1. received a vaccine within 4 weeks prior to the study, or plan to receive a vaccine during the study period, or received treatment with tetrandrine tables prior to enrolling in the study. 2. patient must be on invasive mechanical ventilation/ecmo at baseline. 3. any clinically important serious diseases unstable or uncontrolled. 4. allergy history to any biological or other agent. 5. patient has severe mental or psychological abnormalities, cognitive impairment or intellectual disability before being diagnosed with covid-19. 6. subjects who are pregnant or breastfeeding, or plan to become pregnant during the study. 7. investigator think the subject should not participate in the study.

1. received a vaccine within 4 weeks prior to the study, or plan to receive a vaccine during the study period, or received treatment with tetrandrine tables prior to enrolling in the study. 2. patient must be on invasive mechanical ventilation/ecmo at baseline. 3. any clinically important serious diseases unstable or uncontrolled. 4. allergy history to any biological or other agent. 5. patient has severe mental or psychological abnormalities, cognitive impairment or intellectual disability before being diagnosed with covid-19. 6. subjects who are pregnant or breastfeeding, or plan to become pregnant during the study. 7. investigator think the subject should not participate in the study.

received a vaccine within 4 weeks prior to the study, or plan to receive a vaccine during the study period, or received treatment with tetrandrine tables prior to enrolling in the study. patient must be on invasive mechanical ventilation/ecmo at baseline. any clinically important serious diseases unstable or uncontrolled. allergy history to any biological or other agent. patient has severe mental or psychological abnormalities, cognitive impairment or intellectual disability before being diagnosed with covid-19. subjects who are pregnant or breastfeeding, or plan to become pregnant during the study. investigator think the subject should not participate in the study.

received a vaccine within 4 weeks prior to the study, or plan to receive a vaccine during the study period, or received treatment with tetrandrine tables prior to enrolling in the study. patient must be on invasive mechanical ventilation/ecmo at baseline. any clinically important serious diseases unstable or uncontrolled. allergy history to any biological or other agent. patient has severe mental or psychological abnormalities, cognitive impairment or intellectual disability before being diagnosed with covid-19. subjects who are pregnant or breastfeeding, or plan to become pregnant during the study. investigator think the subject should not participate in the study.