The increase in virus-specific cytotoxic memory T cells at lymph nodes [mCTLL] upon transformation of [CD8+To], natural death of [mCTLL], increase in [mCTLL] with migration of virus-specific cytotoxic memory T cells at sites of infection [mCTLR] and virus-specific cytotoxic memory T cells at sites of vaccine administration [mCTLR(c)], and decrease in [mCTLL] upon migration of [mCTLL] toward sites of infection and vaccine administration. This evidence concerns the gene CD8A and infection.