CompletedPhase 2

Dose-Finding Trial to Evaluate the Safety and Immunogenicity of Cytomegalovirus (CMV) Vaccine mRNA-1647 in Healthy Adults

United States315 participantsStarted 2020-01-09

Plain-language summary

This clinical study will assess the safety and immunogenicity of 3 dose levels of mRNA-1647 cytomegalovirus vaccine in CMV-seronegative and CMV-seropositive healthy adults 18-40 years of age.

Who can participate

Age range

18 Years – 40 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * Male or female 18-40 years of age (Part 1); Female 18-40 years of age (Part 2) * Understands and agrees to comply with the trial procedures and provides written informed consent * According to the assessment of the Investigator, is in good general health and is capable of complying with trial procedures * Body mass index (BMI) 18-35 kilograms/meter (kg/m\^2) * Female participants must either be of non-childbearing potential or use acceptable methods of contraception from at least 28 days prior to the first vaccination and through 3 months following last vaccination and is not breastfeeding. * Male participants must agree to practice adequate contraception from the time of the first vaccination and through 3 months after the last vaccination. Exclusion Criteria: * Acutely ill or febrile on the day of the first vaccination * Prior receipt of any CMV vaccine * Abnormal screening safety laboratory test results * Diagnosis or condition that, in the judgment of Investigator, is clinically unstable or may affect participant safety, assessment of safety endpoints, assessment of immune response, or adherence to trial procedures * Has received or plans to receive a vaccine ≤28 days prior to the first vaccination or plans to receive a non-study vaccine within 28 days prior to or after any study vaccination, except for any licensed influenza vaccine which can be administered \>14 days before or after any study vaccination. COVID-19 vaccines (regardless of manufac…

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Number of Participants With Solicited Local and Systemic Adverse Reactions (ARs)

Timeframe: Up to Day 175 (7 days following last dose administration)

Number of Participants With Unsolicited Adverse Events (AEs)

Timeframe: Up to Day 196 (28 days following last dose administration)

Number of Participants With Medically Attended Adverse Events (MAAEs)

Timeframe: Up to Day 336 (6 months following last dose administration)

Number of Participants With Serious Adverse Events (SAEs)

Timeframe: Up to Day 504 (1 year following last dose administration)

Geometric Mean Titer (GMT) of Serum Neutralizing Anti-CMV Antibodies Against Epithelial Cell Infection and Against Fibroblast Infection

Timeframe: Baseline (Day 1), Day 29, Day 56, Day 84, Day 168, Day 196, Day 336, Day 504

Geometric Mean Ratio (GMR) of Serum Neutralizing Anti-CMV Antibodies Against Epithelial Cell Infection and Against Fibroblast Infection

Timeframe: Day 29, Day 56, Day 84, Day 168, Day 196, Day 336, Day 504

Trial details

NCT IDNCT04232280

SponsorModernaTX, Inc.

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2023-01-04

Results submitted2025-12-18

View on ClinicalTrials.gov More Cytomegalovirus Infection trials