In vitro stimulation of peripheral blood mononuclear cells (PBMC) from vaccinated individuals with vaccine antigens including rabies 5, malaria 19, tetanus toxoid 20, whole cell Bordetella pertussis6, and inactivated influenza virus 2, 6, results in NK cell degranulation (surface expression of CD107a), IFN‐γ production and upregulation of IL‐2Rα/ CD25. Here, IL2RA is linked to malaria.