Study to Evaluate the Safety, Reactogenicity, and Effectiveness of mRNA-1273.214 SARS-CoV-2 (COVID-19) Vaccine in Infants

Study at a glance

From the registry record, last updated by the sponsor on 26 Nov 2025. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title

A Phase 2, Two-Part Study (Open-Label [Part 1] Followed by Observer-Blind/Randomized [Part 2]) to Evaluate the Safety, Tolerability, Reactogenicity, and Effectiveness of mRNA-1273.214 SARS-CoV-2 Vaccine in Participants Aged 12 Weeks to < 6 Months

ClinicalTrials.gov ID

NCT05584202

Acronym / sponsor ID

BabyCOVE / mRNA-1273-P206

Conditions

SARS-CoV-2

Keywords

mRNA-1273, mRNA-1273 vaccine, mRNA-1273.214 vaccine, mRNA-1273.214, SARS-CoV-2, SARS-CoV-2 Vaccine, Coronavirus, Virus Diseases

Phase

Phase 2

Study type

Interventional

Recruitment status

TerminatedReason stopped: The trial was terminated because data from the dose finding part of the trial did not support further evaluation of effectiveness of mRNA-1273. There were no safety concerns.

Enrolment

68 participants (actual)

Lead sponsor

ModernaTX, Inc.Industry (pharma, biotech, devices)

Study start

30 Sep 2022 (actual)

Primary completion

15 Nov 2024 (actual)

Study completion

15 Nov 2024 (actual)

First posted

18 Oct 2022 (actual)

Results

Posted 26 Nov 2025

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Study design

Primary purpose

Prevention

Allocation

Randomised

Intervention model

Sequential

Masking

Quadruple blind (participant, care provider, investigator, outcomes assessor)

Number of arms

4

Model description

Part 1: sequential Part 2: parallel

Who may qualify

Ages

2 to 6 months

Sex

All

Healthy volunteers

Accepted

Age groups

Child

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Primary outcome

1. Number of Participants With Solicited Local and Systemic Adverse Reactions (ARs) After First Injection

   Time frame: Day 1 up to 7 days after first vaccination (up to Day 8)

   Solicited ARs (local and systemic) were collected in an electronic diary (eDiary). Local ARs included injection site pain/tenderness, injection site erythema (redness), injection site swelling/induration (hardness), and groin or underarm swelling or tenderness ipsilateral to the side of injection. Systemic ARs included fever, irritability/crying, sleepiness, and loss of appetite. Solicited AR severity was graded according to a modified version (relevant to age 12 weeks to <6 months) of the Toxicity Grading Scale for Healthy Adult and Adolescent Volunteers Enrolled in Preventative Vaccine Clinical Trials. ARs graded 1-4 are presented. Lower scores indicated lower severity, and higher scores indicated greater severity. A summary of serious adverse events (SAEs) and nonserious adverse events (AEs) (Safety Set), regardless of causality, is located in the AE section.

2. Number of Participants With Solicited Local and Systemic ARs After Second Injection

   Time frame: Day 57 up to 7 days after second vaccination (up to Day 64)

   Solicited ARs (local and systemic) were collected in eDiary. Local ARs included injection site pain/tenderness, injection site erythema (redness), injection site swelling/induration (hardness), and groin or underarm swelling or tenderness ipsilateral to the side of injection. Systemic ARs included fever, irritability/crying, sleepiness, and loss of appetite. Solicited AR severity was graded according to a modified version (relevant to age 12 weeks to <6 months) of the Toxicity Grading Scale for Healthy Adult and Adolescent Volunteers Enrolled in Preventative Vaccine Clinical Trials. ARs graded 1-4 are presented. Lower scores indicated lower severity, and higher scores indicated greater severity. A summary of SAEs and nonserious AEs (Safety Set), regardless of causality, is located in the AE section.

3. Number of Participants With Unsolicited Adverse Events (AEs) After Any Injection

   Time frame: Day 1 up to 28 days after any vaccination (up to Day 85)

   An unsolicited AE was any AE reported by the participant that was not specified as a solicited AR in the protocol or was specified as a solicited AR but started outside the protocol-defined period for reporting solicited ARs (onset after Day 7 of dosing). An AE was defined as any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related. Any abnormal laboratory test result or other safety assessment, including one that worsened from baseline and was considered clinically significant by the Investigator was recorded as an AE. A summary of SAEs and nonserious AEs (Safety Set), regardless of causality, is located in the AE section. COVID-19/SARS-CoV-2 infections were considered clinical events and not AEs.

4. Number of Participants With SAEs, AEs of Special Interest (AESIs), Medically Attended AEs (MAAEs), and AEs Leading to Study or Treatment Discontinuation

   Time frame: Day 1 up to Day 422

   SAE was defined as any AE that resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in disability/permanent damage, was a congenital anomaly/birth defect, or was an important medical event. AESIs were identified based upon medical concepts that may be related to COVID-19 or were of interest in COVID-19 vaccine safety surveillance. MAAE was an AE that led to an unscheduled visit to a healthcare practitioner, included visits to a study site for unscheduled assessments (for example, abnormal laboratory follow-up, and visits to healthcare practitioners external to the study site [for example, urgent care, primary care physician]). A summary of SAEs and nonserious AEs (Safety Set), regardless of causality, is located in the AE section. COVID-19/SARS-CoV-2 infections were considered clinical events and not AEs.

Results and safety

Loading the posted results from ClinicalTrials.gov…

Research links

• Official record on ClinicalTrials.govLast updated by the sponsor 26 Nov 2025.
• Posted resultsParticipant flow, baseline, all outcome measures and adverse events.

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Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

The record lists no contact. Use the official record to reach the sponsor.

39 sites in 1 country: see every site and its status.