A Study to Evaluate the Safety and Immunogenicity of the mRNA COVID-19 Vaccines in Healthy Children Between 6 Months to Less Than 6 Years of Age

NCT05436834 | Completed Phase 3 FDA Drug

• 1 other identifier: mRNA-1273-P306
• Study Type: interventional
• Target: 1,807
• Locations: 7 countries
• Sites: 74

Brief Summary

This study will evaluate the safety and immunogenicity of the mRNA-1273.214 vaccine for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant of concerns (VOCs) in participants aged 6 months to \<6 years, when administered as a primary series in SARS-CoV-2 vaccine-naïve participants (Part 1) and a single booster dose (BD) given to participants who previously received 2 doses of the mRNA-1273 vaccine as a primary series (Part 2); and will evaluate the safety and immunogenicity of the mRNA-1273.815 vaccine, when administered as a BD in participants aged 6 months to \<6 years (Part 3) and when administered to SARS-CoV-2 vaccine-naïve participants aged 2 years to \<5 years of age (Part 4).

Conditions

SARS-CoV-2

Keywords

Coronavirus disease 2019; COVID-19

Outcome Measures

Primary Outcomes (10)

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

  Up to Day 8 (7 days post-vaccination)

• Number of Participants with Unsolicited Adverse Events (AEs)

  Up to Day 29 (28 days after each injection)

• Number of Participants with Medically-Attended AEs (MAAEs)

  Up to Day 394 (12 months after last dose)

• Number of Participants with Serious AEs (SAEs)

  Up to Day 394 (12 months after last dose)

• Number of Participants with Adverse Events of Special Interest (AESI)

  Up to Day 394 (12 months after last dose)

• Number of Participants with AEs Leading to Withdrawal

  Up to Day 394 (12 months after last dose)

• Geometric Mean (GM) of the Serum Antibody (Ab) Level against Omicron BA.1 and Ancestral SARS-CoV-2 after mRNA-1273.214 Administration at Day 57

  Day 57

• GM of the Serum Ab Level against Omicron BA.1 and Ancestral SARS-CoV-2 after mRNA-1273.214 Administration at Day 29

  Day 29

• Seroresponse Rate (SRR) against Omicron BA.1 and Ancestral SARS-CoV-2 after mRNA-1273.214 Administration

  Day 29

• GM of the Serum Ab Level against Omicron XBB.1.5 after mRNA-1273.815 Administration

  Up to Day 57

Secondary Outcomes (3)

• SRR against Omicron BA.1 and Ancestral SARS-CoV-2 after mRNA-1273.214 Administration Regardless of prior SARS-CoV-2 Infection

  Day 57

• GM of the Serum Ab Level against Omicron XBB.1.5 after mRNA-1273.815 Administration Regardless of prior SARS-CoV-2 Infection

  Up to Day 57

• SRR against Omicron XBB.1.5 after mRNA-1273.815 Administration Regardless of prior SARS-CoV-2 Infection

  Up to Day 57

Study Arms (4)

mRNA-1273.214 (Part 1)

EXPERIMENTAL

Participants who have not been previously vaccinated against SARS-CoV-2, will receive 2 intramuscular (IM) injections of mRNA-1273.214 vaccine on Day 1 and Day 29.

Biological: mRNA-1273.214

mRNA-1273.214 (Part 2)

EXPERIMENTAL

Participants who have previously been vaccinated with a mRNA-1273 primary series, will receive a single IM BD of mRNA-1273.214 vaccine at least 4 months after completion of the mRNA-1273 primary series.

Biological: mRNA-1273.214

mRNA-1273.815 (Part 3)

EXPERIMENTAL

Participants who have previously been vaccinated with an authorized/approved COVID-19 vaccine, will receive a single IM BD of mRNA-1273.815 vaccine on BD Day 1, at least 4 months after the last dose of a COVID-19 vaccine.

Biological: mRNA-1273.815

mRNA-1273.815 (Part 4)

EXPERIMENTAL

Participants in Part 4 Cohort A will receive a single IM injection of mRNA-1273.815 vaccine on Day 1. Participants in Part 4 Cohort B will receive IM injections of mRNA-1273.815 vaccine on Day 1 and Day 29.

Biological: mRNA-1273.815

Interventions

mRNA-1273.214 BIOLOGICAL

Sterile liquid for injection

mRNA-1273.214 (Part 1); mRNA-1273.214 (Part 2)

mRNA-1273.815 BIOLOGICAL

Sterile liquid for injection

mRNA-1273.815 (Part 3); mRNA-1273.815 (Part 4)

Eligibility Criteria

• Age: 6 Months - 5 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17)

You may qualify if:

• The participant is 6 months to \<6 years for Parts 1, 2, and 3; 2 years to \<5 years for Part 4A; and 6 months to \<2 years for Part 4B at the time of consent (Screening Visit). Note: for Part 1, participant must be at least 6 months old and must not have reached 6 years of age at the time of administration of first dose. For Part 4B, the participant must be at least 6 months old and must not have reached 2 years of age at the time of administration of first dose.
• In the investigator's opinion, the parent(s)/legally authorized representative(s) (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 2 years or older and has a body mass index (BMI) at or above the second percentile according to World Health Organization (WHO) Child Growth Standards at the Screening Visit.
• The participant is less than 2 years of age and the participant's height and weight are both at or above the second percentile according to WHO Child Growth Standards at the Screening Visit.
• The participant was born at full-term (≥ 37 weeks gestation) with a minimum birth weight of 2.5 kilograms (kg).
• The participant must have received 2 doses of mRNA-1273, approximately 28 to 35 days apart, as 25-μg primary series, and second dose was given at least 4 months prior to enrollment.
• \- The participant must have received an age-appropriate immunization series of an authorized/approved COVID-19 vaccine, with the last dose given at least 4 months prior to enrolment (Previous vaccines NOT allowed are: XBB.1.5-containing formulation).

You may not qualify if:

• Has a known history of SARS-CoV-2 infection (that is, reported AE of COVID-19 or asymptomatic SARS-CoV-2 infection during Study mRNA-1273-P204 at the time of rollover into mRNA-1273-P306 or during Part 1 at the time of rollover into Part 3) in the 90 days prior to dosing in this study.
• Is acutely ill or febrile 24 hours prior to or at the Screening Visit. Fever is defined as a body temperature ≥ 38.0°Celsius (C)/≥ 100.4°Fahrenheit (F). Participants who meet this criterion may have visits rescheduled within the relevant study visit windows. Afebrile participants with minor illnesses can be enrolled at the discretion of the investigator.
• For Parts 1 and 4, participant has previously been administered an investigational or approved CoV (that is, SARS-CoV-2, SARS-CoV, Middle East respiratory syndrome coronavirus \[MERS-CoV\]) vaccine. For Part 2, participant who received any approved/investigational CoV vaccine are ineligible to participate except for those who received mRNA-1273 (prototype) vaccine.
• Has undergone treatment with investigational or approved agents for prophylaxis against COVID-19 (including receipt of SARS-CoV-2 monoclonal antibodies for prophylaxis or treatment) within 90 days prior to enrollment.
• 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 COVID-19 vaccine or any of its components (including polyethylene glycol \[PEG\] or immediate allergic reaction of any severity to polysorbate).
• Has a medical or psychiatric 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.
• Has a history of diagnosis or condition that, in the judgment of the investigator, may affect study endpoint assessment or compromise participant safety, specifically the following:
• Congenital or acquired immunodeficiency, other than well-controlled HIV infection.
• Chronic hepatitis or suspected active hepatitis
• A bleeding disorder that is considered a contraindication to IM injection or phlebotomy
• Dermatologic conditions that could affect local solicited AR assessments
• Any prior diagnosis of malignancy (excluding nonmelanoma skin cancer)
• Has received the following:
• Any routine vaccination with inactivated or live vaccine(s) within 14 days prior to study vaccination or plans to receive such a vaccine through 14 days following study vaccination.
• Note: This excludes influenza vaccine that may be given anytime, but ideally at least 7 days before study dose. If a participant receives an influenza vaccine, this should be captured within the concomitant medication electronic case report form (eCRF).

Sponsors & Collaborators

• ModernaTX, Inc.: lead

Study Sites (74)

Trinity Clinical Research, LLC

Bessemer, Alabama, 34020, United States

Location

Velcocity Clinical Research

Banning, California, 92220, United States

Location

Sera Collection Research Services

Montebello, California, 90640, United States

Location

Center For Clinical Trials LLC -Paramount

Paramount, California, 90723, United States

Location

University of Colorado

Aurora, Colorado, 80045, United States

Location

Meridian Clinical Research

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

Location

Prohealth Research Center

Doral, Florida, 33166, United States

Location

University of Florida Jacksonville

Jacksonville, Florida, 32209, United States

Location

Kissimmee Clinical Research

Kissimmee, Florida, 34741, United States

Location

Med-Care Research

Miami, Florida, 33125, United States

Location

University of South Florida

Tampa, Florida, 33612, United States

Location

IResearch

Decatur, Georgia, 30030, United States

Location

Meridian Clinical Research

Macon, Georgia, 31210, United States

Location

Velcocity Clinical Research

Meridian, Idaho, 83642, United States

Location

Lurie Childrens Hospital

Chicago, Illinois, 60611, United States

Location

Meridian Clinical Research

Overland Park, Kansas, 66210, United States

Location

Michael W. Simon MD, PSC

Lexington, Kentucky, 40517, United States

Location

University of Kentucky

Lexington, Kentucky, 40536, United States

Location

Velocity Clinical Research - Lafayette - PPDS

Lafayette, Louisiana, 70508, United States

Location

MedPharmics

Metairie, Louisiana, 70006, United States

Location

Velocity Clinical Research - Covington - PPDS

Metairie, Louisiana, 70006, United States

Location

Clinical Research Institute

Minneapolis, Minnesota, 55402, United States

Location

University of Missouri Health Care

Columbia, Missouri, 65212, United States

Location

Meridian Clinical Research

Hastings, Nebraska, 68901, United States

Location

Meridian Clinical Research

Lincoln, Nebraska, 68510, United States

Location

Be Well Clinical Studies, LLC - Lincoln - ERN - PPDS

Lincoln, Nebraska, 68516, United States

Location

Quality Clinical Research

Omaha, Nebraska, 68114, United States

Location

Velocity Clinical Research

Albuquerque, New Mexico, 87102, United States

Location

Meridian Clinical Research

Binghamton, New York, 13901, United States

Location

WellNow Urgent Care Clinical Research

East Amherst, New York, 14051, United States

Location

Child Healthcare Associates - East Syracuse

East Syracuse, New York, 13057, United States

Location

Lynn Health Science Institute

Oklahoma City, Oklahoma, 73112, United States

Location

Velcocity Clinical Research

East Greenwich, Rhode Island, 02818, United States

Location

Coastal Pediatric Associates

Charleston, South Carolina, 29414, United States

Location

Meridian Clinical Research

Charleston, South Carolina, 29414, United States

Location

MUSC

Charleston, South Carolina, 29425, United States

Location

Le Bonheur Childrens Hospital

Memphis, Tennessee, 38105, United States

Location

Velocity Clinical Research Austin

Austin, Texas, 78759, United States

Location

REX Clinical Trials, LLC Beaumont

Beaumont, Texas, 77701-3739, United States

Location

Velcocity Clinical Research

Cedar Park, Texas, 78613, United States

Location

BRCR Global Texas

Edinburg, Texas, 78539, United States

Location

Village Health Partners - Frisco Medical Village

Frisco, Texas, 75033, United States

Location

Ventavia Research Group

Houston, Texas, 77008, United States

Location

Cyfair Clinical Reseach Center

Houston, Texas, 77065, United States

Location

Texas Center for Drug Development

Houston, Texas, 77081, United States

Location

Victoria Clinical Research Group

Victoria, Texas, 77901, United States

Location

PI Coor Clinical Research LLC

Burke, Virginia, 22015, United States

Location

Clinical Research Partners

Richmond, Virginia, 23226, United States

Location

AES - AS - Glenny Corp. S.A. Buenos Aires

CABA, Buenos Aires F.D., C1430CKE, Argentina

Location

Hospital Militar Central Cirujano Mayor Dr. Cosme Argerich

Buenos Aires, Ciudad Autónoma de BuenosAires, C1426BOS, Argentina

Location

AES - AS - Clinica Mayo de Urgencias

San Miguel de Tucumán, Tucumán Province, T4000CAM, Argentina

Location

Consultorios Médicos Dr. Doreski - PPDS

Buenos Aires, C1426ABP, Argentina

Location

Centro de Estudios Clinicos e Investigaciones Medicas (CECIM)

Santiago, Santiago Metropolitan, 8320000, Chile

Location

AES - AS - Centro de Investigación Clínica CIC S.A.S (CECIC) Medellín

Medellín, Antioquia, 050021, Colombia

Location

Clínica de Costa S.A.S

Barranquilla, Atlántico, 80020, Colombia

Location

AES- AS- Solano & Terront Servicios Médicos LTDA (UNIENDO) Bogotá

Bogotá, Bogota D.C., 110221, Colombia

Location

Centro de Atencion e Investigacion Medica S.A.S. - CAIMED Aguazul

Aguazul, Casanare Department, 856010, Colombia

Location

Centro de Atencion e Investigacion Medica S.A - Yopal - CAIMED

Yopal, Casanare Department, 850001, Colombia

Location

Policlínico Social del Norte

Bogotá, Cundinamarca, 110131, Colombia

Location

Clínica de la Costa S.A.S- Sede Cartagena

Cartagena, Departamento de Bolívar, 130011, Colombia

Location

Centro de Atención e Investigación Médica S.A.S.- CAIMED - S.A.S. Sede Acacias

Acacías, Meta Department, 507001, Colombia

Location

Caimed Dominicana S.A.S - CAIMED - PPDS

Santo Domingo, Distrito NacionalSanto Domingo, 11903, Dominican Republic

Location

Registrum- La Altagracia

Salvaleón de Higüey, La Altagracia Province, 23000, Dominican Republic

Location

Hospital Materno Infantil San Lorenzo de Los Mina

Santo Domingo Este, Santo Domingo Province, 11901, Dominican Republic

Location

Hospital General Regional Dr. Marcelino Velez Santana

Santo Domingo Iesta, Santo Domingo Province, 11117, Dominican Republic

Location

Unidad de Vacunas e Investigación Instituto Dermatologico Dominicano y Cirugía de Piel Dr. Huberto B

Santo Domingo, 10305, Dominican Republic

Location

CAENSA Clinical Trial

Panama City, Panama

Location

Centro De Vacunacion Internacional, S.A. - David - Cevaxin - PPDS

Panama City, Panama

Location

CEVAXIN 24 de diciembre - PPDS

Panama City, Panama

Location

CEVAXIN Avenida México - PPDS

Panama City, Panama

Location

CEVAXIN Chorrera - PPDS

Panama City, Panama

Location

Curaex Clinical Trial

Panama City, Panama

Location

Instituto de Investigaciones Científicas y Servicios de Alta Tecnología Asociación de Interés Panama

Panama City, Panama

Location

Caribbean Medical Research Center

San Juan, 00918, Puerto Rico

Location

Related Publications (1)

• Dixit A, Bennett R, Ali K, Griffin C, Clifford RA, Turner M, Poston R, Hautzinger K, Yeakey A, Girard B, Zhou W, Deng W, Zhou H, Schnyder Ghamloush S, Kuter BJ, Slobod K, Miller JM, Priddy F, Das R; ROVER Study Investigators. Interim safety and immunogenicity of COVID-19 omicron BA.1 variant-containing vaccine in children in the USA: an open-label non-randomised phase 3 trial. Lancet Infect Dis. 2024 Jul;24(7):687-697. doi: 10.1016/S1473-3099(24)00101-4. Epub 2024 Mar 19.

  PMID: 38518789 DERIVED

MeSH Terms

Conditions

COVID-19

Interventions

mRNA-1273.214 COVID-19 vaccine

Condition Hierarchy (Ancestors)

Pneumonia, Viral; Pneumonia; Respiratory Tract Infections; Infections; Virus Diseases; Coronavirus Infections; Coronaviridae Infections; Nidovirales Infections; RNA Virus Infections; Lung Diseases; Respiratory Tract Diseases

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: SEQUENTIAL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: June 27, 2022
• First Posted: June 29, 2022
• Study Start: June 21, 2022
• Primary Completion: October 20, 2025
• Study Completion: October 20, 2025
• Last Updated: November 26, 2025

Record last verified: 2025-11

Locations

PA (7); CL (1); CO (8); AR (4); US (48); PR (1); DO (5)