Different COVID-19 patients in asymptomatic/mild, moderate, and severe/critical groups also showed significant differences, as a decrease in the count was recorded when comparing them with the healthy control group, with p < 0.001, p < 0.001, and p < 0.0001, respectively, and the lowest count of the CD4+CD38+ subtype was recorded in the severe group. This evidence concerns the gene CD4 and COVID-19.