Study aims

Moderna is studying mRNA-1647, an investigational vaccine (a vaccine that hasn’t been approved yet), to understand whether it can help your immune system protect against cytomegalovirus (CMV). 

The purpose of this study is to: 

1. To understand if mRNA-1647 can prevent CMV infection in participants who have not been previously infected with CMV. A blood test to confirm if you have had CMV infection in the past will be performed as part of the assessment in this study. 

1. To understand the safety of mRNA-1647 study vaccine. 

What does participating in the study involve?

The total length of participation in this clinical trial is 
approximately 2½ years (30 months). 

Clinical trial volunteers will have a screening visit to check whether they are eligible to participate. The visit includes a wellness exam, a review of your medical history, a urine pregnancy test, and some blood tests. 

During the first 7 months, trial participants will attend 6 in-person visits, including 1 screening visit and 3 vaccination visits when they’ll receive injections in the upper arm. 

During the follow-up portion of the trial (Month 8 through Month 30), participants will have in-person visits every 3 months and will provide updates via an eDiary, may be contacted by telephone, or may be requested to come in for unscheduled visits in between such visits. 

Each participant has a 50% chance of receiving the investigational vaccine and a 50% chance of receiving a placebo—like flipping a coin. 

You may be compensated for your time and for each visit you complete. More information about reimbursement can be found in the expenses section of the Patient Information and Informed Consent Form, and your clinical trial team can also give you more details.

We will schedule your visits in a way that minimises disruption to your work and other commitments.