A Study of an Epstein-Barr Virus (EBV) Candidate Vaccine, mRNA-1189, in 10- to 30-Year-Old Healthy Adolescents and Adults

Inclusion Criteria:

• According to the assessment of the investigator, is in good general health and cancomply with study procedures.

Part A: Healthy adult from 18 to 30 years of age (inclusive) at the time of consent (Screening Visit, Day 0).

Part B:

Healthy baseline EBV-seronegative adolescents from 12 to <18 years of age at the time of consent (Screening Visit, Day 0).

Part C:

Healthy adolescents and adults from 10 to 21 years of age (inclusive) at the time of consent (Screening Visit, Day 0).

Exclusion Criteria:

• Has had significant exposure to someone with severe acute respiratory syndromecoronavirus 2 (SARS-CoV-2) infection or COVID-19 in the past 14 days prior to thescreening visit, if the participant has not been fully vaccinated against COVID-19at least 14 days prior to the screening visit.

• Has symptomatic acute or chronic illness requiring ongoing medical or surgical care,to include changes in medication in the past 2 months indicating that chronicillness/disease is not stable (at the discretion of the investigator).

• Significant, progressive, unstable or uncontrolled clinical condition, including anycondition that may affect participant safety, assessment of study endpoints,assessment of immune response, or adherence to study procedures per investigatorjudgement.

• Has a history of myocarditis, and/or pericarditis.

• Has received or plans to receive any licensed or authorized vaccine, to includeCOVID-19 vaccines, ≤28 days prior to the first injection (Day 1) or plans to receivea licensed vaccine within 28 days before or after any study vaccine injection, withthe exception of licensed influenza vaccines, which may be received more than 14days before or after any study vaccine injection.

Note: Other inclusion and exclusion criteria may apply.