A Study to Evaluate the Efficacy, Immune Response, and Safety of a COVID-19 Vaccine in Adults ≥ 18 Years With a Pediatric Expansion in Adolescents (12 to < 18 Years) at Risk for SARS-CoV-2

Open to people ages 12 years and up

Adult Main Study:

1. Adults ≥ 18 years of age at screening who, by virtue of age, race, ethnicity or life circumstances, are considered at substantial risk of exposure to and infection with SARS-CoV-2.
2. Willing and able to give informed consent prior to study enrollment and to comply with study procedures.
3. Participants of childbearing potential (defined as any participant who has experienced menarche and who is NOT surgically sterile [ie, hysterectomy, bilateral tubal ligation, or bilateral oophorectomy] or postmenopausal [defined as amenorrhea at least 12 consecutive months]) must agree to be heterosexually inactive from at least 28 days prior to enrollment and through 3 months after the last vaccination OR agree to consistently use a medically acceptable method of contraception from at least 28 days prior to enrollment and through 3 months after the last vaccination.
4. Is medically stable, as determined by the investigator (based on review of health status, vital signs [to include body temperature], medical history, and targeted physical examination [to include body weight]). Vital signs must be within medically acceptable ranges prior to the first vaccination.
5. Agree to not participate in any other SARS-CoV-2 prevention trial during the study follow-up.

Pediatric Expansion:

1. Pediatric participants 12 to < 18 years of age at screening, determined to be healthy or medically stable by the investigator (based on review of health status, vital signs [to include body temperature], medical history, and targeted physical examination [to include body weight]). Vital signs must be within medically acceptable ranges prior to the first vaccination.
2. Participant and parent(s)/caregiver(s) or legally acceptable representative willing and able to give informed consent and assent, as required, prior to study enrollment and to comply with study procedures.
3. Participants of childbearing potential (defined as any participant who has experienced menarche and who is NOT surgically sterile [ie, hysterectomy, bilateral tubal ligation, or bilateral oophorectomy] must agree to be heterosexually inactive from at least 28 days prior to enrollment and through 3 months after the last vaccination OR agree to consistently use a medically acceptable method of contraception from at least 28 days prior to enrollment and through 3 months after the last vaccination.
4. Agree to not participate in another SARS-CoV-2 prevention trial during the study follow-up

Adult and pediatric participants meeting any of the following criteria will be excluded from the study:

1. Unstable acute or chronic illness. Criteria for unstable medical conditions include:
2. Substantive changes in chronic prescribed medication (change in class or significant change in dose) in the past 2 months.
3. Currently undergoing workup of undiagnosed illness that could lead to a diagnosis of a new condition.
4. Participation in research involving an investigational product (drug/biologic/device) within 45 days prior to the first study vaccination.
5. History of a previous laboratory-confirmed diagnosis of SARS-CoV-2 infection or COVID-19.
6. Received influenza vaccination or any other adult vaccine within 4 days prior to or within 7 days after either study vaccination. Received any vaccine within 4 days prior to first study vaccination or planned receipt of any vaccine before Day 49 (ie, 28 days after second vaccination).
7. Autoimmune or immunodeficiency disease/condition (iatrogenic or congenital) requiring ongoing immunomodulatory therapy.
8. Chronic administration (defined as > 14 continuous days) of immunosuppressants, systemic glucocorticoids, or other immune-modifying drugs causing clinically significant immunocompromise, within 90 days prior to first study vaccination.
9. Received immunoglobulin, blood-derived products, or immunosuppressant drugs within 90 days prior to first study vaccination.
10. Active cancer (malignancy) on therapy within 1 year prior to first study vaccination (with the exception of malignancy cured via excision, at the discretion of the investigator). This criterion is not applicable to participants diagnosed during participation in this trial who accept participation in the Adult Main Study with Booster Amendment.
11. Any known allergies to products contained in the investigational product.
12. . Participants who are breastfeeding, pregnant or who plan to become pregnant within 3 months following last study vaccination.
13. . Any other condition that, in the opinion of the investigator, would pose a health risk to the participant if enrolled or could interfere with evaluation of the trial vaccine or interpretation of study results.
14. . Study team member or first-degree relative of any study team member (inclusive of Sponsor, and study site personnel involved in the study).
15. . Current participation in any other COVID-19 prevention clinical trial.