CD4 and tuberculosis: In this study, we confirmed that IL-7 helped the TB subunit vaccine induce long-term memory T cells by enhancing the proliferation of both CD4+ and CD8+ T cells, promoting more IL-2 production in CD4+ T cells upon antigenic stimulation, and increasing the production of IFN-γ production in both CD4+ and CD8+ T cells after successive BCG and antigen stimulation in vivo and in vitro.