CD4 and COVID-19: Specifically, for lymphocyte subpopulations, counts of CD3+ T cells [579/μL, IQR 424–804/μL vs. 1233/μL, IQR 1143–1552/μL; p < 0.001], CD8+ T cells [263/μL, IQR 185–338/μL vs. 518/μL, IQR 424–631/μL; p < 0.001], CD4+ T cells [315/μL, IQR 194–388/μL vs. 683/μL, IQR 495–966/μL; p < 0.001], and B cells [76/μL, IQR 30–141/μL vs. 143/μL, IQR 98–217/μL; p = 0.004] were lower in the COVID‐19 group than in the stable group, whereas NK‐cell counts [136/μL, IQR 78–246/μL vs. 135/μL, IQR 86–217/μL; p = 0.767] showed no significant difference (Table 1).