Age 18 to 75 years Diagnosis of COVID-19 in the last 24 hours One of the three following: respiratory rate more than 30 per minutes, o2 saturation less than or equal to 93% at room temperature, PaO2/FiO2 less than or equal to 300 Female patients should not be pregnant and should not become pregnant until 30 days after the end of the study

Age 18 to 75 years Diagnosis of COVID-19 in the last 24 hours One of the three following: respiratory rate more than 30 per minutes, o2 saturation less than or equal to 93% at room temperature, PaO2/FiO2 less than or equal to 300 Female patients should not be pregnant and should not become pregnant until 30 days after the end of the study