We're building a better ClinicalTrials.gov. Check it out and tell us what you think!
ClinicalTrials.gov Menu

A Study to Evaluate the Safety and Immunogenicity of the mRNA-1273.214 COVID-19 Vaccine in Healthy Children Between 6 Months to Less Than 6 Years of Age

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details.
ClinicalTrials.gov Identifier: NCT05436834
Recruitment Status : Recruiting
First Posted : June 29, 2022
Last Update Posted : August 24, 2022
Information provided by (Responsible Party):
ModernaTX, Inc.

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 given to participants who previously received 2 doses of the mRNA-1273 vaccine as a primary series (Part 2).

Condition or disease Intervention/treatment Phase
SARS-CoV-2 Biological: mRNA-1273.214 Phase 3

Detailed Description:

Part 1 will enroll participants aged 6 months to <6 years who have not been previously vaccinated against SARS-CoV-2. Participants will receive 2 doses of the mRNA-1273.214 vaccine and will be followed for approximately 12 months after the second dose for safety and additional immunogenicity follow-up.

Part 2 will enroll participants aged 6 months to <6 years who have previously been vaccinated with a mRNA-1273 primary series in Study mRNA-1273-P204. Participants will receive a single booster dose of the mRNA-1273.214 vaccine, at least 4 months after completion of the mRNA-1273 primary series and will be followed for approximately 6 months after the booster dose for safety and immunogenicity.

Layout table for study information
Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 960 participants
Allocation: N/A
Intervention Model: Sequential Assignment
Masking: None (Open Label)
Primary Purpose: Prevention
Official Title: An Open-Label, Phase 3 Study to Evaluate the Safety and Immunogenicity of the mRNA-1273.214 Vaccine for SARS-CoV-2 Variants of Concern in Participants Aged 6 Months to < 6 Years
Actual Study Start Date : June 21, 2022
Estimated Primary Completion Date : October 31, 2023
Estimated Study Completion Date : October 31, 2023

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Experimental: mRNA-1273.214

Part 1: Participants who have not been previously vaccinated against SARS-CoV-2, will receive 2 intramuscular (IM) injections of 25 microgram (μg) mRNA-1273.214 on Day 1 and Day 29.

Part 2: Participants who have previously been vaccinated with a mRNA-1273 primary series, will receive a single IM booster dose (BD) of 10 μg mRNA-1273.214 at least 4 months after the last dose on BD Day 1.

Biological: mRNA-1273.214
Sterile liquid for injection

Primary Outcome Measures :
  1. Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs) [ Time Frame: Up to Day 8 (7 days post-vaccination) ]
  2. Number of Participants with Unsolicited Adverse Events (AEs) [ Time Frame: Up to Day 29 (28 days after each injection) ]
  3. Number of Participants with Medically-Attended AEs (MAAEs) [ Time Frame: Up to Day 575 ]
  4. Number of Participants with Serious AEs (SAEs) [ Time Frame: Up to Day 575 ]
  5. Number of Participants with Adverse Events of Special Interest (AESI) [ Time Frame: Up to Day 575 ]
  6. Number of Participants with AEs Leading to Withdrawal [ Time Frame: Up to Day 575 ]
  7. Geometric Mean (GM) of the Serum Antibody (Ab) Level (Omicron) [ Time Frame: Day 57 (28 days after second dose) ]
  8. Seroresponse Rate (SRR) of Vaccine Recipients (Omicron) [ Time Frame: Day 57 (28 days after second dose) ]
  9. GM of the Serum Ab Level Post BD (Omicron) [ Time Frame: BD-Day 29 ]
  10. SRR of Vaccine Recipients Post BD (Omicron) [ Time Frame: BD-Day 29 ]

Secondary Outcome Measures :
  1. GM of the Serum Ab Level of SARS-CoV-2 VOC (Omicron and Original Strain) [ Time Frame: Day 57; Part 2: BD-Day 29 ]
  2. SRR of Vaccine Recipients of SARS-CoV-2 VOC (Omicron and Original Strain) [ Time Frame: Day 57 ]

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Layout table for eligibility information
Ages Eligible for Study:   6 Months to 5 Years   (Child)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • 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. This includes inability to draw baseline blood samples (minimum amount needed).
  • The participant is 2 years or older and has a body mass index (BMI) at or above the 3rd 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 3rd 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, all age groups based on Study mRNA-1273-P204:

  • Must have received 2 doses of mRNA-1273, approximately 28 days apart, as 25 μg primary series, and 2nd dose was given at least 4 months prior to enrollment.

Exclusion Criteria:

  • Has a known history of SARS-CoV-2 infection (that is, reported AE of coronavirus disease 2019 [COVID-19] or asymptomatic SARS-CoV-2 infection during Study mRNA-1273-P204) 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°C/≥ 100.4°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.
  • 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, this applies to vaccines other than mRNA-1273.
  • Has undergone treatment with investigational or approved agents for prophylaxis against COVID-19 (that is, receipt of SARS-CoV-2 monoclonal antibodies) 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 are allowed.
  • Intravenous (IV) or subcutaneous (SC) blood products (red cells, platelets, immunoglobulins) within 3 months prior to enrollment.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT05436834

Layout table for location contacts
Contact: Moderna Clinical Trials Support Center 1-877-777-7187 clinicaltrials@modernatx.com

Layout table for location information
United States, California
Sera Collection Research Services Not yet recruiting
Montebello, California, United States, 90640
United States, Florida
University of South Florida Recruiting
Tampa, Florida, United States, 33612
United States, Georgia
IResearch Recruiting
Decatur, Georgia, United States, 30030
United States, Idaho
Velcocity Clinical Research Recruiting
Meridian, Idaho, United States, 83642
United States, Illinois
Lurie Childrens Hospital Recruiting
Chicago, Illinois, United States, 60611
United States, Kentucky
University of Kentucky Recruiting
Lexington, Kentucky, United States, 40536
United States, Minnesota
Clinical Research Institute Not yet recruiting
Minneapolis, Minnesota, United States, 55402
United States, Missouri
University of Missouri Health Care Recruiting
Columbia, Missouri, United States, 65212
United States, Nebraska
Quality Clinical Research Not yet recruiting
Omaha, Nebraska, United States, 68114
United States, Oklahoma
Lynn Health Science Institute Not yet recruiting
Oklahoma City, Oklahoma, United States, 73112
United States, South Carolina
Coastal Pediatric Associates Recruiting
Charleston, South Carolina, United States, 29414
MUSC Recruiting
Charleston, South Carolina, United States, 29425
United States, Texas
Village Health Partners - Frisco Medical Village Not yet recruiting
Frisco, Texas, United States, 75033
Cyfair Clinical Reseach Center Recruiting
Houston, Texas, United States, 77065
Texas Center for Drug Development Recruiting
Houston, Texas, United States, 77081
United States, Virginia
Clinical Research Partners Recruiting
Richmond, Virginia, United States, 23226
Sponsors and Collaborators
ModernaTX, Inc.
Layout table for additonal information
Responsible Party: ModernaTX, Inc.
ClinicalTrials.gov Identifier: NCT05436834    
Other Study ID Numbers: mRNA-1273-P306
First Posted: June 29, 2022    Key Record Dates
Last Update Posted: August 24, 2022
Last Verified: August 2022

Layout table for additional information
Studies a U.S. FDA-regulated Drug Product: Yes
Studies a U.S. FDA-regulated Device Product: No