TB bacterial burden in mice upon vaccination.

<p>Mice were challenged by the aerosol route with virulent M. tuberculosis A) 6 weeks and B) 52 weeks after the last immunization. Six weeks post challenge, mice were sacrificed and the bacterial burden (CFU) measured in the lungs (expressed as log10 CFU). As a positive control group, a group of mice received a BCG vaccination ten weeks before challenge.