A Study of a Potential Oral Treatment to Prevent COVID-19 in Adults Who Are Exposed to Household Member(s) With a Confirmed Symptomatic COVID-19 Infection

The purpose of this clinical trial is to learn whether the study medicine prevent symptoms of COVID-19 in adults who have been exposed to household member(s) with a confirmed symptomatic COVID-19 infection. All participants in the study will receive treatment for COVID-19 as needed, based on their regular doctor's recommendation. Two-thirds of participants will also receive two study medicines (PF-07321332 and ritonavir) by mouth twice a day for either five or ten days. We will compare the experiences of people receiving the study medicines to those of the people who do not. This will help us determine if the study medicines are safe and effective