ACTIV-3: Therapeutics for Inpatients With COVID-19

Inclusion Criteria: * Signed informed consent. * Positive test for COVID-19 and progressive disease suggestive of ongoing COVID-19 infection. * Symptoms of COVID-19 for ≤ 12 days. * Require admission to hospital for acute medical care (not for purely public health or quarantine purposes). Exclusion Criteria: * Patients who have received plasma from a person who recovered from COVID-19 or who have received neutralizing monoclonal antibodies at any time prior to hospitalization. * Patients not willing to abstain from participation in other COVID-19 treatment trials until after Day 5 of the study. Co-enrollment in certain trials that compare recommended Standard of Care treatments may be allowed, based on the opinion of the study leadership team. * Any condition which, in the opinion of the responsible investigator, participation would not be in the best interest of the participant or that could prevent, limit, or confound the protocol-specified assessments. * Patients considered unable to participate in study procedures. * Women of child-bearing potential who are not already pregnant at study entry and who are unwilling to acknowledge strong advice to abstain from sexual intercourse with men or practice appropriate contraception through 18 months of the study. * Women of child-bearing potential who are unwilling to acknowledge the strong advice to abstain from sexual intercourse with men or practice appropriate contraception through 5 weeks of the study (PF-07304814 investigational agent). * Pregnant women (PF-07304814 investigational agents). * Nursing mothers (PF-07304814 investigational agents). * Men who are unwilling to acknowledge the strong advice to abstain from sexual intercourse with women of child-bearing potential or to use barrier contraception through 18 months of the study. * Men who are unwilling to acknowledge the strong advice to abstain from sexual intercourse with women of child-bearing potential or to use barrier contraception through 5 weeks of the study (PF-07304814 investigational agent). * Presence at study enrollment of any of the following: 1. stroke 2. meningitis 3. encephalitis 4. myelitis 5. myocardial ischemia 6. myocarditis 7. pericarditis 8. symptomatic congestive heart failure 9. arterial or deep venous thrombosis or pulmonary embolism * Current or imminent requirement for any of the following: 1. invasive mechanical ventilation 2. ECMO (extracorporeal membrane oxygenation) 3. Mechanical circulatory support 4. vasopressor therapy 5. commencement of renal replacement therapy at this admission (i.e. not patients on chronic renal replacement therapy). * Participants with moderate to severe hepatic impairment (i.e. Child-Pugh class B or C) or acute liver failure (PF-07304814 investigational agent). * Participants receiving any medications or substances that are strong inhibitors or inducers of cytochrome P450 (CYP) 3A4 (PF-07304814 investigational agent). * Patients will be excluded if taking drugs which have a narrow therapeutic window that are substrates of CYP3A4, including but not limited to: astemizole, cisapride, cyclosporine, dihydroergotamine, ergotamine, pimozide, quinidine, sirolimus, tacrolimus, and terfenadine (PF-07304814 investigational agent). * Patients with a history of deep vein thrombosis or pulmonary thrombotic embolism (Prior to initial futility assessment of PF-07304814 investigational agent).