• Vaccine Name: rPA with adjuvant Nanoemulsion
• Target Pathogen: Bacillus anthracis
• Target Disease: Anthrax
• Vaccine Ontology ID: VO_0000526
• Type: Toxoid vaccine
• Antigen: For this vaccine, recombinant Bacillus anthracis protective antigen was used (Bielinska et al., 2007).
• Adjuvant:
  • Adjuvant name:
  • VO adjuvant ID: VO_0001319
• Preparation: The NE was manufactured by the emulsification of cetyl pyridum chloride, Tween 20, and ethanol in water with hot-pressed soybean oil, using a high-speed emulsifier. Every rPA-NE formulation was prepared by mixing rPA protein solution with NE, using saline as a diluent 30 to 60 min prior to immunization. For immunization with immunostimulants, 20 μg rPA was mixed with either 5 μg of MPL A or 10 μg CpG oligonucleotides in saline (Bielinska et al., 2007).

Mouse Response

• Host Strain: BALB/c
• Vaccination Protocol: Groups of mice were immunized intranasally with either one or two administrations of experimental vaccine 3 weeks apart. rPA-NE mixes were applied to the nares with a pipette tip administering 10 μl per nare, and the animals were then allowed to inhale the material (Bielinska et al., 2007).
• Immune Response: rPA-NE immunization was effective in inducing both serum anti-PA IgG and bronchial anti-PA IgA and IgG antibodies after either one or two mucosal administrations. Serum anti-PA IgG2a and IgG2b antibodies and PA-specific cytokine induction after immunization indicate a Th1-polarized immune response. rPA-NE immunization also produced high titers of lethal-toxin-neutralizing serum antibodies in mice (Bielinska et al., 2007).
• Challenge Protocol: The immune responses of mice were not challenged.

Guinea pig Response

• Host Strain: Hartley
• Vaccination Protocol: Hartley guinea pigs were vaccinated intranasally with one or two administrations of vaccine, each about 50 μl per nare, 4 weeks apart (Bielinska et al., 2007).
• Immune Response: serum anti-PA immunoglobulin G and bronchial anti-PA IgA and IgG antibodies were produced following either one of two mucosal immunizations of rPA-NE. The anti-PA IgG2a and IgG2b antibodies and PA-specific cytokine induction found in the serum indicated a Th-1-polarized immune response. High titers of lethal-toxin-neatralizing antibodies were also found after rPA-NE immunization (Bielinska et al., 2007).
• Challenge Protocol: The guinea pigs were challenged intradermaly with ~1,000 times the 50% lethal dose of B. anthracis Ames strain spores, which was about 1.38 × 10^3 spores (Bielinska et al., 2007).
• Efficacy: Nasal immunization resulted in 70% and 40% survival rates against intranasal challenge with 1.2 × 10^6 and 1.2 × 10^7 Ames strain spores (Bielinska et al., 2007).