Can an mRNA vaccine shield the most vulnerable from RSV?

NCT ID NCT06067230

Completed ⭐️ VACCINE ⭐️ Sponsor: ModernaTX, Inc. Source: ClinicalTrials.gov ↗

The trial has finished. Results may not be published yet.

First seen Aug 20, 2026 · Last updated Aug 21, 2026 · Updated 1 time

Summary

This phase 3 trial is testing an experimental mRNA vaccine called mRNA-1345 to see if it can protect against respiratory syncytial virus (RSV) in adults who are at high risk of severe illness. The study includes two groups: adults aged 18 to 59 with chronic health conditions like heart or lung disease or diabetes, and adults who have received a solid organ transplant. Researchers will measure the vaccine's safety and the strength of the immune response it triggers, comparing antibody levels before and after vaccination.

What this could mean

Our plain-language read of the trial. This is informational only — not medical advice or a prediction.

Active substance: mRNA-1345, an mRNA vaccine targeting respiratory syncytial virus
What this could lead to: If successful, this vaccine could offer strong protection against RSV for people at high risk, including those with chronic conditions or organ transplants.
What could go wrong: The trial is still in progress, so results are not yet known. The vaccine may cause side effects or may not provide sufficient immunity in all participants.

This is an AI summary of the original study and may miss details. Read our disclaimer.

Study facts

What this study's own registry entry says, in plain language.

Phase

Phase 3

Large-scale testing in a bigger group. Usually the last step before a treatment can be approved.

Participants

1,153 people

The number who actually took part.

Started

Oct 2023

Finished

Jul 2026

Lead sponsor

A company

The lead sponsor is a pharmaceutical, biotech, or medical-device company.

Who can take part

This study's own entry requirements. Only the study team can say for certain whether you qualify.

Ages

18 years and older

Sex

Anyone

Healthy volunteers

Not accepted

This study is not open to healthy volunteers. The entry requirements below say who it is open to.

Show the full entry requirements

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Key Inclusion Criteria: Part A: * Adults ≥18 to \<60 years of age at the time of consent who are primarily responsible for self-care and activities of daily living. * Documented confirmation by a physician of the diagnosis of at least one of the following conditions: 1. Coronary artery disease and/or congestive heart failure. 2. Chronic lung disease (for example, including but not limited to chronic obstructive pulmonary disease or persistent asthma). 3. Stable type 1 or type 2 diabetes mellitus controlled with at least 1 medication started 90 days or more prior to Day 1. Part B: * Adults ≥18 years of age at the time of consent who are primarily responsible for self-care and activities of daily living. * Recipient of an SOT (kidney, liver, or lung transplant) ≥180 days prior to day of consent and receiving chronic immunosuppressive therapy for the prevention of allograft rejection. Parts A and B: \- Able to comply with study requirements. Key Exclusion Criteria: Part A: * Participation in an another clinical research trial where the participant has received an investigational product 180 days prior to Day 1. Participation in an RSV trial at any time prior to Day 1 is exclusionary. * 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. * Reported history of anaphylaxis or severe hypersensitivity reaction after receipt of the mRNA-1345 injection or any components of the mRNA-1345 injection. * Chronic administration (defined as more than 14 continuous days) of immunosuppressants or other immune-modifying drugs within 180 days prior to Day 1. * History of myocarditis, pericarditis, or myopericarditis. Part B: * Previous treatment with alemtuzumab or rituximab within 2 years prior to Day 1. * Previous treatment with plasmapheresis within 30 days prior to Day 1. * A history of complications of immunosuppression. * A history of biopsy proven or clinically diagnosed rejection within 90 days prior to Day 1 or suspected active chronic rejection according to the Investigator's judgment. Note: Other protocol-defined inclusion/exclusion criteria apply

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Conditions

The condition(s) this trial relates to.

chronic asthma chronic obstructive pulmonary disease congestive heart failure coronary artery disorder type 1 diabetes mellitus type 2 diabetes mellitus viral infectious disease respiratory syncytial virus infectious disease prevention target

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

RESPIRATORY SYNCYTIAL VIRUS

Contacts and locations

Locations

AES - DRS - Optimal Research Illinois - Peoria

Peoria, Illinois, 61614-4885, United States
Aberdeen Royal Infirmary - PPDS

Aberdeen, AB25 2ZD, United Kingdom
Artemis Institute For Clinical Research LLC - San Diego - Headlands - PPDS

San Diego, California, 92103-2209, United States
Baptist Health Center for Clinical Research

Little Rock, Arkansas, 72205, United States
Benchmark Research - Covington - HyperCore - PPDS

Covington, Louisiana, 70433, United States
Benchmark Research - Fort Worth - HyperCore - PPDS

Fort Worth, Texas, 76135-5283, United States
Benchmark Research - San Angelo - HyperCore - PPDS

San Angelo, Texas, 76904-7610, United States
Canadian Center for Vaccinology

Halifax, Nova Scotia, L7 8XZ, Canada
Caribbean Medical Research Center

San Juan, 00918, Puerto Rico
CenExel RCA - Hollywood

Hollywood, Florida, 33024-2709, United States
Centricity Research Suffolk Family Medicine

Suffolk, Virginia, 23435-3763, United States
Clinical Research Atlanta - Headlands - PPDS

Stockbridge, Georgia, 30281-9054, United States
Colchester Research Group

Truro, Nova Scotia, B2N 1L2, Canada
Critical Care, Pulmonary and Sleep Associates / CCT Research

Lakewood, Colorado, 80228, United States
DM Clinical Research - Cyfair Clinical Research Center

Houston, Texas, 77065-5685, United States
DM Clinical Research - ERN - PPDS

Tomball, Texas, 77375-6543, United States
DM Clinical Research - Philadelphia - ERN - PPDS

Philadelphia, Pennsylvania, 19107-1530, United States
DM Clinical Research - Southfield - ERN - PPDS

Southfield, Michigan, 48076-5412, United States
David Geffen School of Medicine at UCLA

Los Angeles, California, 90095-3075, United States
Diex Recherche - Québec - PPDS

Québec, G1V 4T3, Canada
Diex Recherche - Sherbrooke - PPDS

Sherbrooke, Quebec, J1L 0H8, Canada
Duke University Medical Center

Durham, North Carolina, 27710, United States
Excel Medical Clinical Trials DBA Flourish

Boca Raton, Florida, 33434, United States
Fiel Family & Sports Medicine - PC - CCT - PPDS

Tempe, Arizona, 85283-1528, United States
Foothills Research Center - CCT - PPDS

Phoenix, Arizona, 85044-6097, United States
Fylde Coast Clinical Research

Blackpool, Lancashire, FY3 7EN, United Kingdom
Henry Ford Hospital

Detroit, Michigan, 48202-2608, United States
Indago Research and Health Center

Hialeah, Florida, 33012-4170, United States
Lenzmeier Family Medicine - CCT - PPDS

Glendale, Arizona, 85308-5093, United States
Liverpool School of Tropical Medicine

Liverpool, Merseyside, L7 8XZ, United Kingdom
Montefiore Medical Center - BRANY - PPDS

The Bronx, New York, 10467-2401, United States
OCT Research ULC (dba Okanagan Clinical Trials)

Kelowna, British Columbia, V1Y 1Z9, Canada
Royal Devon and Exeter Hospital

Exeter, Devon, EX2 5DW, United Kingdom
Snake River Research, PLLC

Idaho Falls, Idaho, 83404-7573, United States
Springville Dermatology - CCT - PPDS

Springville, Utah, 84663, United States
The Royal Free Hospital

London, NW3 2QG, United Kingdom
University of Alberta

Edmonton, Alberta, T6G 2B7, Canada
University of Chicago

Chicago, Illinois, 60637-1443, United States
University of Rochester - Rochester General Hospital - PPDS

Rochester, New York, 14621-3011, United States
Velocity Clinical Research (Lincoln - Nebraska) - PPDS

Lincoln, Nebraska, 68510, United States
Velocity Clinical Research (Rockville - Maryland) - PPDS

Rockville, Maryland, 20854-2960, United States
Velocity Clinical Research - Family Practice - Suffolk - PPDS

Suffolk, Virginia, 23435, United States
Velocity Clinical Research - Hampton - PPDS

Hampton, Virginia, 23666-6262, United States
Yale University School of Medicine

New Haven, Connecticut, 06510-2483, United States

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