inclusion criteria: male or nonpregnant or nonlactating female, aged 18 to 70 years at the time of consenting hospitalized due to infection with sars-cov-2 confirmed on validated local rt-pcr or other equivalent assays within 48 hours prior to screening and within 96 hours prior to randomization assessed to be hospitalized cases (rated at who-osci score 4 [on oxygen therapy by mask or nasal prongs]) within 24 hours prior to randomization admitted to hospital as clinically indicated for management of severe covid-19 defined by the following criteria: positive rt-pcr test for sars-cov-2 or an equivalent test symptom suggestive of severe systemic illness with covid-19, which could include any symptom of moderate illness or shortness of breath at rest, or respiratory distress clinical signs indicative of severe illness with covid-19, being given oxygenation and meeting one of the following: respiratory rate ≥30 breaths per minute heart rate ≥125 beats per minute oxygen saturation (spo2) <94% on room air at sea level arterial partial pressure of oxygen (pao2)/fraction of inspired oxygen (fio2) <300 mmhg or spo2/fio2 <315 mmhg lung infiltrates >50% no criteria for critical severity female of childbearing potential must be postmenopausal for 1 year or longer, surgically sterile or having used a medically effective method of contraception for at least 3 months prior to hospitalization willing and able to provide a signed and dated or electronic informed consent for participation in this study.

inclusion criteria: male or nonpregnant or nonlactating female, aged 18 to 70 years at the time of consenting hospitalized due to infection with sars-cov-2 confirmed on validated local rt-pcr or other equivalent assays within 48 hours prior to screening and within 96 hours prior to randomization assessed to be hospitalized cases (rated at who-osci score 4 [on oxygen therapy by mask or nasal prongs]) within 24 hours prior to randomization admitted to hospital as clinically indicated for management of severe covid-19 defined by the following criteria: positive rt-pcr test for sars-cov-2 or an equivalent test symptom suggestive of severe systemic illness with covid-19, which could include any symptom of moderate illness or shortness of breath at rest, or respiratory distress clinical signs indicative of severe illness with covid-19, being given oxygenation and meeting one of the following: respiratory rate ≥30 breaths per minute heart rate ≥125 beats per minute oxygen saturation (spo2) <94% on room air at sea level arterial partial pressure of oxygen (pao2)/fraction of inspired oxygen (fio2) <300 mmhg or spo2/fio2 <315 mmhg lung infiltrates >50% no criteria for critical severity female of childbearing potential must be postmenopausal for 1 year or longer, surgically sterile or having used a medically effective method of contraception for at least 3 months prior to hospitalization willing and able to provide a signed and dated or electronic informed consent for participation in this study.

inclusion criteria: 1. male or nonpregnant or nonlactating female, aged 18 to 70 years at the time of consenting 2. hospitalized due to infection with sars-cov-2 confirmed on validated local rt-pcr or other equivalent assays within 48 hours prior to screening and within 96 hours prior to randomization 3. assessed to be hospitalized cases (rated at who-osci score 4 [on oxygen therapy by mask or nasal prongs]) within 24 hours prior to randomization 4. admitted to hospital as clinically indicated for management of severe covid-19 defined by the following criteria: - positive rt-pcr test for sars-cov-2 or an equivalent test - symptom suggestive of severe systemic illness with covid-19, which could include any symptom of moderate illness or shortness of breath at rest, or respiratory distress - clinical signs indicative of severe illness with covid-19, being given oxygenation and meeting one of the following: - respiratory rate ≥30 breaths per minute - heart rate ≥125 beats per minute - oxygen saturation (spo2) <94% on room air at sea level - arterial partial pressure of oxygen (pao2)/fraction of inspired oxygen (fio2) <300 mmhg or spo2/fio2 <315 mmhg - lung infiltrates >50% - no criteria for critical severity 5. female of childbearing potential must be postmenopausal for 1 year or longer, surgically sterile or having used a medically effective method of contraception for at least 3 months prior to hospitalization 6. willing and able to provide a signed and dated or electronic informed consent for participation in this study.

inclusion criteria: 1. male or nonpregnant or nonlactating female, aged 18 to 70 years at the time of consenting 2. hospitalized due to infection with sars-cov-2 confirmed on validated local rt-pcr or other equivalent assays within 48 hours prior to screening and within 96 hours prior to randomization 3. assessed to be hospitalized cases (rated at who-osci score 4 [on oxygen therapy by mask or nasal prongs]) within 24 hours prior to randomization 4. admitted to hospital as clinically indicated for management of severe covid-19 defined by the following criteria: - positive rt-pcr test for sars-cov-2 or an equivalent test - symptom suggestive of severe systemic illness with covid-19, which could include any symptom of moderate illness or shortness of breath at rest, or respiratory distress - clinical signs indicative of severe illness with covid-19, being given oxygenation and meeting one of the following: - respiratory rate ≥30 breaths per minute - heart rate ≥125 beats per minute - oxygen saturation (spo2) <94% on room air at sea level - arterial partial pressure of oxygen (pao2)/fraction of inspired oxygen (fio2) <300 mmhg or spo2/fio2 <315 mmhg - lung infiltrates >50% - no criteria for critical severity 5. female of childbearing potential must be postmenopausal for 1 year or longer, surgically sterile or having used a medically effective method of contraception for at least 3 months prior to hospitalization 6. willing and able to provide a signed and dated or electronic informed consent for participation in this study.