CD4 and COVID-19: A recent study proved that when SARS-CoV-2 infect the CNS, it induces the immune cells of brain like microglia cells and astrocytes, as a result large amount of INF- alpha, IL-1beta, IL-15, IL-12 and IL-6 are released inside the brain[33] that lead to severe CNS damage.[6,29] There is a decrease in the number of CD4 + T cells, CD8 + T cells and lymphocytes, which are symptoms of severity in COVID-19 patients.[6,34] The remaining CD4 + T cells activate the macrophages to produce IL-6.