Phase 3 Study of S-217622 in Prevention of Symptomatic SARS-CoV-2 Infection

Inclusion Criteria

• •Index Participants
• •Only 1 index participant from each household will be enrolled in the study. Participants are eligible to be included as an index participant if all of the following criteria apply:
• •1. Pediatric participants or adult participants (of any age)
• •2. The index participant must:
• •1. Have at least 1 COVID-19 symptom within 24 hours before the index participant providing informed consent. COVID-19 symptom(s) must be deemed by the investigator as related to the current SARS-CoV-2 infection (not related to preexisting comorbidities) or deemed as preexisting and worsened due to SARS-CoV-2 infection.
• •2. Must have positive SARS-CoV-2 test (a nucleic acid amplification test or antigen test) from any respiratory tract specimen from a sample collected prior to randomization of the participant
• •3. Must have a potential study participant who can participate in the study after onset of COVID-19 symptoms in an index participant
• •Study Participants
• •Multiple study participants from the same household are allowed to be enrolled in the study. The study intervention randomization will be performed based at the study participant's level. Participants will be eligible to be included in the study only if all of the following criteria apply:
• •1. ≥ 12 years of age at the time of signing the informed consent
• •2. Has a negative screening for SARS-CoV-2 infection, as determined by SARS-CoV-2 test (a nucleic acid amplification test or antigen test) from any respiratory tract specimen (for example, oropharyngeal, nasopharyngeal or nasal swab, or saliva).
• •3. Has lived in household with index participant and will continue to live in same household and share common areas such as dining rooms and bathrooms until the end of the study
• •4. Must not be considered by the investigator or subinvestigator to have SARS-CoV-2 infection and:
• •1. No measured fever at Screening (defined as body temperature ≥ 38.0°Celsius \[C\] per tympanic or rectal thermometer or ≥ 37.5°C per axillary, oral, or forehead/temporal thermometer)
• •2. No COVID-19 symptoms at Screening (if a participant has COVID-19-like symptoms caused by comorbidities, only 1 symptom will be allowed)
• •5. Capable and willing to complete a participant diary
• •6. a. Male participants: Participants with partners that are woman of childbearing potential (WOCBP) must agree to use effective contraception. Participants with pregnant partners must agree to use effective contraception.
• •b. Female participants: A female participant is eligible to participate if she is not pregnant or breastfeeding, and the following conditions applies:
• •* Is not a WOCBP or
• •* All of the following apply:
• •* Is a WOCBP and using a contraceptive method that is effective as described in the protocol.
• •* A WOCBP must have a negative urine pregnancy test within 24 hours before the first dose of study intervention period.
• •* If a urine pregnancy test cannot be confirmed as negative (for example, an ambiguous result), a serum pregnancy test must be negative.
• •* Additional requirements for pregnancy testing during and after study intervention as described in the protocol.
• •* The investigator/subinvestigator will review medical history, menstrual history, and recent sexual activity to decrease the risk of inclusion of a woman with an early undetected pregnancy.
• •7. Participant must be randomized ≤ 72 hours from onset of COVID-19 symptoms in the index participant.