The ESAT‐6, formatted as an ESAT‐6‐Ag85 fusion protein, promoted strong and long‐lived M.tb‐specific T‐cell responses in naïve human volunteers13, 14; the CFP‐10, previously used for disease diagnosis, could induce IFN‐γ release and reduce IL‐4 secretion of CD4+ T cells, as well as promote antibody response with an enhanced IgG2a/IgG1 ratio in mice.15 Although the evaluation is ongoing, establishment of adaptive Th1‐type CD4+ T‐cell response with effector or effector–memory phenotype is one of the targets for vaccine development to prevent TB. Here, CD4 is linked to tuberculosis.