Given the consistency with which recombinant attenuated L. monocytogenes vaccines expressing the 5 M. tuberculosis antigens in rLm5Ag(30) are able to boost the already high level of protection conferred by BCG alone in two rigorous mouse models of pulmonary TB and the broad CD4+ and CD8+ T cell immunity induced by rLm5Ag(30), this vaccine holds considerable promise as a new vaccine to combat the TB pandemic, especially for the majority of the world’s population immunized with BCG in infancy. The gene discussed is CD4; the disease is pulmonary tuberculosis.