The level of CD8+ T cells in the moderate COVID-19 group was significantly lower than that in the asymptomatic COVID-19 group (P = 0.017) (Table 1 and Figure 1A), suggesting that a low level of CD8+ T cells was common in patients with moderate COVID-19, whereas most patients with asymptomatic COVID-19 had normal CD8+ T cell immunity. This evidence concerns the gene CD8A and COVID-19.