inclusion criteria: 1. be ≥18 years of age 2. provide adequate medical history to permit accurate stratification by health status 3. prior to sars cov 2 infection, has no chronic or recurring requirement for supplemental oxygen 4. have lower respiratory tract infection (lrti) confirmed by imaging 5. has laboratory-confirmation of the presence of sars-cov-2 in the respiratory tract 6. at the time of randomization, requires supplemental oxygen ≥2 lpm for treatment of hypoxia or pulmonary stress as evidenced by at least one of the following: 1. respiratory rate ≥ 30 breaths/min 2. spo2 ≤93% at rest 3. pao2/fio2≤300 mmhg 4. showing the progression of lung lesions within 24 to 48h by \>50% 7. if female, subject must meet one of the following conditions: 1. not be of childbearing potential or 2. be of childbearing potential and have a negative urine/serum pregnancy test and agrees to practice an acceptable method of contraception 8. non-vasectomized males are required to practice effective birth control methods 9. capable of understanding and complying with procedures as outlined in the protocol 10. provides signed informed consent prior to the initiation of any screening or study-specific procedures

inclusion criteria: 1. be ≥18 years of age 2. provide adequate medical history to permit accurate stratification by health status 3. prior to sars cov 2 infection, has no chronic or recurring requirement for supplemental oxygen 4. have lower respiratory tract infection (lrti) confirmed by imaging 5. has laboratory-confirmation of the presence of sars-cov-2 in the respiratory tract 6. at the time of randomization, requires supplemental oxygen ≥2 lpm for treatment of hypoxia or pulmonary stress as evidenced by at least one of the following: 1. respiratory rate ≥ 30 breaths/min 2. spo2 ≤93% at rest 3. pao2/fio2≤300 mmhg 4. showing the progression of lung lesions within 24 to 48h by \>50% 7. if female, subject must meet one of the following conditions: 1. not be of childbearing potential or 2. be of childbearing potential and have a negative urine/serum pregnancy test and agrees to practice an acceptable method of contraception 8. non-vasectomized males are required to practice effective birth control methods 9. capable of understanding and complying with procedures as outlined in the protocol 10. provides signed informed consent prior to the initiation of any screening or study-specific procedures

inclusion criteria: be ≥18 years of age provide adequate medical history to permit accurate stratification by health status prior to sars cov 2 infection, has no chronic or recurring requirement for supplemental oxygen have lower respiratory tract infection (lrti) confirmed by imaging has laboratory-confirmation of the presence of sars-cov-2 in the respiratory tract at the time of randomization, requires supplemental oxygen ≥2 lpm for treatment of hypoxia or pulmonary stress as evidenced by at least one of the following: respiratory rate ≥ 30 breaths/min spo2 ≤93% at rest pao2/fio2≤300 mmhg showing the progression of lung lesions within 24 to 48h by >50% if female, subject must meet one of the following conditions: not be of childbearing potential or be of childbearing potential and have a negative urine/serum pregnancy test and agrees to practice an acceptable method of contraception non-vasectomized males are required to practice effective birth control methods capable of understanding and complying with procedures as outlined in the protocol provides signed informed consent prior to the initiation of any screening or study-specific procedures

inclusion criteria: be ≥18 years of age provide adequate medical history to permit accurate stratification by health status prior to sars cov 2 infection, has no chronic or recurring requirement for supplemental oxygen have lower respiratory tract infection (lrti) confirmed by imaging has laboratory-confirmation of the presence of sars-cov-2 in the respiratory tract at the time of randomization, requires supplemental oxygen ≥2 lpm for treatment of hypoxia or pulmonary stress as evidenced by at least one of the following: respiratory rate ≥ 30 breaths/min spo2 ≤93% at rest pao2/fio2≤300 mmhg showing the progression of lung lesions within 24 to 48h by >50% if female, subject must meet one of the following conditions: not be of childbearing potential or be of childbearing potential and have a negative urine/serum pregnancy test and agrees to practice an acceptable method of contraception non-vasectomized males are required to practice effective birth control methods capable of understanding and complying with procedures as outlined in the protocol provides signed informed consent prior to the initiation of any screening or study-specific procedures

inclusion criteria: 1. be ≥18 years of age 2. provide adequate medical history to permit accurate stratification by health status 3. prior to sars cov 2 infection, has no chronic or recurring requirement for supplemental oxygen 4. have lower respiratory tract infection (lrti) confirmed by imaging 5. has laboratory-confirmation of the presence of sars-cov-2 in the respiratory tract 6. at the time of randomization, requires supplemental oxygen ≥2 lpm for treatment of hypoxia or pulmonary stress as evidenced by at least one of the following: 1. respiratory rate ≥ 30 breaths/min 2. spo2 ≤93% at rest 3. pao2/fio2≤300 mmhg 4. showing the progression of lung lesions within 24 to 48h by >50% 7. if female, subject must meet one of the following conditions: 1. not be of childbearing potential or 2. be of childbearing potential and have a negative urine/serum pregnancy test and agrees to practice an acceptable method of contraception 8. non-vasectomized males are required to practice effective birth control methods 9. capable of understanding and complying with procedures as outlined in the protocol 10. provides signed informed consent prior to the initiation of any screening or study-specific procedures

inclusion criteria: 1. be ≥18 years of age 2. provide adequate medical history to permit accurate stratification by health status 3. prior to sars cov 2 infection, has no chronic or recurring requirement for supplemental oxygen 4. have lower respiratory tract infection (lrti) confirmed by imaging 5. has laboratory-confirmation of the presence of sars-cov-2 in the respiratory tract 6. at the time of randomization, requires supplemental oxygen ≥2 lpm for treatment of hypoxia or pulmonary stress as evidenced by at least one of the following: 1. respiratory rate ≥ 30 breaths/min 2. spo2 ≤93% at rest 3. pao2/fio2≤300 mmhg 4. showing the progression of lung lesions within 24 to 48h by >50% 7. if female, subject must meet one of the following conditions: 1. not be of childbearing potential or 2. be of childbearing potential and have a negative urine/serum pregnancy test and agrees to practice an acceptable method of contraception 8. non-vasectomized males are required to practice effective birth control methods 9. capable of understanding and complying with procedures as outlined in the protocol 10. provides signed informed consent prior to the initiation of any screening or study-specific procedures