ACTIV-1 IM is a master protocol designed to evaluate immune modulators for the treatment of moderately or severely ill hospitalized patients infected with COVID-19. Trial participants will be assessed daily while hospitalized. If the participants are discharged from the hospital prior to Day 29, they will have follow-up study visits at Days 8, 11, 15, 22, and 29. For discharged participants, it is preferred that the Day 8, 11, 15, and 29 visits are in person to obtain safety laboratory tests and blood (serum/plasma) samples for secondary research as well as clinical outcome data. However, infection control or other restrictions may limit the ability of the participant to return to the clinic. In this case, these visits may be conducted by phone, and only clinical data will be obtained. The Day 22 visit does not have laboratory tests or collection of samples and is conducted by phone. The Day 60 assessment will be conducted by phone.