CMV Vaccine Study

What is CMV?

Cytomegalovirus, shortened to CMV, is a leading cause of birth defects around the world. CMV is a common viral infection that usually goes unnoticed or only causes mild symptoms in most people. But if a woman becomes infected with CMV while she is pregnant, she can pass the infection to her unborn baby. This can cause her child to suffer long-term disability due to birth defects, including hearing loss, or even death in very severe cases. Currently, there is no approved vaccine against CMV. 

CMV is the #1 infection that causes birth defects in the U.S. and one of the most common infectious causes of birth defects globally.

How Participation Works

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, review of your medical history, a urine pregnancy test for women, and some blood tests.
  • During the first 7 months, trial participants will attend 5 in-person visits, including 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 will be compensated for your time and for each visit you complete. 
  • We will schedule your visits in a way that minimizes disruption to your work and other commitments.

Get to Know the Investigational Vaccine: mRNA-1647

The investigational vaccine may help the body’s immune system recognize and protect itself if it comes into contact with CMV in the future. You cannot become infected with CMV from receiving the investigational vaccine. The investigational vaccine in this trial, mRNA-1647, is a newer type of vaccine known as an mRNA vaccine. 

Map: Every virus has signature features on its surface that can trigger your immune system. Once the features are mapped, an mRNA vaccine provides the blueprint to create the defense that can help your body protect itself if it encounters the virus.

Read: Once your body has the blueprint, it knows exactly what to do. It reads mRNA strands to build a defense by producing antibody proteins that are a lot like the answer key to a test. This means the next time your immune system encounters this type of virus, it already has the answer to help protect you.

Neutralize: Your body now knows how to neutralize the virus and is able to defend itself against the threat if it encounters the virus in the future. The message from the blueprint that was read is retained and recalled when needed. It’s like remembering the answer from an old test without having to re-learn the material.

Activate: Moderna is developing mRNA vaccines, like the investigational vaccine mRNA-1647, that deliver blueprints to create the proteins that help activate immune responses against a variety of viruses.

Who May Take Part

  • This clinical trial is looking for volunteers. To join this clinical trial, you must be: 
  • Between 16-40 years of age
  • In good health
  • If you are a woman:
  • In close contact with at least one child 5 years of age or younger for at least 8 hours a week, if age 20 or older
  • Not pregnant and not planning on becoming pregnant within the next 9 months

Clinical trial staff will explain any additional requirements and answer any questions you or a loved one may have about participation. You may stop participation in the clinical trial at any time, and you do not have to give a reason for doing so.

About Clinical Trials

Vaccines aim to safely protect people against infections, and clinical trials are vital to creating vaccines. A clinical trial can help researchers understand whether an investigational vaccine is safe and effective. By participating in the CMVictory trial, you can help create a future where we may hopefully declare victory and prevent the spread of CMV. 

Moderna is committed to keeping people at the center of everything we do as we continue to explore what is possible through mRNA science. Without people like you, researching potential new treatments and mRNA vaccines would not be possible.

Where will these visits be located?

PriMed Clinical Research
948 Patterson Road
Dayton, Ohio 45419

How can I learn more information or sign up?

For more information about this study, visit or contact:

Our research team at 937-534-4238 if you would like more information or click the Sign-up now link below and complete the research inquiry form.