Trial Outcomes & Findings for Special Investigation for Booster Dose of Comirnaty in Children Ages 6 Months Though 4 Years (NCT NCT06130410)

NCT ID: NCT06130410

Last Updated: 2025-07-14

Results Overview

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.

Recruitment status

COMPLETED

Target enrollment

25 participants

Primary outcome timeframe

For 28 days after the booster (4th) dose

Results posted on

2025-07-14

Participant Flow

The enrollment period ended with 25 participants completed.

Participant milestones

Participant milestones
Measure
COMIRNATY Intramuscular Injection for 6 Months to 4 Years Old (Monovalent: Omicron XBB.1.5) 3μg
Participants aged 6 months to 4 years old were vaccinated with the booster (4th) dose of COMIRNATY intramuscular injection for 6 months to 4 years old (monovalent: Omicron XBB.1.5) on Day 1.
Overall Study
STARTED
25
Overall Study
COMPLETED
25
Overall Study
NOT COMPLETED
0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Race and Ethnicity were not collected from any participant.

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
COMIRNATY Intramuscular Injection for 6 Months to 4 Years Old (Monovalent: Omicron XBB.1.5) 3μg
n=25 Participants
Participants aged 6 months to 4 years old were vaccinated with the booster (4th) dose of COMIRNATY intramuscular injection for 6 months to 4 years old (monovalent: Omicron XBB.1.5) on Day 1.
Age, Customized
≥6 months and <2 years
15 participants
n=25 Participants
Age, Customized
≥2 and ≤4 years
10 participants
n=25 Participants
Sex: Female, Male
Sex · Female
13 Participants
n=25 Participants
Sex: Female, Male
Sex · Male
12 Participants
n=25 Participants

PRIMARY outcome

Timeframe: For 28 days after the booster (4th) dose

Population: The safety analysis set comprised of participants who satisfied the inclusion criteria and were vaccinated with COMIRNATY intramuscular injection for 6 months to 4 years old (monovalent: Omicron XBB.1.5) at least once. Among the 25 participants with fixed CRFs in the study, no participants were excluded from the safety analysis set.

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.

Outcome measures

Outcome measures
Measure
COMIRNATY Intramuscular Injection for 6 Months to 4 Years Old (Monovalent: Omicron XBB.1.5) 3μg
n=25 Participants
Participants aged 6 months to 4 years old were vaccinated with the booster (4th) dose of COMIRNATY intramuscular injection for 6 months to 4 years old (monovalent: Omicron XBB.1.5) on Day 1.
Proportion of Participants With Adverse Reaction (AR)
1 Participants

PRIMARY outcome

Timeframe: For 28 days after the booster (4th) dose

Population: The safety analysis set comprised of participants who satisfied the inclusion criteria and were vaccinated with COMIRNATY intramuscular injection for 6 months to 4 years old (monovalent: Omicron XBB.1.5) at least once. Among the 25 participants with fixed CRFs in the study, no participants were excluded from the safety analysis set.

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.

Outcome measures

Outcome measures
Measure
COMIRNATY Intramuscular Injection for 6 Months to 4 Years Old (Monovalent: Omicron XBB.1.5) 3μg
n=25 Participants
Participants aged 6 months to 4 years old were vaccinated with the booster (4th) dose of COMIRNATY intramuscular injection for 6 months to 4 years old (monovalent: Omicron XBB.1.5) on Day 1.
Proportion of Participants With Serious Adverse Reaction (SAR)
0 Participants

PRIMARY outcome

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

Population: The safety analysis set comprised of participants who satisfied the inclusion criteria and were vaccinated with COMIRNATY intramuscular injection for 6 months to 4 years old (monovalent: Omicron XBB.1.5) at least once. Among the 25 participants with fixed CRFs in the study, no participants were excluded from the safety analysis set. Of the safety analysis set, participants younger than 2 years were included in this analysis.

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.

Outcome measures

Outcome measures
Measure
COMIRNATY Intramuscular Injection for 6 Months to 4 Years Old (Monovalent: Omicron XBB.1.5) 3μg
n=15 Participants
Participants aged 6 months to 4 years old were vaccinated with the booster (4th) dose of COMIRNATY intramuscular injection for 6 months to 4 years old (monovalent: Omicron XBB.1.5) on Day 1.
Proportion of Participants With Reactogenicity (≥ Grade 1) in Those Who Are Younger Than 2 Years of Age
Local reactions (Grade 1 or higher)
5 Participants
Proportion of Participants With Reactogenicity (≥ Grade 1) in Those Who Are Younger Than 2 Years of Age
Systemic events (Grade 1 or higher)
4 Participants

PRIMARY outcome

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

Population: The safety analysis set comprised of participants who satisfied the inclusion criteria and were vaccinated with COMIRNATY intramuscular injection for 6 months to 4 years old (monovalent: Omicron XBB.1.5) at least once. Among the 25 participants with fixed CRFs in the study, no participants were excluded from the safety analysis set. Of the safety analysis set, participants aged 2 years or older were included in this analysis.

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.

Outcome measures

Outcome measures
Measure
COMIRNATY Intramuscular Injection for 6 Months to 4 Years Old (Monovalent: Omicron XBB.1.5) 3μg
n=10 Participants
Participants aged 6 months to 4 years old were vaccinated with the booster (4th) dose of COMIRNATY intramuscular injection for 6 months to 4 years old (monovalent: Omicron XBB.1.5) on Day 1.
Proportion of Participants With Reactogenicity (≥ Grade 1) in Those Who Are Aged 2 Years or Older
Local reactions (Grade 1 or higher)
7 Participants
Proportion of Participants With Reactogenicity (≥ Grade 1) in Those Who Are Aged 2 Years or Older
Systemic events (Grade 1 or higher)
2 Participants

Adverse Events

COMIRNATY Intramuscular Injection for 6 Months to 4 Years Old (Monovalent: Omicron XBB.1.5) 3μg

Serious events: 0 serious events
Other events: 5 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure
COMIRNATY Intramuscular Injection for 6 Months to 4 Years Old (Monovalent: Omicron XBB.1.5) 3μg
n=25 participants at risk
Participants aged 6 months to 4 years old were vaccinated with the booster (4th) dose of COMIRNATY intramuscular injection for 6 months to 4 years old (monovalent: Omicron XBB.1.5) on Day 1.
Infections and infestations
Influenza
4.0%
1/25 • For 28 days after the booster (4th) dose
The frequency of adverse events. The same event may appear as both an adverse event and a serious adverse event. However, what is presented are distinct events. An event may be categorized as serious in one participant and as non-serious in another participant, or one participant may have experienced both serious and non-serious events during the study.
Infections and infestations
Nasopharyngitis
8.0%
2/25 • For 28 days after the booster (4th) dose
The frequency of adverse events. The same event may appear as both an adverse event and a serious adverse event. However, what is presented are distinct events. An event may be categorized as serious in one participant and as non-serious in another participant, or one participant may have experienced both serious and non-serious events during the study.
Respiratory, thoracic and mediastinal disorders
Upper respiratory tract inflammation
8.0%
2/25 • For 28 days after the booster (4th) dose
The frequency of adverse events. The same event may appear as both an adverse event and a serious adverse event. However, what is presented are distinct events. An event may be categorized as serious in one participant and as non-serious in another participant, or one participant may have experienced both serious and non-serious events during the study.

Additional Information

Pfizer ClinicalTrials.gov Call Center

Pfizer, Inc.

Phone: 1-800-718-1021

Results disclosure agreements

  • Principal investigator is a sponsor employee Pfizer has the right to review disclosures, requesting a delay of less than 60 days. Investigator will postpone single center publications until after disclosure of pooled data (all sites), less than 12 months from study completion/termination at all participating sites. Investigator may not disclose previously undisclosed confidential information other than study results.
  • Publication restrictions are in place

Restriction type: OTHER