Protection against bubonic and pneumonic plague of mice vaccinated with VTnF1.

<p>Mice having received a single oral dose of VTnF1 (10⁸ CFU) were challenged via i.n. or s.c. routes, with various doses of bacteria as indicated. (A-D) Animals were challenged four weeks after vaccination by injection of (A, B) <i>Y</i>. <i>pestis</i> CO92, or (C, D) the un-encapsulated CO92Δ<i>caf</i>. (E) Vaccinated mice were challenged six months after vaccination. Mouse survival was recorded daily for 21 days. The number of mice surviving / number of animals tested is indicated above the corresponding bar for each condition. The Fisher Exact test was used for statistical analysis: *: p≤0.05; ***: p<0.001.