inclusion criteria: * male or female, aged 18 years-old or older * laboratory-confirmed sars-cov-2 infection determined by reverse-transcription polymerase chain reaction (rt-pcr) prior to randomization * hospitalized patients * severe covid-19 pneumonia defined as patients who cannot saturate \> 96% on 4 l/min but are not on "non-invasive" ventilation nor invasive mechanical ventilation nor extracorporeal membrane oxygenation (ecmo). patients on high flow would be eligible if they receive treatment in a non-critical care unit only. * use of contraception or acceptable birth control for the duration of the study in women of childbearing potential * provision of written or verbal informed consent by the patient or designated substitute decision maker

inclusion criteria: * male or female, aged 18 years-old or older * laboratory-confirmed sars-cov-2 infection determined by reverse-transcription polymerase chain reaction (rt-pcr) prior to randomization * hospitalized patients * severe covid-19 pneumonia defined as patients who cannot saturate \> 96% on 4 l/min but are not on "non-invasive" ventilation nor invasive mechanical ventilation nor extracorporeal membrane oxygenation (ecmo). patients on high flow would be eligible if they receive treatment in a non-critical care unit only. * use of contraception or acceptable birth control for the duration of the study in women of childbearing potential * provision of written or verbal informed consent by the patient or designated substitute decision maker

inclusion criteria: - male or female, aged 18 years-old or older - laboratory-confirmed sars-cov-2 infection determined by reverse-transcription polymerase chain reaction (rt-pcr) prior to randomization - hospitalized patients - severe covid-19 pneumonia defined as patients who cannot saturate > 96% on 4 l/min but are not on "non-invasive" ventilation nor invasive mechanical ventilation nor extracorporeal membrane oxygenation (ecmo). patients on high flow would be eligible if they receive treatment in a non-critical care unit only. - use of contraception or acceptable birth control for the duration of the study in women of childbearing potential - provision of written or verbal informed consent by the patient or designated substitute decision maker

inclusion criteria: - male or female, aged 18 years-old or older - laboratory-confirmed sars-cov-2 infection determined by reverse-transcription polymerase chain reaction (rt-pcr) prior to randomization - hospitalized patients - severe covid-19 pneumonia defined as patients who cannot saturate > 96% on 4 l/min but are not on "non-invasive" ventilation nor invasive mechanical ventilation nor extracorporeal membrane oxygenation (ecmo). patients on high flow would be eligible if they receive treatment in a non-critical care unit only. - use of contraception or acceptable birth control for the duration of the study in women of childbearing potential - provision of written or verbal informed consent by the patient or designated substitute decision maker