Figure 1. Enhanced protection against M. tuberculosis challenge by DNAacr boosting subsequent to BCG vaccination.

For evaluation of protective efficacy two guinea pig experiments were performed. The figure depicts the bacillary load in the lungs and spleen of vaccinated and saline treated guinea pigs at (A) 10 weeks (Exp-I, n = 5) and (B) 16 weeks (Exp-II, n = 6) post-infection. Immunization with B/D regimen resulted in a significantly lower bacillary load in lungs and spleen, when compared to both BCG and saline groups. Log₁₀ CFU were measured and graphically represented by box plot, wherein median values are denoted by horizontal line, the mean is represented by ‘+’, inter quartile range by boxes, and the maximum and minimum values by whiskers. The lower limit of detection was 1.0 log₁₀ CFU/g of tissue and animals with undetectable bacilli were allotted a CFU value of 1.0 log₁₀/g. B/D, BCG prime – DNAacr boost and B/V, BCG prime – vector boost. *, p<0.05, **, p<0.01, ***, p<0.001, when compared to the saline group or as indicated (One-way ANOVA).