The following are among the advantages of human recognition as an essential criterion in our antigen selection process: (i) antigens recognized during the course of human M. tuberculosis infection are ideal candidates for human vaccine development, (ii) the antigens are recognized by individuals with active and latent infection; therefore, a vaccine designed to contain these antigens can be used as a pre- and postexposure vaccine; and (iii) candidate antigens are known to also induce CD8+ T cells, which play an important role in protection but are somewhat neglected (24, 25, 40). This evidence concerns the gene CD8A and disease arising from reactivation of latent virus.