inclusion criteria: * signs and symptoms suggestive of covid-19 infection including cough or dyspnea * laboratory-confirmed sars-cov-2 infection as determined by polymerase chain reaction (pcr) test ≤7 days before randomization * currently hospitalized or in an emergency department with planned hospitalization * peripheral capillary oxygen saturation (spo2) ≤93% on room air or partial pressure of oxygen (pao2)/fraction of inspired oxygen (fio2) \<300 at screening

inclusion criteria: * signs and symptoms suggestive of covid-19 infection including cough or dyspnea * laboratory-confirmed sars-cov-2 infection as determined by polymerase chain reaction (pcr) test ≤7 days before randomization * currently hospitalized or in an emergency department with planned hospitalization * peripheral capillary oxygen saturation (spo2) ≤93% on room air or partial pressure of oxygen (pao2)/fraction of inspired oxygen (fio2) \<300 at screening

inclusion criteria: - signs and symptoms suggestive of covid-19 infection including cough or dyspnea - laboratory-confirmed sars-cov-2 infection as determined by polymerase chain reaction (pcr) test ≤7 days before randomization - currently hospitalized or in an emergency department with planned hospitalization - peripheral capillary oxygen saturation (spo2) ≤93% on room air or partial pressure of oxygen (pao2)/fraction of inspired oxygen (fio2) <300 at screening

inclusion criteria: - signs and symptoms suggestive of covid-19 infection including cough or dyspnea - laboratory-confirmed sars-cov-2 infection as determined by polymerase chain reaction (pcr) test ≤7 days before randomization - currently hospitalized or in an emergency department with planned hospitalization - peripheral capillary oxygen saturation (spo2) ≤93% on room air or partial pressure of oxygen (pao2)/fraction of inspired oxygen (fio2) <300 at screening