A Study of Secutrelvir in Participants With Coronavirus Disease 2019 (COVID-19) Who Are at High Risk for Progression to Severe Disease

Key Inclusion Criteria: * Must be 12 to \<18 years of age (where permitted by local regulations) with a body weight ≥40 kilograms, or ≥18 years of age regardless of body weight, at the time of signing the informed consent form. * Presence of risk factors for progression to severe COVID-19 at the time of screening. * Must have ≥1 COVID-19 signs/symptoms that are at least mild in severity, and the symptoms must still be present in the 24 hours prior to randomization. * Confirmed SARS-CoV-2 infection, as determined by any SARS-CoV-2 test (for example, quantitative reverse transcription polymerase chain reaction, antigen test) approved according to local regulations, of any respiratory tract specimen (for example, oropharyngeal, nasopharyngeal or nasal swab, or saliva), collected ≤72 hours prior to randomization. * Must be randomized within 72 hours of symptom onset, defined as the time when the first COVID-19 symptom occurs. * Contraceptive use by women should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies. * A women of childbearing potential must have a negative urine pregnancy test within 24 hours prior to receiving the investigational intervention. * Unable or unwilling to take other locally available COVID-19 antivirals (for example, nirmatrelvir/ritonavir, molnupiravir, remdesivir, ensitrelvir). Key Exclusion Criteria: * Planned \>24 hours hospitalization for any medical procedure through Day 28. * …