In the current study, we also observed that ESAT-6-specific IFN-γ/IL-17A-producing multifunctional CD4+ T-cells were maintained at 12 weeks post-infection, and BCG-primed immune responses were notably elevated as evidenced by increased frequency of PPD-specific IFN-γ/IL-17A-producing multifunctional CD4+ T-cells in HEHR/CIA09A boosted mice. This evidence concerns the gene IL17A and infection.