FAQ

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 common and for most people does not pose a health risk. But for those who are pregnant or have a weak immune system due to a health condition, the virus could have serious consequences. CMV can spread silently and often affects the most vulnerable of us.

• Pregnant women can unknowingly become infected during pregnancy and expose their unborn babies to CMV.
• People with weakened immune systems due to an underlying health condition are also at risk of experiencing serious symptoms of CMV.
• Women can also become infected with CMV and potentially pass it on to newborn babies through bodily fluids including saliva and breast milk.

CMV infection is common and affects people of all ages. However, CMV has an unevenly high presence in communities of lower socioeconomic status and minority populations, including African American and Latinx.

Traditionally, vaccines for viruses are made from a weakened or inactive (not live) version of the virus, but mRNA-1647 is different. It is made from an information molecule called mRNA that tells your cells how to make protein. In this case, the protein is similar to a small part of the virus that is thought to help the body’s immune system protect itself if you ever come in contact with CMV. You cannot become infected with CMV from receiving the investigational vaccine.

In order to understand if the investigational vaccine works, medical researchers are comparing the mRNA-1647 investigational vaccine to a saltwater placebo. A placebo looks like the investigational vaccine being tested but does not contain the investigational vaccine.

Neither you nor the study doctor will know whether you receive mRNA-1647 or a placebo. Every clinical trial participant will receive the same level of quality care regardless of whether they are assigned to the investigational vaccine or the placebo.

To join this clinical trial, participants must be:

• A woman between 16-40 years of age
• In good health
• 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 or planning on becoming pregnant within the next 9 months

There are more requirements for participation. The clinical trial staff will explain the additional requirements and can answer any questions that you may have.

Diseases do not discriminate—and neither should clinical trials. Moderna is committed to researching safe and effective mRNA-based vaccines and therapies to bring better health and living to people of all ages, sexes, and backgrounds.

Taking part in a clinical trial is voluntary. If the study doctor determines that you qualify for participation based on a screening process, you may choose to participate or not participate. You will be given time and the opportunity to ask questions before deciding what you want to do. Your decision will in no way affect current or future treatment you receive outside the clinical trial. If you choose to participate, you will need to follow trial instructions and complete trial-related activities. However, you may withdraw from the trial at any time for any reason.

Clinical trials follow a specific set of standards and are closely regulated to help protect participants. Any known risks or side effects will be discussed during the informed consent process, and clinical trial staff will monitor you for side effects throughout the trial. You should contact the study doctor if you think you are having side effects or are experiencing a change in your medical condition.

All clinical trials and investigational treatments have risks, including the potential to make participants sick or uncomfortable. Although safety precautions are in place, your condition could remain the same, improve, or get worse. If you choose to take part in this trial, you are at risk for side effects. Side effects may include, but are not limited to, pain at the injection site, headache, and muscle/joint pain. You should discuss these with the clinical trial staff and, if you choose, with your regular doctor.

Taking part in this trial is your choice. Taking part in a clinical trial may have an impact on your daily schedule. When deciding whether to volunteer, please consider the time needed for visits (possibly including travel away from home) and any responsibilities that may interfere with the clinical trial.

There are still other ways to contribute to preventing the spread of CMV, such as helping to raise awareness in your community and online. We also hope that you continue exploring treatment and clinical trial options with your doctor.