Intracellular staining of T cells for cytokines showed that the percentage of IFN-γ-producing CD8+ T (Tc1) cells was reduced, whereas the percentage of IL-4-producing CD8+ T (Tc2) increased in both mild and severe COVID-19 patients compared to healthy donors, suggesting an impaired type 1 response in CD8 T cells. This evidence concerns the gene CD8A and COVID-19.