About the Trial

This clinical trial is sponsored by Moderna. Moderna is studying the mRNA-1647 trial vaccine to understand the most effective dose for preventing cytomegalovirus (CMV) in children ages 9 to 15. mRNA 1647 has already been looked at for safety in people ages 16 and older.

What Is CMV?

CMV is a common and often overlooked virus with lifelong impact. For most people, the symptoms of CMV—if any—may resemble the common cold with fatigue, headache, and sore throat. Unfortunately, once CMV is in the body it’s there for life, “sleeping” in the body. At certain times in a person’s life, such as pregnancy, CMV can reactivate. Currently, there is no approved vaccine for the prevention of CMV infection.

An active CMV infection during pregnancy puts the unborn baby at risk of birth defects. These include hearing loss, vision loss, or cerebral palsy, which can lead to long-term disability or, in severe cases, death.2

Hearing Loss

Vision Loss

Cerebral Palsy

Cerebral palsy, caused by abnormal brain development, makes muscle control difficult. Children with cerebral palsy may need special equipment to walk or may not be able to walk at all. They may also have joint problems, speech problems, or seizures.

If we advance research of a potential vaccine for kids and teens against CMV, we could potentially help protect them against getting this infection before it has the chance to impact their futures—and their future children.

What to Expect in the CMVibe Trial

The total length of participation in this clinical trial is approximately 1½ years (18 months).

  • Potential participants will have a screening visit to check whether they are eligible to join. The visit includes a wellness exam, review of medical history, and some blood tests.
  • It includes 12 scheduled in-person visits and 11 phone calls to check in with participants, or their parent(s) or caregiver(s), about any updates in health.
  • Participants will get a total of 3 injections of the trial vaccine. An injection will be given in the upper arm at 3 different visits during the first 6 months of the clinical trial.
  • Participants, or their parent(s) or caregiver(s), will enter information about how they are feeling into a device called an eDiary on the day they get each injection and for 6 days after each injection.

Participants ages 16 to 25 will get 1 dose level that has already been tested in their age group. They will get the same dose of mRNA-1647 in all 3 injections. Information from this group will help researchers more quickly compare what we see in the younger age group.

Participants ages 9 to 15 will get 1 of 3 dose levels of mRNA-1647: low, medium, or high. Because this is the first time the trial vaccine is being given to kids and teens, we will do the trial in 3 steps to ensure maximum safety, starting with the lowest dose. Once the dose level is set for each participant, the same dose level will be given to them in all 3 injections

The participants and researchers will both know which dose the participant is getting. Every clinical trial participant will get the same level of care regardless of which dose level they receive.

Clinical Trial Participants Are Essential

Vaccines aim to protect people against viral infections, and clinical trials are an important step in creating vaccines. Without clinical trial participants, researching potential new vaccines would not be possible.