A Study of an Epstein-Barr Virus (EBV) Candidate Vaccine, mRNA-1189 in Healthy Adults 18 to 30 Years of Age

Inclusion Criteria: * Healthy as determined by medical evaluation including medical history and physical examination. * Participants who are assigned female at birth or could become pregnant are eligible to participate if the participant is not pregnant or breast/chest feeding. Exclusion Criteria: * Have undergone surgical procedures within 7 days prior to Day 1 or Day 57 or are scheduled to undergo a surgical procedure within 28 days after study intervention administration. * Reported history of congenital or acquired immunodeficiency, immunosuppressive condition, asplenia, or recurrent severe infectious disease. * Received corticosteroids at ≥10 milligrams per day (mg/day) of prednisone or equivalent for \>14 days in total within 90 days prior to Day 1 or is anticipating the need for corticosteroids at any time during the study. * Received systemic immunosuppressive treatment, including long-acting biological therapies that affect immune responses, within 180 days prior to Day 1 or plans to do so during the study. * Received or plans to receive any nonstudy vaccine from 28 days prior to first dose/Day 1 up to 28 days after the second dose/Day 57. * History of myocarditis, pericarditis, or myopericarditis prior to Day 1. * Has previously received an investigational EBV vaccine. Note: Other inclusion and exclusion criteria may apply.