CD4 and infection: The level of inflammation during SARS-CoV-2 infection is significantly reliant on the association between the CD4+/CD8+ ratio and the total lymphocytes, namely CD4+ T-cells, CD8+ T-cells, and B-cells and natural killer cells.10 In both mild and severe cases, there is a decrease in the absolute numbers of T lymphocytes, CD4+ T-cells, and CD8+ T-cells, but the decrease is more in severe than in mild cases.10 The implication of the lymphopenia observed is that it reduces the ability of the immune system to fight the infection and increases the chances of severe illness.