that these animals do not represent a potential CSFV reservoir. PMID:17123422

  1. Differentiation of field isolates and vaccine strains of infectious laryngotracheitis virus by DNA sequencing.

    PubMed

    Chacón, Jorge Luis; Ferreira, Antonio J Piantino

    2009-11-12

    Two different regions of the infected cell protein 4 (ICP4) gene of infectious laryngotracheitis virus (ILTV) were amplified and sequenced for characterization of field isolates and tissue culture-origin (TCO) and chicken embryo-origin (CEO) vaccine strains. Phylogenetic analysis of the two regions showed differences in nucleotide and amino acid sequences between field isolates and attenuated vaccines. The PCR-RFLP results were identical to those obtained by DNA sequencing and validated their use to differentiate ILTV strains. The approach using the sequencing of the two fragments of the ICP4 gene showed to be an efficient and practical procedure to differentiate between field isolates and vaccine strains of ILTV. PMID:19747995

  2. Efficacy of dart or booster vaccination with strain RB51 in protecting bison against experimental Brucella abortus challenge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vaccination is an effective tool for reducing the prevalence of brucellosis in natural hosts. In this study, we characterized the efficacy of the Brucella abortus strain RB51 (RB51) vaccine in bison when delivered by single intramuscular vaccination (Hand RB51), single pneumatic dart delivery (Dart ...

  3. [Production of a vaccine against enterotoxemia from Clostridium perfringens strains isolated in the field].

    PubMed

    Cherfaoui, S; Kadra, B

    1992-01-01

    We have isolated eight strains of C. perfringens from cases of enterotoxaemia. Five of these strains have revealed themselves toxic with respective types (type "A":2, type "C":2, type "D":1). In order to produce anti-enterotoxaemia vaccine, we have proceeded at the cultivation in fermenter of isolated strains and reference strains CWA 35, CWC and CWD AF. At the end of fermentation, we have evaluated the two following parameters: obtained biomass, and toxin titers. With the two classes of strains we reached an important biomass but toxins titers relatively weak comparatively to that which is usually required. It will be necessary then, to demonstrate the immunogen value of the produced vaccines by testing their efficacity. PMID:1309137

  4. Identification of the pXO1 plasmid in attenuated Bacillus anthracis vaccine strains.

    PubMed

    Liang, Xudong; Zhang, Huijuan; Zhang, Enmin; Wei, Jianchun; Li, Wei; Wang, Bingxiang; Dong, Shulin; Zhu, Jin

    2016-07-01

    Anthrax toxins and capsule are the major virulence factors of Bacillus anthracis. They are encoded by genes located on the plasmids pXO1 and pXO2, respectively. The vaccine strain Pasteur II was produced from high temperature subcultures of B. anthracis, which resulted in virulence attenuation through the loss of the plasmid pXO1. However, it is unclear whether the high temperature culture completely abolishes the plasmid DNA or affects the replication of the plasmid pXO1. In this study, we tested 3 B. anthracis vaccine strains, including Pasteur II from France, Qiankefusiji II from Russia, and Rentian II from Japan, which were all generated from subcultures at high temperatures. Surprisingly, we detected the presence of pXO1 plasmid DNA using overlap PCR in all these vaccine strains. DNA sequencing analysis of overlap PCR products further confirmed the presence of pXO1. Moreover, the expression of the protective antigen (PA) encoded on pXO1 was determined by using SDS-PAGE and western blotting. In addition, we mimicked Pasteur's method and exposed the A16R vaccine strain, which lacks the pXO2 plasmid, to high temperature, and identified the pXO1 plasmid in the subcultures at high temperatures. This indicated that the high temperature treatment at 42.5°C was unable to eliminate pXO1 plasmid DNA from B. anthracis. Our results suggest that the attenuation of the Pasteur II vaccine strain is likely due to the impact of high temperature stress on plasmid replication, which in turn limits the copy number of pXO1. Our data provide new insights into the mechanisms of the remaining immunogenicity and toxicity of the vaccine strains. PMID:27029580

  5. Attenuation of Chikungunya Virus Vaccine Strain 181/Clone 25 Is Determined by Two Amino Acid Substitutions in the E2 Envelope Glycoprotein

    PubMed Central

    Gorchakov, Rodion; Wang, Eryu; Leal, Grace; Forrester, Naomi L.; Plante, Kenneth; Rossi, Shannan L.; Partidos, Charalambos D.; Adams, A. Paige; Seymour, Robert L.; Weger, James; Borland, Erin M.; Sherman, Michael B.; Powers, Ann M.; Osorio, Jorge E.

    2012-01-01

    Chikungunya virus (CHIKV) is the mosquito-borne alphavirus that is the etiologic agent of massive outbreaks of arthralgic febrile illness that recently affected millions of people in Africa and Asia. The only CHIKV vaccine that has been tested in humans, strain 181/clone 25, is a live-attenuated derivative of Southeast Asian human isolate strain AF15561. The vaccine was immunogenic in phase I and II clinical trials; however, it induced transient arthralgia in 8% of the vaccinees. There are five amino acid differences between the vaccine and its parent, as well as five synonymous mutations, none of which involves cis-acting genome regions known to be responsible for replication or packaging. To identify the determinants of attenuation, we therefore tested the five nonsynonymous mutations by cloning them individually or in different combinations into infectious clones derived from two wild-type (WT) CHIKV strains, La Reunion and AF15561. Levels of virulence were compared with those of the WT strains and the vaccine strain in two different murine models: infant CD1 and adult A129 mice. An attenuated phenotype indistinguishable from that of the 181/clone 25 vaccine strain was obtained by the simultaneous expression of two E2 glycoprotein substitutions, with intermediate levels of attenuation obtained with the single E2 mutations. The other three amino acid mutations, in nsP1, 6K, and E1, did not have a detectable effect on CHIKV virulence. These results indicate that the attenuation of strain 181/clone 25 is mediated by two point mutations, explaining the phenotypic instability observed in human vaccinees and also in our studies. PMID:22457519

  6. Live recombinant Salmonella Typhi vaccines constructed to investigate the role of rpoS in eliciting immunity to a heterologous antigen.

    PubMed

    Shi, Huoying; Santander, Javier; Brenneman, Karen E; Wanda, Soo-Young; Wang, Shifeng; Senechal, Patti; Sun, Wei; Roland, Kenneth L; Curtiss, Roy

    2010-01-01

    We hypothesized that the immunogenicity of live Salmonella enterica serovar Typhi vaccines expressing heterologous antigens depends, at least in part, on its rpoS status. As part of our project to develop a recombinant attenuated S. Typhi vaccine (RASTyV) to prevent pneumococcal diseases in infants and children, we constructed three RASTyV strains synthesizing the Streptococcus pneumoniae surface protein PspA to test this hypothesis. Each vector strain carried ten engineered mutations designed to optimize safety and immunogenicity. Two S. Typhi vector strains (chi9639 and chi9640) were derived from the rpoS mutant strain Ty2 and one (chi9633) from the RpoS(+) strain ISP1820. In chi9640, the nonfunctional rpoS gene was replaced with the functional rpoS gene from ISP1820. Plasmid pYA4088, encoding a secreted form of PspA, was moved into the three vector strains. The resulting RASTyV strains were evaluated for safety in vitro and for immunogenicity in mice. All three RASTyV strains were similar to the live attenuated typhoid vaccine Ty21a in their ability to survive in human blood and human monocytes. They were more sensitive to complement and were less able to survive and persist in sewage and surface water than their wild-type counterparts. Adult mice intranasally immunized with any of the RASTyV strains developed immune responses against PspA and Salmonella antigens. The RpoS(+) vaccines induced a balanced Th1/Th2 immune response while the RpoS(-) strain chi9639(pYA4088) induced a strong Th2 immune response. Immunization with any RASTyV provided protection against S. pneumoniae challenge; the RpoS(+) strain chi9640(pYA4088) provided significantly greater protection than the ISP1820 derivative, chi9633(pYA4088). In the pre-clinical setting, these strains exhibited a desirable balance between safety and immunogenicity and are currently being evaluated in a Phase 1 clinical trial to determine which of the three RASTyVs has the optimal safety and immunogenicity profile

  7. 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. PMID:21917319

  8. Increased level of Eimeria sensitivity to diclazuril after using a live coccidial vaccine.

    PubMed

    Mathis, G F; Broussard, C

    2006-09-01

    Anticoccidial vaccine and an anticoccidial drug rotation program were compared to determine which program was more effective in producing coccidia populations sensitive of 1 ppm diclazuril. The study used an anticoccidial drug-sensitivity battery test (AST) to determine the baseline level of diclazuril sensitivity to field isolates of Eimeria spp. from seven broiler complexes that had used diclazuril. Based on percentage reduction in weight gain and lesion scores, 25% or fewer of the isolates were effectively controlled by diclazuril. Following the baseline sampling, four of the complexes switched to a nondiclazuril in-feed anticoccidial drug program and three of the complexes switched to a vaccination program for two broiler grow-out cycles as the sole coccidiosis-control program. This study demonstrated that the vaccine used (Coccivac-B) contained anticoccidial drug-sensitive strains. Eimeria isolates were subsequently collected from the identical houses and diclazuril AST results were compared with the baseline AST results. Following the two grow-out cycles, sensitivity of the isolates to diclazuril from the four complexes that continued to use in-feed anticoccidial drugs remained essentially unchanged. The isolates from the three complexes that switched to the vaccination program demonstrated a marked increase in diclazuril sensitivity, with 60%-100% of the isolates from each complex effectively controlled by diclazuril. Vaccination with the anticoccidial drug-sensitive strains produced a measurable increase in the level of sensitivity to diclazuril. PMID:17039828

  9. Transmission Dynamics of Rift Valley Fever Virus: Effects of Live and Killed Vaccines on Epizootic Outbreaks and Enzootic Maintenance

    PubMed Central

    Chamchod, Farida; Cosner, Chris; Cantrell, R. Stephen; Beier, John C.; Ruan, Shigui

    2016-01-01

    Rift Valley fever virus (RVFV) is an arthropod-borne viral pathogen that causes significant morbidity and mortality in small ruminants throughout Africa and the Middle East. Due to the sporadic and explosive nature of RVF outbreaks, vaccination has proved challenging to reduce RVFV infection in the ruminant population. Currently, there are two available types of vaccines, live and killed, in endemic areas. In this study, two mathematical models have been developed to explore the impact of live and killed vaccines on the transmission dynamics of RVFV. We demonstrate in general that vaccination helps reduce the severity of RVF outbreaks and that less delay in implementation and more vaccination attempts and effective vaccines can reduce the outbreak magnitude and the endemic number of RVFV. However, an introduction of a number of ruminants vaccinated by live vaccines in RVFV-free areas may cause an outbreak and RVFV may become endemic if there is sustained use of live vaccines. Other factors that are the important determinants of RVF outbreaks include: unsustained vaccination programs, recruitment of susceptible ruminants, and the seasonal abundance of mosquitoes. PMID:26869999

  10. High-resolution melting-curve analysis of obg gene to differentiate the temperature-sensitive Mycoplasma synoviae vaccine strain MS-H from non-temperature-sensitive strains.

    PubMed

    Shahid, Muhammad A; Markham, Philip F; Marenda, Marc S; Agnew-Crumpton, Rebecca; Noormohammadi, Amir H

    2014-01-01

    Temperature-sensitive (ts+) vaccine strain MS-H is the only live attenuated M. synoviae vaccine commercially available for use in poultry. With increasing use of this vaccine to control M. synoviae infections, differentiation of MS-H from field M. synoviae strains and from rarely occurring non-temperature-sensitive (ts-) MS-H revertants has become important, especially in countries where local strains are indistinguishable from MS-H by sequence analysis of variable lipoprotein haemagglutinin (vlhA) gene. Single nucleotide polymorphisms (SNPs) in the obg of MS-H have been found to associate with ts phenotype. In this study, four PCRs followed by high-resolution melting (HRM)-curve analysis of the regions encompassing these SNPs were developed and evaluated for their potential to differentiate MS-H from 36 M. synoviae strains/isolates. The nested-obg PCR-HRM differentiated ts+ MS-H vaccine not only from field M. synoviae strains/isolates but also from ts- MS-H revertants. The mean genotype confidence percentages, 96.9±3.4 and 8.8±11.2 for ts+ and ts- strains, respectively, demonstrated high differentiating power of the nested-obg PCR-HRM. Using a combination of nested-obg and obg-F3R3 PCR-HRM, 97% of the isolates/strains were typed according to their ts phenotype with all MS-H isolates typed as MS-H. A set of respiratory swabs from MS-H vaccinated specific pathogen free chickens and M. synoviae infected commercial chicken flocks were tested using obg PCR-HRM system and results were consistent with those of vlhA genotyping. The PCR-HRM system developed in this study, proved to be a rapid and reliable tool using pure M. synoviae cultures as well as direct clinical specimens. PMID:24643035

  11. Genetic characterisation of the rabies virus vaccine strains used for oral immunization of foxes in Poland to estimate the effectiveness of vaccination.

    PubMed

    Orłowska, Anna; Żmudziński, Jan Franciszek

    2015-02-01

    The main reservoir of rabies virus in Poland has been the red fox. To control rabies in wildlife, oral immunization of foxes was introduced in 1993. The vaccine is effective when it confers immunity against the virus circulating in the environment. To assess the above issue, a study of the molecular characteristics of 570-bp fragments of the N and G genes of vaccine strains SAD B19 and SAD Bern against street virus strains was performed. The results confirmed the similarity of the vaccine strains and rabies virus strains circulating in the environment and also demonstrate the genetic stability of vaccine strains that have been distributed in Poland for 20 years. PMID:25408374

  12. Meningococcal Factor H Binding Proteins in Epidemic Strains from Africa: Implications for Vaccine Development

    PubMed Central

    Pajon, Rolando; Fergus, Andrew M.; Koeberling, Oliver; Caugant, Dominique A.; Granoff, Dan M.

    2011-01-01

    Background Factor H binding protein (fHbp) is an important antigen for vaccines against meningococcal serogroup B disease. The protein binds human factor H (fH), which enables the bacteria to resist serum bactericidal activity. Little is known about the vaccine-potential of fHbp for control of meningococcal epidemics in Africa, which typically are caused by non-group B strains. Methodology/Principal Findings We investigated genes encoding fHbp in 106 serogroup A, W-135 and X case isolates from 17 African countries. We determined complement-mediated bactericidal activity of antisera from mice immunized with recombinant fHbp vaccines, or a prototype native outer membrane vesicle (NOMV) vaccine from a serogroup B mutant strain with over-expressed fHbp. Eighty-six of the isolates (81%) had one of four prevalent fHbp sequence variants, ID 4/5 (serogroup A isolates), 9 (W-135), or 74 (X) in variant group 1, or ID 22/23 (W-135) in variant group 2. More than one-third of serogroup A isolates and two-thirds of W-135 isolates tested had low fHbp expression while all X isolates tested had intermediate or high expression. Antisera to the recombinant fHbp vaccines were generally bactericidal only against isolates with fHbp sequence variants that closely matched the respective vaccine ID. Low fHbp expression also contributed to resistance to anti-fHbp bactericidal activity. In contrast to the recombinant vaccines, the NOMV fHbp ID 1 vaccine elicited broad anti-fHbp bactericidal activity, and the antibodies had greater ability to inhibit binding of fH to fHbp than antibodies elicited by the control recombinant fHbp ID 1 vaccine. Conclusion/Significance NOMV vaccines from mutants with increased fHbp expression elicit an antibody repertoire with greater bactericidal activity than recombinant fHbp vaccines. NOMV vaccines are promising for prevention of meningococcal disease in Africa and could be used to supplement coverage conferred by a serogroup A polysaccharide-protein conjugate

  13. Evaluation of the safety, immunogenicity and efficacy of three capripoxvirus vaccine strains against lumpy skin disease virus.

    PubMed

    Gari, Getachew; Abie, Getnet; Gizaw, Daniel; Wubete, Alehegn; Kidane, Membere; Asgedom, Hagos; Bayissa, Berecha; Ayelet, Gelagay; Oura, Christopher A L; Roger, Francois; Tuppurainen, Eeva S M

    2015-06-22

    The safety, immunogenicity and efficacy of three commercially available vaccines against lumpy skin disease (LSD) in cattle have been evaluated using a combination of vaccine challenge experiments and the monitoring of immune responses in vaccinated animals in the field. The three vaccines evaluated in the study included two locally produced (Ethiopian) vaccines (lumpy skin disease virus (LSDV) Neethling and Kenyan sheep and goat pox (KSGP) O-180 strain vaccines) and a Gorgan goat pox (GTP) vaccine manufactured by Jordan Bio-Industries Centre (JOVAC). The latter vaccine was evaluated for the first time in cattle against LSDV. The Ethiopian Neethling and KSGPO-180 vaccines failed to provide protection in cattle against LSDV, whereas the Gorgan GTP vaccine protected all the vaccinated calves from clinical signs of LSD. There was no significant difference in protective efficacy detected between two dosage levels (P=0.2, P=0.25, and P=0.1 for KSGP, Neethling and Gorgan vaccines, respectively). Additionally, the Gorgan GTP vaccinated cattle showed stronger levels of cellular immune responses measured using Delayed-Type Hypersensitivity (DTH) reactions at the vaccination site indicating higher levels of immunogenicity produced by the GTPV vaccine in cattle, as opposed to the other two vaccines. This study indicated, for the first time, that the Gorgan GTP vaccine can effectively protect cattle against LSDV and that the Neethling and KSGP O-180 vaccine were not protective. The results emphasise the need for molecular characterization of the Neethling and KSGP O-180 vaccine seed viruses used for vaccine production in Ethiopia. In addition, the potency and efficacy testing process of the Ethiopian LSD Neethling and KSGP O-180 vaccines should be re-evaluated. PMID:26056063

  14. Use of the alpha-hemolysin secretion system of Escherichia coli for antigen delivery in the Salmonella typhi Ty21a vaccine strain.

    PubMed

    Gentschev, Ivaylo; Dietrich, Guido; Spreng, Simone; Neuhaus, Beatrice; Maier, Elke; Benz, Roland; Goebel, Werner; Fensterle, Joachim; Rapp, Ulf R

    2004-10-01

    This study examined the suitability of the hemolysin secretion system of Escherichia coli for expression and delivery of alpha-hemolysin (HlyA) by the S. typhi Ty21a strain, the only live oral Salmonella vaccine strain licensed for human use, under in vitro and in vivo conditions. For this purpose, two plasmid vectors encoding either the whole alpha-hemolysin of E. coli (pANN202-812/pMOhly2) or the hemolysin secretion signal (pMOhly1) were transferred into S. typhi Ty21a. S. typhi Ty21a carrying pANN202-812/pMOhly2 revealed efficient secretion of hemolysin in vitro. After formulation according to a process suitable for commercial production of Salmonella-based live bacterial vaccines, plasmids were shown to be stable in Ty21a and hemolysin secretion was demonstrated even after storage of the strains under real-time and stress conditions. After intranasal immunization of mice with S. typhi Ty21a/pANN202-812 plasmids are stable in vivo, and immunization induced a profound immune response against the heterologous HlyA antigen. Therefore, the combination of the hemolysin secretion system and S. typhi Ty21a could form the basis for a new generation of live bacterial vaccines. PMID:15595386

  15. Safety and protective efficacy of a spiC and crp deletion mutant of Salmonella gallinarum as a live attenuated vaccine for fowl typhoid.

    PubMed

    Cheng, Zhao; Yin, Junlei; Kang, Xilong; Geng, Shizhong; Hu, Maozhi; Pan, Zhiming; Jiao, Xinan

    2016-08-01

    With an aim to develop a safe, immunogenic fowl typhoid (FT) vaccine, the safety and efficacy of 1009ΔspiCΔcrp, a spiC and crp deletion mutant of Salmonella gallinarum, were evaluated in chickens. Three-day-old chickens were intramuscularly immunized with 1009ΔspiCΔcrp (1×10(7)CFU) and boosted 7days later (at 10-days old) with the same dose and via the same route (vaccinated group). The vaccinated group showed no clinical symptoms and no differences in body weight compared to the unvaccinated control group. 1009ΔspiCΔcrp bacteria colonized and persisted in the liver and spleen of vaccinated chickens for >14days, and significant specific humoral and cellular immune responses were induced. Vaccinated chickens were challenged with S. gallinarum strain SG9 at 21days post-immunization (24-day-old chickens), and efficient protection was observed based on the mortality and clinical symptoms, as compared to those in the control group. These results demonstrate that 1009ΔspiCΔcrp can be used as a live attenuated vaccine. PMID:27473974

  16. Genetic Vaccination against Experimental Infection with Myotropic Parasite Strains of Trypanosoma cruzi

    PubMed Central

    Araújo, Adriano Fernando; de Oliveira, Gabriel; Vasconcelos, Juliana Fraga; Ersching, Jonatan; Dominguez, Mariana Ribeiro; Vasconcelos, José Ronnie; Machado, Alexandre Vieira; Gazzinelli, Ricardo Tostes; Bruna-Romero, Oscar; Soares, Milena Botelho; Rodrigues, Mauricio Martins

    2014-01-01

    In earlier studies, we reported that a heterologous prime-boost regimen using recombinant plasmid DNA followed by replication-defective adenovirus vector, both containing Trypanosoma cruzi genes encoding trans-sialidase (TS) and amastigote surface protein (ASP) 2, provided protective immunity against experimental infection with a reticulotropic strain of this human protozoan parasite. Herein, we tested the outcome of genetic vaccination of F1 (CB10XBALB/c) mice challenged with myotropic parasite strains (Brazil and Colombian). Initially, we determined that the coadministration during priming of a DNA plasmid containing the murine IL-12 gene improved the immune response and was essential for protective immunity elicited by the heterologous prime-boost regimen in susceptible male mice against acute lethal infections with these parasites. The prophylactic or therapeutic vaccination of resistant female mice led to a drastic reduction in the number of inflammatory infiltrates in cardiac and skeletal muscles during the chronic phase of infection with either strain. Analysis of the electrocardiographic parameters showed that prophylactic vaccination reduced the frequencies of sinus arrhythmia and atrioventricular block. Our results confirmed that prophylactic vaccination using the TS and ASP-2 genes benefits the host against acute and chronic pathologies caused by T. cruzi and should be further evaluated for the development of a veterinary or human vaccine against Chagas disease. PMID:25061263

  17. [Antigenic determination of human anti-rabies vaccine against viral street strains common in the wild animal population in Poland].

    PubMed

    Seroka, D

    1994-01-01

    The aim of the study was to compare the antigen properties of a vaccine strain with street strains isolated from various animal hosts throughout the country. Investigation was carried out using monoclonal antibodies against NC protein. Also, two tests were carried out: the modified NIH test for potency and the neutralization test using the sera of people vaccinated against rabies (PM vaccine strain). The investigated street strains were used in both tests as the challenge viruses. A suspension of these strains diluted five times made it possible to avoid extreme values of animal survival (0% or 100%) what, consequently, made calculation of the LD50 value easier. A different rabies virus serotype (EBLI virus) in the population of insectivore bats Eptesicus serotinus and antigen variants within the first serotype, having common epitopes with strains of the vaccine virus SAD B19 and the polar rabies virus, were found to be present throughout the country. The concentrated and purified vaccine containing the PM virus did not protect mice against infection with strains of viruses isolated from bats (protection index 10 and lower). For the remaining strains, depending on the animal source of their isolation, the protection index ranged from 10 to 1000 and higher. The properties neutralizing a dose of 5 i.u./ml of serum from the subject inoculated with the vaccine containing the PM strain were similar for all the investigated strains; 0,5 i.u./ml did not neutralize the strain isolated from a racoon dog. PMID:7541494

  18. A Live Salmonella Gallinarum Vaccine Candidate Secreting an Adjuvant Protein Confers Enhanced Safety and Protection Against Fowl Typhoid.

    PubMed

    Shafiq, Muhammad Hassan; Kamble, Nitin M; Kim, Tae Hoon; Choi, Yoonyoung; Lee, John Hwa

    2015-12-01

    Live attenuated vaccines are used for effective protection against fowl typhoid (FT) in domestic poultry. In this study, a lon/cpxR/asd deletion mutant of Salmonella Gallinarum expressing the B subunit of a heat labile toxin (LTB) from Escherichia coli, a known adjuvant, was cloned in a recombinant p15A ori plasmid, JOL1355, and evaluated as a vaccine candidate in chickens. The plasmid was shown to be stable inside the attenuated Salmonella Gallinarum cell after three successive generations. Moreover, from an environmental safety point of view, apart from day 1 the JOL1355 strain was not detected in feces through day 21 postinoculation. For the efficacy of JOL1355, a total of 100 chickens were equally divided into two groups. Group A (control) chickens were intramuscularly inoculated with phosphate-buffered saline at 4 and 8 wk of age. Group B chickens were primed and boosted via the intramuscular route with 200 μL of a bacterial suspension of JOL1355 containing 1 × 10(8) colony forming units. All the chickens in Group A and B were challenged at 3 wk postbooster by oral inoculation with a wild-type Salmonella Gallinarum strain, JOL420. The JOL1355-immunized group showed significant protection and survival against the virulent challenge compared to the nonimmunized group. In addition, Group B exhibited a significantly higher humoral immune response, and the chickens remained healthy without any symptoms of anorexia, diarrhea, or depression. Group B also exhibited a significantly lower mortality rate of 4% compared to the 46% of the control group, which can be attributed to higher immunogenicity and better protection. The Group B chickens had significantly lower lesion scores for affected organs, such as the liver and spleen, compared to those of the control chickens (P < 0.01). These findings suggest that JOL1355 is a promising candidate for a safe and highly immunogenic vaccine against FT. PMID:26629629

  19. An invasive and low virulent Edwardsiella tarda esrB mutant promising as live attenuated vaccine in aquaculture.

    PubMed

    Yang, Weizheng; Wang, Lixia; Zhang, Lingzhi; Qu, Jiangbo; Wang, Qiyao; Zhang, Yuanxing

    2015-02-01

    Edwardsiella tarda is a leading fish pathogen haunting worldwide aquaculture industry. In E. tarda, two-component system EsrA-EsrB positively regulates type III and VI secretion systems (T3SS and T6SS) and negatively regulates hemolysin EthA, which has been demonstrated to be essential for the invasion processes in fish. In order to develop a live attenuated vaccine (LAV) with high invasiveness to be practically and economically used as immersion-administered vaccine in aquaculture, here, we generated a random mutation library of esrB sequences by error-prone PCR and introduced them into the E. tarda esrB deletion mutant. The mutant YWZ47 with significantly increased hemolytic activity and low T3SS and T6SS secretion was screened. Phenotypes including extracellular protein profiles, invasion in macrophages, lethality toward fish, and infection kinetics were investigated in the wild-type strain EIB202 and the mutants ΔesrB, ΔT3SS, ΔT6SS, ΔT3SS/ΔT6SS, and YWZ47. Compared to the documented LAV strain ΔesrB, YWZ47 showed higher invasive capability and low in vivo virulence toward fish. Significantly higher relative percent survival (RPS) could be generated in turbot (Scophthalmus maximus) against the challenge of the wild-type EIB202 when inoculated through immersion route, and the RPS was comparable with that of ΔesrB through intraperitoneal (i.p.) injection inoculation. Two mutated points, K167M and H197L, were found by sequence analysis of EsrBYWZ47 variant. These structural modifications underpin the variations in the regulatory functions of the mutant and wild-type EsrB. This study promoted understanding of virulence regulation by EsrB in E. tarda and presented a promising candidate of invasive attenuated vaccine used in aquaculture industries. PMID:25431010

  20. Whole genome analyses of G1P[8] rotavirus strains from vaccinated and non-vaccinated South African children presenting with diarrhea.

    PubMed

    Magagula, Nonkululeko B; Esona, Mathew D; Nyaga, Martin M; Stucker, Karla M; Halpin, Rebecca A; Stockwell, Timothy B; Seheri, Mapaseka L; Steele, A Duncan; Wentworth, David E; Mphahlele, M Jeffrey

    2015-01-01

    Group A rotaviruses (RVAs) are the leading cause of severe gastroenteritis and eventually death among infants and young children worldwide, and disease prevention and management through vaccination is a public health priority. In August 2009, Rotarix™ was introduced in the South African Expanded Programme on Immunisation. As a result, substantial reductions in RVA disease burden have been reported among children younger than 5 years old. Rotavirus strain surveillance post-vaccination is crucial to, inter alia, monitor and study the evolution of vaccine escape strains. Here, full-genome sequence data for the 11 gene segments from 11 South African G1P[8] rotavirus strains were generated, including 5 strains collected from non-vaccinated children during the 2004-2009 rotavirus seasons and 6 strains collected from vaccinated children during the 2010 rotavirus season. These data were analyzed to gain insights into the overall genetic makeup and evolution of South African G1P[8] rotavirus strains and to compare their genetic backbones with those of common human Wa-like RVAs from other countries, as well as with the Rotarix™ and RotaTeq™ G1P[8] vaccine components. All 11 South African G1P[8] strains revealed a complete Wa-like genotype constellation of G1-P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1. On the basis of sequence similarities, the South African G1P[8] strains (with the exception of strain RVA/Human-wt/ZAF/1262/2004/G1P[8]) were closely related to each other (96-100% identity in all gene segments). Comparison to the Rotarix™ and RotaTeq™ G1P[8] vaccine components revealed a moderate nucleotide identity of 89-96% and 93-95%, respectively. The results indicated that none of the gene segments of these 11 South African G1P[8] strains were vaccine-derived. This study illustrates that large-scale next generation sequencing will provide crucial information on the influence of the vaccination program on evolution of rotavirus strains. This is the first report to describe

  1. Live attenuated Salmonella vaccines displaying regulated delayed lysis and delayed antigen synthesis to confer protection against Mycobacterium tuberculosis.

    PubMed

    Juárez-Rodríguez, María Dolores; Yang, Jiseon; Kader, Rebin; Alamuri, Praveen; Curtiss, Roy; Clark-Curtiss, Josephine E

    2012-02-01

    Live recombinant attenuated Salmonella vaccine (RASV) strains have great potential to induce protective immunity against Mycobacterium tuberculosis by delivering M. tuberculosis antigens. Recently, we reported that, in orally immunized mice, RASV strains delivering the M. tuberculosis early secreted antigenic target 6-kDa (ESAT-6) protein and culture filtrate protein 10 (CFP-10) antigens via the Salmonella type III secretion system (SopE amino-terminal region residues 1 to 80 with two copies of ESAT-6 and one copy of CFP-10 [SopE(Nt80)-E2C]) afforded protection against aerosol challenge with M. tuberculosis. Here, we constructed and evaluated an improved Salmonella vaccine against M. tuberculosis. We constructed translational fusions for the synthesis of two copies of ESAT-6 plus CFP-10 fused to the OmpC signal sequence (OmpC(SS)-E2C) and amino acids 44 to 338 of antigen 85A (Ag85A(294)) flanked by the signal sequence (SS) and C-terminal peptide (CT) of β-lactamase (Bla(SS)-Ag85A(294)-Bla(CT)) to enable delivery via the Salmonella type II secretion system. The genes expressing these proteins were cloned as an operon transcribed from P(trc) into isogenic Asd(+)/MurA(+) pYA3681 lysis vector derivatives with different replication origins (pBR, p15A, pSC101), resulting in pYA4890, pYA4891, and pYA4892 for SopE(Nt80)-E2C/Ag85A(294) synthesis and pYA4893 and pYA4894 for OmpC(SS)-E2C/Ag85A(294) synthesis. Mice orally immunized with the RASV χ11021 strain engineered to display regulated delayed lysis and regulated delayed antigen synthesis in vivo and harboring pYA4891, pYA4893, or pYA4894 elicited significantly greater humoral and cellular immune responses, and the RASV χ11021 strain afforded a greater degree of protection against M. tuberculosis aerosol challenge in mice than RASVs harboring any other Asd(+)/MurA(+) lysis plasmid and immunization with M. bovis BCG, demonstrating that RASV strains displaying regulated delayed lysis with delayed antigen synthesis

  2. Choice of High-Efficacy Strains for the Annual Influenza Vaccine

    NASA Astrophysics Data System (ADS)

    Deem, Michael

    2005-03-01

    We introduce a model of protein evolution to explain limitations in the immune system response to vaccination and disease [1]. The phenomenon of original antigenic sin, wherein vaccination creates memory sequences that can increase susceptibility to future exposures to the same disease, is explained as stemming from localization of the immune system response in antibody sequence space. This localization is a result of the roughness in sequence space of the evolved antibody affinity constant for antigen and is observed for diseases with high year-to-year mutation rates, such as influenza. We show that the order parameter within this theory correlates well with efficacies of the H3N2 influenza A component of the annual vaccine between 1971 and 2004 [2,3]. This new measure of antigenic distance predicts vaccine efficacy significantly more accurately than do current state-of-the-art phylogenetic sequence analyses or ferret antisera inhibition assays. We discuss how this new measure of antigenic distance may be used in the context of annual influenza vaccine design and monitoring of vaccine efficacy. 1) M. W. Deem and H. Y. Lee, Phys. Rev. Lett. 91 (2003) 068101. 2) E. T. Munoz and M. W. Deem,q-bio.BM/0408016. 3) V. Gupta, D. J. Earl, and M. W. Deem, ``Choice of High-Efficacy Strains for the Annual Influenza Vaccine,'' submitted.

  3. Newcastle Disease Virus-Based Live Attenuated Vaccine Completely Protects Chickens and Mice from Lethal Challenge of Homologous and Heterologous H5N1 Avian Influenza Viruses▿

    PubMed Central

    Ge, Jinying; Deng, Guohua; Wen, Zhiyuan; Tian, Guobing; Wang, Yong; Shi, Jianzhong; Wang, Xijun; Li, Yanbing; Hu, Sen; Jiang, Yongping; Yang, Chinglai; Yu, Kangzhen; Bu, Zhigao; Chen, Hualan

    2007-01-01

    H5N1 highly pathogenic avian influenza virus (HPAIV) has continued to spread and poses a significant threat to both animal and human health. Current influenza vaccine strategies have limitations that prevent their effective use for widespread inoculation of animals in the field. Vaccine strains of Newcastle disease virus (NDV), however, have been used successfully to easily vaccinate large numbers of animals. In this study, we used reverse genetics to construct a NDV that expressed an H5 subtype avian influenza virus (AIV) hemagglutinin (HA). Both a wild-type and a mutated HA open reading frame (ORF) from the HPAIV wild bird isolate, A/Bar-headed goose/Qinghai/3/2005 (H5N1), were inserted into the intergenic region between the P and M genes of the LaSota NDV vaccine strain. The recombinant viruses stably expressing the wild-type and mutant HA genes were found to be innocuous after intracerebral inoculation of 1-day-old chickens. A single dose of the recombinant viruses in chickens induced both NDV- and AIV H5-specific antibodies and completely protected chickens from challenge with a lethal dose of both velogenic NDV and homologous and heterologous H5N1 HPAIV. In addition, BALB/c mice immunized with the recombinant NDV-based vaccine produced H5 AIV-specific antibodies and were completely protected from homologous and heterologous lethal virus challenge. Our results indicate that recombinant NDV is suitable as a bivalent live attenuated vaccine against both NDV and AIV infection in poultry. The recombinant NDV vaccine may also have potential use in high-risk human individuals to control the pandemic spread of lethal avian influenza. PMID:17050610

  4. Lactobacillus GG as an Immune Adjuvant for Live Attenuated Influenza Vaccine in Healthy Adults: A Randomized Double Blind Placebo Controlled Trial

    PubMed Central

    Davidson, Lisa E; Fiorino, Anne-Maria; Snydman, David R; Hibberd, Patricia L

    2011-01-01

    Background/Objectives Live attenuated influenza vaccine (LAIV) protects against influenza by mucosal activation of the immune system. Studies in animals and adults have demonstrated that probiotics improve the immune response to mucosally delivered vaccines. We hypothesized that Lactobacillus GG (LGG) would act as an immune adjuvant to increase rates of seroconversion after LAIV administration. Subjects/Methods We conducted a randomized double-blind placebo-controlled pilot study to determine if LGG improved rates of seroconversion after administration of LAIV. We studied 42 healthy adults during the 2007–8 influenza season. All subjects received LAIV and then were randomized to LGG or placebo twice daily for 28 days. HAI titers were assessed at baseline, day 28, and day 56 to determine rates of seroconversion. Subjects were assessed for adverse events throughout the study period. Results 39 subjects completed the per protocol analysis. Both LGG and LAIV were well tolerated. Protection rates against the vaccine H1N1 and B strains was similar suboptimal in subjects receiving LGG and placebo. For the H3N2 strain, 84% receiving LGG vs. 55% receiving placebo had a protective titer 28 days after vaccination (odds of having a protective titer was 1.84 95% CI 1.04–3.22, P=0.048). Conclusion Lactobacillus GG is potential as an important adjuvant to improve influenza vaccine immunogenicity. Future studies of probiotics as immune adjuvants may need to consider specifically examining vaccine naïve or seronegative subjects, target mucosal immune responses, or focus on groups known to have poor response to influenza vaccines. PMID:21285968

  5. Novel vaccines against influenza viruses

    PubMed Central

    Kang, Sang-Moo; Song, Jae-Min; Compans, Richard W.

    2011-01-01

    Killed and live attenuated influenza virus vaccines are effective in preventing and curbing the spread of influenza epidemics when the strains present in the vaccines are closely matched with the predicted epidemic strains. These vaccines are primarily targeted to induce immunity to the variable major target antigen, hemagglutinin (HA) of influenza virus. However, current vaccines are not effective in preventing the emergence of new pandemic or highly virulent viruses. New approaches are being investigated to develop universal influenza virus vaccines as well as to apply more effective vaccine delivery methods. Conserved vaccine targets including the influenza M2 ion channel protein and HA stalk domains are being developed using recombinant technologies to improve the level of cross protection. In addition, recent studies provide evidence that vaccine supplements can provide avenues to further improve current vaccination. PMID:21968298

  6. Some guidelines for determining foot-and-mouth disease vaccine strain matching by serology.

    PubMed

    Mattion, Nora; Goris, Nesya; Willems, Tom; Robiolo, Blanca; Maradei, Eduardo; Beascoechea, Claudia Perez; Perez, Alejandro; Smitsaart, Eliana; Fondevila, Norberto; Palma, Eduardo; De Clercq, Kris; La Torre, José

    2009-01-29

    The selection of matching strains for use in outbreaks of foot-and-mouth disease (FMD) virus can be assessed in vivo or by serological r-value determination. Sera from animals involved in vaccine potency and cross-protection trials performed using the "Protection against Podal Generalization" (PPG) test for two serotype A strains were collected and analyzed by the virus neutralization test (VNT) and liquid-phase ELISA (lpELISA) in three laboratories. The average VNT r-values for medium and high serum titer classes from the A(24) Cruzeiro vaccinated animals were in line with the A/Arg/01 heterologous PPG outcome for all testing laboratories, suggesting that the vaccine strain A(24) Cruzeiro is unlikely to protect against the field isolate A/Arg/01. The corresponding lpELISA r-values were slightly higher and indicate a closer relationship between both strains. Pooling of serum samples significantly reduced the inter-animal and inter-trial variation. The results suggest that a suitable reference serum for vaccine matching r-value experiments might be a pool or a medium to high VNT or lpELISA titer serum. Furthermore, the VNT seems to produce the most reproducible inter-laboratory results. More work is, however, needed in order to substantiate these claims. PMID:19041355

  7. [Evaluation of the vaccine potentiality of 2 strains from Leptospira interrogans serogroup Ballum].

    PubMed

    Rodríguez, Andrés González; Jiménez, Yoandra Rodríguez; Santiesteban, Niurka Batista; Abreu, Yolanda Valdés; Osenes, Juan Francisco Núñez; González, Marta González

    2005-01-01

    Two vacine candidate strains from Ballum serogroup were characterized and their immunogenicity and protective power were studied in hamster. The monovalent vaccine formulations obtained showed a high immunogenicity and capacity of homologous protection and, in a lesser degree, of cross protection. PMID:17966485

  8. Draft Genome Sequence of the Vaccination Strain Mycobacterium bovis BCG S4-Jena.

    PubMed

    Wibberg, Daniel; Winkler, Anika; Straube, Eberhard; Karrasch, Matthias; Keller, Peter M; Kalinowski, Jörn

    2016-01-01

    Here, we present the draft genome sequence of ITALIC! Mycobacterium bovisBCG S4-Jena, a tuberculosis vaccine strain. The genome of S4-Jena is represented by 48 scaffolds, consisting of 132 scaffolded contigs and amounting to a size of about 4.2 Mb. New genes potentially encoding a phage fragment were identified in the genome. PMID:27103721

  9. Draft Genome Sequence of the Vaccination Strain Mycobacterium bovis BCG S4-Jena

    PubMed Central

    Wibberg, Daniel; Winkler, Anika; Straube, Eberhard; Karrasch, Matthias; Keller, Peter M.

    2016-01-01

    Here, we present the draft genome sequence of Mycobacterium bovis BCG S4-Jena, a tuberculosis vaccine strain. The genome of S4-Jena is represented by 48 scaffolds, consisting of 132 scaffolded contigs and amounting to a size of about 4.2 Mb. New genes potentially encoding a phage fragment were identified in the genome. PMID:27103721

  10. Rapid generation of pandemic influenza virus vaccine candidate strains using synthetic DNA

    PubMed Central

    Verity, Erin E.; Camuglia, Sarina; Agius, Catherine T.; Ong, Chi; Shaw, Robert; Barr, Ian; Middleton, Deborah; Rockman, Steven

    2011-01-01

    Please cite this paper as: Verity et al. (2011) Rapid generation of pandemic influenza virus vaccine candidate strains using synthetic DNA. Influenza and Other Respiratory Viruses DOI:10.1111/j.1750‐2659.2011.00273.x. Background  Vaccination is considered the most effective means of reducing influenza burden. The emergence of H5N1 and pandemic spread of novel H1N1/2009 viruses reinforces the need to have strategies in place to rapidly develop seed viruses for vaccine manufacture. Methods  Candidate pandemic vaccine strains consisting of the circulating strain haemagglutinin (HA) and neuraminidase (NA) in an A/PR/8/34 backbone were generated using alternative synthetic DNA approaches, including site‐directed mutagenesis of DNA encoding related virus strains, and rapid generation of virus using synthetic DNA cloned into plasmid vectors. Results  Firstly, synthetic A/Bar Headed Goose/Qinghai/1A/2005 (H5N1) virus was generated from an A/Vietnam/1194/2004 template using site‐directed mutagenesis. Secondly, A/Whooper Swan/Mongolia/244/2005 (H5N1) and A/California/04/09 (H1N1) viruses were generated using synthetic DNA encoding the viral HA and NA genes. Replication and antigenicity of the synthetic viruses were comparable to that of the corresponding non‐synthetic viruses. Conclusions  In the event of an influenza pandemic, the use of these approaches may significantly reduce the time requi