CD4 and obesity due to melanocortin 4 receptor deficiency: Obesity (OR, 3.31; 95% CI, 1.08–10.09), positive rectal swab (OR, 3.43; 95% CI, 1.53–7.7), treatment by lopinavir/ritonavir with chloroquine phosphate (OR, 2.5; 95% CI, 1.04–6.03), the interval from onset to antiviral treatment more than 7 days (OR, 2.26; 95% CI, 1.04–4.93), lower CD4+ T cell (OR, 0.92; 95% CI, 0.86–0.99) and higher NK cells (OR, 1.11; 95% CI, 1.02–1.20) were significantly associated with prolonged respiratory tract viral shedding.