A Study of Zika Vaccine mRNA-1893 in Adult Participants Living in Endemic and Non-Endemic Flavivirus Areas

Key Inclusion Criteria: * Understands and agrees to comply with the study procedures and provides written informed consent. * According to investigator assessment, is in good general health and can comply with study procedures. * Female participants of childbearing potential may be enrolled in the study if the participant: has a negative pregnancy test at the Eligibility Visit and on the day of the first investigational product (IP) injection; has practiced adequate contraception or has abstained from all activities that could result in pregnancy for at least 28 days prior to the first IP injection; has agreed to continue adequate contraception through 3 months following the last IP injection; and is not currently breastfeeding. Key Exclusion Criteria: * Participant is acutely ill or febrile (temperature ≥38.0°Celsius/100.4°Farenheight) on the day of the first or second vaccination. * Participant had prior administration of a ZIKV vaccine candidate during a clinical study investigation. * Participant had prior administration of a marketed dengue vaccine or dengue vaccine candidate under clinical study investigation. * Participant has a body mass index (BMI) from ≤18 or ≥35 kilograms (kg)/square meter (m\^2). * Participant has a history of myocarditis, pericarditis, or myopericarditis. * Participant has a history of a diagnosis or condition that, in the judgement of the investigator, is clinically unstable or may affect participant safety, assessment of safety endpoints, as…