Figure 7.
Protection of BALB/c mice against lethal challenge with aerosolized Y. pestis C12 by a vaccination and post-challenge antibiotic treatment strategy. (A) Female mice (n=10/group) were immunized with PBS only; P:rF1-V B: Δcaf1 (optimal regimen); or regimens with P: Δcaf1 or P: ΔyopD/Δcaf1 and B: rF1-V (suboptimal regimens). All mice were challenged with C12 (6.7 x 105 CFU) at 31 d post-boost. Mice immunized with PBS or suboptimal regimens were given attempted rescue doses of streptomycin (20 mg/kg every 6 h) starting 60 h post-boost. (B) Male mice (n=8-10/group) were immunized, challenged with C12 (7.7 x 105 CFU), and given streptomycin as described in (A) Clinical progression was monitored daily for 21 days. *p < 0.05, **p < 0.01 in pairwise comparison of groups by probability of survival (%) using a Fisher exact test.