Although SARS-CoV-2 reactive CD4 and CD8 T cells can be found in severe COVID-19 and can correlate with AB appearance and lower viral loads, CD4 T cells in severe disease are often dysfunctional or deregulated compared to mild COVID-19 (10, 23, 28, 30, 32, 37, 44, 45). This evidence concerns the gene CD8A and COVID-19.