A Study to Learn About the Safety of an Expanded Pneumococcal Vaccine in Healthy Infants

September 11, 2026 updated by: Pfizer

A PHASE 3, RANDOMIZED, DOUBLE-BLINDED TRIAL TO EVALUATE THE SAFETY AND TOLERABILITY OF A MULTIVALENT PNEUMOCOCCAL CONJUGATE VACCINE IN HEALTHY INFANTS

The purpose of this study is to learn about the safety of a new pneumococcal vaccine and how the new pneumococcal vaccine helps to fight against germs that can cause pneumonia (lung infections), meningitis (brain infections), and otitis media (ear infections) in infants when compared to the pneumococcal vaccine that is currently in use, 20vPnC (Prevnar 20®).

This study will test if the new pneumococcal vaccine is as safe as the one that is currently in use. This new vaccine can possibly provide additional protection against germs that cause pneumococcal disease that are not included in the vaccines that are currently given to infants. Pneumococcal disease includes a variety of infections caused by a specific germ, Streptococcus pneumoniae.

There are two groups in this study. All participants will be assigned to one of the two groups. This study is seeking participants who are:

- infants who are about 2 months of age

About 2400 infants will be assigned by chance to one of the two groups to receive either PG4 (new vaccine) or 20vPnC (currently in use) into the left thigh muscle at 2, 4, 6, and 12 to 15 months of age.

Infants will take part in this study for about 16 to 19 months (about 1 and a half years). During this time, infants will have 6 study clinic visits and 1 phone call. At these study clinic visits, parent(s)/legal guardian(s) will be asked if the infant experienced any side effects. A side effect is an unintentional or unexpected reaction to a vaccine.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
2400

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Australia
    • New South Wales
      • Westmead, New South Wales, Australia, 2145
        • Not yet recruiting
        • The Children's Hospital at Westmead
    • Queensland
      • Brisbane, Queensland, Australia, 4101
        • Not yet recruiting
        • Queensland Children's Hospital
      • South Brisbane, Queensland, Australia, 4101
        • Not yet recruiting
        • Centre for Children's Health Research
    • Victoria
      • Clayton, Victoria, Australia, 3168
        • Not yet recruiting
        • Monash Health
      • Parkville, Victoria, Australia, 3052
        • Recruiting
        • Murdoch Children's Research Institute
    • Western Australia
      • Nedlands, Western Australia, Australia, 6009
        • Recruiting
        • Perth Children's Hospital
      • Nedlands, Western Australia, Australia, 6009
        • Recruiting
        • The Kids Research Institute Australia
  • Canada
    • Ontario
      • London, Ontario, Canada, N5W 6A2
        • Recruiting
        • Milestone Research Inc.
      • Sarnia, Ontario, Canada, N7T 4X3
        • Recruiting
        • Bluewater Clinical Research Group Inc.
  • Finland
    • Keski-Pohjanmaa
      • Kokkola, Keski-Pohjanmaa, Finland, 67100
        • Not yet recruiting
        • FVR, Kokkolan rokotetutkimusklinikka
    • North Ostrobothnia
      • Oulu, North Ostrobothnia, Finland, 90220
        • Not yet recruiting
        • FVR, Oulun rokotetutkimusklinikka
    • Pirkanmaa
      • Tampere, Pirkanmaa, Finland, 33100
        • Not yet recruiting
        • FVR, Tampereen rokotetutkimusklinikka
    • Uusimaa
      • Espoo, Uusimaa, Finland, 02230
        • Not yet recruiting
        • FVR, Espoon rokotetutkimusklinikka
      • Helsinki, Uusimaa, Finland, 00290
        • Not yet recruiting
        • MeVac - Meilahti Vaccine Research Center
      • Helsinki, Uusimaa, Finland, 00100
        • Not yet recruiting
        • FVR, Etelä-Helsingin rokotetutkimusklinikka
      • Jarvenpaa, Uusimaa, Finland, 04400
        • Not yet recruiting
        • FVR, Järvenpään rokotetutkimusklinikka
  • Germany
    • Bavaria
      • Schönau am Königssee, Bavaria, Germany, 83471
        • Not yet recruiting
        • Kinder- und Jugendarztpraxis Dr. med. Michael Horn
  • Poland
      • Dziekanów Leśny, Poland, 05-092
        • Not yet recruiting
        • SZPZOZ im. Dzieci Warszawy w Dziekanowie Lesnym
  • United States
    • Florida
      • Estero, Florida, United States, 33928
        • Recruiting
        • Starz Pediatrics
      • Fort Lauderdale, Florida, United States, 33304
        • Recruiting
        • Innovate Research Centers, LLC
      • Fort Myers, Florida, United States, 33908
        • Recruiting
        • MacKoul Pediatrics Fort Myers
      • Miami, Florida, United States, 33135
        • Not yet recruiting
        • Dr. Gala, LLC
    • Georgia
      • Union City, Georgia, United States, 30291
        • Recruiting
        • Rophe Adult and Pediatric Medicine/SKYCRNG
    • Idaho
      • Idaho Falls, Idaho, United States, 83404
        • Recruiting
        • Rosemark Women Care Specialists
    • Illinois
      • Chicago, Illinois, United States, 60621
        • Recruiting
        • Eagle Clinical Research
    • Kentucky
      • Bardstown, Kentucky, United States, 40004
        • Recruiting
        • Kentucky Pediatric/ Adult Research
    • Louisiana
      • Shreveport, Louisiana, United States, 71101
        • Recruiting
        • LSU Health Shreveport Clinical Trials Office
      • Shreveport, Louisiana, United States, 71101
        • Recruiting
        • Ochsner/LSU Health Shreveport - Progressive Pediatrics
      • Shreveport, Louisiana, United States, 71103
        • Recruiting
        • Ochsner LSU Health Shreveport Ambulatory Care Center
      • Shreveport, Louisiana, United States, 71103
        • Recruiting
        • Ochsner/LSU Health Shreveport Academic Medical Center
    • Massachusetts
      • Fall River, Massachusetts, United States, 02721
        • Recruiting
        • Pediatric Associates of Fall River
    • New York
      • Hawthorne, New York, United States, 10532
        • Recruiting
        • Boston Children's Health Physicians
      • Valhalla, New York, United States, 10595
        • Recruiting
        • Maria Fareri Children's Hospital
    • Ohio
      • South Euclid, Ohio, United States, 44121
        • Recruiting
        • Senders Pediatrics
    • Oklahoma
      • Oklahoma City, Oklahoma, United States, 73103
        • Recruiting
        • Legacy Clinical Trials
    • Oregon
      • Gresham, Oregon, United States, 97030
        • Recruiting
        • Cyn3rgy Research Corporation
    • Pennsylvania
      • Sayre, Pennsylvania, United States, 18840
        • Recruiting
        • Donald Guthrie Foundation
      • Sayre, Pennsylvania, United States, 18840
        • Recruiting
        • Guthrie Medical Group
    • South Carolina
      • Simpsonville, South Carolina, United States, 29680
        • Recruiting
        • Tribe Clinical Research LLC. at Parkside Pediatrics Five Forks
    • Texas
      • Plano, Texas, United States, 75093
        • Not yet recruiting
        • National Research Centers, Plano LLC
    • Virginia
      • Gordonsville, Virginia, United States, 22942
        • Recruiting
        • Pediatric Research of Charlottesville, LLC.

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Child

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Infants who are about 2 months of age
  • Healthy infants determined by clinical assessment, including medical history and clinical judgment, to be eligible for the study.

Exclusion Criteria:

  • History of severe adverse reaction associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis).
  • Major known congenital malformation or serious chronic disorder.
  • Other acute or chronic medical or psychiatric condition or laboratory abnormality that may increase the risk associated with study participation or investigational product administration or may interfere with the interpretation of study results and, in the judgment of the investigator, would make the participant inappropriate for entry into this study.
  • Previous vaccination with any licensed or investigational pneumococcal vaccine, or planned receipt through study participation.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: PG4 (intramuscular)
Multivalent Pneumococcal Vaccine
Biological: PG4
Multivalent Pneumococcal Vaccine
Active Comparator: 20-valent pneumococcal conjugate vaccine (20vPnC) (intramuscular)
20-valent pneumococcal conjugate vaccine (20vPnC)
Biological: 20-valent pneumococcal conjugate vaccine (20vPnC)
20-valent pneumococcal conjugate vaccine (20vPnC)
Other Names:
  • Prevnar 20

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Percentage of participants reporting local reactions within 7 days after each dose
Time Frame: Day 7
Prompted local reactions after each dose
Day 7
Percentage of participants reporting serious adverse events (SAEs)
Time Frame: Dose 1 to 6 months after Dose 4
SAEs occurring from Dose 1 to 6 months after Dose 4
Dose 1 to 6 months after Dose 4
Percentage of participants reporting systemic events within 7 days after each dose
Time Frame: Day 7
Prompted systemic events after each dose
Day 7
Percentage of participants reporting adverse events (AEs) from Dose 1 to 1 month after Dose 3
Time Frame: Dose 1 to 1 month after Dose 3
AEs occurring from Dose 1 to 1 month after Dose 3
Dose 1 to 1 month after Dose 3
Percentage of participants reporting AEs from Dose 4 to 1 month after Dose 4
Time Frame: Dose 4 to 1 month after Dose 4
AEs occurring from Dose 4 to 1 month after Dose 4
Dose 4 to 1 month after Dose 4

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Pfizer

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: Pfizer CT.gov Call Center, Pfizer

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
May 4, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 30, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 30, 2028

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
April 30, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 30, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
May 7, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 15, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 11, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • C4931007
  • 2025 (U.S. NIH Grant/Contract: Faculty of Social Sciences Scientific Grant at the University of Gdańsk)
  • 2025-523447-35-00 (Registry Identifier: CTIS (EU))

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical_trials/trial_data_and_results/data_requests.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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