Rate of mortality within 28‐days, Improvement of clinical symptoms including duration of fever and respiratory (At Baseline, Day 3, 7, 10, 14, 21, 28), Time of nucleic acid turning negative (28 days), CD4+ and CD8+ T cell count (At Baseline, Day 3, 6, 10, 14, 21, and 28), changes of blood oxygen (At Baseline, Day 3, 6, 10, 14, 21, and Day 28), side effects in the treatment group (28 days)  NCT04315987/Not yet recruiting, Apr‐Jun 2020