First-in-human Study to Evaluate Safety, Tolerability, and Pharmacokinetics Following Single Ascending and Multiple Ascending Doses of PF-07304814 in Hospitalized Participants with COVID-19.  A Phase 1b, 2-Part, Double-Blind, Placebo- Controlled, Sponsor Open Study, to Evaluate the Safety, Tolerability and Pharmacokinetics of Single Ascending (24-Hour, Part 1) and Multiple Ascending (120-Hour, Part 2) Intravenous Infusions of PF-07304814 in Hospitalized Participants With COVID-19.