IFNG and mumps infectious disease: To begin to explore the relation between IFN-γ and IL-2 producing T cells in a recall antigen specific response, we measured memory IFN-γ and IL-2 producing CD4 and CD8 T cell frequencies in the periphery of healthy individuals previously exposed to mumps (by immunization), candida (usual cutaneous exposure), or viral antigen (seropositive for these antigens).