Den här översättningen är inte klar ännu. Den här sidan är just nu på engelska.

Gå till den engelska sidan

Cure My Disease

Don't miss your cure!

 Log in / Sign up

New mRNA vaccines for kids under 6 show promise in phase 3 trial

NCT ID NCT05436834

Vaccine Sponsor: ModernaTX, Inc. Source: ClinicalTrials.gov ↗

What the study statuses mean

This study's is highlighted.

Recruitment status, easiest to join first

Recruiting now
This trial is taking on new participants right now.
Not yet recruiting
Registered, but not yet taking participants.
By invitation only
Not open to general applications. Only people the study team invites can take part.
Paused
Paused for now. It may or may not start again.
Ongoing
Running, but no longer taking on new participants.
Completed This study
The trial has finished. Results may not be published yet.
Stopped early
Stopped early, before it reached the end. That can be for many reasons, including safety.
Cancelled
Cancelled before anyone took part.

Expanded access (not trials)

Expanded access
Not a trial. This treatment can be requested outside a study, case by case, for people who qualify.
Expanded access (paused)
Not a trial. The treatment can normally be requested outside a study, but is unavailable right now.
Expanded access (ended)
Not a trial. The treatment could once be requested outside a study, but no longer can.
Approved
The treatment has been approved, so it is available normally rather than through this programme.

When the status isn't known

Details not published
The full record has not been published yet, so there is little to show here.
Status unknown
This status has not been confirmed recently, so it may be out of date.

First seen Jun 27, 2026 · Last updated Jun 27, 2026

Summary

This study tested two updated mRNA COVID-19 vaccines in over 1,800 children aged 6 months to under 6 years. The vaccines were given as a primary series or booster to see if they are safe and trigger a strong immune response against variants like Omicron. The goal is to protect young children from COVID-19.

What this could mean

Our plain-language read of the trial. This is informational only, not medical advice or a prediction.

Active substance
mRNA-1273.214 and mRNA-1273.815 vaccines
What this could lead to
If successful, this could provide safe and effective COVID-19 vaccine options tailored for young children, including protection against newer variants.
What could go wrong
This is a completed phase 3 trial, but results are not yet published. The vaccines may not work as well against future variants, and side effects like fever or injection-site reactions are possible.

This is an AI summary of the original study and may miss details. Read our disclaimer.

Study facts

What this study's own registry entry says, in plain language.

Phase

Phase 3

Large-scale testing in a bigger group. Usually the last step before a treatment can be approved.

Participants

1,807 people

The number who actually took part.

Started

Jun 2022

Finished

Oct 2025

Lead sponsor

A company

The lead sponsor is a pharmaceutical, biotech, or medical-device company.

Who can take part

This study's own entry requirements. Only the study team can say for certain whether you qualify.

Ages

6 months to 5 years

Sex

Anyone

Healthy volunteers

Accepted

You do not need to have the condition being studied to take part.

Show the full entry requirements

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * 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. * If the participant has a chronic disease (that is, asthma, diabetes mellitus, cystic fibrosis, human immunodeficiency virus \[HIV\] infection), the disease should be stable, per investigator assessment, so that the participant can be considered eligible for inclusion. Stable diseases are those which have had no change in their status or in the medications required to control them in the 6 months prior to Screening Visit. Note: a change in medication for dose optimization (that is, insulin dose changes, adjustments for age-related weight gain), change within class of medication, or reduction in dose are not considered signs of instability. * 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. OR * 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. Special inclusion criteria for participants aged 6 months to \< 12 months: * The participant was born at full-term (≥ 37 weeks gestation) with a minimum birth weight of 2.5 kilograms (kg). Inclusion criteria for Part 2: * 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. Inclusion criteria for Part 3 only: \- 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). Exclusion Criteria: * 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). * Systemic immunosuppressants or immune-modifying drugs for \>14 days in total within 6 months prior to the day of enrollment (for corticosteroids, ≥1 milligrams (mg)/kg/day or ≥ 10 mg/day prednisone equivalent, if participant weighs \>10 kg). Participants may have visits rescheduled for enrollment if they no longer meet this criterion within the Screening Visit window. Inhaled, nasal, and topical steroids, and palivizumab are allowed. * Intravenous (IV) or subcutaneous (SC) blood products (red cells, platelets, immunoglobulins) within 3 months prior to enrollment. Note: Other inclusion and exclusion criteria may apply.

Get updates

Get notified about this study

Sign up to get updates when this study changes or when new studies for SARS-CoV-2 are added.

Vår säkerhetsrekommendation!

Genom att skicka in godkänner du våra Användarvillkor

Conditions

The condition(s) this trial relates to.

COVID-19 prevention target

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

SARS-CoV-2

Contacts and locations

Locations

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

    Medellín, Antioquia, 050021, Colombia

  • AES - AS - Clinica Mayo de Urgencias

    San Miguel de Tucumán, Tucumán Province, T4000CAM, Argentina

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

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

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

    Bogotá, Bogota D.C., 110221, Colombia

  • BRCR Global Texas

    Edinburg, Texas, 78539, United States

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

    Lincoln, Nebraska, 68516, United States

  • CAENSA Clinical Trial

    Panama City, Panama

  • CEVAXIN 24 de diciembre - PPDS

    Panama City, Panama

  • CEVAXIN Avenida México - PPDS

    Panama City, Panama

  • CEVAXIN Chorrera - PPDS

    Panama City, Panama

  • Caimed Dominicana S.A.S - CAIMED - PPDS

    Santo Domingo, Distrito NacionalSanto Domingo, 11903, Dominican Republic

  • Caribbean Medical Research Center

    San Juan, 00918, Puerto Rico

  • Center For Clinical Trials LLC -Paramount

    Paramount, California, 90723, United States

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

    Panama City, Panama

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

    Yopal, Casanare Department, 850001, Colombia

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

    Aguazul, Casanare Department, 856010, Colombia

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

    Acacías, Meta Department, 507001, Colombia

  • Centro de Estudios Clinicos e Investigaciones Medicas (CECIM)

    Santiago, Santiago Metropolitan, 8320000, Chile

  • Child Healthcare Associates - East Syracuse

    East Syracuse, New York, 13057, United States

  • Clinical Research Institute

    Minneapolis, Minnesota, 55402, United States

  • Clinical Research Partners

    Richmond, Virginia, 23226, United States

  • Clínica de Costa S.A.S

    Barranquilla, Atlántico, 80020, Colombia

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

    Cartagena, Departamento de Bolívar, 130011, Colombia

  • Coastal Pediatric Associates

    Charleston, South Carolina, 29414, United States

  • Consultorios Médicos Dr. Doreski - PPDS

    Buenos Aires, C1426ABP, Argentina

  • Curaex Clinical Trial

    Panama City, Panama

  • Cyfair Clinical Reseach Center

    Houston, Texas, 77065, United States

  • Hospital General Regional Dr. Marcelino Velez Santana

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

  • Hospital Materno Infantil San Lorenzo de Los Mina

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

  • Hospital Militar Central Cirujano Mayor Dr. Cosme Argerich

    Buenos Aires, Ciudad Autónoma de BuenosAires, C1426BOS, Argentina

  • IResearch

    Decatur, Georgia, 30030, United States

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

    Panama City, Panama

  • Kissimmee Clinical Research

    Kissimmee, Florida, 34741, United States

  • Le Bonheur Childrens Hospital

    Memphis, Tennessee, 38105, United States

  • Lurie Childrens Hospital

    Chicago, Illinois, 60611, United States

  • Lynn Health Science Institute

    Oklahoma City, Oklahoma, 73112, United States

  • MUSC

    Charleston, South Carolina, 29425, United States

  • Med-Care Research

    Miami, Florida, 33125, United States

  • MedPharmics

    Metairie, Louisiana, 70006, United States

  • Meridian Clinical Research

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

  • Meridian Clinical Research

    Macon, Georgia, 31210, United States

  • Meridian Clinical Research

    Overland Park, Kansas, 66210, United States

  • Meridian Clinical Research

    Hastings, Nebraska, 68901, United States

  • Meridian Clinical Research

    Lincoln, Nebraska, 68510, United States

  • Meridian Clinical Research

    Binghamton, New York, 13901, United States

  • Meridian Clinical Research

    Charleston, South Carolina, 29414, United States

  • Michael W. Simon MD, PSC

    Lexington, Kentucky, 40517, United States

  • PI Coor Clinical Research LLC

    Burke, Virginia, 22015, United States

  • Policlínico Social del Norte

    Bogotá, Cundinamarca, 110131, Colombia

  • Prohealth Research Center

    Doral, Florida, 33166, United States

  • Quality Clinical Research

    Omaha, Nebraska, 68114, United States

  • REX Clinical Trials, LLC Beaumont

    Beaumont, Texas, 77701-3739, United States

  • Registrum- La Altagracia

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

  • Sera Collection Research Services

    Montebello, California, 90640, United States

  • Texas Center for Drug Development

    Houston, Texas, 77081, United States

  • Trinity Clinical Research, LLC

    Bessemer, Alabama, 34020, United States

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

    Santo Domingo, 10305, Dominican Republic

  • University of Colorado

    Aurora, Colorado, 80045, United States

  • University of Florida Jacksonville

    Jacksonville, Florida, 32209, United States

  • University of Kentucky

    Lexington, Kentucky, 40536, United States

  • University of Missouri Health Care

    Columbia, Missouri, 65212, United States

  • University of South Florida

    Tampa, Florida, 33612, United States

  • Velcocity Clinical Research

    Banning, California, 92220, United States

  • Velcocity Clinical Research

    Meridian, Idaho, 83642, United States

  • Velcocity Clinical Research

    East Greenwich, Rhode Island, 02818, United States

  • Velcocity Clinical Research

    Cedar Park, Texas, 78613, United States

  • Velocity Clinical Research

    Albuquerque, New Mexico, 87102, United States

  • Velocity Clinical Research - Covington - PPDS

    Metairie, Louisiana, 70006, United States

  • Velocity Clinical Research - Lafayette - PPDS

    Lafayette, Louisiana, 70508, United States

  • Velocity Clinical Research Austin

    Austin, Texas, 78759, United States

  • Ventavia Research Group

    Houston, Texas, 77008, United States

  • Victoria Clinical Research Group

    Victoria, Texas, 77901, United States

  • Village Health Partners - Frisco Medical Village

    Frisco, Texas, 75033, United States

  • WellNow Urgent Care Clinical Research

    East Amherst, New York, 14051, United States

More trials for these conditions

Other studies related to the condition(s) this trial covers.