A clinical trial of an investigational COVID-19 vaccine for young children

Trial ID: ROVER-mRNA-1273-P306 (Part 3)
The ROVER Study is a Phase 3 clinical trial being conducted by Moderna to evaluate investigational vaccines that may protect children 6 months to 5 years of age from getting sick if they come into contact with SARS-CoV-2 (also called coronavirus), which causes COVID-19.

Trial Details

The ROVER Study has completed enrollment for Parts 1 and 2 of the trial, but are now enrolling participants in Part 3.

Part 3 of the ROVER Study has been added to understand if the dosing schedule for children could be simplified, which in turn may help to increase vaccine usage within the pediatric population.

The purpose of this clinical trial is to evaluate a booster dose of mRNA-1273.815, Moderna’s investigational COVID-19 vaccine, to learn more about whether the investigational vaccine is safe when given as a booster that is the same dose as an initial COVID-19 vaccination. An investigational vaccine is not yet approved by a country’s drug regulatory agency.

Estimated Enrollment

Approximately 300 for Part 3 Participants



Eligibility Criteria

Participants must:

  • Be 6 months to 5 years old
  • Be in good health
  • Have completed an age-appropriate vaccination series of an authorized COVID-19 vaccine
  • Have parents/guardians willing and able to attend all trial visits

Participants must not:

  • Have received or plan to receive any vaccine 14 days before or after the trial injection
  • Have received the most recent authorized COVID-19 vaccination (Omicron XBB.1.5) This would typically mean they received the COVID-19 vaccination sometime after September 11, 2023

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Site Locations

Participants will need to go to one of the clinics taking part in this clinical trial.

Sites are located in the cities/states identified with the red pin:

What to Expect

Participation in Part 3 of the ROVER Study will last approximately 7 months and includes phone calls with the trial team and 2 in-person visits to a clinical trial site. Participants will receive 1 booster injection.

All participants will receive the investigational vaccine, mRNA-1273.815.

You will be asked to use an eDiary app on your smartphone (or a provided device) to answer questions about how your child is feeling. During in-person clinical trial site visits, you and your child will answer questions about how they are feeling and complete study tests, including physical exams and blood tests.

Insurance is not required to participate, and all trial-related procedures and exams will be covered at no cost to you. Qualified participants will receive payment for their trial-related time and travel.

Check Your Child's Eligibility

We'll check to see if your child is eligible by asking you some questions.

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Frequently Asked Questions (FAQs)