Special Investigation for Booster Dose of Comirnaty in Children Ages 6 Months Though 4 Years

NCT06130410 | Completed Results

• 1 other identifier: C4591057
• Study Type: observational
• Target: 25
• Locations: 1 country
• Sites: 1

Brief Summary

The purpose of this post-marketing study is to assess the safety of Comirnaty monovalent XBB.1.5. for booster vaccination children ages 6 months though 4 years under actual use medical practice.

Conditions

SARS-CoV-2; COVID-19

Keywords

COVID-19; SARS-CoV-2; Children (6 months though 4 years old); RNA Vaccine; Post-Marketing Study; Pediatric

Outcome Measures

Primary Outcomes (4)

• Proportion of Participants With Adverse Reaction (AR)

  An adverse event was defined as any untoward medical occurrence attributed to COMIRNATY intramuscular injection for 6 months to 4 years old (monovalent: Omicron XBB.1.5) in a participant who was vaccinated. The relatedness was assessed by the physician. Events for which a causal relationship with intramuscular injection could not be ruled out were handled as ARs.

  For 28 days after the booster (4th) dose

• Proportion of Participants With Serious Adverse Reaction (SAR)

  An SAR was defined as any AR resulting in any of the following outcomes or deemed significant for any other reason: death; life-threatening; hospitalization or prolongation of existing hospitalization; persistent or significant disability/malfunction; congenital anomaly/birth defect; or other medically important events.

  For 28 days after the booster (4th) dose

• Proportion of Participants With Reactogenicity (≥ Grade 1) in Those Who Are Younger Than 2 Years of Age

  Local reactions and systemic events recorded in the health observation diary collected by the physician from study participants were handled as reactogenicity events. They were aggregated for the vaccinated participants by age group and grade. The results were aggregated by age group for local reactions and systemic events of grade 1 or higher. If the participants were younger than 2 years of age on the date of the booster (4th) dose, the following reactogenicity events were aggregated. Local reactions: injection site tenderness, redness, and injection site swelling. Systemic events: pyrexia, decreased appetite, somnolence, and irritability. If the participants were 2 years or older on the date of the booster (4th) dose, the following reactogenicity events were aggregated. Local reactions: injection site pain, redness, and injection site swelling. Systemic events: pyrexia, vomiting, diarrhoea, headache, malaise, chills, myalgia, and arthralgia.

  Within 7 days after the date of the booster (4th) dose

• Proportion of Participants With Reactogenicity (≥ Grade 1) in Those Who Are Aged 2 Years or Older

  Local reactions and systemic events recorded in the health observation diary collected by the physician from study participants were handled as reactogenicity events. They were aggregated for the vaccinated participants by age group and grade. The results were aggregated by age group for local reactions and systemic events of grade 1 or higher. If the participants were younger than 2 years of age on the date of the booster (4th) dose, the following reactogenicity events were aggregated. Local reactions: injection site tenderness, redness, and injection site swelling. Systemic events: pyrexia, decreased appetite, somnolence, and irritability. If the participants were 2 years or older on the date of the booster (4th) dose, the following reactogenicity events were aggregated. Local reactions: injection site pain, redness, and injection site swelling. Systemic events: pyrexia, vomiting, diarrhoea, headache, malaise, chills, myalgia, and arthralgia.

  Within 7 days after the date of the booster (4th) dose

Study Arms (1)

COMIRNATY intramuscular injection for 6 months to 4 years old (monovalent, omicron XBB.1.5.)

Biological: COMIRNATY intramuscular injection

Interventions

COMIRNATY intramuscular injection BIOLOGICAL

Booster injection in the muscle, 1 dose

COMIRNATY intramuscular injection for 6 months to 4 years old (monovalent, omicron XBB.1.5.)

Eligibility Criteria

• Age: 6 Months - 4 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17)
• Sampling Method: Probability Sample

Study Population

Children of 6 months though 4years of age, at the time of booster vaccination(4th dose)

You may qualify if:

• Children aged 6 months to 4 years at the time of the booster vaccination (4th dose) who (or whose representative) gave written consent to take part in the study.

Sponsors & Collaborators

• Pfizer: lead

Study Sites (1)

Pfizer Local Country

Tokyo, 1518589, Japan

Location

Related Links

• To obtain contact information for a study center near you, click here.

MeSH Terms

Conditions

COVID-19

Condition Hierarchy (Ancestors)

Pneumonia, Viral; Pneumonia; Respiratory Tract Infections; Infections; Virus Diseases; Coronavirus Infections; Coronaviridae Infections; Nidovirales Infections; RNA Virus Infections; Lung Diseases; Respiratory Tract Diseases

Results Point of Contact

• Title: Pfizer ClinicalTrials.gov Call Center
• Organization: Pfizer, Inc.

ClinicalTrials.gov_Inquiries@pfizer.com

1-800-718-1021

Study Officials

• Pfizer CT.gov Call Center

  Pfizer

  STUDY DIRECTOR

Publication Agreements

• PI is Sponsor Employee: No
• Restriction Type: OTHER
• Restrictive Agreement: Yes

Study Design

• Study Type: observational
• Observational Model: CASE ONLY
• Time Perspective: PROSPECTIVE
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 8, 2023
• First Posted: November 14, 2023
• Study Start: March 6, 2024
• Primary Completion: July 26, 2024
• Study Completion: July 26, 2024
• Last Updated: July 14, 2025
• Results First Posted: July 14, 2025

Record last verified: 2025-06

Data Sharing

• IPD Sharing: Will not share

Locations

JP (1)