Figure 2.

BALB/c mice vaccinated with rF1V are more susceptible to non-encapsulated Y. pestis C12 strain. BALB/c mice were vaccinated once, subcutaneously, with mock/PBS, 10 µg or 20 µg of rF1V (n=10). At 29 days post vaccination, BALB/c mice were exposed to aerosolized bacteria with (A) 2.63x10⁶ CFU of Y. pestis CO92 (approximately 39 LD₅₀ equivalents) or (B) 2.31x10⁶ CFU of Y. pestis C12 (approximately 30 LD₅₀ equivalents), respectively. Survival was monitored for 21 days post challenge.