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Learning about a new pneumococcal vaccine in toddlers

A PHASE 2, RANDOMIZED, PARTIALLY DOUBLE-BLIND TRIAL TO EVALUATE THE SAFETY, TOLERABILITY, AND IMMUNOGENICITY OF A MULTIVALENT PNEUMOCOCCAL CONJUGATE VACCINE ADMINISTERED IN HEALTHY TODDLERS 12 THROUGH 15 MONTHS OF AGE

Phase 2 Interventional Pfizer · NCT06531538

This study is testing a new pneumococcal vaccine in toddlers aged 12 to 15 months to see how safe it is and how well it helps their immune system.

Quick facts

PhasePhase 2
Study typeInterventional
Enrollment300 (estimated)
Ages12 Months to 15 Months
SexAll
SponsorPfizer Industry-sponsored
Locations47 sites (Miami Lakes, Florida and 46 other locations)
Trial IDNCT06531538 on ClinicalTrials.gov

What this trial studies

This study aims to evaluate the safety, tolerability, and immune response of a new pneumococcal vaccine in toddlers aged 12 to 15 months. Participants will be assigned to either a 1-Dose or 2-Dose group and will attend clinic visits to monitor for side effects and provide blood samples. The study duration is approximately 6 to 8 months, depending on the group assignment, with a combination of clinic and phone visits for follow-up. The goal is to gather important data on how well the vaccine works in this age group.

Who should consider this trial

Good fit: Ideal candidates are healthy toddlers aged 12 to 15 months who have received prior doses of the pneumococcal vaccine.

Not a fit: Patients with a history of severe allergic reactions to vaccines or significant chronic health issues may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to improved vaccination strategies against pneumococcal disease in young children.

How similar studies have performed: Other studies on pneumococcal vaccines have shown positive outcomes, indicating that this approach is supported by previous research.

Eligibility criteria

Show full inclusion / exclusion criteria 
Inclusion Criteria:

* Male or female toddlers ≥12 to ≤15 months of age at the time of consent.
* Healthy toddlers determined by clinical assessment, including medical history and clinical judgment, to be eligible for the study.
* Have received 3 infant doses of 20vPnC at 2, 4, and 6 months of age, with the last dose administered \>56 days before enrollment into the study. Documented confirmation of receipt will be collected prior to randomization.

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 (other than 20vPnC) or planned receipt during study participation.

Where this trial is running

Miami Lakes, Florida and 46 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
View on ClinicalTrials.gov → Find more trials like this →
Conditions Pneumococcal Disease
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.