A Clinical Study of Molnupiravir to Prevent Severe Illness From Coronavirus Disease 2019 (COVID-19) in People Who Are High Risk (MK-4482-023)

Inclusion Criteria The main inclusion criteria include but are not limited to the following: * Is an individual of any sex/gender, ≥18 years of age * Has documentation of SARS-CoV-2 infection with sample collection ≤4 days prior to randomization * Has initial onset of signs/symptoms attributable to COVID-19 for ≤4 days prior to the day of randomization and ≥2 of the following signs/symptoms attributable to COVID-19 on the day of randomization: cough, sore throat, nasal congestion, shortness of breath or difficulty breathing with exertion, muscle or body aches, fatigue, fever \>38.0°C or chills, nausea or vomiting or diarrhea, change in sense of smell or change in sense of taste, or headache * Has ≥1 of the following characteristics or medical conditions associated with the highest risk of severe illness from COVID-19: * Advanced age of ≥75 years of age * Immunocompromised * Neurocognitive or physical disability * Has ≥3 characteristics or medical conditions which increase the risk of severe illness due to COVID-19 (e.g., chronic lung disease, obesity with body mass index (BMI) ≥35, diabetes) * Is unable or unwilling to receive treatment with nirmatrelvir/ritonavir (NMV/r) due to 1 or more of the following: * Is receiving drug(s) highly dependent on cytochrome P450 3A (CYP3A) for clearance and for which elevated concentrations are associated with serious and/or life-threatening consequences or drug(s) with a clinically significant drug-drug interaction for which …