The study also found IL-15, a cytokine important for maintenance of memory T cells and often produced during acute viral infection, selectively activates HCMV- and EBV-specific, but not influenza-specific, CD8 T cells, is sufficient for spontaneous IFN-γ production, and enhances anti-viral cytokine production in conjunction with TCR stimulation (50). Here, IL15 is linked to influenza.