inclusion criteria: all participants must have read, understood, and signed the informed consent form (icf). participants of either gender aged 56 years or older at screening. medically stable such that, according to the judgment of the investigator, hospitalization within the study period is not anticipated and the participant appears likely to be able to remain on study through the end of protocol-specified follow-up. participant has a body mass index (bmi) of 18.0-35.0 kg/m2, inclusive, at screening (visit 0). must be able to attend all visits of the study and comply with all study procedures, including daily completion of the e-diary for 7 days following each vaccination. women of childbearing potential (wocbp), who are sexually active with a man, must be able and willing to use at least 1 highly effective method of contraception (i.e. implant contraceptive, intra-uterine device (iud) containing either copper or levonorgestrel, male sterilization [vasectomy], female sterilization, injectable contraceptive, oral contraceptive pill, vaginal contraceptive ring, barrier type of birth control measure) from study start until a minimum of 3 months after the last dose of study vaccine (i.e. 3 months after second dose or 3 months after booster dose). wocbps must have a negative pregnancy test prior to each vaccination.

inclusion criteria: all participants must have read, understood, and signed the informed consent form (icf). participants of either gender aged 56 years or older at screening. medically stable such that, according to the judgment of the investigator, hospitalization within the study period is not anticipated and the participant appears likely to be able to remain on study through the end of protocol-specified follow-up. participant has a body mass index (bmi) of 18.0-35.0 kg/m2, inclusive, at screening (visit 0). must be able to attend all visits of the study and comply with all study procedures, including daily completion of the e-diary for 7 days following each vaccination. women of childbearing potential (wocbp), who are sexually active with a man, must be able and willing to use at least 1 highly effective method of contraception (i.e. implant contraceptive, intra-uterine device (iud) containing either copper or levonorgestrel, male sterilization [vasectomy], female sterilization, injectable contraceptive, oral contraceptive pill, vaginal contraceptive ring, barrier type of birth control measure) from study start until a minimum of 3 months after the last dose of study vaccine (i.e. 3 months after second dose or 3 months after booster dose). wocbps must have a negative pregnancy test prior to each vaccination.

inclusion criteria: all participants must have read, understood, and signed the informed consent form (icf). participants of either gender aged 56 years or older at screening. medically stable such that, according to the judgment of the investigator, hospitalization within the study period is not anticipated and the participant appears likely to be able to remain on study through the end of protocol-specified follow-up. participant has a body mass index (bmi) of 18.0-35.0 kg/m2, inclusive, at screening (visit 0). must be able to attend all visits of the study and comply with all study procedures, including daily completion of the e-diary for 7 days following each vaccination. women of childbearing potential (wocbp), who are sexually active with a man, must be able and willing to use at least 1 highly effective method of contraception (i.e. implant contraceptive, intra-uterine device (iud) containing either copper or levonorgestrel, male sterilization [vasectomy], female sterilization, injectable contraceptive, oral contraceptive pill, vaginal contraceptive ring, barrier type of birth control measure) from study start until a minimum of 3 months after the last dose of study vaccine. wocbps must have a negative pregnancy test prior to each vaccination.

inclusion criteria: all participants must have read, understood, and signed the informed consent form (icf). participants of either gender aged 56 years or older at screening. medically stable such that, according to the judgment of the investigator, hospitalization within the study period is not anticipated and the participant appears likely to be able to remain on study through the end of protocol-specified follow-up. participant has a body mass index (bmi) of 18.0-35.0 kg/m2, inclusive, at screening (visit 0). must be able to attend all visits of the study and comply with all study procedures, including daily completion of the e-diary for 7 days following each vaccination. women of childbearing potential (wocbp), who are sexually active with a man, must be able and willing to use at least 1 highly effective method of contraception (i.e. implant contraceptive, intra-uterine device (iud) containing either copper or levonorgestrel, male sterilization [vasectomy], female sterilization, injectable contraceptive, oral contraceptive pill, vaginal contraceptive ring, barrier type of birth control measure) from study start until a minimum of 3 months after the last dose of study vaccine. wocbps must have a negative pregnancy test prior to each vaccination.

inclusion criteria: parent(s)/legal representative(s) and participants who have an understanding of the study and its procedures as explained by the investigator and agree to its provisions: cohort 1: participants of either gender aged 56 years or older at screening. cohort 2: participants of either gender aged 12 years or older at screening. medically stable such that, according to the judgment of the investigator, hospitalization within the study period is not anticipated and the participant appears likely to be able to remain on study through the end of protocol-specified follow-up. participant has a body mass index (bmi) of 18.0-35.0 kg/m2, inclusive, at screening. must be able to attend all visits of the study and comply with all study procedures, including daily completion of the e-diary for 7 days following each vaccination. women of childbearing potential (wocbp), who are sexually active with a man, must be able and willing to use at least 1 highly effective method of contraception from study start until a minimum of 3 months after the last dose of study vaccine. wocbps must have a negative pregnancy test prior to each vaccination.

inclusion criteria: parent(s)/legal representative(s) and participants who have an understanding of the study and its procedures as explained by the investigator and agree to its provisions: cohort 1: participants of either gender aged 56 years or older at screening. cohort 2: participants of either gender aged 12 years or older at screening. medically stable such that, according to the judgment of the investigator, hospitalization within the study period is not anticipated and the participant appears likely to be able to remain on study through the end of protocol-specified follow-up. participant has a body mass index (bmi) of 18.0-35.0 kg/m2, inclusive, at screening. must be able to attend all visits of the study and comply with all study procedures, including daily completion of the e-diary for 7 days following each vaccination. women of childbearing potential (wocbp), who are sexually active with a man, must be able and willing to use at least 1 highly effective method of contraception from study start until a minimum of 3 months after the last dose of study vaccine. wocbps must have a negative pregnancy test prior to each vaccination.

inclusion criteria: 1. parent(s)/legal representative(s) and participants who have an understanding of the study and its procedures as explained by the investigator and agree to its provisions: 2. cohort 1: participants of either gender aged 56 years or older at screening. cohort 2: participants of either gender aged 12 years or older at screening. 3. medically stable such that, according to the judgment of the investigator, hospitalization within the study period is not anticipated and the participant appears likely to be able to remain on study through the end of protocol-specified follow-up. 4. participant has a body mass index (bmi) of 18.0-35.0 kg/m2, inclusive, at screening. 5. must be able to attend all visits of the study and comply with all study procedures, including daily completion of the e-diary for 7 days following each vaccination. 6. women of childbearing potential (wocbp), who are sexually active with a man, must be able and willing to use at least 1 highly effective method of contraception from study start until a minimum of 3 months after the last dose of study vaccine. 7. wocbps must have a negative pregnancy test prior to each vaccination.

inclusion criteria: 1. parent(s)/legal representative(s) and participants who have an understanding of the study and its procedures as explained by the investigator and agree to its provisions: 2. cohort 1: participants of either gender aged 56 years or older at screening. cohort 2: participants of either gender aged 12 years or older at screening. 3. medically stable such that, according to the judgment of the investigator, hospitalization within the study period is not anticipated and the participant appears likely to be able to remain on study through the end of protocol-specified follow-up. 4. participant has a body mass index (bmi) of 18.0-35.0 kg/m2, inclusive, at screening. 5. must be able to attend all visits of the study and comply with all study procedures, including daily completion of the e-diary for 7 days following each vaccination. 6. women of childbearing potential (wocbp), who are sexually active with a man, must be able and willing to use at least 1 highly effective method of contraception from study start until a minimum of 3 months after the last dose of study vaccine. 7. wocbps must have a negative pregnancy test prior to each vaccination.