Overview
The purpose of the study is to evaluate the safety, reactogenicity, and immunogenicity of mRNA-1345 in children aged 2 to <5 years of age and in children at high risk of respiratory syncytial virus (RSV) disease 5 to <18 years of age to inform the dose level selection for the next phase of development (Phase 3).
Eligibility
Key Inclusion Criteria:
Cohort 1:
- 2 to <5 years of age, at the time the informed consent is signed.
- Healthy, or with stable chronic conditions increasing the risk of RSV disease, per the clinical judgment of the Investigator.
Cohort 2:
- 5 to <18 years of age, at the time the informed consent is signed.
- Participants with stable chronic conditions increasing the risk of RSV disease.
- Female participants of child-bearing potential may be enrolled in the study, if the participant: 1) has a negative urine pregnancy test at Screening and on the day of injection (Day 1); 2) has practiced adequate contraception or has abstained from all activities that could lead to pregnancy for 28 days prior to Day 1; 3) has agreed to continue adequate contraception through 90 days following injection; and 4) is not currently breastfeeding.
Key Exclusion Criteria:
- Acutely ill or febrile (temperature ≥38.0°Celsius [100.4°Fahrenheit]) within 72 hours prior to or at the Screening Visit or Day 1.
- History of a diagnosis or condition that, in the judgment of the Investigator, may affect study assessment or compromise participant safety.
- Has received or plans to receive any licensed or authorized vaccine ≤14 days prior to the study vaccine injection (Day 1) or plans to receive a licensed or authorized vaccine within 14 days after the study vaccine injection.
- Receipt of any prior systemic immunosuppressants or immune-modifying drugs. Short courses (<7 days) of oral corticosteroids are allowed if completed at least 3 months prior to enrollment.
- Receipt of RSV monoclonal antibodies within 6 months prior to enrollment in the study.
- Participated in an interventional clinical study within 28 days (6 months for a study assessing a product unlicensed in this age group) prior to the day of enrollment or plans to do so while enrolled in this study.
Note: Other protocol-defined inclusion and exclusion criteria may apply.