IFNG and infection: Tangentially, differences in IFN-γ intensity from mono- compared to tri-functional T cells may explain the discordance observed between enzyme-linked immunosorbent spot (ELISPOT) and ELISA assay results to the same antigen and why the cytokine level measured by ELISA correlates with protection from infection when the frequency of IFN-γ producing cells specific to MSP-1 does not (Moormann AM, Chelimo K, Dent AE, et al, unpublished data).