CD4 and infection: As shown in Figure 5a, the CD4+CD44+IFN-γ+IL-17+ T-cell (R = −0.8641, p < 0.0001) responses to ESAT-6 in BCG-HSP90-E6/CIA05-vaccinated mice correlated with bacterial loads in both pre-and post-infections; CD4+CD44+IFN-γ+IL-17+TNF-α+IL-2+ T-cells (R = −0.9082, p < 0.0001), CD4+CD44+IL-17+ T-cells (R = −0.8183, p < 0.0001), and CD4+CD44+IL-17+IL-2+ T-cells (R = −0.6333, p = 0.0002) appeared to be significantly correlated only in pre-infected mice, which suggested that these cell populations could be the key factors correlating with BCG-HSP90-E6/CIA05 vaccination-induced protection.