IL2 and infection: In addition, similar frequencies of polyfunctional CD8+ T cells specific to TB10.44–12 MHC-I-restricted epitope which dominantly elicited IFN-γ-producing CD8+ T cells36 were detected in both vaccinated group only except for TB10.44–12-specific IFN-γ+TNF-α+IL-2+ response which was significantly induced by BCG compared with BCGΔBCG1419c (IFN-γ+TNF-α+IL-2+; p = 0.0113 BCG-vaccinated versus BCGΔBCG1419c-vaccinated) at 10 weeks post-infection (Fig. 3b).