Indeed, in some persons we also observed a significant decrease at t1 in CD4 T cells specific for vaccine preparation (donors 2, 16, 23, 27, 30, 31, 35, 41), specific for influenza (H5N1) (donors 4, 16, 27), and specific for H5/N1 peptides (donors 2, 27, 34, 39, 41). This evidence concerns the gene CD4 and influenza.