A Clinical Study to Evaluate the Safety, Tolerability, and Immunogenicity of VAX-31 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

The objective of the study is to evaluate the safety, tolerability, and immunogenicity of 4 injections of VAX-31 (at 4 dose levels) compared to PCV20 in infants at 2, 4, 6, and 12-15 months of age, in addition to receiving routine US concomitant vaccines. Stage 1 of the study will comprise 3 dose ascending cohorts. Stage 2 of the study will enroll approximately 352 subjects. Stage 3 of the study will enroll approximately 500 subjects.

Study Overview

• Status: Active, not recruiting
• Conditions: Pneumococcal Vaccines
• Intervention / Treatment: Biological: 0.5 mL of the low dose VAX-31; Biological: 0.5 mL of the mid dose VAX-31; Biological: 0.5 mL of the high dose VAX-31; Biological: 0.5 mL dose of PCV20; Biological: 0.5 mL of the High-PFS dose VAX-31

• Study Type: Interventional
• Enrollment (Actual): 900
• Phase: Phase 2

Contacts and Locations

Study Locations

• Puerto Rico
  • Ponce, Puerto Rico, PR 716
    • Ponce Medical School Foundation Inc. / CAIMED Center
  • San Juan, Puerto Rico, PR 907
    • BRCR Global Puerto Rico
  • San Juan, Puerto Rico, PR 918
    • Caribbean Medical Research Center
• United States
  • Arkansas
    • Jonesboro, Arkansas, United States, 72401
      • The Children's Clinic of Jonesboro, P.A
  • California
    • Gardena, California, United States, 90237
      • Matrix Clinical Research
    • Los Angeles, California, United States, 90057
      • Matrix Clinical Research
    • Ontario, California, United States, 91762
      • Orange County Research Institute
    • West Covina, California, United States, 91790
      • Center for Clinical Trials of San Gabriel
  • Colorado
    • Aurora, Colorado, United States, 80045
      • Children's Hospital of Colorado - Dept. of Infectious Disease
  • Florida
    • Pensacola, Florida, United States, 32503
      • SEC Clinical Research
    • Tampa, Florida, United States, 33613
      • PAS Research
  • Idaho
    • Idaho Falls, Idaho, United States, 83404
      • Clinical Research Prime, LLP
    • Rexburg, Idaho, United States, 83440
      • Clinical Research Prime - Rexburg
  • Kentucky
    • Bardstown, Kentucky, United States, 40004
      • Kentucky Pediatrics/Adult Research
  • Louisiana
    • Haughton, Louisiana, United States, 71037
      • ACC Pediatric Research
  • Nebraska
    • Lincoln, Nebraska, United States, 68504
      • Complete Children's Health
    • Lincoln, Nebraska, United States, 68505
      • Complete Children's Health
    • Lincoln, Nebraska, United States, 68516
      • Be Well Clinical Studies Nebraska
    • Lincoln, Nebraska, United States, 68516
      • Complete Children's Health
    • Lincoln, Nebraska, United States, 68522
      • Complete Children's Health
  • Ohio
    • Dayton, Ohio, United States, 45414
      • Ohio Pediatric Research Association
    • South Euclid, Ohio, United States, 44121
      • Senders Pediatrics
  • Oregon
    • Gresham, Oregon, United States, 97030
      • Cyn3rgy Research
  • Pennsylvania
    • Cranberry Township, Pennsylvania, United States, 16066
      • UPMC Children's Community Pediatrics - Bass Wolfson, Cranberry
    • Erie, Pennsylvania, United States, 16506
      • Allegheny Health & Wellness Pavilion West
    • N. Huntingdon, Pennsylvania, United States, 15642
      • UPMC Children's Community Pediatrics - Norwin
    • Pittsburgh, Pennsylvania, United States, 15217
      • UPMC Children's Community Pediatrics Bass Wolfson-Squirrel Hill
    • Pittsburgh, Pennsylvania, United States, 15234
      • UPMC Children's Community Pediatrics-Castle Shannon
    • Pittsburgh, Pennsylvania, United States, 15025
      • UPMC Children's Community Pediatrics South Hills-Jefferson Hills
    • Pittsburgh, Pennsylvania, United States, 15213
      • UPMC Children's Hospital of Pittsburgh - General Academic Pediatrics (GAP)
  • South Carolina
    • Charleston, South Carolina, United States, 29407
      • Tribe Clinical Research, LLC dba Neighbors Clinical Research
    • Simpsonville, South Carolina, United States, 29680
      • Tribe Clinical Research/Parkside Pediatrics
  • Texas
    • Brownsville, Texas, United States, 78520
      • Proactive RGV LLC
    • Dallas, Texas, United States, 75001-
      • Javara Inc. /Texas Health Care, PLLC
    • Dallas, Texas, United States, 75287
      • Oak Cliff Research Company
    • Houston, Texas, United States, 77077
      • Sunrise Pediatrics
    • Houston, Texas, United States, 77087
      • Mercury Clinical Research - Pediatric Associates
    • Houston, Texas, United States, 77065
      • Kool Kids Pediatrics (Dynamed)
    • League City, Texas, United States, 77573
      • University of Texas Medical Branch - Sealy Institute for Vaccine Sciences, Clinical Trials Program
    • Richmond, Texas, United States, 77469
      • Pediatric Center/Neutra Life Sciences
  • Utah
    • Layton, Utah, United States, 84041
      • AMR - Layton
    • Murray, Utah, United States, 84107
      • AMR - Cottonwood
    • Roy, Utah, United States, 84067
      • AMR - Roy
    • South Jordan, Utah, United States, 84095
      • AMR South Jordan
    • Syracuse, Utah, United States, 84075
      • AMR - Syracuse
  • Virginia
    • Charlottesville, Virginia, United States, 22902
      • Pediatric Research of Charlottesville, LLC
    • Gordonsville, Virginia, United States, 22942
      • Pediatric Research of Charlottesville, LLC
    • Richmond, Virginia, United States, 23226
      • Clinical Research Partners, LLC.

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: Yes

Description

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.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

5

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: PCV20; Participants will receive 4 doses of PCV20 administered as an intramuscular injection of the standard dose at 2, 4, 6, and 12-15 months of age.	Biological: 0.5 mL dose of PCV20; 20 valent pneumococcal conjugate vaccine
Experimental: VAX-31 Low; Participants will receive 4 doses of VAX-31 administered as an intramuscular injection at 2, 4, 6, and 12-15 months of age at one of four dose levels.	Biological: 0.5 mL of the low dose VAX-31; 31 valent pneumococcal conjugate vaccine
Experimental: VAX-31 Mid; Participants will receive 4 doses of VAX-31 administered as an intramuscular injection at 2, 4, 6, and 12-15 months of age at one of four dose levels.	Biological: 0.5 mL of the mid dose VAX-31; 31 valent pneumococcal conjugate vaccine
Experimental: VAX-31 High; Participants will receive 4 doses of VAX-31 administered as an intramuscular injection at 2, 4, 6, and 12-15 months of age at one of four dose levels.	Biological: 0.5 mL of the high dose VAX-31; 31 valent pneumococcal conjugate vaccine
Experimental: VAX-31 High-PFS; Participants will receive 4 doses of VAX-31 administered as an intramuscular injection at 2, 4, 6, and 12-15 months of age at one of four dose levels.	Biological: 0.5 mL of the High-PFS dose VAX-31; 31 valent pneumococcal conjugate vaccine

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percentage of subjects with any solicited local injection site adverse events (AE) within 7 days after each vaccination	Solicited local reactions include erythema, edema, and tenderness at the injection site	7 days after each vaccination
Percentage of subjects with any solicited systemic AE within 7 days after each vaccination	Solicited systemic reactions include fever, irritability, decreased appetite, decreased sleep, and increased sleep	7 days after each vaccination
Percentage of subjects with any unsolicited AE within 1 month after each vaccination	Percentage of subjects with unsolicited AE	1 months after each vaccination
Percentage of subjects with any medically attended adverse events (MAAE) within 6 months after last vaccination	Percentage of subjects with MAAE	6 months after last vaccination
Percentage of subjects with any Serious Adverse Events (SAE) within 6 months after last vaccination	Percentage of subjects with SAE	6 months after last vaccination
Percentage of subjects with any new onset of chronic illness (NOCI) within 6 months after last vaccination	Percentage of subjects with NOCI	6 months after last vaccination

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percentage of subjects achieving a serotype-specific anti-pneumococcal IgG antibody concentration ≥0.35 mcg/mL 1 month after Dose 3	Percentage of subjects achieving a serotype-specific anti-pneumococcal IgG antibody concentration ≥0.35 mcg/mL	1 month after Dose 3
Serotype-specific IgG antibody geometric mean concentration (GMC) 1 month after Dose 3	Antibody geometric mean concentrations as measured by IgG for the 31 pneumococcal serotypes in VAX-31	1 month after Dose 3
Serotype-specific IgG antibody GMC 1 month after Dose 4	Antibody geometric mean concentrations as measured by IgG for the 31 pneumococcal serotypes in VAX-31	1 month after Dose 4

Collaborators and Investigators

• Sponsor: Vaxcyte, Inc.

Study record dates

Study Major Dates

• Study Start (Actual): November 25, 2024
• Primary Completion (Estimated): December 1, 2027
• Study Completion (Estimated): December 1, 2027

Study Registration Dates

• First Submitted: December 2, 2024
• First Submitted That Met QC Criteria: December 2, 2024
• First Posted (Actual): December 6, 2024

Study Record Updates

• Last Update Posted (Actual): May 15, 2026
• Last Update Submitted That Met QC Criteria: May 12, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Pneumonia; Pneumococcal Infection; 31 Valent PCV
• Additional Relevant MeSH Terms: Respiratory Tract Infections; Infections; Respiratory Tract Diseases; Lung Diseases; Gram-Positive Bacterial Infections; Bacterial Infections; Bacterial Infections and Mycoses; Streptococcal Infections; Pneumonia; Pneumococcal Infections
• Other Study ID Numbers: VAX31-201

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Vaxcyte is committed to providing access to anonymized data from the company's clinical trials for the purpose of legitimate scientific research. Requests for data may be addressed to datasharing@vaxcyte.com. Requests must be accompanied by a detailed analysis plan and will be reviewed for scientific validity. Data will be made available after initial product approval. Sharing of data may require execution of a data-sharing agreement.
• IPD Sharing Time Frame: Individual participant data will be shared after deidentification and made available starting 6 months after initial product approval.
• IPD Sharing Access Criteria: Criteria will depend on the specific proposal received and may include qualification of the scientific researchers, potential contribution to the research field, scientific rigor of statistical and analytical methods, and other criteria appropriate for the proposal.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No