A Study to Evaluate the Efficacy, Safety, and Immunogenicity of mRNA-1647 Cytomegalovirus (CMV) Vaccine in Healthy Participants 16 to 40 Years of Age
Reason given: The Sponsor decided to terminate the study after it did not meet the primary efficacy endpoint at final analysis. The safety profile was consistent with prior studies, and no safety concerns were raised by the Data and Safety Monitoring Board.
Key facts
- Where
- Albuquerque, Atlanta, Aurora, Austin, Banning, Beaumont, Binghamton, Birmingham, Bridgeport, Brookline, Burlington, Canton, Cedar Park, Chamblee, Chandler, Charlotte, Chickasha, Chula Vista, Cincinnati, Coconut Creek, Columbia, Columbus, Coral Gables, Coral Springs, Dacula, Dallas, Dayton, Decatur, Des Moines, Detroit, Doral, Dothan, East Amherst, Edgewater, El Paso, Elkridge, Fair Oaks, Fargo, Fayetteville, Frisco, Fullerton, Grand Island, Great Falls, Gulfport, Guntersville, Hammond, Hastings, Hialeah, Houston, Idaho Falls, Irving, Irvington, Kalispell, Keller, Kennesaw, La Mesa, Las Vegas, Layton, League City, Lenexa, Lexington, Lincoln, Little Rock, Long Beach, Madison, Marietta, McAllen, McDonough, Medford, Meridian, Mesa, Metairie, Methuen, Miami, Miami Lakes, Milford, Minneapolis, Mishawaka, Missoula, Missouri City, Monroe, Montclair, Morehead City, Mt. Pleasant, Newnan, Newport News, Newton, Norcross, Norfolk, North Charleston, North Hollywood, Oak Brook, Oklahoma City, Omaha, Ormond Beach, Panama City, Pembroke Pines, Peoria, Petal, Pflugerville, Pharr, Phoenix, Plano, Plantation, Pomona, Raleigh, Red Oak, Redding, Renton, Riverton, Rochester, Rockville, Rolling Hills Estates, Sacramento, Salt Lake City, San Antonio, San Diego, Sandy Springs, Santa Clarita, Savannah, Seattle, South Euclid, Southfield, Spokane, St. Petersburg, Stanford, Suffolk, Surprise, Syracuse, Tampa, Tempe, Thousand Oaks, Tomball, Tucson, Valley Village, Victoria, Washington D.C., Waxahachie, West Covina, West Jordan, Wheat Ridge, and Yukon, United StatesSee the 180 sites
- Phase
- Phase 3
Where in United States
- Albuquerque Clinical Trials, Inc.Albuquerque, United StatesNo longer taking part
- MedPharmics, LLC. - AlbuquerqueAlbuquerque, United StatesNo longer taking part
- CVS HealthHub - AtlantaAtlanta, United StatesNo longer taking part
- CVS HealthHub - Atlanta SAtlanta, United StatesNo longer taking part
- Care Access Research - AuroraAurora, United StatesNo longer taking part
- University of Colorado Anschutz Medical CampusAurora, United StatesNo longer taking part
- ARC Clinical Research at William CannonAustin, United StatesNo longer taking part
- ARC Clinical Research at Wilson ParkeAustin, United StatesNo longer taking part
- Premier Family Physicians - Austin - HuntAustin, United StatesNo longer taking part
- Tekton Research, IncAustin, United StatesNo longer taking part
- Velocity Clinical Research - BanningBanning, United StatesNo longer taking part
- Gadolin Research, LLCBeaumont, United StatesNo longer taking part
- REX Clinical TrialsBeaumont, United StatesNo longer taking part
- Tekton Research - BeaumontBeaumont, United StatesNo longer taking part
- Meridian Clinical Research (Endwell-New York) - Platinum - PPDSBinghamton, United StatesNo longer taking part
- Accel Research Site - Achieve - Birmingham - ERN - PPDSBirmingham, United StatesNo longer taking part
- Central Research Associates, IncBirmingham, United StatesNo longer taking part
- New England Research Associates LLC - ERN - PPDSBridgeport, United StatesNo longer taking part
- DM Clinical Research - The Brook HouseBrookline, United StatesNo longer taking part
- Skylight Health Research - BurlingtonBurlington, United StatesNo longer taking part
- Voyage Medical - MichiganCanton, United StatesNo longer taking part
- Velocity Clinical Research - AustinCedar Park, United StatesNo longer taking part
- Tekton Research - Georgia - PlatinumChamblee, United StatesNo longer taking part
- Chandler Clinical Trials, LLCChandler, United StatesNo longer taking part
- Onsite Clinical Solutions, LLCCharlotte, United StatesNo longer taking part
- Epic Medical Research - OklahomaChickasha, United StatesNo longer taking part
- Velocity Clinical Research, Chula VistaChula Vista, United StatesNo longer taking part
- CTI Clinical Research Center - ClinEdge - PPDSCincinnati, United StatesNo longer taking part
- Meridian CincinnatiCincinnati, United StatesNo longer taking part
- University of Cincinnati Medical Center - Goodman StCincinnati, United StatesNo longer taking part
- Invictus Clinical Research Group, LLCCoconut Creek, United StatesNo longer taking part
- SPICA Clinical ResearchColumbia, United StatesNo longer taking part
- Aventiv Research IncColumbus, United StatesNo longer taking part
- Centricity Research - RoswelColumbus, United StatesNo longer taking part
- ClinOhio Research ServicesColumbus, United StatesNo longer taking part
- WellNow Urgent Care & Research - Huber HeightsColumbus, United StatesNo longer taking part
- Herco Medical and Research Center, IncCoral Gables, United StatesNo longer taking part
- Luna Research LLCCoral Gables, United StatesNo longer taking part
- Precision Clinical Research, LLCCoral Springs, United StatesNo longer taking part
- CVS HealthHub - DaculaDacula, United StatesNo longer taking part
- Global Medical ResearchDallas, United StatesNo longer taking part
- Zenos Clinical ResearchDallas, United StatesNo longer taking part
- PriMed Clinical Research - ClinEdgeDayton, United StatesNo longer taking part
- iResearch Atlanta, LLCDecatur, United StatesNo longer taking part
- Iowa ClinicDes Moines, United StatesNo longer taking part
- Wayne State UniversityDetroit, United StatesNo longer taking part
- Unique Clinical Trials, LLCDoral, United StatesNo longer taking part
- Universal Axon Clinical ResearchDoral, United StatesNo longer taking part
- SEC Clinical Research LLC - Dothan - ClinEdge - PPDSDothan, United StatesNo longer taking part
- WellNow Urgent Care Clinical ResearchEast Amherst, United StatesNo longer taking part
- Velocity Clinical Research New Smyrna BeachEdgewater, United StatesNo longer taking part
- ANRC ResearchEl Paso, United StatesNo longer taking part
- Centennial Medical Group - Elkridge - Rx TrialsElkridge, United StatesNo longer taking part
- Apex Research GroupFair Oaks, United StatesNo longer taking part
- Lillestol ResearchFargo, United StatesNo longer taking part
- Carolina Institute for Clinical Research - M3 WR - ERN - PPDSFayetteville, United StatesNo longer taking part
- Village Health Partners Frisco Medical VillageFrisco, United StatesNo longer taking part
- Ascada Research LLCFullerton, United StatesNo longer taking part
- Meridian Clinical Research (Grand Island, Nebraska)Grand Island, United StatesNo longer taking part
- Boeson Research GTF - Great FallsGreat Falls, United StatesNo longer taking part
- MedPharmics, LLCGulfport, United StatesNo longer taking part
- Lakeview Clinical ResearchGuntersville, United StatesNo longer taking part
- ASHA Clinical Research - ClinEdgeHammond, United StatesNo longer taking part
- Meridian Clinical Research (Hastings, Nebraska)Hastings, United StatesNo longer taking part
- Best Quality Research, IncHialeah, United StatesNo longer taking part
- Indago Research and Health CenterHialeah, United StatesNo longer taking part
- New Horizon Medical Group, LLCHouston, United StatesNo longer taking part
- Trio Clinical Trials, LLC.Houston, United StatesNo longer taking part
- Vilo Research Group, L.L.C.Houston, United StatesNo longer taking part
- Clinical Research Prime - ClinedgeIdaho Falls, United StatesNo longer taking part
- Cedar Health Research - Fort Worth - PPDSIrving, United StatesNo longer taking part
- Med Clinic Research Partners, LLCIrvington, United StatesNo longer taking part
- Boeson Research KAL - Kalispell - ERN - PPDSKalispell, United StatesNo longer taking part
- Helios CCR, Inc.-keller-PPDSKeller, United StatesNo longer taking part
- CVS HealthHub - KennesawKennesaw, United StatesNo longer taking part
- Paradigm Clinical Research CenterLa Mesa, United StatesNo longer taking part
- Velocity Clinical Research, San DiegoLa Mesa, United StatesNo longer taking part
- Clinical Research Center Of NevadaLas Vegas, United StatesNo longer taking part
- Tanner ClinicLayton, United StatesNo longer taking part
- University of Texas Medical Branch - Bay Colony, SIVS Clinical Trials ProgramLeague City, United StatesNo longer taking part
- Johnson Country Clin-TrialsLenexa, United StatesNo longer taking part
- Alliance for Multispecialty Research, LLCLexington, United StatesNo longer taking part
- Be Well Clinical Studies, LLC - Lincoln - ERN - PPDSLincoln, United StatesNo longer taking part
- Applied Research Center of Arkansas - Clinedge - PPDSLittle Rock, United StatesNo longer taking part
- Baptist Health Center for Clinical ResearchLittle Rock, United StatesNo longer taking part
- Preferred Research PartnersLittle Rock, United StatesNo longer taking part
- Long Beach Clinical Trials Services, IncLong Beach, United StatesNo longer taking part
- Long Beach Research Institute, LLCLong Beach, United StatesNo longer taking part
- University of Wisconsin - MadisonMadison, United StatesNo longer taking part
- Drug Studies America - ClinEdge - PPDSMarietta, United StatesNo longer taking part
- BRCR Medical Center Inc - McAllenMcAllen, United StatesNo longer taking part
- CVS HealthHub - McdonoughMcDonough, United StatesNo longer taking part
- Velocity Clinical Research, MedfordMedford, United StatesNo longer taking part
- Velocity Clinical ResearchMeridian, United StatesNo longer taking part
- Arizona Clinical TrialsMesa, United StatesNo longer taking part
- Velocity Clinical Research - CovingtonMetairie, United StatesNo longer taking part
- ActivMed Practices & Research, IncMethuen, United StatesNo longer taking part
- Florida International Medical ResearchMiami, United StatesNo longer taking part
- Miami Clinical ResearchMiami, United StatesNo longer taking part
- Spotlight Research Center, LLCMiami, United StatesNo longer taking part
- Floridian Clinical Research - ClinEdge - PPDSMiami Lakes, United StatesNo longer taking part
- Clinical Research Consultants LLCMilford, United StatesNo longer taking part
- Clinical Research Institute, Inc - CRN - PPDSMinneapolis, United StatesNo longer taking part
- University of Minnesota Clinical Research UnitMinneapolis, United StatesNo longer taking part
- Del Pilar Medical and Urgent CareMishawaka, United StatesNo longer taking part
- Boeson Research MSO - MissoulaMissoula, United StatesNo longer taking part
- Synergy Group US, LLCMissouri City, United StatesNo longer taking part
- Monroe Biomedical Research (Venus St)Monroe, United StatesNo longer taking part
- Catalina Research Institute, LLCMontclair, United StatesNo longer taking part
- Lucas ResearchMorehead City, United StatesNo longer taking part
- PMG Research of Charleston LLCMt. Pleasant, United StatesNo longer taking part
- CVS HealthHub - NewmanNewnan, United StatesNo longer taking part
- Health Research of Hampton Roads Inc. - ClinEdgeNewport News, United StatesNo longer taking part
- Alliance for Multispecialty Research, LLCNewton, United StatesNo longer taking part
- One Health Research Clinic, Inc.Norcross, United StatesNo longer taking part
- Meridian Clinical Research (Norfolk-Nebraska)Norfolk, United StatesNo longer taking part
- York Clinical ResearchNorfolk, United StatesNo longer taking part
- Coastal Carolina Research CenterNorth Charleston, United StatesNo longer taking part
- Carbon Health- NoHo West Urgent Care and Primary CareNorth Hollywood, United StatesNo longer taking part
- Affinity HealthOak Brook, United StatesNo longer taking part
- Lynn Health Science InstituteOklahoma City, United StatesNo longer taking part
- Meridian Clinical Research-(Omaha Nebraska)Omaha, United StatesNo longer taking part
- Quality Clinical ResearchOmaha, United StatesNo longer taking part
- Ormond Beach Clinical ResearchOrmond Beach, United StatesNo longer taking part
- Emerald Coast OBGYN Clinical ResearchPanama City, United StatesNo longer taking part
- Ideal Clinical Research, Inc. - ClinEdge - PPDSPembroke Pines, United StatesNo longer taking part
- Optimal ResearchPeoria, United StatesNo longer taking part
- MediSync Clinical Research Hattiesburg ClinicPetal, United StatesNo longer taking part
- Austin Regional Clinic ARC Clinical Research at Kelly LanePflugerville, United StatesNo longer taking part
- GLRI McAllen ResearchPharr, United StatesNo longer taking part
- Hope Research Institute LLCPhoenix, United StatesNo longer taking part
- MedPharmics, LLCPhoenix, United StatesNo longer taking part
- Phoenix Clinical LLCPhoenix, United StatesNo longer taking part
- ACRC Trials - Independence Parkway - Plano - Hunt - PPDSPlano, United StatesNo longer taking part
- Precision Clinical Research - PlantationPlantation, United StatesNo longer taking part
- Empire Clinical ResearchPomona, United StatesNo longer taking part
- M3 Wake Research, Inc - M3 WR - ERN - PPDSRaleigh, United StatesNo longer taking part
- Epic Medical Research, LLCRed Oak, United StatesNo longer taking part
- Paradigm Clinical Research Institute Inc - ClinEdgeRedding, United StatesNo longer taking part
- Rainier Clinical Research CenterRenton, United StatesNo longer taking part
- Granger Medical Clinic - RivertonRiverton, United StatesNo longer taking part
- Rochester Clinical Research, IncRochester, United StatesNo longer taking part
- Meridian Clinical Research-(Rockville Maryland)Rockville, United StatesNo longer taking part
- Smart Cures Clinical ResearchRolling Hills Estates, United StatesNo longer taking part
- Northern California Research CorpSacramento, United StatesNo longer taking part
- Foothill Family ClinicSalt Lake City, United StatesNo longer taking part
- Foothill Family Clinic - South ClinicSalt Lake City, United StatesNo longer taking part
- Clinical Trials of Texas, Inc. - HyperCorSan Antonio, United StatesNo longer taking part
- Diagnostics Research GroupSan Antonio, United StatesNo longer taking part
- Womens Healthcare Research Corporation ERN PPDSSan Diego, United StatesNo longer taking part
- Mount Vernon Clinical Research, LLC - M3 WR - ERN - PPDSSandy Springs, United StatesNo longer taking part
- Care Access Research - Santa ClaritaSanta Clarita, United StatesNo longer taking part
- CVS HealthHub - SavannahSavannah, United StatesNo longer taking part
- Seattle Clinical Research CenterSeattle, United StatesNo longer taking part
- Senders PediatricsSouth Euclid, United StatesNo longer taking part
- DM Clinical Research - SouthfieldSouthfield, United StatesNo longer taking part
- Great Lakes Research InstituteSouthfield, United StatesNo longer taking part
- Velocity Clinical Research - Spokane - PPDSSpokane, United StatesNo longer taking part
- GCP, Global Clinical ProfessionalsSt. Petersburg, United StatesNo longer taking part
- Stanford University School of MedicineStanford, United StatesNo longer taking part
- David Ramstad Associates Research - IACT - HyperCore - PPDSSuffolk, United StatesNo longer taking part
- Epic Medical Research ArizonaSurprise, United StatesNo longer taking part
- SUNY Upstate Medical CenterSyracuse, United StatesNo longer taking part
- Tampa Bay Health CareTampa, United StatesNo longer taking part
- Hope Research Institute LLCTempe, United StatesNo longer taking part
- Voyage MedicalTempe, United StatesNo longer taking part
- Clinical Trials Management Services, LLCThousand Oaks, United StatesNo longer taking part
- DM Clinical ResearchTomball, United StatesNo longer taking part
- Del Sol Research Management - ClinEdge - PPDSTucson, United StatesNo longer taking part
- Noble Clinical ResearchTucson, United StatesNo longer taking part
- The Institute for Liver Health - TucsonTucson, United StatesNo longer taking part
- Tucson Neuroscience Research - M3 WR - ERN - PPDSTucson, United StatesNo longer taking part
- Bayview Research GroupValley Village, United StatesNo longer taking part
- Crossroads Clinical Research (Victoria)Victoria, United StatesNo longer taking part
- Emerson Clinical Research Institute LLC - Kennedy StWashington D.C., United StatesNo longer taking part
- ClinPoint Trials LLCWaxahachie, United StatesNo longer taking part
- Next Level Clinical TrialsWest Covina, United StatesNo longer taking part
- Velocity Clinical ResearchWest Jordan, United StatesNo longer taking part
- Paradigm Clinical Research Institute Inc - ClinEdgeWheat Ridge, United StatesNo longer taking part
- Tekton Research - Oklahoma - PlatinumYukon, United StatesNo longer taking part
Trial details
- Who runs it
- ModernaTX, Inc.
- Trial code
- NCT05085366EU 2023-508820-37-00
- Record updated
- 15 December 2025
- Original description
The main purpose of this study is to evaluate the efficacy of mRNA 1647 vaccine in CMV-seronegative female participants and to evaluate the safety and reactogenicity of mRNA-1647 vaccine in all participants. The purpose of the Phase 3 extension substudy is to extend the observation period of the main study and to assess the longer-term immunogenicity, efficacy, and safety of the mRNA-1647 vaccine against primary CMV infection in healthy females who were CMV-seronegative at Baseline of the mRNA-1647-P301 main study (including participants who remain CMV-seronegative upon entry into the extension substudy and participants who seroconverted during the main study). The extension substudy will also evaluate the immune persistence and safety of mRNA-1647 in a subset of female participants who were CMV-seropositive at Baseline of the main study. No interventional vaccine will be administered in the extension substudy.Read full original descriptionShow less
A Phase 3, Randomized, Observer-Blind, Placebo-Controlled Study to Evaluate the Efficacy, Safety, and Immunogenicity of mRNA-1647 Cytomegalovirus (CMV) Vaccine in Healthy Participants 16 to 40 Years of Age
The main purpose of this study is to evaluate the efficacy of mRNA 1647 vaccine in CMV-seronegative female participants and to evaluate the safety and reactogenicity of mRNA-1647 vaccine in all participants. The purpose of the Phase 3 extension substudy is to extend the observation period of the main study and to assess the longer-term immunogenicity, efficacy, and safety of the mRNA-1647 vaccine against primary CMV infection in healthy females who were CMV-seronegative at Baseline of the mRNA-1647-P301 main study (including participants who remain CMV-seronegative upon entry into the extension substudy and participants who seroconverted during the main study). The extension substudy will also evaluate the immune persistence and safety of mRNA-1647 in a subset of female participants who were CMV-seropositive at Baseline of the main study. No interventional vaccine will be administered in the extension substudy.
Inclusion: Participants aged ≥20 years, has or anticipates having direct exposure within 7 months after the planned first dose (in the home, socially, or occupationally) to at least 1 child ≤5 years of age. Direct exposure is defined as either participant is the parent, or participant has close contact (feeding, diaper changes, childcare/supervision) for at least 8 hours per week; CMV-seronegative Cohort is CMV-seronegative based on CMV testing at Screening; CMV-seropositive Cohort is CMV-seropositive based on CMV testing at Screening; Investigator assessment confirms that the participant (including in the case of an emancipated minor), or parent(s)/legally acceptable representative (LAR)(s), as applicable, understand and are willing and physically able to comply with protocol-mandated follow-up including all study visits and procedures anticipated during the 30 month study period; Female participants of child-bearing potential: Urine pregnancy test is negative at Screening and negative on the day of the first injection (Day 1). If the participant is sexually active with men, has practiced adequate contraception or has abstained from all activities that could result in pregnancy for at least 28 days prior to the first injection (Day 1) and agrees to continue adequate contraception through 3 months following the third study injection (Month 9/Day 257); Extension substudy:; All consenting participants who were CMV-seronegative at Baseline in the mRNA-1647-P301 main study (including those who did seroconvert and did not seroconvert during the main study), received at least one study injection in the main study but did not withdraw study consent, and completed the final study visit in mRNA-1647-P301 main study; Consenting participants in mRNA-1647-P301 main study who were CMV-seropositive at Baseline, received all 3 study injections, did not withdraw study consent, and completed the final study visit in the main study.
Exclusion: Received or plans to receive any nonstudy vaccine <28 days prior to and after any study injection; in addition, the following criteria for COVID-19 and influenza vaccines apply:; Any COVID-19 primary vaccination series must have been completed a minimum 28 days prior to receiving any dose of the study injection; COVID-19 vaccines (including any booster dose, regardless of manufacturer) must be administered at least 28 days prior to or after any study injection; Influenza vaccines may be administered > 14 days prior to or after any study injection; Received systemic immunosuppressants or immune-modifying drugs for >14 days in total within 6 months prior to the day of first injection (Day 1) (for corticosteroids, ≥5 milligrams (mg)/day of prednisone equivalent) or plans to do so during the course of the study. Inhaled, nasal, and topical steroids are allowed. Stable immunomodulator regimens used for managing environmental allergies are allowed; Receipt of an antiviral with activity against CMV (ganciclovir, valganciclovir, foscarnet, cidofovir, letermovir, acyclovir, valacyclovir) <2 weeks prior to the day of first injection or plans to do so during the course of the study; Previous receipt of an investigational CMV vaccine; Receipt of systemic immunoglobulins or blood products <3 months prior to the day of first injection; Participated in an interventional clinical study <28 days prior to the day of first injection (Day 1) or plans to do so while enrolled in this study; Participant has donated ≥450 milliliters (mL) of blood products <28 days prior to Screening; Receipt of any CMV vaccine other than mRNA-1647; History of a diagnosis or condition that, in the judgment of the Investigator, is clinically unstable or may affect participant safety, assessment of safety endpoints, assessment of immune response, or adherence to study procedures; Diagnosis or condition that, in the judgment of the Investigator, may affect participant safety, assessment of safety endpoints, assessment of immune response, or adherence to study procedures, including any medical, psychiatric, or occupational condition that, in the opinion of the Investigator, might pose additional risk due to participation in the study or could interfere with the interpretation of study results; Participant is a member of study team or is an immediate family member or household member of study personnel; Extension substudy:.