NCT07117487

Brief Summary

The purpose of this study is to evaluate safety, tolerability and immunogenicity of mRNA-1345 in participants who have been previously vaccinated with either Arexvy or Abrysvo at least 12 months prior to enrollment, are medically stable and aged ≥60 years.

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
507

participants targeted

Target at P50-P75 for phase_3

Timeline
Completed

Started Aug 2025

Shorter than P25 for phase_3

Geographic Reach
1 country

11 active sites

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

August 5, 2025

Completed
Same day until next milestone

Study Start

First participant enrolled

August 5, 2025

Completed
7 days until next milestone

First Posted

Study publicly available on registry

August 12, 2025

Completed
8 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

March 27, 2026

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

March 27, 2026

Completed
Last Updated

May 4, 2026

Status Verified

April 1, 2026

Enrollment Period

8 months

First QC Date

August 5, 2025

Last Update Submit

April 30, 2026

Conditions

Respiratory Syncytial Virus

Keywords

Viral DiseasesMessenger RNAModernamRNA-1345Respiratory syncytial virusSafetyVaccines

Outcome Measures

Primary Outcomes (5)

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

    Day 1 up to Day 7 (7 days post-injection)

  • Number of Participants with Unsolicited Adverse Events (AEs)

    Day 1 up to Day 28 (28 days post-injection)

  • Number of Participants with Medically Attended AEs (MAAEs), Serious AEs (SAEs), AEs of Special Interest (AESIs), and AEs Leading to Discontinuation

    Day 1 up to Day 181 (End of study)

  • Geometric Mean Titer (GMT) of Serum RSV-A Neutralizing Antibodies (Abs) at Day 29

    Day 29

  • GMT of Serum RSV-B Neutralizing Abs at Day 29

    Day 29

Secondary Outcomes (8)

  • GMT of Serum RSV-A Neutralizing Abs

    Day 1 up to Day 181 (End of study)

  • Geometric Mean Fold Rise (GMFR) of Serum RSV-A Neutralizing Abs

    Day 181

  • GMT of Serum RSV-B Neutralizing Abs

    Day 1 up to Day 181 (End of study)

  • GMFR of Serum RSV-B Neutralizing Abs

    Day 181

  • Percentage of Participants With Seroresponse in RSV-A Neutralizing Abs

    Day 181

  • +3 more secondary outcomes

Study Arms (1)

mRNA-1345

EXPERIMENTAL

Participants will receive a single dose of mRNA-1345 injection administered intramuscularly on Day 1.

Biological: mRNA-1345

Interventions

mRNA-1345BIOLOGICAL

Suspension for injection

mRNA-1345

Eligibility Criteria

Age60 Years+
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Participants may have one or more chronic medical diagnoses, but should be medically stable as assessed by:
  • Absence of changes in medical therapy within 60 days of Visit 1 due to treatment failure or toxicity.
  • Absence of serious or significant medical events within 30 days of Visit 1.
  • Absence of known, current, and life-limiting diagnoses which, in the opinion of the Investigator, would make completion of the protocol unlikely.
  • Participant has received a single dose of Arexvy or Abrysvo at least 12 months prior to Visit 1. Participants must provide proof of RSV vaccination status (including brand and date received) prior to enrollment.

You may not qualify if:

  • Participant has received or plans to receive any vaccine authorized or approved by a local health agency ≤14 days prior to study injection (Day 1) or plans to receive a vaccine authorized or approved by a local health agency within 14 days after the study injection. Nonstudy vaccination(s) should not be delayed.
  • Prior participation in research involving receipt of any investigational RSV product (drug/biologic).
  • Has received systemic immunoglobulins, long-acting biological therapies that affect immune responses (for example, infliximab) or blood products within 90 days prior to Visit 1 or plans to receive them during the study.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (11)

Velocity Clinical Research, Denver

Denver, Colorado, 80110, United States

Location

Indago Research & Health Center, Inc.

Hialeah, Florida, 33012, United States

Location

Velocity Clinical Research, Savannah

Savannah, Georgia, 31406, United States

Location

Velocity Clinical Research, Valparaiso

Valparaiso, Indiana, 46383, United States

Location

Velocity Clinical Research, Covington

Covington, Louisiana, 70433, United States

Location

Velocity Clinical Research, Rockville

Rockville, Maryland, 20854, United States

Location

Velocity Clinical Research, Lincoln

Lincoln, Nebraska, 68510, United States

Location

Velocity Clinical Research, Medford

Medford, Oregon, 97504, United States

Location

Velocity Clinical Research, Austin

Austin, Texas, 78759, United States

Location

Velocity Clinical Research, Hampton

Hampton, Virginia, 23666, United States

Location

Velocity Clinical Research, Spokane

Spokane, Washington, 99218, United States

Location

MeSH Terms

Conditions

Virus Diseases

Interventions

mRNA-1345 respiratory syncytial virus vaccine

Condition Hierarchy (Ancestors)

Infections

Study Design

Study Type
interventional
Phase
phase 3
Allocation
NA
Masking
NONE
Purpose
PREVENTION
Intervention Model
SINGLE GROUP
Sponsor Type
INDUSTRY
Responsible Party
SPONSOR

Study Record Dates

First Submitted

August 5, 2025

First Posted

August 12, 2025

Study Start

August 5, 2025

Primary Completion

March 27, 2026

Study Completion

March 27, 2026

Last Updated

May 4, 2026

Record last verified: 2026-04

Locations

US(11)