In our study, we found that the absolute counts of naïve CD4+, CD4+ memory, naïve CD8+, and CD8+ memory T-lymphocytes in patients with COVID-19 are lower than those of healthy individuals, and the relative counts of naïve CD4+ T-lymphocytes, the relative counts of naïve CD8+ T-lymphocytes, the CD4 + CD45RA+/CD4 + CD45RO + ratio, and the CD8 + CD45RA+/CD8 + CD45RO + ratio are also lower than those of healthy controls, while the relative counts of CD4+ and CD8+ memory T-lymphocytes are elevated compared to those of healthy controls. This evidence concerns the gene CD4 and COVID-19.