The COVID-19+ patients had significantly lower levels of total lymphocytes (1.0 ± 0.1 versus 1.6 ± 0.7 G/L in the control group, p < 0.0001) and CD8+ T cells (170.3 ± 63.8 versus 389.4/mm3 ± 312.1 in the control group, p < 0.0001) (Fig. 1A). This evidence concerns the gene CD8A and COVID-19.