Three factors were observed to be independently associated with progression to severe COVID-19 during 14 days after admission: (a) age 65 years or older (hazard ratio [HR] = 8.456; 95% CI: 2.706–26.426); (b) creatine kinase (CK) ≥ 180 U/L (HR = 3.667; 95% CI: 1.253–10.733); and (c) CD4+ T-cell counts <300 cells/μL (HR = 4.695; 95% CI: 1.483–14.856). Here, CD4 is linked to COVID-19.