A Long-Term Extension Study to Evaluate the Immunogenicity and Safety of Cytomegalovirus (CMV) mRNA-1647 Vaccine
NCT ID: NCT04975893
Last Updated: 2026-02-02
Study Results
The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.
Basic Information
Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.
COMPLETED
PHASE2
135 participants
INTERVENTIONAL
2021-06-18
2026-01-19
Brief Summary
Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.
Related Clinical Trials
Explore similar clinical trials based on study characteristics and research focus.
A Study of mRNA-1647 Cytomegalovirus Vaccine in Healthy Participants 9 to 15 Years of Age and Participants 16 to 25 Years of Age
NCT05575492
A Study to Evaluate the Efficacy, Safety, and Immunogenicity of mRNA-1647 Cytomegalovirus (CMV) Vaccine in Healthy Participants 16 to 40 Years of Age
NCT05085366
Safety, Reactogenicity, and Immunogenicity of Cytomegalovirus Vaccines mRNA-1647 and mRNA-1443 in Healthy Adults
NCT03382405
Dose-Finding Trial to Evaluate the Safety and Immunogenicity of Cytomegalovirus (CMV) Vaccine mRNA-1647 in Healthy Adults
NCT04232280
A Study to Evaluate the Efficacy, Safety, and Immunogenicity of mRNA-1647 Cytomegalovirus (CMV) Vaccine in Allogenic Hematopoietic Cell Transplantation (HCT) Participants.
NCT05683457
Detailed Description
Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.
No study treatment will be administered during the primary extension phase of this study. Eligible participants enrolling in the primary extension phase who completed Study mRNA-1647-P202 may have received mRNA-1647 (either low dose, medium dose, or high dose) or placebo in CMV-seronegative participants and mRNA-1647 (either low dose, medium dose, or high dose) in CMV-seropositive participants.
In the optional BP, consenting and eligible participants will receive a single BD of the mRNA-1647 vaccine (medium dose). In the Observational Group of the optional BP, consenting and eligible participants will not receive study treatment.
Conditions
See the medical conditions and disease areas that this research is targeting or investigating.
Study Design
Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.
NON_RANDOMIZED
SEQUENTIAL
PREVENTION
NONE
Study Groups
Review each arm or cohort in the study, along with the interventions and objectives associated with them.
Primary Extension Phase
CMV-seropositive and CMV-seronegative participants who completed Study mRNA-1647-P202 will be followed every 6 months for 3 years in this study after the final visit in Study mRNA-1647-P202.
mRNA-1647
No investigational product will be administered during the Primary Extension Phase or to the participants in the Observational Group.
Optional Booster Phase - BD Recipients
Participants who opted to enroll into the optional Booster Phase will receive a single mRNA-1647 vaccine dose.
mRNA-1647
Lyophilized product that is reconstituted with saline then diluted with a special diluent to reach the desired concentration
Optional Booster Phase - Observational Group
Participants who opted to enroll into the Observational Group will be followed in the optional BP until BP Month 12.
mRNA-1647
No investigational product will be administered during the Primary Extension Phase or to the participants in the Observational Group.
Interventions
Learn about the drugs, procedures, or behavioral strategies being tested and how they are applied within this trial.
mRNA-1647
No investigational product will be administered during the Primary Extension Phase or to the participants in the Observational Group.
mRNA-1647
Lyophilized product that is reconstituted with saline then diluted with a special diluent to reach the desired concentration
Eligibility Criteria
Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.
Inclusion Criteria
* Male and female participants who were CMV-seronegative at the Study mRNA-1647-P202 Screening visit, completed the final Study mRNA-1647-P202 visit, and remained CMV-seronegative at Screening for Study mRNA-1647-P202-EXT.
* Male and female participants who were CMV-seropositive at the Study mRNA-1647-P202 Screening visit, were randomized to receive mRNA-1647 injection (and not placebo), and completed the final visit in Study mRNA-1647-P202.
* 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.
Optional Booster Phase:
For BD Recipients:
\- CMV-seronegative and CMV-seropositive participants who received mRNA-1647 medium dose injection (and not placebo or other dose levels) in Study mRNA-1647-P202, including participants who enrolled in the Primary Extension Phase of Study mRNA-1647-P202-EXT and participants who were eligible but did not previously enroll in the Primary Extension Phase of Study mRNA-1647-P202-EXT are eligible to receive a BD in the optional BP.
For Observational Group:
\- CMV-seronegative and CMV-seropositive participants who received mRNA-1647 low dose or high dose injection (and not placebo or mRNA-1647 medium dose injection) in Study mRNA-1647-P202, including participants who enrolled in the Primary Extension Phase of Study mRNA-1647-P202-EXT and participants who were eligible but did not previously enroll in the Primary Extension Phase of Study mRNA-1647-P202-EXT are eligible to enroll in the observational group.
Exclusion Criteria
* Receipt of any CMV vaccine other than mRNA-1647.
* 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 trial 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.
Optional Booster Phase:
For BD Recipients:
\- Participants from the placebo, mRNA-1647 low dose, or mRNA-1647 medium dose groups in Study mRNA-1647-P202.
For Observational Group:
\- Participants from the placebo or mRNA-1647 medium dose groups in study mRNA-1647-P202.
18 Years
40 Years
ALL
No
Sponsors
Meet the organizations funding or collaborating on the study and learn about their roles.
ModernaTX, Inc.
INDUSTRY
Responsible Party
Identify the individual or organization who holds primary responsibility for the study information submitted to regulators.
Locations
Explore where the study is taking place and check the recruitment status at each participating site.
Optimal Research, LLC
Peoria, Illinois, United States
Johnson County Clin-Trials, Inc.
Lenexa, Kansas, United States
Alliance for Multispeciality Research, LLC
Lexington, Kentucky, United States
Tekton Research Inc
Austin, Texas, United States
Crossroads Clinical Research (Victoria)
Victoria, Texas, United States
J. Lewis Research, Inc. / Foothill Family Clinic South
Salt Lake City, Utah, United States
J. Lewis Research, Inc. / Foothill Family Clinic South
Salt Lake City, Utah, United States
Countries
Review the countries where the study has at least one active or historical site.
Other Identifiers
Review additional registry numbers or institutional identifiers associated with this trial.
mRNA-1647-P202-EXT
Identifier Type: -
Identifier Source: org_study_id
More Related Trials
Additional clinical trials that may be relevant based on similarity analysis.