title: Experimental anthrax vaccines: efficacy of adjuvants combined with protective antigen against an aerosol Bacillus anthracis spore challenge in guinea pigs.
abstract: The efficacy of several human anthrax vaccine candidates comprised of different adjuvants together with Bacillus anthracis protective antigen (PA) was evaluated in guinea pigs challenged by an aerosol of virulent B. anthracis spores. The most efficacious vaccines tested were formulated with PA plus monophosphoryl lipid A (MPL) in a squalene/lecithin/Tween 80 emulsion (SLT) and PA plus the saponin QS-21. The PA+MPL in SLT vaccine, which was lyophilized and then reconstituted before use, demonstrated strong protective immunogenicity, even after storage for 2 years at 4 degrees C. The MPL component was required for maximum efficacy of the vaccine. Eliminating lyophilization of the vaccine did not diminish its protective efficacy. No significant alteration in efficacy was observed when PA was dialyzed against different buffers before preparation of vaccine. PA+MPL in SLT proved superior in efficacy to the licensed United States human anthrax vaccine in the guinea pig model.
authors.affiliation: Bacteriology Division, United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, MD 21702-5011, USA.
authors.forename: B
authors.initials: B
authors.lastname: Ivins
authors.forename: P
authors.initials: P
authors.lastname: Fellows
authors.forename: L
authors.initials: L
authors.lastname: Pitt
authors.forename: J
authors.initials: J
authors.lastname: Estep
authors.forename: J
authors.initials: J
authors.lastname: Farchaus
authors.forename: A
authors.initials: A
authors.lastname: Friedlander
authors.forename: P
authors.initials: P
authors.lastname: Gibbs
mesh_terms: D000276:Adjuvants, Immunologic; D000336:Aerosols; D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology*; D001408:Bacillus anthracis / Q000276:immunology* / Q000472:pathogenicity; D001428:Bacterial Vaccines / Q000276:immunology*; D005260:Female; D006168:Guinea Pigs; D006801:Humans; D013171:Spores, Bacterial / Q000276:immunology; D014774:Virulence
chemical_list: D000276:Adjuvants, Immunologic; D000336:Aerosols; D000942:Antigens, Bacterial; D001428:Bacterial Vaccines