Healthy adults aged 18-65 years. Documented result of not being infected with HIV (including screening by a rapid HIV antibody test) within two weeks of randomization into the study for Group-1 and Group-2 participants only. Able and willing (in the Investigator’s opinion) to comply with all study requirements. Willing to allow investigators review available medical records, and review all medical and laboratory records if participant is admitted to hospital with respiratory tract infection suspected or confirmed to be COVID-19. For females only, willingness to practice continuous effective contraception during the study and a negative pregnancy test on the day(s) of screening (within 14 days of randomization) or vaccination. For Group-3 only (i.e. HIV-infected), need to have been on anti-retroviral treatment for at least three months and HIV-1 viral load is <1,000 copies/ml within two weeks of randomization. Agreement to refrain from blood donation during the course of the study. Provide written informed consent.

Healthy adults aged 18-65 years. Documented result of not being infected with HIV (including screening by a rapid HIV antibody test) within two weeks of randomization into the study for Group-1 and Group-2 participants only. Able and willing (in the Investigator’s opinion) to comply with all study requirements. Willing to allow investigators review available medical records, and review all medical and laboratory records if participant is admitted to hospital with respiratory tract infection suspected or confirmed to be COVID-19. For females only, willingness to practice continuous effective contraception during the study and a negative pregnancy test on the day(s) of screening (within 14 days of randomization) or vaccination. For Group-3 only (i.e. HIV-infected), need to have been on anti-retroviral treatment for at least three months and HIV-1 viral load is <1,000 copies/ml within two weeks of randomization. Agreement to refrain from blood donation during the course of the study. Provide written informed consent.