COVID-19 Prophylaxis South Africa (COVER HCW)

Inclusion Criteria: 1. Age ≥18 years of age, inclusive, at the time of signing the informed consent. 2. Willing and able to provide informed consent via an electronic process. 3. Healthcare worker employed at a participating institution that has been identified as high-risk for SARS-CoV-2 exposure (may include doctors, nurses, nurse aids, radiographers, physiotherapists, phlebotomists, technicians, porters, cleaners, laboratory or other personnel identified as being at high risk of exposure), CHW involved in the collection of samples for the identification of SARS-CoV-2 through PCR, and inner city inhabitants at high risk for SARS-CoV-2 exposure due to the nature of their work and frequent use of public transport (may include essential services employees such as fire fighters, law enforcement officers, grocery store employees; and non healthcare workers using public transport at least three times a week). 4. Women of reproductive potential must be using a highly effective method of contraception prior to enrolment or must be willing to start a method at enrolment and continue its use throughout the duration of the study. 5. Body weight ≥45 kg. 6. Access to reliable video conference, telephone, direct/text messaging, or other device permitting real-time, reliable information transfer. Exclusion Criteria: 1. Pregnant or lactating women. 2. PCR and/or serology confirmed SARS-Cov-2 infection at screening. 3. Current symptoms of COVID-19 disease (including, but not limited to, fever or chills, cough, myalgia, sore throat, shortness of breath, or new onset of anosmia or ageusia, or diarrhea). 4. Self-reported presence or history of any of the following conditions: * Chronic kidney disease (Stage IV or receiving dialysis) * Cirrhosis (Child-Pugh Class B or greater) * Porphyria cutanea tarda. 5. Currently on treatment for epilepsy or other seizure disorder. 6. Currently on treatment with a protease inhibitor-based antiretroviral regimen, or efavirenz, or on treatment with amiodarone, carbamazepine, phenobarbitone, phenytoin, primidone, rifampicin,St. John's wort or any herbal products which may potentially decrease the concentration of the IMP. 7. Known hypersensitivity or specific contraindications to the use of any of the active drugs in the treatment arms or similar compounds. 8. Current enrolment in another COVID-19 prevention trial. 9. History of alcohol abuse within the last 6 months. 10. Having history or have risk factors for brady-arrhythmias (those with undiagnosed cardiac conditions). 11. History of malignancies in the last 5 years, excluding in-situ or non-invasive malignancies. 12. Concurrent or recent (within 3 months) participation in other research with a compound likely to interfere with any of the investigational products. 13. Any surgical or medical condition which might significantly alter the absorption, distribution, metabolism, or excretion of drugs, or which may jeopardize the safety of the volunteer or the objectives of the study. The Investigator should make this determination in consideration of the volunteer's medical history. 14. Inability or unwillingness to be followed up for the study period. 15. Personnel (e.g. investigator, sub-investigator, research assistant, pharmacist, study coordinator or anyone mentioned in the delegation log) directly involved in the conduct of the study. (Personnel employed at a study site, but not directly involved in the conduct of the study, who would like to participate in the study, may only do so if they are enrolled in the study through a different site at which they are not employed.) 16. Participant is judged by the Investigator to be at significant risk of failing to comply with the provisions of the protocol as to cause harm to self or seriously interfere with the validity of the study results. 17. Confirmed vaccination against SARS-Cov-2.