inclusion criteria: 1. ability to understand and provide informed consent; 2. males and non-pregnant females 18 years of age or older at the time of screening; 3. laboratory-confirmed active sars-cov-2 infection within 72 hours prior to randomization, or (if testing results cannot be obtained) by evidence of progressive disease suggestive of ongoing sars-cov-2 infection; 4. females of childbearing potential must be willing to completely abstain or agree to use a highly effective method of contraception through day 28; and have a negative urine pregnancy test during screening; 5. currently hospitalized, receiving standard of care therapy for covid-19, and meets the criteria for moderate or severe covid-19, as follows: moderate = symptoms of moderate illness with covid-19, which could include any symptom of mild illness or shortness of breath with exertion and with respiratory rate at 20 or greater breaths/min, peripheral capillary oxygen saturation (spo2) \>93% on room air at sea level, or heart rate at 90 or greater beats/min; severe = symptoms suggestive of severe systemic illness with covid-19, which could include any symptom of moderate illness, shortness of breath at rest, or respiratory distress, and respiratory rate at 30 or greater breaths/min, heart rate at 125 or greater beats/min, or spo2 \>93% on room air at sea level or (partial pressure of oxygen:fraction of inspired oxygen (pao2:fio2) \<300.

inclusion criteria: 1. ability to understand and provide informed consent; 2. males and non-pregnant females 18 years of age or older at the time of screening; 3. laboratory-confirmed active sars-cov-2 infection within 72 hours prior to randomization, or (if testing results cannot be obtained) by evidence of progressive disease suggestive of ongoing sars-cov-2 infection; 4. females of childbearing potential must be willing to completely abstain or agree to use a highly effective method of contraception through day 28; and have a negative urine pregnancy test during screening; 5. currently hospitalized, receiving standard of care therapy for covid-19, and meets the criteria for moderate or severe covid-19, as follows: moderate = symptoms of moderate illness with covid-19, which could include any symptom of mild illness or shortness of breath with exertion and with respiratory rate at 20 or greater breaths/min, peripheral capillary oxygen saturation (spo2) \>93% on room air at sea level, or heart rate at 90 or greater beats/min; severe = symptoms suggestive of severe systemic illness with covid-19, which could include any symptom of moderate illness, shortness of breath at rest, or respiratory distress, and respiratory rate at 30 or greater breaths/min, heart rate at 125 or greater beats/min, or spo2 \>93% on room air at sea level or (partial pressure of oxygen:fraction of inspired oxygen (pao2:fio2) \<300.

inclusion criteria: ability to understand and provide informed consent; males and non-pregnant females 18 years of age or older at the time of screening; laboratory-confirmed active sars-cov-2 infection within 72 hours prior to randomization, or (if testing results cannot be obtained) by evidence of progressive disease suggestive of ongoing sars-cov-2 infection; females of childbearing potential must be willing to completely abstain or agree to use a highly effective method of contraception through day 28; and have a negative urine pregnancy test during screening; currently hospitalized, receiving standard of care therapy for covid-19, and meets the criteria for moderate or severe covid-19, as follows: moderate = symptoms of moderate illness with covid-19, which could include any symptom of mild illness or shortness of breath with exertion and with respiratory rate at 20 or greater breaths/min, peripheral capillary oxygen saturation (spo2) >93% on room air at sea level, or heart rate at 90 or greater beats/min; severe = symptoms suggestive of severe systemic illness with covid-19, which could include any symptom of moderate illness, shortness of breath at rest, or respiratory distress, and respiratory rate at 30 or greater breaths/min, heart rate at 125 or greater beats/min, or spo2 >93% on room air at sea level or (partial pressure of oxygen:fraction of inspired oxygen (pao2:fio2) <300.

inclusion criteria: ability to understand and provide informed consent; males and non-pregnant females 18 years of age or older at the time of screening; laboratory-confirmed active sars-cov-2 infection within 72 hours prior to randomization, or (if testing results cannot be obtained) by evidence of progressive disease suggestive of ongoing sars-cov-2 infection; females of childbearing potential must be willing to completely abstain or agree to use a highly effective method of contraception through day 28; and have a negative urine pregnancy test during screening; currently hospitalized, receiving standard of care therapy for covid-19, and meets the criteria for moderate or severe covid-19, as follows: moderate = symptoms of moderate illness with covid-19, which could include any symptom of mild illness or shortness of breath with exertion and with respiratory rate at 20 or greater breaths/min, peripheral capillary oxygen saturation (spo2) >93% on room air at sea level, or heart rate at 90 or greater beats/min; severe = symptoms suggestive of severe systemic illness with covid-19, which could include any symptom of moderate illness, shortness of breath at rest, or respiratory distress, and respiratory rate at 30 or greater breaths/min, heart rate at 125 or greater beats/min, or spo2 >93% on room air at sea level or (partial pressure of oxygen:fraction of inspired oxygen (pao2:fio2) <300.

inclusion criteria: ability to understand and provide informed consent; males and non-pregnant females 18 years of age or older at the time of screening; laboratory-confirmed active sars-cov-2 infection within 72 hours prior to randomization, or (if testing results cannot be obtained) by evidence of progressive disease suggestive of ongoing sars-cov-2 infection; females of childbearing potential must be willing to completely abstain or agree to use a highly effective method of contraception through day 28; and have a negative urine pregnancy test during screening; currently hospitalized, receiving standard of care therapy for covid-19, and meets the criteria for moderate or severe covid-19, as follows: moderate = symptoms of moderate illness with covid-19, which could include any symptom of mild illness or shortness of breath with exertion and with respiratory rate at 20 or greater breaths/min, spo2 >93% on room air at sea level, or heart rate at 90 or greater beats/min; severe = symptoms suggestive of severe systemic illness with covid-19, which could include any symptom of moderate illness, shortness of breath at rest, or respiratory distress, and respiratory rate at 30 or greater breaths/min, heart rate at 125 or greater beats/min, or spo2 >93% on room air at sea level or pao2:fio2 <300.

inclusion criteria: ability to understand and provide informed consent; males and non-pregnant females 18 years of age or older at the time of screening; laboratory-confirmed active sars-cov-2 infection within 72 hours prior to randomization, or (if testing results cannot be obtained) by evidence of progressive disease suggestive of ongoing sars-cov-2 infection; females of childbearing potential must be willing to completely abstain or agree to use a highly effective method of contraception through day 28; and have a negative urine pregnancy test during screening; currently hospitalized, receiving standard of care therapy for covid-19, and meets the criteria for moderate or severe covid-19, as follows: moderate = symptoms of moderate illness with covid-19, which could include any symptom of mild illness or shortness of breath with exertion and with respiratory rate at 20 or greater breaths/min, spo2 >93% on room air at sea level, or heart rate at 90 or greater beats/min; severe = symptoms suggestive of severe systemic illness with covid-19, which could include any symptom of moderate illness, shortness of breath at rest, or respiratory distress, and respiratory rate at 30 or greater breaths/min, heart rate at 125 or greater beats/min, or spo2 >93% on room air at sea level or pao2:fio2 <300.

inclusion criteria: 1. ability to understand and provide informed consent; 2. males and non-pregnant females 18 years of age or older at the time of screening; 3. laboratory-confirmed active sars-cov-2 infection within 72 hours prior to randomization, or (if testing results cannot be obtained) by evidence of progressive disease suggestive of ongoing sars-cov-2 infection; 4. females of childbearing potential must be willing to completely abstain or agree to use a highly effective method of contraception through day 28; and have a negative urine pregnancy test during screening; 5. currently hospitalized, receiving standard of care therapy for covid-19, and meets the criteria for moderate or severe covid-19, as follows: moderate = symptoms of moderate illness with covid-19, which could include any symptom of mild illness or shortness of breath with exertion and with respiratory rate at 20 or greater breaths/min, spo2 >93% on room air at sea level, or heart rate at 90 or greater beats/min; severe = symptoms suggestive of severe systemic illness with covid-19, which could include any symptom of moderate illness, shortness of breath at rest, or respiratory distress, and respiratory rate at 30 or greater breaths/min, heart rate at 125 or greater beats/min, or spo2 >93% on room air at sea level or pao2:fio2 <300.

inclusion criteria: 1. ability to understand and provide informed consent; 2. males and non-pregnant females 18 years of age or older at the time of screening; 3. laboratory-confirmed active sars-cov-2 infection within 72 hours prior to randomization, or (if testing results cannot be obtained) by evidence of progressive disease suggestive of ongoing sars-cov-2 infection; 4. females of childbearing potential must be willing to completely abstain or agree to use a highly effective method of contraception through day 28; and have a negative urine pregnancy test during screening; 5. currently hospitalized, receiving standard of care therapy for covid-19, and meets the criteria for moderate or severe covid-19, as follows: moderate = symptoms of moderate illness with covid-19, which could include any symptom of mild illness or shortness of breath with exertion and with respiratory rate at 20 or greater breaths/min, spo2 >93% on room air at sea level, or heart rate at 90 or greater beats/min; severe = symptoms suggestive of severe systemic illness with covid-19, which could include any symptom of moderate illness, shortness of breath at rest, or respiratory distress, and respiratory rate at 30 or greater breaths/min, heart rate at 125 or greater beats/min, or spo2 >93% on room air at sea level or pao2:fio2 <300.