Figure 6: Survival, histomorphometry and lung bacillary loads after long term vaccination: (A) M. bovis strain AN5 was used to challenge after six months of vaccination with mce2A mutant or BCG and the survival compared with nonvaccinated control animals (20 mice per strain). (B) Percentage of lung surface affected by pneumonia, determined by automated morphometry and lung bacillary loads (C), both determinations after 60 days of challenge. Asterisks represent statistical significance (P < 0.05).