1. Participant is 18 to 55 years of age, inclusive, or 65 years of age or older on the day of signing the ICF. 2. Participant must have a body mass index (BMI) <30.0 kg/m2. 3. Participant 18 to 55 years of age, inclusive: Participant must be healthy, in the investigator’s clinical judgment, as confirmed by medical history, physical examination, and vital signs performed at screening, and must not have comorbidities related to an increased risk of severe COVID-19, except for smoking, which is allowed. Participant 65 years of age and older: in the investigator’s clinical judgment, participant must be either in good or stable health. 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 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. 4. All 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. 5. 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.

1. Participant is 18 to 55 years of age, inclusive, or 65 years of age or older on the day of signing the ICF. 2. Participant must have a body mass index (BMI) <30.0 kg/m2. 3. Participant 18 to 55 years of age, inclusive: Participant must be healthy, in the investigator’s clinical judgment, as confirmed by medical history, physical examination, and vital signs performed at screening, and must not have comorbidities related to an increased risk of severe COVID-19, except for smoking, which is allowed. Participant 65 years of age and older: in the investigator’s clinical judgment, participant must be either in good or stable health. 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 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. 4. All 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. 5. 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.

1. Participant is 18 to 55 years of age, inclusive, or 65 years of age or older on the day of signing the ICF. 2. Participant must have a body mass index (BMI) <30.0 kg/m2. 3. Participant 18 to 55 years of age, inclusive: Participant must be healthy, in the investigator’s clinical judgment, as confirmed by medical history, physical examination, and vital signs performed at screening, and must not have comorbidities related to an increased risk of severe COVID-19, except for smoking, which is allowed. Participant 65 years of age and older: in the investigator’s clinical judgment, participant must be either in good or stable health. 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 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. 4. All 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. 5. 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. Please refer to the protocol for more info

1. Participant is 18 to 55 years of age, inclusive, or 65 years of age or older on the day of signing the ICF. 2. Participant must have a body mass index (BMI) <30.0 kg/m2. 3. Participant 18 to 55 years of age, inclusive: Participant must be healthy, in the investigator’s clinical judgment, as confirmed by medical history, physical examination, and vital signs performed at screening, and must not have comorbidities related to an increased risk of severe COVID-19, except for smoking, which is allowed. Participant 65 years of age and older: in the investigator’s clinical judgment, participant must be either in good or stable health. 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 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. 4. All 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. 5. 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. Please refer to the protocol for more info

1. Participant is 18 to 55 years of age, inclusive, or 65 years of age or older on the day of signing the ICF. 2. Participant must have a body mass index (BMI) <30.0 kg/m2. 3. Participant 18 to 55 years of age, inclusive: Participant must be healthy, in the investigator’s clinical judgment, as confirmed by medical history, physical examination, and vital signs performed at screening, and must not have comorbidities related to an increased risk of severe COVID-19, except for smoking, which is allowed. Participant 65 years of age and older: in the investigator’s clinical judgment, participant must be either in good or stable health. 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 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. 4. All 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. 5. 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.

1. Participant is 18 to 55 years of age, inclusive, or 65 years of age or older on the day of signing the ICF. 2. Participant must have a body mass index (BMI) <30.0 kg/m2. 3. Participant 18 to 55 years of age, inclusive: Participant must be healthy, in the investigator’s clinical judgment, as confirmed by medical history, physical examination, and vital signs performed at screening, and must not have comorbidities related to an increased risk of severe COVID-19, except for smoking, which is allowed. Participant 65 years of age and older: in the investigator’s clinical judgment, participant must be either in good or stable health. 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 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. 4. All 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. 5. 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.