inclusion criteria: 1. are ≥18 years of age at the time of randomization 2. subject has a household contact with a confirmed covid-19 cohabiting individual as subject. initial diagnosis of the covid-19 positive individual has been within 3 days of screening. covid-19 positive result (pcr or antigen) must have been performed by an accredited lab or medical professional. current and uninterrupted household contacts were defined as family members or close relatives who had unprotected contact with the index case. 3. subject must have a negative result with the study provided rapid antigen test at baseline and be covid-19 symptom free. 4. are men or non-pregnant women. reproductive and contraceptive agreements and guidance is provided in appendix 2. contraceptive use by men or women should be consistent with local regulations for those participating in clinical studies. 5. understand and agree to comply with planned study procedures 6. agree to the collection of nasopharyngeal swabs 7. the participant or legally authorized representative gives signed informed consent as described in section 10.1.1.2 which includes compliance with the requirements and restrictions listed in the informed consent form (icf) and in this protocol.

inclusion criteria: 1. are ≥18 years of age at the time of randomization 2. subject has a household contact with a confirmed covid-19 cohabiting individual as subject. initial diagnosis of the covid-19 positive individual has been within 3 days of screening. covid-19 positive result (pcr or antigen) must have been performed by an accredited lab or medical professional. current and uninterrupted household contacts were defined as family members or close relatives who had unprotected contact with the index case. 3. subject must have a negative result with the study provided rapid antigen test at baseline and be covid-19 symptom free. 4. are men or non-pregnant women. reproductive and contraceptive agreements and guidance is provided in appendix 2. contraceptive use by men or women should be consistent with local regulations for those participating in clinical studies. 5. understand and agree to comply with planned study procedures 6. agree to the collection of nasopharyngeal swabs 7. the participant or legally authorized representative gives signed informed consent as described in section 10.1.1.2 which includes compliance with the requirements and restrictions listed in the informed consent form (icf) and in this protocol.

inclusion criteria: are ≥18 years of age at the time of randomization subject has a household contact with a confirmed covid-19 cohabiting individual as subject. initial diagnosis of the covid-19 positive individual has been within 3 days of screening. covid-19 positive result (pcr or antigen) must have been performed by an accredited lab or medical professional. current and uninterrupted household contacts were defined as family members or close relatives who had unprotected contact with the index case. subject must have a negative result with the study provided rapid antigen test at baseline and be covid-19 symptom free. are men or non-pregnant women. reproductive and contraceptive agreements and guidance is provided in appendix 2. contraceptive use by men or women should be consistent with local regulations for those participating in clinical studies. understand and agree to comply with planned study procedures agree to the collection of nasopharyngeal swabs the participant or legally authorized representative gives signed informed consent as described in section 10.1.1.2 which includes compliance with the requirements and restrictions listed in the informed consent form (icf) and in this protocol.

inclusion criteria: are ≥18 years of age at the time of randomization subject has a household contact with a confirmed covid-19 cohabiting individual as subject. initial diagnosis of the covid-19 positive individual has been within 3 days of screening. covid-19 positive result (pcr or antigen) must have been performed by an accredited lab or medical professional. current and uninterrupted household contacts were defined as family members or close relatives who had unprotected contact with the index case. subject must have a negative result with the study provided rapid antigen test at baseline and be covid-19 symptom free. are men or non-pregnant women. reproductive and contraceptive agreements and guidance is provided in appendix 2. contraceptive use by men or women should be consistent with local regulations for those participating in clinical studies. understand and agree to comply with planned study procedures agree to the collection of nasopharyngeal swabs the participant or legally authorized representative gives signed informed consent as described in section 10.1.1.2 which includes compliance with the requirements and restrictions listed in the informed consent form (icf) and in this protocol.