1. . positive sars-cov-2 pcror antigen detection test 2. . persons with undocumented hiv status 3. . hiv-infected persons with cd4count \<1 00 cells/mm3and/or viral load \> 1000 copies/ml 4. . known allergy or history of anaphylaxis or other serious adverse reactions to specific covid-19 vaccine constituents 5. . history of capillary leak syndrome, thrombosis with thrombocytopenia syndrome (tts), heparin-induced thrombocytopenia (hit), history of any neurological disorders or seizures including guillain-barré syndrome, with the exception of febrile seizures during childhood 6. . participants with acute illness (this does not include minor illnesses such as diarrhoea or mild upper respiratory tract infection) or body temperature ≥38.0ºc on day 1 will be excluded from randomization at that time but may be rescheduled for randomization and/or vaccination at a later date. 7. . participants who cannot communicate reliably with the investigator 8. . pregnant or breastfeeding 9. . women of childbearing potential who are not on an effective long-acting contraceptive method for at least 21 days prior to enrollment (date of signed informed consent) and not intending to continue contraception for up to 9 months post first vaccination.(see section 10.5.1 below) 10. . prior administration of an investigational coronavirus vaccine (for example, sars-cov-2, sars-cov, middle east respiratory syndrome \[mers-cov\] vaccine), except for participants of the sisonke trial 11. . prior administration of any sars-cov-2 vaccine boost 12. . has a medical, psychiatric, or occupational condition that may pose additional risk as a result of participation, or that could interfere with safety assessments or interpretation of results according to the investigator's judgment 13. . history of harmful substance or alcohol use within the past 2 years. this exclusion does not apply to cannabis use. 14. . receipt of: 1. . systemic immunosuppressants or immune-modifying drugs for \>14 days in total within 6 months prior to the day of randomization (for corticosteroids, ≥20 mg/day prednisone equivalent). topical tacrolimus is allowed if not used within 14 days prior to the day of randomization. inhaled, nasal, and topical steroids are allowed. 2. . intravenous blood products (red cells, platelets, immunoglobulins, monoclonal antibodies specific for sars-cov-2) within 3 months prior to enrollment 3. . experimental vaccine within the past 6 months before first vaccination 4. . any inactivated vaccines received within 14 days prior to first vaccination or planned within 14 days of first vaccination, or live attenuated vaccines received with 30 days prior to the first vaccination or planned within 30 days of the first vaccination. 15. . participated in an interventional clinical study within 28 days prior to the screening visit (day 1) or plans to do so while participating in this study. 16. . employee of the investigator or study site, with direct involvement in the proposed study or other studies under the direction of that investigator or study site, as well as family members of the employees or the investigator.

1. . positive sars-cov-2 pcror antigen detection test 2. . persons with undocumented hiv status 3. . hiv-infected persons with cd4count \<1 00 cells/mm3and/or viral load \> 1000 copies/ml 4. . known allergy or history of anaphylaxis or other serious adverse reactions to specific covid-19 vaccine constituents 5. . history of capillary leak syndrome, thrombosis with thrombocytopenia syndrome (tts), heparin-induced thrombocytopenia (hit), history of any neurological disorders or seizures including guillain-barré syndrome, with the exception of febrile seizures during childhood 6. . participants with acute illness (this does not include minor illnesses such as diarrhoea or mild upper respiratory tract infection) or body temperature ≥38.0ºc on day 1 will be excluded from randomization at that time but may be rescheduled for randomization and/or vaccination at a later date. 7. . participants who cannot communicate reliably with the investigator 8. . pregnant or breastfeeding 9. . women of childbearing potential who are not on an effective long-acting contraceptive method for at least 21 days prior to enrollment (date of signed informed consent) and not intending to continue contraception for up to 9 months post first vaccination.(see section 10.5.1 below) 10. . prior administration of an investigational coronavirus vaccine (for example, sars-cov-2, sars-cov, middle east respiratory syndrome \[mers-cov\] vaccine), except for participants of the sisonke trial 11. . prior administration of any sars-cov-2 vaccine boost 12. . has a medical, psychiatric, or occupational condition that may pose additional risk as a result of participation, or that could interfere with safety assessments or interpretation of results according to the investigator's judgment 13. . history of harmful substance or alcohol use within the past 2 years. this exclusion does not apply to cannabis use. 14. . receipt of: 1. . systemic immunosuppressants or immune-modifying drugs for \>14 days in total within 6 months prior to the day of randomization (for corticosteroids, ≥20 mg/day prednisone equivalent). topical tacrolimus is allowed if not used within 14 days prior to the day of randomization. inhaled, nasal, and topical steroids are allowed. 2. . intravenous blood products (red cells, platelets, immunoglobulins, monoclonal antibodies specific for sars-cov-2) within 3 months prior to enrollment 3. . experimental vaccine within the past 6 months before first vaccination 4. . any inactivated vaccines received within 14 days prior to first vaccination or planned within 14 days of first vaccination, or live attenuated vaccines received with 30 days prior to the first vaccination or planned within 30 days of the first vaccination. 15. . participated in an interventional clinical study within 28 days prior to the screening visit (day 1) or plans to do so while participating in this study. 16. . employee of the investigator or study site, with direct involvement in the proposed study or other studies under the direction of that investigator or study site, as well as family members of the employees or the investigator.

. positive sars-cov-2 pcror antigen detection test . persons with undocumented hiv status . hiv-infected persons with cd4count <1 00 cells/mm3and/or viral load > 1000 copies/ml . known allergy or history of anaphylaxis or other serious adverse reactions to specific covid-19 vaccine constituents . history of capillary leak syndrome, thrombosis with thrombocytopenia syndrome (tts), heparin-induced thrombocytopenia (hit), history of any neurological disorders or seizures including guillain-barré syndrome, with the exception of febrile seizures during childhood . participants with acute illness (this does not include minor illnesses such as diarrhoea or mild upper respiratory tract infection) or body temperature ≥38.0ºc on day 1 will be excluded from randomization at that time but may be rescheduled for randomization and/or vaccination at a later date. . participants who cannot communicate reliably with the investigator . pregnant or breastfeeding . women of childbearing potential who are not on an effective long-acting contraceptive method for at least 21 days prior to enrollment (date of signed informed consent) and not intending to continue contraception for up to 9 months post first vaccination.(see section 10.5.1 below) . prior administration of an investigational coronavirus vaccine (for example, sars-cov-2, sars-cov, middle east respiratory syndrome [mers-cov] vaccine), except for participants of the sisonke trial . prior administration of any sars-cov-2 vaccine boost . has a medical, psychiatric, or occupational condition that may pose additional risk as a result of participation, or that could interfere with safety assessments or interpretation of results according to the investigator's judgment . history of harmful substance or alcohol use within the past 2 years. this exclusion does not apply to cannabis use. . receipt of: . systemic immunosuppressants or immune-modifying drugs for >14 days in total within 6 months prior to the day of randomization (for corticosteroids, ≥20 mg/day prednisone equivalent). topical tacrolimus is allowed if not used within 14 days prior to the day of randomization. inhaled, nasal, and topical steroids are allowed. . intravenous blood products (red cells, platelets, immunoglobulins, monoclonal antibodies specific for sars-cov-2) within 3 months prior to enrollment . experimental vaccine within the past 6 months before first vaccination . any inactivated vaccines received within 14 days prior to first vaccination or planned within 14 days of first vaccination, or live attenuated vaccines received with 30 days prior to the first vaccination or planned within 30 days of the first vaccination. . participated in an interventional clinical study within 28 days prior to the screening visit (day 1) or plans to do so while participating in this study. . employee of the investigator or study site, with direct involvement in the proposed study or other studies under the direction of that investigator or study site, as well as family members of the employees or the investigator.

. positive sars-cov-2 pcror antigen detection test . persons with undocumented hiv status . hiv-infected persons with cd4count <1 00 cells/mm3and/or viral load > 1000 copies/ml . known allergy or history of anaphylaxis or other serious adverse reactions to specific covid-19 vaccine constituents . history of capillary leak syndrome, thrombosis with thrombocytopenia syndrome (tts), heparin-induced thrombocytopenia (hit), history of any neurological disorders or seizures including guillain-barré syndrome, with the exception of febrile seizures during childhood . participants with acute illness (this does not include minor illnesses such as diarrhoea or mild upper respiratory tract infection) or body temperature ≥38.0ºc on day 1 will be excluded from randomization at that time but may be rescheduled for randomization and/or vaccination at a later date. . participants who cannot communicate reliably with the investigator . pregnant or breastfeeding . women of childbearing potential who are not on an effective long-acting contraceptive method for at least 21 days prior to enrollment (date of signed informed consent) and not intending to continue contraception for up to 9 months post first vaccination.(see section 10.5.1 below) . prior administration of an investigational coronavirus vaccine (for example, sars-cov-2, sars-cov, middle east respiratory syndrome [mers-cov] vaccine), except for participants of the sisonke trial . prior administration of any sars-cov-2 vaccine boost . has a medical, psychiatric, or occupational condition that may pose additional risk as a result of participation, or that could interfere with safety assessments or interpretation of results according to the investigator's judgment . history of harmful substance or alcohol use within the past 2 years. this exclusion does not apply to cannabis use. . receipt of: . systemic immunosuppressants or immune-modifying drugs for >14 days in total within 6 months prior to the day of randomization (for corticosteroids, ≥20 mg/day prednisone equivalent). topical tacrolimus is allowed if not used within 14 days prior to the day of randomization. inhaled, nasal, and topical steroids are allowed. . intravenous blood products (red cells, platelets, immunoglobulins, monoclonal antibodies specific for sars-cov-2) within 3 months prior to enrollment . experimental vaccine within the past 6 months before first vaccination . any inactivated vaccines received within 14 days prior to first vaccination or planned within 14 days of first vaccination, or live attenuated vaccines received with 30 days prior to the first vaccination or planned within 30 days of the first vaccination. . participated in an interventional clinical study within 28 days prior to the screening visit (day 1) or plans to do so while participating in this study. . employee of the investigator or study site, with direct involvement in the proposed study or other studies under the direction of that investigator or study site, as well as family members of the employees or the investigator.