We next probed memory NP338+CD8+ T cell responses in individuals expressing HLA-B*37:01, HLA-B*44:02, HLA-B*44:03, or HLA-B*18:01 (Fig. 1e–g, Supplementary Table 3) by stimulating their peripheral blood mononuclear cells (PBMCs) with a pool of NP338 peptides corresponding to the main variants in the circulating influenza A strains (Table 2). Here, HLA-B is linked to influenza.