A Safety, Tolerability, and Immunogenicity Study of mRNA-1345 and mRNA-1365 in Participants Aged 5 Months to <24 Months

NCT ID: NCT05743881

Last Updated: 2025-11-24

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

ACTIVE_NOT_RECRUITING

Clinical Phase

PHASE1

Total Enrollment

186 participants

Study Classification

INTERVENTIONAL

Study Start Date

2023-02-15

Study Completion Date

2026-09-30

Brief Summary

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The purpose of this study is to assess the safety and immunogenicity of mRNA-1365, an mRNA vaccine targeting respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) and mRNA-1345, an mRNA vaccine targeting RSV, in participants aged 5 months to \<24 months.

Detailed Description

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Conditions

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Respiratory Syncytial Virus Human Metapneumovirus

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

TREATMENT

Blinding Strategy

TRIPLE

Participants Investigators Outcome Assessors
Parts A and B are blinded, and Part C is open-label.

Study Groups

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Part A: mRNA-1345, Dose 1 (Age Group: 8 to <24 months)

Participants will receive mRNA-1345 vaccine by intramuscular (IM) injection on Days 1, 57 and 113.

Group Type EXPERIMENTAL

mRNA-1345

Intervention Type BIOLOGICAL

Sterile liquid for injection

Part A: mRNA-1365, Dose 1 (Age Group: 8 to <24 months)

Participants will receive mRNA-1365 vaccine by IM injection on Days 1, 57 and 113.

Group Type EXPERIMENTAL

mRNA-1365

Intervention Type BIOLOGICAL

Sterile liquid for injection

Part A: Placebo (Age Group: 8 to <24 months)

Participants will receive mRNA-1345/ mRNA-1365 vaccine matching placebo by IM injection on Days 1, 57 and 113. In countries where applicable, participants may receive Nimenrix instead of placebo on Day 113.

Group Type PLACEBO_COMPARATOR

Placebo

Intervention Type BIOLOGICAL

0.9% sodium chloride (normal saline) solution for injection

Nimenrix

Intervention Type DRUG

Solution for injection

Part B: mRNA-1345, Dose 2 (Age Group: 5 to <8 months)

Participants will receive mRNA-1345 by IM injection on Days 1, 57 and 113.

Group Type EXPERIMENTAL

mRNA-1345

Intervention Type BIOLOGICAL

Sterile liquid for injection

Part B: mRNA-1365, Dose 2 (Age Group: 5 to <8 months)

Participants will receive mRNA-1365 by IM injection on Days 1, 57 and 113.

Group Type EXPERIMENTAL

mRNA-1365

Intervention Type BIOLOGICAL

Sterile liquid for injection

Part B: mRNA-1345 Dose 1 (Age Group: 5 to <8 months)

Participants will receive mRNA-1345 by IM injection on Days 1, 57 and 113.

Group Type EXPERIMENTAL

mRNA-1345

Intervention Type BIOLOGICAL

Sterile liquid for injection

Part B: mRNA-1365 Dose 1 (Age Group: 5 to <8 months)

Participants will receive mRNA-1365 by IM injection on Days 1, 57 and 113.

Group Type EXPERIMENTAL

mRNA-1365

Intervention Type BIOLOGICAL

Sterile liquid for injection

Part B: Placebo (Age Group: 5 to <8 months)

Participants will receive mRNA-1345/ mRNA-1365 vaccine matching placebo by IM injection on Days 1, 57 and 113. In countries where applicable, participants may receive Nimenrix instead of placebo on Day 113.

Group Type PLACEBO_COMPARATOR

Placebo

Intervention Type BIOLOGICAL

0.9% sodium chloride (normal saline) solution for injection

Nimenrix

Intervention Type DRUG

Solution for injection

Part C: mRNA-1345 Dose 1 (Age Group 8 to <12 months exposed to nirsevimab)

Participants who have been previously exposed to nirsevimab will receive mRNA 1345 by IM on Days 1, 57, and 113.

Group Type EXPERIMENTAL

mRNA-1345

Intervention Type BIOLOGICAL

Sterile liquid for injection

Part C: mRNA-1345 Dose 1 (Age Group 8 to <12 months not exposed to nirsevimab)

Participants who have not been previously exposed to nirsevimab will receive mRNA 1345 by IM on Days 1, 57, and 113.

Group Type EXPERIMENTAL

mRNA-1345

Intervention Type BIOLOGICAL

Sterile liquid for injection

Interventions

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mRNA-1345

Sterile liquid for injection

Intervention Type BIOLOGICAL

mRNA-1365

Sterile liquid for injection

Intervention Type BIOLOGICAL

Placebo

0.9% sodium chloride (normal saline) solution for injection

Intervention Type BIOLOGICAL

Nimenrix

Solution for injection

Intervention Type DRUG

Eligibility Criteria

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Inclusion Criteria

* The participant is 8 months to \<24 months (Part A), 5 months to \<8 months (Part B), or 8 months to \<12 months (Part C) of age at the time of randomization (Day 1/Baseline visit), who is in good general health, in the opinion of the Investigator, based on review of medical history and screening physical examination.
* In the Investigator's opinion, the parent(s)/ legally authorized representative (LAR)(s) understand and are willing and physically able to comply with protocol-mandated follow up, including all procedures, and provide written informed consent.
* The participant is growing normally for age in the opinion of the site clinician in the months prior to enrollment.
* The participant was born at full-term (≥37 weeks gestation) with a minimum birth weight of 2.5 kilograms (kg).
* For Part C Cohort 7: participant must have received nirsevimab ≥6 months prior to Day 1 Visit.
* For Part C Cohort 8: participant was eligible at any time since birth, according to national guidelines, to receive nirsevimab prior to Day 1 Visit but did not do so.

Exclusion Criteria

* Has a known history of symptomatic RSV (Part A: within 3 months; Part B and Part C: since birth) or hMPV infection (Part A: within 3 months; Part B: since birth) prior to administration of the first dose of investigational product (IP) or has a known close contact with anyone with laboratory-confirmed RSV (Parts A, B, and C) or hMPV infection (Parts A or B) within 14 days prior to administration of the first dose of IP.
* Is acutely ill or febrile 24 hours prior to or at the screening visit. Fever is defined as a body temperature ≥38.0°Celsius/≥100.4°Fahrenheit. Participants who meet this criterion may have visits rescheduled within the relevant study visit windows.
* Has previously been administered an investigational or approved vaccine for prevention of RSV (Parts A, B, and C) or hMPV (Parts A and B) infection or if the participant's mother received an investigational or approved vaccine for the prevention of RSV (Parts A, B, and C) or hMPV (Parts A and B) infection during pregnancy.
* Has received investigational or approved agents for prophylaxis against RSV or hMPV (for example, monoclonal antibodies) or is intending to receive these during the course of the study. For Part C (Cohort 7 only), use of nirsevimab ≥6 months before Day 1 Visit is allowed.
* Has a known hypersensitivity to a component of the vaccine or its excipients. Hypersensitivity includes, but is not limited to, anaphylaxis or immediate allergic reaction of any severity to a previous dose of an mRNA vaccine or any of its components (including polyethylene glycol or immediate allergic reaction of any severity to polysorbate).
* Has a medical condition that, according to the Investigator's judgment, may pose additional risk as a result of participation, interfere with safety assessments, or interfere with interpretation of results.
Minimum Eligible Age

5 Months

Maximum Eligible Age

24 Months

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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ModernaTX, Inc.

INDUSTRY

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Locations

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Matrix Clinical Research

Los Angeles, California, United States

Site Status

Los Angeles Children's Hospital

Los Angeles, California, United States

Site Status

Velocity Clinical Research, Denver

Englewood, Colorado, United States

Site Status

Meridian Clinical Research

Washington D.C., District of Columbia, United States

Site Status

Meridian Clinical Research

Washington D.C., District of Columbia, United States

Site Status

University Of Florida Health Science Center

Jacksonville, Florida, United States

Site Status

Accel Research Sites - Nona Pediatric Center

Orlando, Florida, United States

Site Status

Clinical Research Prime

Idaho Falls, Idaho, United States

Site Status

MedPharmics - Platinum - PPDS

Lafayette, Louisiana, United States

Site Status

Umass Memorial Medical Center

Worcester, Massachusetts, United States

Site Status

UMASS Chan Medical School

Worcester, Massachusetts, United States

Site Status

Henry Ford Health System

Detroit, Michigan, United States

Site Status

Great Lakes Research Institute

Southfield, Michigan, United States

Site Status

Pediatric Specialty Care Discovery Clinic

Minneapolis, Minnesota, United States

Site Status

Washington University School of Medicine in St. Louis

St Louis, Missouri, United States

Site Status

Meridian Clinical Research

Hastings, Nebraska, United States

Site Status

Duke Vaccine and Trials Unit

Durham, North Carolina, United States

Site Status

Senders Pediatrics

South Euclid, Ohio, United States

Site Status

Velocity Clinical Research - Providence

Providence, Rhode Island, United States

Site Status

Palmetto Pediatrics, PA

North Charleston, South Carolina, United States

Site Status

Vanderbilt Vaccine Research Program

Nashville, Tennessee, United States

Site Status

Texas Tech University Health Sciences Center

El Paso, Texas, United States

Site Status

Mercury Clinical Research, Inc.

Houston, Texas, United States

Site Status

CyFair

Houston, Texas, United States

Site Status

Pediatric Associates

Houston, Texas, United States

Site Status

Village Pediatrics

Plano, Texas, United States

Site Status

Mercury Clinical Research, Inc.

Richmond, Texas, United States

Site Status

Pediatric Center

Richmond, Texas, United States

Site Status

North Houston Internal Medicine &amp; Pediatric Clinic

Tomball, Texas, United States

Site Status

Childrens Hospital Regional Medical Center

Seattle, Washington, United States

Site Status

Telethon Kids Institute

Nedlands, Western Australia, Australia

Site Status

BC Children's Hospital - Vaccine Evaluation Centre - Neonatology

Vancouver, British Columbia, Canada

Site Status

Dalhousie University IWK Health Centre

Halifax, Nova Scotia, Canada

Site Status

London Health Sciences Centre - Victoria Hospital

London, Ontario, Canada

Site Status

Universite de Montreal - Centre Hospitalier Universitaire (CHU) Sainte-Justine

Montreal, Quebec, Canada

Site Status

CEVAXIN David

David, Chiriquí Province, Panama

Site Status

CEVAXIN Chorrera

La Chorrera, Panamá Oeste Province, Panama

Site Status

CEVAXIN Avenida Mexico

Panama City, , Panama

Site Status

CEVAXIN 24 de Diciembre

Panama City, , Panama

Site Status

Shandukani Research CRS

Hillbrow, Gauteng, South Africa

Site Status

Wits Health Consortium

Johannesburg, Gauteng, South Africa

Site Status

Setshaba Research centre

Soshanguve, Gauteng, South Africa

Site Status

Family Centre for Research with Ubuntu (FAMCRU)- Tygerberg

Cape Town, Western Cape, South Africa

Site Status

Practice Dr Jan Vermeulen

Cape Town, Western Cape, South Africa

Site Status

Alder Hey NHS Foundation Trust - Pharmacy Clinical Trials

Liverpool, , United Kingdom

Site Status

St George's Hospital

London, , United Kingdom

Site Status

Imperial College London and Imperial College Healthcare NHS

London, , United Kingdom

Site Status

Norfolk and Norwich University Hospitals

Norwich, , United Kingdom

Site Status

John Radcliffe Hospital

Oxford, , United Kingdom

Site Status

Southampton General Hospital

Southampton, , United Kingdom

Site Status

Countries

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United States Australia Canada Panama South Africa United Kingdom

References

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Amodio D, Angelidou A, Cotugno N, Sherman AC, Levy O, Palma P; IPVC 2023 Speakers' group. Biomarkers of vaccine safety and efficacy in vulnerable populations: Lessons from the fourth international precision vaccines conference. Vaccine. 2025 Jan 1;43(Pt 2):126477. doi: 10.1016/j.vaccine.2024.126477. Epub 2024 Nov 28.

Reference Type DERIVED
PMID: 39608233 (View on PubMed)

Other Identifiers

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2022-502022-41

Identifier Type: EUDRACT_NUMBER

Identifier Source: secondary_id

2022-502022-41-00

Identifier Type: OTHER

Identifier Source: secondary_id

mRNA-1365-P101

Identifier Type: -

Identifier Source: org_study_id

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