Bacterial replication in lungs and spleen of BALB/c mice vaccinated with MGM1991, or BCG and challenged with 10<sup>5</sup> CFU of virulent luminescent <i>M. tuberculosis</i>.

<p>Mean number of bacteria in lungs and spleen of C57BL/6 mice vaccinated with 5x10<sup>5</sup>CFU of MGM1991 mutant or BCG or unvaccinated mice (naïve), challenged 12 weeks later with 10<sup>5</sup>CFU of virulent <i>M.tb</i> by the intratracheal route and sacrificed 6 or 12 weeks after challenge. Results are reported as mean log<sub>10</sub> relative light units (RLU) ± SD of 5 mice tested individually; * <i>P</i> < 0.05; ** <i>P</i> < 0.01 (Mann-Whitney test).</p>