A Study to Learn About a Study Medicine Called Ibuzatrelvir in Adult and Adolescent Patients With COVID-19 Who Are Not Hospitalized But Are at Risk For Severe Disease

A Study to Learn About the Study Medicine Ibuzatrelvir in Adults With COVID-19 Who Are Severely Immunocompromised

EPIC-Peds: A Study to Learn About the Study Medicine Called PF-07321332 (Nirmatrelvir)/Ritonavir in Patients Under 18 Years of Age With COVID-19 That Are Not Hospitalized But Are at Risk for Severe Disease

A Study to Learn About Variant-Adapted COVID-19 RNA Vaccine Candidate(s) in Healthy Children

A Study to Learn About The COVID-19 (Study) Vaccine (Called COMIRNATY) in People That Are Less Than 21 Years Old.

A Study to Look at the Health Outcomes of Patients With COVID-19 and Influenza

A Study to Learn About COVID-19 RNA-Based Variant-Adapted Vaccine Candidate(s) Against SARS-CoV-2 in Adults, Including Those at Higher Risk of Severe COVID-19

A Study on Paxlovid Once in the Market, to Observe Its Safety and Effectiveness in Patients Who Have a High Chance of Getting Severe COVID-19

A Study to Learn About Effects of Living With COVID-19 and the Use of the Medicines Nirmatrelvir-Ritonavir in Treating COVID-19.

A Study to Learn About How the Flu and COVID-19 Vaccines Act in Healthy People