CD4 and COVID-19: Active COVID-19 patients showed a characteristic immune profile (Figure S2 and Table 3), with a lower percentage of lymphocytes (20.31% vs. 31.41% of controls; p < 0.05); CD4+ Tregs and CD8+ Tregs were also lower in the active COVID-19 group, but only differences for CD4+ Tregs were statistically significant (0.86% vs. 2.05% of controls; p < 0.001).