inclusion criteria: 1. sign informed consent form voluntarily for the trial. 2. male or female aged between 18 and 85 years (inclusive). 3. clinically or laboratory confirmed covid-19 within the past 7 days, as determined by a positive rt-pcr test or a positive antigen test. 4. under resting conditions, oxygen saturation ≤93% when breathing air, or p/f value ≤ 300 mmhg (1 mmhg = 0.133 kpa). 5. no birth plan and must agree to take effective contraceptive methods.

inclusion criteria: 1. sign informed consent form voluntarily for the trial. 2. male or female aged between 18 and 85 years (inclusive). 3. clinically or laboratory confirmed covid-19 within the past 7 days, as determined by a positive rt-pcr test or a positive antigen test. 4. under resting conditions, oxygen saturation ≤93% when breathing air, or p/f value ≤ 300 mmhg (1 mmhg = 0.133 kpa). 5. no birth plan and must agree to take effective contraceptive methods.

inclusion criteria: sign informed consent form voluntarily for the trial. male or female aged between 18 and 85 years (inclusive). clinically or laboratory confirmed covid-19 within the past 7 days, as determined by a positive rt-pcr test or a positive antigen test. under resting conditions, oxygen saturation ≤93% when breathing air, or p/f value ≤ 300 mmhg (1 mmhg = 0.133 kpa). no birth plan and must agree to take effective contraceptive methods.

inclusion criteria: sign informed consent form voluntarily for the trial. male or female aged between 18 and 85 years (inclusive). clinically or laboratory confirmed covid-19 within the past 7 days, as determined by a positive rt-pcr test or a positive antigen test. under resting conditions, oxygen saturation ≤93% when breathing air, or p/f value ≤ 300 mmhg (1 mmhg = 0.133 kpa). no birth plan and must agree to take effective contraceptive methods.