The study will evaluate the safety, tolerability, reactogenicity, and effectiveness of mRNA-1273.214 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine in infants aged 12 weeks to < 6 months.



Eligible Ages
Between 2 Months and 6 Months
Eligible Genders
Accepts Healthy Volunteers

Inclusion Criteria

  • Participant is male or female, between 2 and <6 months of age at the time of consent (Screening Visit), who is in good general health, in the opinion of the investigator, based on review of medical history and screening physical examination. 1. Participant must be at least 12 weeks completed age and must not have completed 6 months at the time of administration of first dose. 2. If the participant has a chronic, stable disease, they may be eligible to enroll in Part 2, but ineligible for Part 1. The chronic condition (for example, gastroesophageal reflux disease) should be stable, per investigator assessment, so that the participant can be considered eligible for inclusion in Part 2. - Participant was born at ≥37 weeks gestation (Part 1) or ≥34 weeks gestation (Part 2), with a minimum birth weight of 2.5 kilograms (kg), without fetal growth restriction, and the participant's height and weight are both at or above the second percentile for age according to the Centers for Disease Control and Prevention/World Health Organization Child Growth Standard at the Screening Visit. - In the investigator's opinion, the parent(s)/legally authorized representative(s) understand and are willing and physically able to comply with protocol-mandated follow-up, including all procedures, and provide written informed consent.

Exclusion Criteria

  • Participant has a known history of SARS-CoV-2 infection within 2 weeks prior to administration of study drug or has a known close contact in the past 2 weeks to someone diagnosed with SARS-CoV-2 infection or coronavirus disease 2019 (COVID-19). Participants may be rescreened after 14 days provided that they remain asymptomatic. - Participant is acutely ill or febrile 72 hours prior to or at the Screening Visit. Fever is defined as a body temperature ≥38.0°Celcius/≥100.4°Farenheit. 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. - Participant has previously been administered an investigational or approved CoV (for example, SARS-CoV-2, SARS-CoV, Middle East respiratory syndrome [MERS]-CoV) vaccine. - Participant has undergone treatment with investigational or approved agents for prophylaxis against COVID-19 (for example, receipt of SARS-CoV-2 monoclonal antibodies) within 90 days prior to enrollment. - Participant 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 any of the components of messenger ribonucleic acid (mRNA) COVID-19 vaccines (including polyethylene glycol or immediate allergic reaction of any severity to polysorbate). - Participant has a medical, psychiatric, or occupational 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. - Participant has a history of diagnosis or condition that, in the judgment of the investigator, may affect study endpoint assessment or compromise participant safety. - Participant has received the following: 1. Any routine vaccination with inactivated or live vaccine(s) within 14 days prior to first or second vaccination or plans to receive such a vaccine within 14 days of any study vaccination. 2. Systemic immunosuppressants or immune-modifying drugs (including maternal use during pregnancy or lactation) for >14 days in total within 6 months prior to the day of enrollment (for corticosteroids, ≥ 1 milligrams (mg)/kg/day or, if participant weighs >10 kg: ≥10 mg/day prednisone equivalent). 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. 3. Intravenous or subcutaneous blood products (red blood cells, platelets, immunoglobulins) within 3 months prior to enrollment. - Participant has participated in an interventional clinical study within 28 days prior to the Screening Visit or plans to do so while participating in this study, or maternal participation in an interventional clinical study during pregnancy. Note: Other inclusion and exclusion criteria may apply.

Study Design

Phase 2
Study Type
Intervention Model
Sequential Assignment
Intervention Model Description
Part 1: sequential Part 2: parallel
Primary Purpose
Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Masking Description
Part 1: open-label Part 2: observer-blinded, randomized, placebo-controlled

Arm Groups

ArmDescriptionAssigned Intervention
Part 1: mRNA-1273.214 Dose A
Participants will receive 2 doses of mRNA-1273.214 Dose A by intramuscular (IM) injection approximately 8 weeks apart (Day 1 and Day 57).
  • Biological: mRNA-1273.214
    Sterile liquid for injection
Part 1: mRNA-1273.214 Dose B
Participants will receive 2 doses of mRNA-1273.214 Dose B by IM injection approximately 8 weeks apart (Day 1 and Day 57).
  • Biological: mRNA-1273.214
    Sterile liquid for injection
Part 2: mRNA-1273.214
Participants will receive 2 doses of mRNA-1273.214 by IM injection approximately 8 weeks apart (Day 1 and Day 57).
  • Biological: mRNA-1273.214
    Sterile liquid for injection
Placebo Comparator
Part 2: Placebo
Participants will receive 2 doses of placebo by IM injection approximately 8 weeks apart (Day 1 and Day 57).
  • Other: Placebo
    0.9% sodium chloride
    Other names:
    • normal saline

Recruiting Locations

Center For Clinical Trials LLC
Paramount, California 90723

Meridian Clinical Research (Washington) - PPDS
Washington, District of Columbia 20016

Acevedo Clinical Research
Miami, Florida 33142-2946

Dedicated Research Facility
Miami, Florida 33174-3245

MedPharmics - Platinum - PPDS
Covington, Louisiana 70433-7237

MedPharmics - Platinum - PPDS
Lafayette, Louisiana 70508

Be Well Clinical Studies
Lincoln, Nebraska 68516

Coastal Pediatric Research
Charleston, South Carolina 29414

C & R Research Services USA
Houston, Texas 77022

DM Clinical Research - Kool Kids Pediatrics - ERN - PPDS
Houston, Texas 77065-5471

Victoria Clinical Research Group
Port Lavaca, Texas 77979

Clinical Research Partners, LLC
Richmond, Virginia 23226

More Details

ModernaTX, Inc.

Study Contact

Moderna Clinical Trials Support Center

Detailed Description

The study will be conducted in 2 parts. Part 1 will be open-label and evaluate 2 dose levels. The dose level selected from Part 1 will be further evaluated in Part 2, which will be blinded and randomized. This pediatric study is intended to confirm safety and effectiveness of mRNA-1273.214 in infants between 12 weeks to < 6 months of age by comparing the immune response of infants in this study to adults (>18 years of age) enrolled in the mRNA-1273-P301 study [NCT04470427]).


Study information shown on this site is derived from ClinicalTrials.gov (a public registry operated by the National Institutes of Health). The listing of studies provided is not certain to be all studies for which you might be eligible. Furthermore, study eligibility requirements can be difficult to understand and may change over time, so it is wise to speak with your medical care provider and individual research study teams when making decisions related to participation.