CD8A and COVID-19: From there, the presence of SARS-CoV-2 viremia and its duration were directly correlated with the degree of inflammation and mortality (Hagman et al., 2022), while depletion rate of peripheral CD8 + T cells reflected the severity of the disease, and reduced CD4 +T cell count was independently associated with increased in-hospital mortality in patients with COVID-19 (Wen et al., 2021).