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

NCT05743881 | Active Not Recruiting Phase 1 FDA Drug

• 3 other identifiers: mRNA-1365-P1012022-502022-412022-502022-41-00
• Study Type: interventional
• Target: 186
• Locations: 6 countries
• Sites: 50

Brief Summary

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.

Conditions

Respiratory Syncytial Virus; Human Metapneumovirus

Keywords

mRNA-1345; mRNA-1365; RSV vaccine; hMPV vaccine; RSV/hMPV vaccine

Outcome Measures

Primary Outcomes (4)

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

  Up to Day 120 (7 days after each injection)

• Number of Participants with Unsolicited Adverse Events (AEs)

  Up to Day 141 (28 days after each injection)

• Number of Participants with Medically-Attended Adverse Events (MAAEs)

  Day 1 through Day 730

• Number of Participants with Adverse Event of Special Interests (AESIs), Serious Adverse Events (SAEs) and Adverse Events Leading to Discontinuation

  Day 1 through Day 730

Secondary Outcomes (7)

• Number of Participants with Respiratory Tract Illness (RTI), Lower Respiratory Tract Illness (LRTI), Severe LRTI, Very Severe LRTI, and Hospitalizations Associated with RSV or hMPV

  Day 1 through Day 730

• Parts A and B: Geometric Mean Titer (GMT) of Serum RSV and hMPV Neutralizing Antibodies

  Baseline up to Month 12

• Part C: GMT of Serum RSV Neutralizing Antibodies

  Baseline up to Month 12

• Parts A and B: Geometric Mean Concentration (GMC) of Serum RSV F- and hMPV F-Binding Antibodies

  Baseline up to Month 12

• Part C: GMC of Serum RSV F-Binding Antibodies

  Baseline up to Month 12

Study Arms (10)

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

EXPERIMENTAL

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

Biological: mRNA-1345

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

EXPERIMENTAL

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

Biological: mRNA-1365

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

PLACEBO COMPARATOR

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.

Biological: Placebo; Drug: Nimenrix

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

EXPERIMENTAL

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

Biological: mRNA-1345

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

EXPERIMENTAL

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

Biological: mRNA-1365

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

EXPERIMENTAL

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

Biological: mRNA-1345

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

EXPERIMENTAL

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

Biological: mRNA-1365

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

PLACEBO COMPARATOR

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.

Biological: Placebo; Drug: Nimenrix

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

EXPERIMENTAL

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

Biological: mRNA-1345

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

EXPERIMENTAL

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

Biological: mRNA-1345

Interventions

mRNA-1345 BIOLOGICAL

Sterile liquid for injection

Part A: mRNA-1345, Dose 1 (Age Group: 8 to <24 months); Part B: mRNA-1345 Dose 1 (Age Group: 5 to <8 months); Part B: mRNA-1345, Dose 2 (Age Group: 5 to <8 months); Part C: mRNA-1345 Dose 1 (Age Group 8 to <12 months exposed to nirsevimab); Part C: mRNA-1345 Dose 1 (Age Group 8 to <12 months not exposed to nirsevimab)

mRNA-1365 BIOLOGICAL

Sterile liquid for injection

Part A: mRNA-1365, Dose 1 (Age Group: 8 to <24 months); Part B: mRNA-1365 Dose 1 (Age Group: 5 to <8 months); Part B: mRNA-1365, Dose 2 (Age Group: 5 to <8 months)

Placebo BIOLOGICAL

0.9% sodium chloride (normal saline) solution for injection

Part A: Placebo (Age Group: 8 to <24 months); Part B: Placebo (Age Group: 5 to <8 months)

Nimenrix DRUG

Solution for injection

Part A: Placebo (Age Group: 8 to <24 months); Part B: Placebo (Age Group: 5 to <8 months)

Eligibility Criteria

• Age: 5 Months - 24 Months
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17)

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• ModernaTX, Inc.: lead

Study Sites (50)

Matrix Clinical Research

Los Angeles, California, 90057, United States

Location

Los Angeles Children's Hospital

Los Angeles, California, 90095, United States

Location

Velocity Clinical Research, Denver

Englewood, Colorado, 80110, United States

Location

Meridian Clinical Research

Washington D.C., District of Columbia, 20016-4358, United States

Location

Meridian Clinical Research

Washington D.C., District of Columbia, 20016, United States

Location

University Of Florida Health Science Center

Jacksonville, Florida, 32209, United States

Location

Accel Research Sites - Nona Pediatric Center

Orlando, Florida, 32829-8070, United States

Location

Clinical Research Prime

Idaho Falls, Idaho, 83404, United States

Location

MedPharmics - Platinum - PPDS

Lafayette, Louisiana, 70508, United States

Location

Umass Memorial Medical Center

Worcester, Massachusetts, 01655-0002, United States

Location

UMASS Chan Medical School

Worcester, Massachusetts, 01655, United States

Location

Henry Ford Health System

Detroit, Michigan, 48202-2608, United States

Location

Great Lakes Research Institute

Southfield, Michigan, 48075-5400, United States

Location

Pediatric Specialty Care Discovery Clinic

Minneapolis, Minnesota, 55454-1404, United States

Location

Washington University School of Medicine in St. Louis

St Louis, Missouri, 63110, United States

Location

Meridian Clinical Research

Hastings, Nebraska, 68901-2640, United States

Location

Duke Vaccine and Trials Unit

Durham, North Carolina, 27703, United States

Location

Senders Pediatrics

South Euclid, Ohio, 44121, United States

Location

Velocity Clinical Research - Providence

Providence, Rhode Island, 02886, United States

Location

Palmetto Pediatrics, PA

North Charleston, South Carolina, 29406-9170, United States

Location

Vanderbilt Vaccine Research Program

Nashville, Tennessee, 37232, United States

Location

Texas Tech University Health Sciences Center

El Paso, Texas, 79905, United States

Location

Mercury Clinical Research, Inc.

Houston, Texas, 77054, United States

Location

CyFair

Houston, Texas, 77065, United States

Location

Pediatric Associates

Houston, Texas, 77087, United States

Location

Village Pediatrics

Plano, Texas, 75024, United States

Location

Mercury Clinical Research, Inc.

Richmond, Texas, 77469-3348, United States

Location

Pediatric Center

Richmond, Texas, 77469, United States

Location

North Houston Internal Medicine &amp; Pediatric Clinic

Tomball, Texas, 77375, United States

Location

Childrens Hospital Regional Medical Center

Seattle, Washington, 98105, United States

Location

Telethon Kids Institute

Nedlands, Western Australia, 6009, Australia

Location

BC Children's Hospital - Vaccine Evaluation Centre - Neonatology

Vancouver, British Columbia, V5Z 4H4, Canada

Location

Dalhousie University IWK Health Centre

Halifax, Nova Scotia, B3K 6R8, Canada

Location

London Health Sciences Centre - Victoria Hospital

London, Ontario, N6A 5W9, Canada

Location

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

Montreal, Quebec, Canada

Location

CEVAXIN David

David, Chiriquí Province, 0401, Panama

Location

CEVAXIN Chorrera

La Chorrera, Panamá Oeste Province, Panama

Location

CEVAXIN Avenida Mexico

Panama City, 0801, Panama

Location

CEVAXIN 24 de Diciembre

Panama City, Panama

Location

Shandukani Research CRS

Hillbrow, Gauteng, 2001, South Africa

Location

Wits Health Consortium

Johannesburg, Gauteng, 2013, South Africa

Location

Setshaba Research centre

Soshanguve, Gauteng, 0152, South Africa

Location

Family Centre for Research with Ubuntu (FAMCRU)- Tygerberg

Cape Town, Western Cape, 7440, South Africa

Location

Practice Dr Jan Vermeulen

Cape Town, Western Cape, 7530, South Africa

Location

Alder Hey NHS Foundation Trust - Pharmacy Clinical Trials

Liverpool, L12 2AP, United Kingdom

Location

St George's Hospital

London, SW170RE, United Kingdom

Location

Imperial College London and Imperial College Healthcare NHS

London, United Kingdom

Location

Norfolk and Norwich University Hospitals

Norwich, NR4 7UY, United Kingdom

Location

John Radcliffe Hospital

Oxford, OX3 9DU, United Kingdom

Location

Southampton General Hospital

Southampton, SO16 6YD, United Kingdom

Location

Related Publications (1)

• 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.

  PMID: 39608233 DERIVED

MeSH Terms

Interventions

mRNA-1345 respiratory syncytial virus vaccine

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: Parts A and B are blinded, and Part C is open-label.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: February 15, 2023
• First Posted: February 24, 2023
• Study Start: February 15, 2023
• Primary Completion (Estimated): August 31, 2026
• Study Completion (Estimated): September 30, 2026
• Last Updated: November 24, 2025

Record last verified: 2025-11

Locations

AU (1); CA (4); ZA (5); GB (6); PA (4); US (30)