CD4 and influenza: Here, influenza+ patients’ PBMCs were incubated with live seasonal H1N1, H3N2, B/YAM and B/VIC viruses to measure influenza-specific innate (NK, γδ, CD161+TRAV1-2+ or MAIT cells) and adaptive (CD4+ and CD8+ T cells) immune responses elicited via IFN-γ production after 18 h (Fig. 5a, b, Supplementary Fig. 5a).