Figure 1.

BALB/c mice vaccinated with rF1V are more susceptible than CD1 vaccinated mice to Y. pestis infection. (A) BALB/c or (B) CD1 mice were vaccinated once, subcutaneously, with mock/PBS, 0.1 µg, 1 µg or 10 µg of rF1V (n=10). At 26 days post vaccination, BALB/c and CD1 mice were exposed to 2.02x10⁶ CFU (approximately 30 LD₅₀ equivalents) or 1.75x10⁶ CFU (approximately 53 LD₅₀ equivalents) of aerosolized Y. pestis CO92, respectively. Survival was monitored for 21 days post challenge.