1. The participant is a household contact of an index case. The index case is a person with documented COVID-19 (laboratory-confirmed SARS-CoV-2 infection with symptoms case) and must have: a) A first detectable SARS-CoV-2 test result from a sample collected within <5 days prior to randomization of the participant(s), AND b) At least 1 of the following symptoms attributable to COVID-19: fever ≥38.0ºC, chills, cough, sore throat, shortness of breath or difficulty breathing with exertion, fatigue, nasal congestion, runny nose, headache, muscle or body aches, nausea, vomiting, diarrhea, loss of taste, or loss of smell, with symptom onset no earlier than 5 days prior to randomization of the participant(s). 2. The participant does not have confirmed or suspected COVID-19. 3. The participant is willing and able to take oral medication. 4. The participant is male or female ≥18 years of age, at the time of providing documented informed consent. 5. There are no contraceptive requirements for male participants per protocol. However, where applicable, male participants are only eligible to participate if they agree to follow local labelling (or local ethics or regulatory authority requirement) regarding contraception. 6. A female participant is eligible to participate if she is not pregnant or breastfeeding, and at least one of the following conditions applies: Is not a WOCBP OR Is a WOCBP and uses a contraceptive method that is highly effective (a low user dependency method OR a user dependent hormonal method in combination with barrier method), or be abstinent from heterosexual intercourse as their preferred and usual lifestyle (abstinent on a long-term and persistent basis), during the intervention period and for at least 4 days after the last dose of study intervention. The investigator should evaluate the potential for contraceptive method failure (ie, noncompliance, recently initiated) in relationship to the first dose of study intervention. - Contraceptive use by women should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies. - Has a negative highly sensitive pregnancy test (urine or serum as required by local regulations) within 24 hours before the first dose of study intervention. - Has had her medical history, menstrual history, and recent sexual activity reviewed by the investigator to decrease the risk for inclusion of a woman with an early undetected pregnancy. - If contraceptives are interrupted in case of standard of care management of COVID-19 and resumed at a later time point, such as at hospital discharge, then abstinence must be practiced for the defined period of back-up contraception per the contraceptive product labeling. After this period, contraceptive use must adhere to protocol. 7. The participant’s index case (or legally acceptable representative of the index case) has provided documented informed consent/assent for the collection of COVID-19 documentation requirements. 8. The participant (or legally acceptable representative) has provided documented informed consent to participate in the study. The participant may also provide consent for participation in FBR but may participate in the study without participating in FBR.

1. The participant is a household contact of an index case. The index case is a person with documented COVID-19 (laboratory-confirmed SARS-CoV-2 infection with symptoms case) and must have: a) A first detectable SARS-CoV-2 test result from a sample collected within <5 days prior to randomization of the participant(s), AND b) At least 1 of the following symptoms attributable to COVID-19: fever ≥38.0ºC, chills, cough, sore throat, shortness of breath or difficulty breathing with exertion, fatigue, nasal congestion, runny nose, headache, muscle or body aches, nausea, vomiting, diarrhea, loss of taste, or loss of smell, with symptom onset no earlier than 5 days prior to randomization of the participant(s). 2. The participant does not have confirmed or suspected COVID-19. 3. The participant is willing and able to take oral medication. 4. The participant is male or female ≥18 years of age, at the time of providing documented informed consent. 5. There are no contraceptive requirements for male participants per protocol. However, where applicable, male participants are only eligible to participate if they agree to follow local labelling (or local ethics or regulatory authority requirement) regarding contraception. 6. A female participant is eligible to participate if she is not pregnant or breastfeeding, and at least one of the following conditions applies: Is not a WOCBP OR Is a WOCBP and uses a contraceptive method that is highly effective (a low user dependency method OR a user dependent hormonal method in combination with barrier method), or be abstinent from heterosexual intercourse as their preferred and usual lifestyle (abstinent on a long-term and persistent basis), during the intervention period and for at least 4 days after the last dose of study intervention. The investigator should evaluate the potential for contraceptive method failure (ie, noncompliance, recently initiated) in relationship to the first dose of study intervention. - Contraceptive use by women should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies. - Has a negative highly sensitive pregnancy test (urine or serum as required by local regulations) within 24 hours before the first dose of study intervention. - Has had her medical history, menstrual history, and recent sexual activity reviewed by the investigator to decrease the risk for inclusion of a woman with an early undetected pregnancy. - If contraceptives are interrupted in case of standard of care management of COVID-19 and resumed at a later time point, such as at hospital discharge, then abstinence must be practiced for the defined period of back-up contraception per the contraceptive product labeling. After this period, contraceptive use must adhere to protocol. 7. The participant’s index case (or legally acceptable representative of the index case) has provided documented informed consent/assent for the collection of COVID-19 documentation requirements. 8. The participant (or legally acceptable representative) has provided documented informed consent to participate in the study. The participant may also provide consent for participation in FBR but may participate in the study without participating in FBR.