NCT06097299

Brief Summary

Part A: The purpose is to evaluate the safety, reactogenicity, and immunogenicity of mRNA-1345 in children aged 2 to \<5 years (Cohort 1) and in children at high risk of respiratory syncytial virus (RSV) disease 5 to \<18 years of age (Cohort 2) to inform the dose level selection for the next phase of development (Phase 3). Part B: The purpose is to provide surveillance for RSV disease for the next RSV season (6 months after re-enrollment) and safety follow-up for Cohort 1 participants that were enrolled and dosed in Part A.

Trial Health

90
On Track

Trial Health Score

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

Enrollment
349

participants targeted

Target at P75+ for phase_2

Timeline
Completed

Started Oct 2023

Geographic Reach
2 countries

50 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

October 18, 2023

Completed
6 days until next milestone

First Posted

Study publicly available on registry

October 24, 2023

Completed
Same day until next milestone

Study Start

First participant enrolled

October 24, 2023

Completed
1.7 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

June 27, 2025

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

June 27, 2025

Completed
1.1 years until next milestone

Results Posted

Study results publicly available

August 18, 2026

Completed
Last Updated

August 18, 2026

Status Verified

July 1, 2026

Enrollment Period

1.7 years

First QC Date

October 18, 2023

Results QC Date

June 11, 2026

Last Update Submit

July 27, 2026

Conditions

Keywords

PediatricmRNA-1345RSV vaccineViral DiseasesMessenger RNAModerna

Outcome Measures

Primary Outcomes (4)

  • Part A (Cohorts 1 and 2): Number of Participants With Solicited Local and Systemic Adverse Reactions (ARs)

    Solicited ARs were collected in an electronic diary (eDiary). Local ARs: injection site pain, erythema (redness), swelling/induration (hardness); and axillary (underarm) swelling or tenderness ipsilateral to the side of injection. Systemic ARs: fever, headache, fatigue, myalgia, arthralgia, nausea/vomiting, and chills. Note, not all solicited ARs were considered adverse events (AEs). Investigator reviewed whether the solicited AR was also to be recorded as an AE. A summary of serious AEs (SAEs) and nonserious AEs ("Other"), regardless of causality, is located in the "Reported Adverse Events" section.

    Up to 7 days post-injection

  • Part A (Cohorts 1 and 2): Number of Participants With Unsolicited Adverse Events (AEs)

    An AE was defined as any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related. Any abnormal laboratory test result (hematology, clinical chemistry, or prothrombin time \[PT\]/partial thromboplastin time \[PTT\]) or other safety assessment (for example, electrocardiogram, radiological scan, vital sign measurement), including one that worsened from baseline and was considered clinically significant in the medical and scientific judgment of the Investigator was recorded as an AE. A summary of SAEs and all nonserious AEs ("Other"), regardless of causality, is located in the "Reported Adverse Events" section.

    Up to 28 days post-injection

  • Part A (Cohorts 1 and 2): Number of Participants With Medically Attended AEs (MAAEs), Adverse Events of Special Interest (AESIs), Serious Adverse Events (SAEs), and AEs Leading to Study Discontinuation

    A MAAE was an AE that led to an unscheduled visit to a healthcare practitioner. An AESI was an AE (serious or nonserious) of scientific and medical concern specific to the Sponsor's product or program, for which ongoing monitoring and immediate notification by the Investigator to the Sponsor are required. An SAE was defined as any AE that resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in disability, was a congenital anomaly/birth defect, or was an important medical event. A summary of SAEs and all nonserious AEs ("Other"), regardless of causality, is located in the "Reported Adverse Events" section.

    Day 1 through end of Part A (Month 6)

  • Part B (Cohort 1): Number of Participants With RSV-RTD, Respiratory Syncytial Virus- Lower Respiratory Tract Disease (RSV-LRTD), Severe RSV-LRTD, Very Severe RSV-LRTD and RSV Hospitalization Classified by Clinical Assessment Team (CAT)

    RSV-RTD: Runny nose or blocked nose or cough and confirmed RSV infection. RSV-LRTD: Cough or difficulty breathing (Based on Investigator's observation; difficulty breathing included signs of wheezing, stridor, tachypnoea, chest in-drawing or subcostal or intercostal retractions) and peripheral oxygen saturation (SpO2) \<95%, or respiratory rate (RR) increased and confirmed RSV infection. RSV Severe-LRTD: Meeting the definition of RSV-LRTD and SpO2 \<93%, or lower chest wall in-drawing. RSV Very Severe LRTD: Meeting the definition of RSV-LRTD and SpO2 \<90%, or failure to respond/unconscious. RSV Hospitalization: Confirmed RSV and hospitalized for acute medical condition.

    Day 1 through end of Part B (Month 6)

Secondary Outcomes (13)

  • Part A (Cohort 1): Geometric Mean Titer (GMT) of Serum RSV Neutralizing Antibody

    Day 1, Day 29, and Month 6

  • Part A (Cohort 1): Geometric Mean Concentration (GMC) of Serum RSV Prefusion F (Pre-F) Binding Antibody

    Day 1, Day 29, and Month 6

  • Part A (Cohort 1): Geometric Mean Fold Rise (GMFR) of Post-baseline/Baseline Neutralizing Antibody Titers

    Day 29 and Month 6

  • Part A (Cohort 1): GMFR of Post-baseline/Baseline Binding Antibody Concentrations

    Day 29 and Month 6

  • Part A (Cohort 1): Percentage of Participants With Seroresponse in RSV Neutralizing Antibody

    Baseline to Day 29 and Month 6

  • +8 more secondary outcomes

Study Arms (2)

Part A and Part B: Cohort 1 (2 to <5 Years of Age)

EXPERIMENTAL

Part A: Participants 2 to \<5 years of age will receive either a single intramuscular (IM) injection of mRNA-1345 or placebo on Day 1. Part B: Participants will have the option to be re-enrolled into a 6-month safety-follow up period.

Biological: mRNA-1345Biological: Placebo

Part A: Cohort 2 (5 to <18 Years of Age)

EXPERIMENTAL

Participants 5 to \<18 years of age will receive a single IM injection of mRNA-1345 on Day 1.

Biological: mRNA-1345

Interventions

mRNA-1345BIOLOGICAL

Sterile liquid for injection

Part A and Part B: Cohort 1 (2 to <5 Years of Age)Part A: Cohort 2 (5 to <18 Years of Age)
PlaceboBIOLOGICAL

0.9% sodium chloride (normal saline) injection

Part A and Part B: Cohort 1 (2 to <5 Years of Age)

Eligibility Criteria

Age2 Years - 17 Years
Sexall
Healthy VolunteersYes
Age GroupsChild (0-17)

You may qualify if:

  • Part A Cohort 1:
  • to \<5 years of age at Day 1.
  • Healthy, or with stable chronic conditions increasing the risk of RSV disease, per the clinical judgment of the Investigator.
  • Cohort 2:
  • to \<18 years of age at Day 1.
  • Participants with stable chronic conditions increasing the risk of RSV disease.
  • Female participants of child-bearing potential may be enrolled in the study, if the participant: 1) has a negative urine pregnancy test at Screening and on the day of injection (Day 1); 2) has practiced adequate contraception or has abstained from all activities that could lead to pregnancy for 28 days prior to Day 1; 3) has agreed to continue adequate contraception through 90 days following injection; and 4) is not currently breastfeeding.
  • Part B: Cohort 1 Re-enrollment
  • Participants are eligible to be included in the study only if all of the following criteria apply:
  • Enrolled and dosed in Part A of Cohort 1; either reached EoS for Part A or were dosed and subsequently discontinued from study for various reasons. This includes participants who were lost to follow-up, if they can be re-engaged.
  • Participant's parent(s)/LAR(s) has provided written informed consent for participation in this study.

You may not qualify if:

  • Acutely ill or febrile (temperature ≥38.0°Celsius \[100.4°Fahrenheit\]) within 72 hours prior to or at the Screening Visit or Day 1.
  • History of a diagnosis or condition that, in the judgment of the Investigator, may affect study assessment or compromise participant safety.
  • Has received or plans to receive any licensed or authorized vaccine ≤14 days prior to the study vaccine injection (Day 1) or plans to receive a licensed or authorized vaccine within 14 days after the study vaccine injection.
  • Receipt of any prior systemic immunosuppressants. Short courses (\<7 days) of oral corticosteroids are allowed if completed at least 3 months prior to enrollment.
  • Receipt of RSV monoclonal antibodies within 6 months prior to enrollment in the study.
  • Participated in an interventional clinical study within 28 days (6 months for a study assessing a product unlicensed/unauthorized in this age group in country of residence at time of enrollment) prior to the day of enrollment or plans to do so while enrolled in this study.
  • Part B: Cohort 1 Re-enrollment
  • \. Participant is currently enrolled in another interventional clinical study.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (50)

Velocity Clinical Research, Phoenix

Phoenix, Arizona, 85006, United States

Location

Headlands Research - Scottsdale

Scottsdale, Arizona, 85260, United States

Location

Velocity Clinical Research - Banning

Banning, California, 92220, United States

Location

ASCADA Research, LLC - Family Medicine

Fullerton, California, 92835, United States

Location

Ark Clinical Research

Long Beach, California, 90815, United States

Location

Peninsula Research Associates (PRA)

Rolling Hills Estates, California, 90274, United States

Location

D&amp;H Doral Research Center, LLC

Doral, Florida, 33122, United States

Location

Kissimmee Clinical Research

Kissimmee, Florida, 34741, United States

Location

Accel Clinical

Largo, Florida, 33777, United States

Location

Med-Care Research

Miami, Florida, 33125, United States

Location

Accel Research Sites - Nona Pediatric Center

Orlando, Florida, 32829, United States

Location

SEC Clinical Research

Pensacola, Florida, 32501, United States

Location

D&H Tamarac Research Center

Tamarac, Florida, 33321, United States

Location

Javara, Inc.

Fayetteville, Georgia, 30214, United States

Location

Velocity Clinical Research-Primary Pediatrics, Macon

Macon, Georgia, 31210, United States

Location

CenExel iResearch, LLC

Savannah, Georgia, 31405, United States

Location

Clinical Research Prime

Idaho Falls, Idaho, 83404, United States

Location

Velocity Clinical Research - Boise

Meridian, Idaho, 83642, United States

Location

Alliance for Multispeciality Research, LLC

El Dorado, Kansas, 67042, United States

Location

Velocity Clinical Research-Kansas City

Overland Park, Kansas, 66210, United States

Location

Velocity Clinical Research - Lafayette

Lafayette, Louisiana, 70508, United States

Location

Velocity Clinical Research Metairie

Metairie, Louisiana, 70006, United States

Location

Great Lakes Research Institute

Southfield, Michigan, 48075, United States

Location

Pediatric &amp; Adolescent Center

Southgate, Michigan, 48195-1896, United States

Location

Clinical Research Institute

Minneapolis, Minnesota, 55402, United States

Location

Velocity Clinical Research, Gulfport

Gulfport, Mississippi, 39503, United States

Location

Velocity Clinical Research- Albuquerque

Albuquerque, New Mexico, 87107, United States

Location

Velocity Clinical Research-Binghamton

Binghamton, New York, 13905, United States

Location

University of Rochester Medical Center (URMC) - Golisano Children's Hospital (GCH)

Rochester, New York, 14620, United States

Location

Senders Pediatrics

South Euclid, Ohio, 44121, United States

Location

The Children's Hospital of Philadelphia - Pediatrics

Philadelphia, Pennsylvania, 19104-4318, United States

Location

DM Clinical Research - Philadelphia

Philadelphia, Pennsylvania, 19107, United States

Location

Velocity Clinical Research - Providence

Providence, Rhode Island, 02886, United States

Location

Coastal Pediatric Research

Charleston, South Carolina, 29414, United States

Location

Tribe Clinical Research

Simpsonville, South Carolina, 29680, United States

Location

Elligo Clinical Research Center

Austin, Texas, 78704, United States

Location

REX Clinical Trials, LLC

Beaumont, Texas, 77701, United States

Location

Javara Inc (Conroe)

Conroe, Texas, 77384, United States

Location

West Houston Clinical Research Service

Houston, Texas, 77055, United States

Location

DM Clinical Research - CyFair

Houston, Texas, 77065, United States

Location

Village Pediatrics

Plano, Texas, 75024, United States

Location

Javara Inc/Texas Health Care, PLLC d/b/a/ Privia Medical Group-North Texas

Stephenville, Texas, 76401, United States

Location

Victoria Clinical Research Group

Victoria, Texas, 77901, United States

Location

Velocity Clinical Research - Salt Lake City

West Jordan, Utah, 84088, United States

Location

PI-Coor Clinical Research, LLC

Annandale, Virginia, 22003, United States

Location

Clinical Research Partners

Richmond, Virginia, 23226, United States

Location

National Clinical Research, Inc.

Richmond, Virginia, 23294, United States

Location

CEVAXIN Chorrera

La Chorrera, 07066, Panama

Location

CEVAXIN Avenida Mexico

Panama City, 07093, Panama

Location

CEVAXIN 24 de Diciembre

Panama City, 07114, Panama

Location

MeSH Terms

Conditions

Virus Diseases

Interventions

mRNA-1345 respiratory syncytial virus vaccine

Condition Hierarchy (Ancestors)

Infections

Results Point of Contact

Title
Moderna WeCare Team
Organization
ModernaTX, Inc.

Publication Agreements

PI is Sponsor Employee
No
Restrictive Agreement
Yes

Study Design

Study Type
interventional
Phase
phase 2
Allocation
RANDOMIZED
Masking
QUADRUPLE
Who Masked
PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
Purpose
PREVENTION
Intervention Model
PARALLEL
Sponsor Type
INDUSTRY
Responsible Party
SPONSOR

Study Record Dates

First Submitted

October 18, 2023

First Posted

October 24, 2023

Study Start

October 24, 2023

Primary Completion

June 27, 2025

Study Completion

June 27, 2025

Last Updated

August 18, 2026

Results First Posted

August 18, 2026

Record last verified: 2026-07

Locations