inclusion criteria: * participant must be 18 years of age and older, at the time of signing the informed consent. * participants who are healthy or medically stable as determined by medical evaluation including medical history, physical examination, clinical laboratory tests, and medical judgement of the investigator. * participants who are able to attend all scheduled visits and comply with all study procedures. * participants who received primary vaccination of 1 of 6 different who eua qualified covid-19 vaccine (mrna-1273, chadox1 ncov-19, ad26.cov2.s, bnt162b2, bbibp-corv, coronavac) at least 12 weeks prior to study vaccination, and with no history of other covid-19 vaccination, including booster doses. * participants who have a qualitative test result for antibody to sars-cov-2 nucleocapsid proteins at screening for assessment of previous sars-cov-2 infection * female participants of childbearing potential must agree to be heterosexually inactive, or agree to consistently use at least one acceptable method of contraception from at least 4 weeks prior to the study vaccination to 12 weeks after the study vaccination * female participants with a negative urine or serum pregnancy test at screening. * capable of giving signed informed consent as described in appendix 10.1.3 which includes compliance with the requirements and restrictions listed in the informed consent form (icf) and in this protocol.

inclusion criteria: * participant must be 18 years of age and older, at the time of signing the informed consent. * participants who are healthy or medically stable as determined by medical evaluation including medical history, physical examination, clinical laboratory tests, and medical judgement of the investigator. * participants who are able to attend all scheduled visits and comply with all study procedures. * participants who received primary vaccination of 1 of 6 different who eua qualified covid-19 vaccine (mrna-1273, chadox1 ncov-19, ad26.cov2.s, bnt162b2, bbibp-corv, coronavac) at least 12 weeks prior to study vaccination, and with no history of other covid-19 vaccination, including booster doses. * participants who have a qualitative test result for antibody to sars-cov-2 nucleocapsid proteins at screening for assessment of previous sars-cov-2 infection * female participants of childbearing potential must agree to be heterosexually inactive, or agree to consistently use at least one acceptable method of contraception from at least 4 weeks prior to the study vaccination to 12 weeks after the study vaccination * female participants with a negative urine or serum pregnancy test at screening. * capable of giving signed informed consent as described in appendix 10.1.3 which includes compliance with the requirements and restrictions listed in the informed consent form (icf) and in this protocol.

inclusion criteria: participant must be 18 years of age and older, at the time of signing the informed consent. participants who are healthy or medically stable as determined by medical evaluation including medical history, physical examination, clinical laboratory tests, and medical judgement of the investigator. participants who are able to attend all scheduled visits and comply with all study procedures. participants who received primary vaccination of 1 of 6 different who eua qualified covid-19 vaccine (mrna-1273, chadox1 ncov-19, ad26.cov2.s, bnt162b2, bbibp-corv, coronavac) at least 12 weeks prior to study vaccination, and with no history of other covid-19 vaccination, including booster doses. participants who have a qualitative test result for antibody to sars-cov-2 nucleocapsid proteins at screening for assessment of previous sars-cov-2 infection female participants of childbearing potential must agree to be heterosexually inactive, or agree to consistently use at least one acceptable method of contraception from at least 4 weeks prior to the study vaccination to 12 weeks after the study vaccination female participants with a negative urine or serum pregnancy test at screening. capable of giving signed informed consent as described in appendix 10.1.3 which includes compliance with the requirements and restrictions listed in the informed consent form (icf) and in this protocol.

inclusion criteria: participant must be 18 years of age and older, at the time of signing the informed consent. participants who are healthy or medically stable as determined by medical evaluation including medical history, physical examination, clinical laboratory tests, and medical judgement of the investigator. participants who are able to attend all scheduled visits and comply with all study procedures. participants who received primary vaccination of 1 of 6 different who eua qualified covid-19 vaccine (mrna-1273, chadox1 ncov-19, ad26.cov2.s, bnt162b2, bbibp-corv, coronavac) at least 12 weeks prior to study vaccination, and with no history of other covid-19 vaccination, including booster doses. participants who have a qualitative test result for antibody to sars-cov-2 nucleocapsid proteins at screening for assessment of previous sars-cov-2 infection female participants of childbearing potential must agree to be heterosexually inactive, or agree to consistently use at least one acceptable method of contraception from at least 4 weeks prior to the study vaccination to 12 weeks after the study vaccination female participants with a negative urine or serum pregnancy test at screening. capable of giving signed informed consent as described in appendix 10.1.3 which includes compliance with the requirements and restrictions listed in the informed consent form (icf) and in this protocol.

inclusion criteria: participant must be 18 years of age and older, at the time of signing the informed consent. participants who are healthy or medically stable as determined by medical evaluation including medical history, physical examination, clinical laboratory tests, and medical judgement of the investigator. participants who are able to attend all scheduled visits and comply with all study procedures. participants who received primary vaccination of 1 of 6 different who eua qualified covid-19 vaccine (mrna-1273, chadox1 ncov-19, ad26.cov2.s, bnt162b2, bbibp-corv, coronavac) at least 12 weeks prior to study vaccination, and with no history of other covid-19 vaccination, including booster doses. participants who have a qualitative test result for antibody to sars-cov-2 nucleocapsid proteins at screening for confirmation of previous sars-cov-2 infection female participants of childbearing potential must agree to be heterosexually inactive, or agree to consistently use at least one acceptable method of contraception from at least 4 weeks prior to the study vaccination to 12 weeks after the study vaccination female participants with a negative urine or serum pregnancy test at screening. capable of giving signed informed consent as described in appendix 10.1.3 which includes compliance with the requirements and restrictions listed in the informed consent form (icf) and in this protocol.

inclusion criteria: participant must be 18 years of age and older, at the time of signing the informed consent. participants who are healthy or medically stable as determined by medical evaluation including medical history, physical examination, clinical laboratory tests, and medical judgement of the investigator. participants who are able to attend all scheduled visits and comply with all study procedures. participants who received primary vaccination of 1 of 6 different who eua qualified covid-19 vaccine (mrna-1273, chadox1 ncov-19, ad26.cov2.s, bnt162b2, bbibp-corv, coronavac) at least 12 weeks prior to study vaccination, and with no history of other covid-19 vaccination, including booster doses. participants who have a qualitative test result for antibody to sars-cov-2 nucleocapsid proteins at screening for confirmation of previous sars-cov-2 infection female participants of childbearing potential must agree to be heterosexually inactive, or agree to consistently use at least one acceptable method of contraception from at least 4 weeks prior to the study vaccination to 12 weeks after the study vaccination female participants with a negative urine or serum pregnancy test at screening. capable of giving signed informed consent as described in appendix 10.1.3 which includes compliance with the requirements and restrictions listed in the informed consent form (icf) and in this protocol.