COVID-19, SARS-CoV 2 Infection

The purpose of the study is to evaluate whether ibuzatrelvir is effective and safe in adults and adolescents with COVID-19 who do not need to be in the hospital but who are at high risk for progression to severe disease. Eligible participants will be randomly assigned (by chance) to receive ibuzatrelvir or matching placebo orally for 5 days. Co-administration of locally available standard of care is allowed. The total duration of the study is around 6 months.

The purpose of this study is to comprehensively describe the temporal and geographic utilization of COVID-19 therapies used for mild to moderate disease during different periods of SARS-CoV-2 variant circulation as well as to compare demographic and clinical characteristics of Veterans who are treated or do not receive these different therapies. The investigators will also perform similar descriptive epidemiology for other respiratory viruses, including RSV and influenza and other infectious diseases. This first phase will critically inform feasibility and direction of the second phase, in which the investigators will use target trial emulation design to study the comparative effectiveness of therapies and vaccines for COVID-19, respiratory viruses, including RSV, and influenza, and other infectious diseases.