First, PBMC from 16 HLA-A*0201 donors were screened for the presence of influenza M1-specific T-cell responses by IFN-γ-ELISPOT (both T-helper and CTL ELISPOT) [11, 19, 24], 15 of whom showed a response in either the T-helper and/or the CTL ELISPOT (not shown). This evidence concerns the gene HLA-A and influenza.