inclusion criteria: 1. age 18 to 90, male and female subject of any race 2. reverse transcriptase polymerase chain reaction (rt-pcr)-confirmed covid-19 infection based on a nasal / oropharyngeal swab within 10 days before randomization 3. at least one of the following: 1) respiratory distress with tachypnea (rr ≥ 24 breaths/min without oxygen); 2) partial arterial oxygen pressure (pao2) / fraction of inspiration o2 (fio2), p/f \>100 and \<300 mmhg (1mmhg = 0.133kpa), 3) spo2 ≤ 94% while breathing ambient air. calculation through validated sat/fio2 scales is allowed. p/f value of reference if the last available before the signature of consent. 4. need of supplemental oxygen (i.e. new use of supplemental oxygen, or increased oxygen requirement if on chronic oxygen) requiring low- or high-flow oxygen or non-invasive mechanical ventilation (7-point who-os category 4 or 5). 5. radiological chest imaging (x-rays, ct scan) confirms lung involvement and inflammation.

inclusion criteria: 1. age 18 to 90, male and female subject of any race 2. reverse transcriptase polymerase chain reaction (rt-pcr)-confirmed covid-19 infection based on a nasal / oropharyngeal swab within 10 days before randomization 3. at least one of the following: 1) respiratory distress with tachypnea (rr ≥ 24 breaths/min without oxygen); 2) partial arterial oxygen pressure (pao2) / fraction of inspiration o2 (fio2), p/f \>100 and \<300 mmhg (1mmhg = 0.133kpa), 3) spo2 ≤ 94% while breathing ambient air. calculation through validated sat/fio2 scales is allowed. p/f value of reference if the last available before the signature of consent. 4. need of supplemental oxygen (i.e. new use of supplemental oxygen, or increased oxygen requirement if on chronic oxygen) requiring low- or high-flow oxygen or non-invasive mechanical ventilation (7-point who-os category 4 or 5). 5. radiological chest imaging (x-rays, ct scan) confirms lung involvement and inflammation.

inclusion criteria: age 18 to 90, male and female subject of any race reverse transcriptase polymerase chain reaction (rt-pcr)-confirmed covid-19 infection based on a nasal / oropharyngeal swab within 10 days before randomization at least one of the following: 1) respiratory distress with tachypnea (rr ≥ 24 breaths/min without oxygen); 2) partial arterial oxygen pressure (pao2) / fraction of inspiration o2 (fio2), p/f >100 and <300 mmhg (1mmhg = 0.133kpa), 3) spo2 ≤ 94% while breathing ambient air. calculation through validated sat/fio2 scales is allowed. p/f value of reference if the last available before the signature of consent. need of supplemental oxygen (i.e. new use of supplemental oxygen, or increased oxygen requirement if on chronic oxygen) requiring low- or high-flow oxygen or non-invasive mechanical ventilation (7-point who-os category 4 or 5). radiological chest imaging (x-rays, ct scan) confirms lung involvement and inflammation.

inclusion criteria: age 18 to 90, male and female subject of any race reverse transcriptase polymerase chain reaction (rt-pcr)-confirmed covid-19 infection based on a nasal / oropharyngeal swab within 10 days before randomization at least one of the following: 1) respiratory distress with tachypnea (rr ≥ 24 breaths/min without oxygen); 2) partial arterial oxygen pressure (pao2) / fraction of inspiration o2 (fio2), p/f >100 and <300 mmhg (1mmhg = 0.133kpa), 3) spo2 ≤ 94% while breathing ambient air. calculation through validated sat/fio2 scales is allowed. p/f value of reference if the last available before the signature of consent. need of supplemental oxygen (i.e. new use of supplemental oxygen, or increased oxygen requirement if on chronic oxygen) requiring low- or high-flow oxygen or non-invasive mechanical ventilation (7-point who-os category 4 or 5). radiological chest imaging (x-rays, ct scan) confirms lung involvement and inflammation.

inclusion criteria: 1. age 18 to 90, male and female subject of any race 2. reverse transcriptase polymerase chain reaction (rt-pcr)-confirmed covid-19 infection based on a nasal / oropharyngeal swab within 10 days before randomization 3. at least one of the following: 1) respiratory distress with tachypnea (rr ≥ 24 breaths/min without oxygen); 2) partial arterial oxygen pressure (pao2) / fraction of inspiration o2 (fio2), p/f >100 and <300 mmhg (1mmhg = 0.133kpa), 3) spo2 ≤ 94% while breathing ambient air. calculation through validated sat/fio2 scales is allowed. p/f value of reference if the last available before the signature of consent. 4. need of supplemental oxygen (i.e. new use of supplemental oxygen, or increased oxygen requirement if on chronic oxygen) requiring low- or high-flow oxygen or non-invasive mechanical ventilation (7-point who-os category 4 or 5). 5. radiological chest imaging (x-rays, ct scan) confirms lung involvement and inflammation.

inclusion criteria: 1. age 18 to 90, male and female subject of any race 2. reverse transcriptase polymerase chain reaction (rt-pcr)-confirmed covid-19 infection based on a nasal / oropharyngeal swab within 10 days before randomization 3. at least one of the following: 1) respiratory distress with tachypnea (rr ≥ 24 breaths/min without oxygen); 2) partial arterial oxygen pressure (pao2) / fraction of inspiration o2 (fio2), p/f >100 and <300 mmhg (1mmhg = 0.133kpa), 3) spo2 ≤ 94% while breathing ambient air. calculation through validated sat/fio2 scales is allowed. p/f value of reference if the last available before the signature of consent. 4. need of supplemental oxygen (i.e. new use of supplemental oxygen, or increased oxygen requirement if on chronic oxygen) requiring low- or high-flow oxygen or non-invasive mechanical ventilation (7-point who-os category 4 or 5). 5. radiological chest imaging (x-rays, ct scan) confirms lung involvement and inflammation.