A Study of an Epstein-Barr Virus (EBV) Candidate Vaccine, mRNA-1195, in 18- to 55-Year-Old Healthy Participants

Key Inclusion Criteria:

• For Part A: Positive EBV serostatus at Screening. For Part B: Negative EBVserostatus or Positive EBV serostatus at Screening.

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

• For participants of childbearing potential: negative pregnancy test, adequatecontraception or has abstained from all activities that could result in pregnancyfor at least 28 days prior to Day 1, agreement to continue adequate contraceptionthrough 3 months following last study injection and is not currently breast/chestfeeding.

Key Exclusion Criteria:

• Participant is acutely ill or febrile (temperature ≥38.0 degrees Celsius [°C]/100.4degrees Fahrenheit [°F]) 72 hours prior to or at the Screening Visit or Day 1.

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

• Any medical, psychiatric, or occupational condition, including reported history ofdrug or alcohol abuse, that, in the opinion of the Investigator, might poseadditional risk due to participation in the study or could interfere with theinterpretation of study results.

• History of myocarditis, pericarditis, or myopericarditis.

• Participant has received systemic immunosuppressants or immune-modifying drugs for >14 days in total within 6 months prior to Screening Visit (for corticosteroids ≥10milligrams [mg]/day of prednisone or equivalent) or is anticipating the need forimmunosuppressive treatment at any time during participation in the study. Topicalcorticosteroids and tacrolimus are allowed.

• Participant has received or plans to receive any licensed or authorized vaccine, toinclude COVID-19 vaccines, ≤28 days prior to the first injection (Day 1) or plans toreceive a licensed vaccine within 28 days before or after any study injection, withthe exception of licensed/authorized influenza vaccines, which may be received morethan 14 days before or after any study injection.

• Participant has donated ≥450 milliliters (mL) of blood products within 28 days priorto the Screening Visit or plans to donate blood products during the study.

Note: Other inclusion and exclusion criteria may apply.