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Evaluating a new pneumococcal vaccine in healthy infants

A Phase 2, Randomized, Double-Blind, Active-Controlled, Dose-Finding Clinical Study to Evaluate the Safety, Tolerability, and Immunogenicity of VAX-31 in Healthy Infants Given 4 Doses at 2, 4, 6, and 12-15 Months of Age Concomitantly With Routine Pediatric Vaccines

PHASE2 · Vaxcyte, Inc. · NCT06720038

This study is testing a new pneumococcal vaccine in healthy infants to see if it's safe and effective when given alongside their regular vaccinations.

Quick facts

PhasePHASE2
Study typeInterventional
Enrollment800 (estimated)
Ages42 Days to 89 Days
SexAll
SponsorVaxcyte, Inc. (industry)
Locations48 sites (Jonesboro, Arkansas and 47 other locations)
Trial IDNCT06720038 on ClinicalTrials.gov

What this trial studies

This clinical study aims to assess the safety, tolerability, and immunogenicity of VAX-31, a 31-valent pneumococcal vaccine, in healthy infants. Participants will receive four injections of VAX-31 at different dose levels, alongside routine vaccinations, at specified ages. The study is divided into two stages, with the first stage focusing on dose escalation and the second stage enrolling additional participants to complete the sample size.

Who should consider this trial

Good fit: Ideal candidates for this study are healthy infants aged between 42 days and 89 days who are full-term and meet specific health criteria.

Not a fit: Patients who are not healthy infants or those who do not meet the eligibility criteria will not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to a more effective pneumococcal vaccine for infants, potentially reducing the incidence of pneumonia and pneumococcal infections.

How similar studies have performed: Other studies have shown success with similar pneumococcal vaccine approaches, indicating potential for this new vaccine to be effective.

Eligibility criteria

Show full inclusion / exclusion criteria 
Inclusion Criteria:

1. Healthy male or female infant ≥42 days to ≤89 days.
2. Full-term infant at least 37 weeks gestational age at birth.
3. Afebrile for ≥72 hours with an tympanic or rectal temperature \<38.0°C (\<100.4°F) before receipt of study vaccine.\*Criterion applies to each vaccination. If not met, visit may be rescheduled for a time when no longer febrile for ≥72 hours.
4. Able to attend all scheduled visits and comply with the study procedures.
5. Subject's parent/legal guardian is able to read and understands the study procedures, alternate treatments, risks and benefits, and provides written informed consent.
6. Subject's parent/legal guardian is able to fill out an eDiary of solicited AE and take daily tympanic temperature and measurements of local injection site reactions for the 7 days after each study vaccination.
7. Subject's parent/legal guardian has an email address and access to a computer or smartphone with internet to complete the eDiary.

Exclusion Criteria:

1. History of invasive pneumococcal disease (positive blood culture, positive cerebrospinal fluid culture, or other sterile site) or known history of other culture positive pneumococcal disease.
2. Previous receipt of a licensed or investigational vaccine (excluding 1 dose of hepatitis B vaccine).
3. Known hypersensitivity to any vaccine.
4. Known or suspected impairment of immunological function (e.g., asplenia, human immunodeficiency virus, primary immunodeficiency).
5. Use of any immunosuppressive therapy or planned use through the last blood draw (Visit 6). Receipt of a \<14-day course of systemic corticosteroids is not exclusionary if completed ≥1 month prior to first study vaccination. Topical and inhaled/nebulized steroids are also permitted.
6. History of failure to thrive or prior hospitalization for any chronic condition.
7. Subject has a bleeding disorder contraindicating IM vaccination.
8. Subject or his/her mother has documented hepatitis B surface antigen-positive test.
9. Subject has a known neurologic or cognitive behavioral disorder.
10. Subject has a known clinically significant congenital malformation or serious chronic disorder.
11. Receipt of a blood transfusion or blood products, including immunoglobulins.
12. Receipt of any investigational study product since birth, currently participating in another interventional investigational study, or plans to receive another investigational product while on study.
13. Any infant who cannot be adequately followed for safety according to the protocol plan.
14. Any other reason that in the opinion of the Investigator may interfere with the evaluation required by the study.

Where this trial is running

Jonesboro, Arkansas and 47 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 →

Conditions: Pneumococcal Vaccines, 31 Valent PCV, Pneumonia, Pneumococcal Infection

Last reviewed 2026-05-15 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.