FIG. 6.
Vaccination with KBMA Sterne4 protects guinea pigs from a lethal intranasal Ames spore challenge. Hartley guinea pigs were vaccinated i.m. on day 0 and day 28 with HBSS, 4 × 109 particles of KBMA Sterne2, or 200 μl AVA. (A) Serum samples were obtained 14 days prior to (white bars) and 21 days after the boost vaccination (black bars) and analyzed for anti-PA IgG titers by ELISA. (B) Four weeks after the boost vaccination, the animals were challenged intranasally with 1.48 × 108 Ames spores. Survival after vaccination with Sterne2 or AVA was statistically different from the HBSS control (**, P < 0.01) but not statistically different from each other. The data are representative of two independent guinea pig challenge studies. The error bars represent the 95% confidence interval. *, P < 0.05; ***, P < 0.001.