Moreover, a majority of convalescent patients display robust antiviral SARS-CoV-2–specific T cell responses, with enhanced in vivo priming and expansion of CD8+ cytotoxic T cells and a higher frequency of CD4+ memory T cells in those who recovered from severe COVID-19, which may provide long-term antiviral protection even if antibodies wane [310]. This evidence concerns the gene CD8A and COVID-19.