inclusion criteria: * participant must sign an informed consent form (icf) indicating that he or she understands the purpose, procedures and potential risks and benefits of the study, and is willing to participate in the study * participant must be healthy, in the investigator's clinical judgment, as confirmed by medical history, physical examination, and vital signs performed at screening. participant may have underlying illnesses, as long as the symptoms and signs are medically controlled and not considered to be comorbidities related to an increased risk of severe coronavirus disease 2019 (covid-19), except for smoking, which is allowed. if on medication for a condition, the medication dose must have been stable for at least 12 weeks preceding vaccination and expected to remain stable for the duration of the study. participant will be included on the basis of physical examination, medical history, and vital signs * all female participants of childbearing potential must: a) have a negative highly sensitive urine pregnancy test at screening; b) have a negative highly sensitive urine pregnancy test immediately prior to each study vaccine administration * participant agrees to not donate bone marrow, blood, and blood products from the first study vaccine administration until 3 months after receiving the last dose of study vaccine * participant must be willing to provide verifiable identification, has means to be contacted and to contact the investigator during the study

inclusion criteria: * participant must sign an informed consent form (icf) indicating that he or she understands the purpose, procedures and potential risks and benefits of the study, and is willing to participate in the study * participant must be healthy, in the investigator's clinical judgment, as confirmed by medical history, physical examination, and vital signs performed at screening. participant may have underlying illnesses, as long as the symptoms and signs are medically controlled and not considered to be comorbidities related to an increased risk of severe coronavirus disease 2019 (covid-19), except for smoking, which is allowed. if on medication for a condition, the medication dose must have been stable for at least 12 weeks preceding vaccination and expected to remain stable for the duration of the study. participant will be included on the basis of physical examination, medical history, and vital signs * all female participants of childbearing potential must: a) have a negative highly sensitive urine pregnancy test at screening; b) have a negative highly sensitive urine pregnancy test immediately prior to each study vaccine administration * participant agrees to not donate bone marrow, blood, and blood products from the first study vaccine administration until 3 months after receiving the last dose of study vaccine * participant must be willing to provide verifiable identification, has means to be contacted and to contact the investigator during the study

inclusion criteria: participant must sign an informed consent form (icf) indicating that he or she understands the purpose, procedures and potential risks and benefits of the study, and is willing to participate in the study participant must be healthy, in the investigator's clinical judgment, as confirmed by medical history, physical examination, and vital signs performed at screening. participant may have underlying illnesses, as long as the symptoms and signs are medically controlled and not considered to be comorbidities related to an increased risk of severe coronavirus disease 2019 (covid-19), except for smoking, which is allowed. if on medication for a condition, the medication dose must have been stable for at least 12 weeks preceding vaccination and expected to remain stable for the duration of the study. participant will be included on the basis of physical examination, medical history, and vital signs all female participants of childbearing potential must: a) have a negative highly sensitive urine pregnancy test at screening; b) have a negative highly sensitive urine pregnancy test immediately prior to each study vaccine administration participant agrees to not donate bone marrow, blood, and blood products from the first study vaccine administration until 3 months after receiving the last dose of study vaccine participant must be willing to provide verifiable identification, has means to be contacted and to contact the investigator during the study

inclusion criteria: participant must sign an informed consent form (icf) indicating that he or she understands the purpose, procedures and potential risks and benefits of the study, and is willing to participate in the study participant must be healthy, in the investigator's clinical judgment, as confirmed by medical history, physical examination, and vital signs performed at screening. participant may have underlying illnesses, as long as the symptoms and signs are medically controlled and not considered to be comorbidities related to an increased risk of severe coronavirus disease 2019 (covid-19), except for smoking, which is allowed. if on medication for a condition, the medication dose must have been stable for at least 12 weeks preceding vaccination and expected to remain stable for the duration of the study. participant will be included on the basis of physical examination, medical history, and vital signs all female participants of childbearing potential must: a) have a negative highly sensitive urine pregnancy test at screening; b) have a negative highly sensitive urine pregnancy test immediately prior to each study vaccine administration participant agrees to not donate bone marrow, blood, and blood products from the first study vaccine administration until 3 months after receiving the last dose of study vaccine participant must be willing to provide verifiable identification, has means to be contacted and to contact the investigator during the study