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

  • End date
    Oct 31, 2023
  • participants needed
  • sponsor
    ModernaTX, Inc.
Updated on 24 October 2022
Accepts healthy volunteers


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).


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.

Condition SARS-CoV-2
Treatment mRNA-1273.214
Clinical Study IdentifierNCT05436834
SponsorModernaTX, Inc.
Last Modified on24 October 2022


Yes No Not Sure

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
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
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Additional screening procedures may be conducted by the study team before you can be confirmed eligible to participate.

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If you are confirmed eligible after full screening, you will be required to understand and sign the informed consent if you decide to enroll in the study. Once enrolled you may be asked to make scheduled visits over a period of time.

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Complete your scheduled study participation activities and then you are done. You may receive summary of study results if provided by the sponsor.

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