Protective activity and immunogenicity of two recombinant anthrax vaccines for veterinary use.
ABSTRACT In this study, the efficacy of two experimental vaccines against Bacillus anthracis toxinaemia was evaluated in the rabbit model. A recombinant Protective Antigen (rPA) mutant and a trivalent vaccine (TV) composed by the rPA, a inactive mutant of Lethal Factor (mLF-Y728A; E735A) and a inactive mutant of Edema Factor (mEF-K346R), both emulsified with mineral oils, were evaluated for their immunogenicity and protective activity in New Zealand white rabbits. Rabbits vaccinated subcutaneously with rPA and TV rapidly produced high level of anti-PA, anti-LF and anti-EF antibodies, which were still present 6 months later. In the efficacy test, these vaccines protected 100% of rabbits challenged with B. anthracis virulent strain 0843 one week after the vaccination. Moreover, all animals vaccinated twice with rPA and TV, resisted B. anthracis infection 6 months later. Our data indicate that rPA and TV could be good vaccine candidates for inducing protection against B. anthracis infection in target animal host. They could successfully be used in an emergency with simultaneous long-acting antibiotics to halt incubating infections or during an anthrax epidemic.
SourceAvailable from: Juri VencatoLarge Animal Review 01/2012; 18(3):123-127. · 0.18 Impact Factor
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ABSTRACT: Over recent years great attention has been directed to the discovery of novel antigens from Bacillus anthracis, because of the potential of its spores in the development of weapons for mass destruction. Substantial effort has been directed to the identification and immunochemical evaluation of glycans that might be used for specific diagnostic detection of the spores or immune-mediated prevention of anthrax. Carbohydrate structures found on surfaces of vegetative cells and spores are herein discussed. Among them, the cell wall polysaccharide and the tetrasaccharide unit isolated from the exosporium protein BclA were proven immunogenic in an animal model after covalent linkage to carrier protein. Further investigation is needed to fully assess the potential of these promising carbohydrate antigens for vaccine development.Expert Review of Vaccines 05/2014; DOI:10.1586/14760584.2014.924404 · 4.22 Impact Factor
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ABSTRACT: Infections of humans with Bacillus anthracis are an issue with respect to the biothreat both to civilians and military personnel, infections of individuals by infected livestock in endemic regions and, recently, infections of intravenous drug users injecting anthrax-contaminated heroin. Existing vaccination regimens are reliant on protective antigen neutralization induced by repeated boosts with the AVA or AVP vaccines. However, there is ongoing interest in updated approaches in light of the intensive booster regime and extent of reactogenicity inherent in the current protocols. Several other immunogens from the B. anthracis proteome have been characterized in recent years, including lethal factor. Lethal factor induces strong CD4 T-cell immunity and encompasses immunodominant epitopes of relevance across diverse HLA polymorphisms. Taken together, recent studies emphasize the potential benefits of vaccines able to confer synergistic immunity to protective antigen and to other immunogens, targeting both B-cell and T-cell repertoires.Expert Review of Vaccines 11/2014; 14(3). DOI:10.1586/14760584.2015.981533 · 4.22 Impact Factor