1. known history of sars-cov-2 or sars-cov-1 infection; 2. previously received an investigational coronavirus vaccine; 3. previously received a sars-cov-2 monoclonal antibody; 4. current or planned simultaneous participation in another interventional study; 5. a history of anaphylaxis, urticaria, or other significant adverse reaction requiring medical intervention after receipt of a covid-19 vaccine, or otherwise have a contraindication to one of the available study vaccines per the approved label; 6. individuals who are immunocompromised (e.g. active leukaemia or lymphoma, generalised malignancy, aplastic anaemia, solid organ transplant, bone marrow transplant, current radiation therapy congenital immunodeficiency, hiv/aids with cd4 lymphocyte count \< 200 and patients on immunosuppressant medications); 7. received systemic immunosuppressants or immune-modifying drugs for \>14 days in total within 6 months prior to screening (for corticosteroids \>/= 20 milligram per day of prednisone equivalent). topical tacrolimus is allowed if not used within 14 days prior to day 1; 8. individuals who are pregnant or breast feeding; 9. chronic illness that, in the opinion of the study team, is at a stage where it might interfere with trial conduct or completion; 10. deprived of freedom by an administrative or court order, or in an emergency setting, or hospitalised involuntarily; 11. current alcohol abuse or drug addiction that might interfere with the ability to comply with trial procedures in the opinion of the study team; 12. moderate or severe acute illness/infection (according to study team's judgement) on the day of vaccination, or febrile illness (temperature ≥ 37.5°c). a prospective participant should not be included in the study until the condition has resolved or the febrile event has subsided. for phase d of the trial exclusion criteria 1 and 4 will no longer apply: exclusion criteria 1 is no longer relevant as it not a consideration in moh recommendations for covid-19 booster vaccination, and exclusion criteria 4 because of the broad recommendations from moh for keeping up to date with covid-19 boosters.

1. known history of sars-cov-2 or sars-cov-1 infection; 2. previously received an investigational coronavirus vaccine; 3. previously received a sars-cov-2 monoclonal antibody; 4. current or planned simultaneous participation in another interventional study; 5. a history of anaphylaxis, urticaria, or other significant adverse reaction requiring medical intervention after receipt of a covid-19 vaccine, or otherwise have a contraindication to one of the available study vaccines per the approved label; 6. individuals who are immunocompromised (e.g. active leukaemia or lymphoma, generalised malignancy, aplastic anaemia, solid organ transplant, bone marrow transplant, current radiation therapy congenital immunodeficiency, hiv/aids with cd4 lymphocyte count \< 200 and patients on immunosuppressant medications); 7. received systemic immunosuppressants or immune-modifying drugs for \>14 days in total within 6 months prior to screening (for corticosteroids \>/= 20 milligram per day of prednisone equivalent). topical tacrolimus is allowed if not used within 14 days prior to day 1; 8. individuals who are pregnant or breast feeding; 9. chronic illness that, in the opinion of the study team, is at a stage where it might interfere with trial conduct or completion; 10. deprived of freedom by an administrative or court order, or in an emergency setting, or hospitalised involuntarily; 11. current alcohol abuse or drug addiction that might interfere with the ability to comply with trial procedures in the opinion of the study team; 12. moderate or severe acute illness/infection (according to study team's judgement) on the day of vaccination, or febrile illness (temperature ≥ 37.5°c). a prospective participant should not be included in the study until the condition has resolved or the febrile event has subsided. for phase d of the trial exclusion criteria 1 and 4 will no longer apply: exclusion criteria 1 is no longer relevant as it not a consideration in moh recommendations for covid-19 booster vaccination, and exclusion criteria 4 because of the broad recommendations from moh for keeping up to date with covid-19 boosters.

1. known history of sars-cov-2 or sars-cov-1 infection; 2. previously received an investigational coronavirus vaccine; 3. previously received a sars-cov-2 monoclonal antibody; 4. current or planned simultaneous participation in another interventional study; 5. a history of anaphylaxis, urticaria, or other significant adverse reaction requiring medical intervention after receipt of a covid-19 vaccine, or otherwise have a contraindication to one of the available study vaccines per the approved label; 6. individuals who are immunocompromised (e.g. active leukaemia or lymphoma, generalised malignancy, aplastic anaemia, solid organ transplant, bone marrow transplant, current radiation therapy congenital immunodeficiency, hiv/aids with cd4 lymphocyte count \< 200 and patients on immunosuppressant medications); 7. received systemic immunosuppressants or immune-modifying drugs for \>14 days in total within 6 months prior to screening (for corticosteroids \>/= 20 milligram per day of prednisone equivalent). topical tacrolimus is allowed if not used within 14 days prior to day 1; 8. individuals who are pregnant or breast feeding; 9. chronic illness that, in the opinion of the study team, is at a stage where it might interfere with trial conduct or completion; 10. deprived of freedom by an administrative or court order, or in an emergency setting, or hospitalised involuntarily; 11. current alcohol abuse or drug addiction that might interfere with the ability to comply with trial procedures in the opinion of the study team; 12. moderate or severe acute illness/infection (according to study team's judgement) on the day of vaccination, or febrile illness (temperature ≥ 37.5°c). a prospective participant should not be included in the study until the condition has resolved or the febrile event has subsided.

1. known history of sars-cov-2 or sars-cov-1 infection; 2. previously received an investigational coronavirus vaccine; 3. previously received a sars-cov-2 monoclonal antibody; 4. current or planned simultaneous participation in another interventional study; 5. a history of anaphylaxis, urticaria, or other significant adverse reaction requiring medical intervention after receipt of a covid-19 vaccine, or otherwise have a contraindication to one of the available study vaccines per the approved label; 6. individuals who are immunocompromised (e.g. active leukaemia or lymphoma, generalised malignancy, aplastic anaemia, solid organ transplant, bone marrow transplant, current radiation therapy congenital immunodeficiency, hiv/aids with cd4 lymphocyte count \< 200 and patients on immunosuppressant medications); 7. received systemic immunosuppressants or immune-modifying drugs for \>14 days in total within 6 months prior to screening (for corticosteroids \>/= 20 milligram per day of prednisone equivalent). topical tacrolimus is allowed if not used within 14 days prior to day 1; 8. individuals who are pregnant or breast feeding; 9. chronic illness that, in the opinion of the study team, is at a stage where it might interfere with trial conduct or completion; 10. deprived of freedom by an administrative or court order, or in an emergency setting, or hospitalised involuntarily; 11. current alcohol abuse or drug addiction that might interfere with the ability to comply with trial procedures in the opinion of the study team; 12. moderate or severe acute illness/infection (according to study team's judgement) on the day of vaccination, or febrile illness (temperature ≥ 37.5°c). a prospective participant should not be included in the study until the condition has resolved or the febrile event has subsided.

known history of sars-cov-2 or sars-cov-1 infection; previously received an investigational coronavirus vaccine; previously received a sars-cov-2 monoclonal antibody; current or planned simultaneous participation in another interventional study; a history of anaphylaxis, urticaria, or other significant adverse reaction requiring medical intervention after receipt of a covid-19 vaccine, or otherwise have a contraindication to one of the available study vaccines per the approved label; individuals who are immunocompromised (e.g. active leukaemia or lymphoma, generalised malignancy, aplastic anaemia, solid organ transplant, bone marrow transplant, current radiation therapy congenital immunodeficiency, hiv/aids with cd4 lymphocyte count < 200 and patients on immunosuppressant medications); received systemic immunosuppressants or immune-modifying drugs for >14 days in total within 6 months prior to screening (for corticosteroids >/= 20 milligram per day of prednisone equivalent). topical tacrolimus is allowed if not used within 14 days prior to day 1; individuals who are pregnant or breast feeding; chronic illness that, in the opinion of the study team, is at a stage where it might interfere with trial conduct or completion; deprived of freedom by an administrative or court order, or in an emergency setting, or hospitalised involuntarily; current alcohol abuse or drug addiction that might interfere with the ability to comply with trial procedures in the opinion of the study team; moderate or severe acute illness/infection (according to study team's judgement) on the day of vaccination, or febrile illness (temperature ≥ 37.5°c). a prospective participant should not be included in the study until the condition has resolved or the febrile event has subsided.

known history of sars-cov-2 or sars-cov-1 infection; previously received an investigational coronavirus vaccine; previously received a sars-cov-2 monoclonal antibody; current or planned simultaneous participation in another interventional study; a history of anaphylaxis, urticaria, or other significant adverse reaction requiring medical intervention after receipt of a covid-19 vaccine, or otherwise have a contraindication to one of the available study vaccines per the approved label; individuals who are immunocompromised (e.g. active leukaemia or lymphoma, generalised malignancy, aplastic anaemia, solid organ transplant, bone marrow transplant, current radiation therapy congenital immunodeficiency, hiv/aids with cd4 lymphocyte count < 200 and patients on immunosuppressant medications); received systemic immunosuppressants or immune-modifying drugs for >14 days in total within 6 months prior to screening (for corticosteroids >/= 20 milligram per day of prednisone equivalent). topical tacrolimus is allowed if not used within 14 days prior to day 1; individuals who are pregnant or breast feeding; chronic illness that, in the opinion of the study team, is at a stage where it might interfere with trial conduct or completion; deprived of freedom by an administrative or court order, or in an emergency setting, or hospitalised involuntarily; current alcohol abuse or drug addiction that might interfere with the ability to comply with trial procedures in the opinion of the study team; moderate or severe acute illness/infection (according to study team's judgement) on the day of vaccination, or febrile illness (temperature ≥ 37.5°c). a prospective participant should not be included in the study until the condition has resolved or the febrile event has subsided.