IFNG and parasitic infectious disease: In fact, BCG vaccination, which can enhance non-specific protection to unrelated infections especially by activation of NK cells with non-specific memory by production of pro-inflammatory cytokines is provides an example (Kleinnijenhuis et al., 2014); however, parasitic infections often lead to lower antibody and IFN-γ levels, which represent a decrease in the quality of the humoral and cellular immune responses (Rowe et al., 2000).