Fig. 3.

Protective immunity against B. anthracis Sterne. (A) Vaccination schedule. Groups of mice were orally vaccinated with L. acidophilus 1838, 1839, or 1895 (10⁹ CFU in 250 μL). The oral route was repeated 3 times weekly. Two weeks later, the groups of mice were boosted twice. Seven days after the final boost, the mice were challenged i.p. with B. anthracis Sterne pXO1⁺/pXO2⁻ (5 × 10⁴ CFU per mouse). Survival was then monitored until day 40. (B and C) Mouse survival. Vaccinated and nonvaccinated mice were challenged i.p. with B. anthracis Sterne. Survival was then monitored until day 40. Data are representative of 2 independent experiments.