inclusion criteria: 1. laboratory diagnosis: respiratory specimen is positive for sars-cov-2 nucleic acid by rt-pcr; or, the viral gene sequencing of the respiratory specimen is highly homologous to known novel coronavirus. 2. fever: axillary temperature \>37.3℃ 3. respiratory variables (meets one of the following criteria): * respiratory rate: rr ≥25 breaths/min * oxygen saturation ≤93% at rest on room air * pao2/fio2 ≤300 mmhg（1 mmhg=0.133 kpa） * pulmonary imaging showed that the lesions progressed more than 50% within 24-48 hours, and the patients were managed as severe 4. hbsag negative, or hbv dna ≤10\^4 copy/ml if hbsag positive; anti-hcv negative; hiv negative two weeks prior to signed informed consent form (icf) 5. appropriate ethics approval and 6. icf -

inclusion criteria: 1. laboratory diagnosis: respiratory specimen is positive for sars-cov-2 nucleic acid by rt-pcr; or, the viral gene sequencing of the respiratory specimen is highly homologous to known novel coronavirus. 2. fever: axillary temperature \>37.3℃ 3. respiratory variables (meets one of the following criteria): * respiratory rate: rr ≥25 breaths/min * oxygen saturation ≤93% at rest on room air * pao2/fio2 ≤300 mmhg（1 mmhg=0.133 kpa） * pulmonary imaging showed that the lesions progressed more than 50% within 24-48 hours, and the patients were managed as severe 4. hbsag negative, or hbv dna ≤10\^4 copy/ml if hbsag positive; anti-hcv negative; hiv negative two weeks prior to signed informed consent form (icf) 5. appropriate ethics approval and 6. icf -

inclusion criteria: laboratory diagnosis: respiratory specimen is positive for sars-cov-2 nucleic acid by rt-pcr; or, the viral gene sequencing of the respiratory specimen is highly homologous to known novel coronavirus. fever: axillary temperature >37.3℃ respiratory variables (meets one of the following criteria): respiratory rate: rr ≥25 breaths/min oxygen saturation ≤93% at rest on room air pao2/fio2 ≤300 mmhg（1 mmhg=0.133 kpa） pulmonary imaging showed that the lesions progressed more than 50% within 24-48 hours, and the patients were managed as severe hbsag negative, or hbv dna ≤10^4 copy/ml if hbsag positive; anti-hcv negative; hiv negative two weeks prior to signed informed consent form (icf) appropriate ethics approval and icf -

inclusion criteria: laboratory diagnosis: respiratory specimen is positive for sars-cov-2 nucleic acid by rt-pcr; or, the viral gene sequencing of the respiratory specimen is highly homologous to known novel coronavirus. fever: axillary temperature >37.3℃ respiratory variables (meets one of the following criteria): respiratory rate: rr ≥25 breaths/min oxygen saturation ≤93% at rest on room air pao2/fio2 ≤300 mmhg（1 mmhg=0.133 kpa） pulmonary imaging showed that the lesions progressed more than 50% within 24-48 hours, and the patients were managed as severe hbsag negative, or hbv dna ≤10^4 copy/ml if hbsag positive; anti-hcv negative; hiv negative two weeks prior to signed informed consent form (icf) appropriate ethics approval and icf -

inclusion criteria: 1. laboratory diagnosis: respiratory specimen is positive for sars-cov-2 nucleic acid by rt-pcr; or, the viral gene sequencing of the respiratory specimen is highly homologous to known novel coronavirus. 2. fever: axillary temperature >37.3℃ 3. respiratory variables (meets one of the following criteria): - respiratory rate: rr ≥25 breaths/min - oxygen saturation ≤93% at rest on room air - pao2/fio2 ≤300 mmhg（1 mmhg=0.133 kpa） - pulmonary imaging showed that the lesions progressed more than 50% within 24-48 hours, and the patients were managed as severe 4. hbsag negative, or hbv dna ≤10^4 copy/ml if hbsag positive; anti-hcv negative; hiv negative two weeks prior to signed informed consent form (icf) 5. appropriate ethics approval and 6. icf -

inclusion criteria: 1. laboratory diagnosis: respiratory specimen is positive for sars-cov-2 nucleic acid by rt-pcr; or, the viral gene sequencing of the respiratory specimen is highly homologous to known novel coronavirus. 2. fever: axillary temperature >37.3℃ 3. respiratory variables (meets one of the following criteria): - respiratory rate: rr ≥25 breaths/min - oxygen saturation ≤93% at rest on room air - pao2/fio2 ≤300 mmhg（1 mmhg=0.133 kpa） - pulmonary imaging showed that the lesions progressed more than 50% within 24-48 hours, and the patients were managed as severe 4. hbsag negative, or hbv dna ≤10^4 copy/ml if hbsag positive; anti-hcv negative; hiv negative two weeks prior to signed informed consent form (icf) 5. appropriate ethics approval and 6. icf -