CD38 and COVID-19: Data analysis demonstrated that, regardless of the decrease in CD3+ T-cells, a mixed profile of activation/exhaustion was observed in the COVID-19 group in comparison to the HC group, as illustrated by increased frequencies of CD69+, CD223+, CD107a+, T-bet+, and TIM-3+, along with decreased percentages of CD28+, CD38+, CD62L− and CD45RO+ T-cell subsets.