IFNG and immunodeficiency disease: bovis BCG infection associated with primaryimmunodeficiency.(10) Santos et al. described the cases of three patients with vaccine-inducedinfection, one of whom had IFN-γ/IL-12 pathway deficiency.(3) An IFN-γ/IL-12 pathway defect is an immunodeficiency disorder in whichthere is increased susceptibility to infections with microorganisms of the generaMycobacterium and Salmonella. (11,12) It is classified as a congenital defect of phagocyte number, function, orboth.