CD4 and infection: Altogether, clinical variables and alterations in the cells of the immune system, evaluated by t-SNE, have established three profiles of patients infected with SARS-CoV-2: (1) They present robust activation and proliferation of CD4+ T lymphocytes together with CD8+ T lymphocytes highly activated and exhausted; (2) discrete response of CD4+ T lymphocytes and CD8+ T lymphocytes with high expression of t-bet and memory B cells; and 3) lymphocytes deficient for the activation process and therefore inefficient to face infection [67].