Safety, Tolerability, and Immunogenicity of VAX-31 in Adults ≥50 Years With Immunobridging to Adults 18-49

NCT07284654 | Active Not Recruiting Phase 3 DMC FDA Drug

• 1 other identifier: VAX31-103
• Study Type: interventional
• Target: 4,049
• Locations: 1 country
• Sites: 30

Brief Summary

The primary objectives of this study are to evaluate the safety, tolerability, immunologic noninferiority (for shared serotypes) and immunologic superiority (for novel serotypes) of VAX-31 compared to PCV21 and PCV20 in adults ≥50 years of age, and to bridge the immune responses induced by VAX-31 in adults 50-64 years of age to adults 18-49 years of age.

Conditions

Pneumococcal Vaccines

Keywords

31 Valent PCV; Pneumonia; Pneumococcal Infection

Outcome Measures

Primary Outcomes (6)

• Serotype-specific OPA geometric mean titers (GMT) in 50 year olds and above

  1 month after vaccination

• Percentage of subjects reporting solicited local adverse events (AE) (redness, swelling, and pain at injection site)

  up to 7 days after vaccination

• Percentage of subjects reporting solicited systemic AE (fever, headache, fatigue, muscle pain, and joint pain)

  up to 7 days after vaccination

• Percentage of subjects reporting unsolicited AE

  up to 31 days after vaccination

• Percentage of subjects reporting serious adverse events (SAE), new onset of chronic illness (NOCI), and medically attended adverse events (MAAE)

  up to 6 Months after vaccination

• Serotype-specific OPA geometric mean titers (GMT) in 18 to 49 year olds and 50 to 64 year olds

  1 month after vaccination

Secondary Outcomes (2)

• Serotype-specific IgG geometric mean concentrations (GMC) in 50 year olds and above

  1 month after vaccination

• Serotype-specific IgG GMC in 18 to 49 year olds and 50 to 64 year olds

  1 month after vaccination

Study Arms (5)

Cohort 1 (VAX-31), participant ≥ 50 years of age

EXPERIMENTAL

Participants will receive a single dose of VAX-31 administered via intramuscular injection at Day 1

Biological: 31 valent pneumococcal conjugate vaccine

Cohort 1 (PCV21), participant ≥ 50 years of age

ACTIVE COMPARATOR

Participants will receive a single dose of PCV21 (Capvaxive) administered via intramuscular injection at Day 1

Biological: PCV21

Cohort 1 (PCV20), participant ≥ 50 years of age

ACTIVE COMPARATOR

Participants will receive a single dose of PCV20 (Prevnar 20) administered via intramuscular injection at Day 1

Biological: PCV20

Cohort 2 (VAX-31), participant 18-49 years of age

EXPERIMENTAL

Participants will receive a single dose of VAX-31 administered via intramuscular injection at Day 1

Biological: 31 valent pneumococcal conjugate vaccine

Cohort 2 (PCV20), participant 18-49 years of age

ACTIVE COMPARATOR

Participants will receive a single dose of PCV20 (Prevnar 20) administered via intramuscular injection at Day 1

Biological: PCV20

Interventions

31 valent pneumococcal conjugate vaccine BIOLOGICAL

0.5 mL of VAX-31 will be administered into the deltoid muscle

Cohort 1 (VAX-31), participant ≥ 50 years of age; Cohort 2 (VAX-31), participant 18-49 years of age

PCV20 BIOLOGICAL

0.5 mL of the 20 valent pneumococcal conjugate vaccine will be administered into the deltoid muscle

Also known as: Prevnar 20

Cohort 1 (PCV20), participant ≥ 50 years of age; Cohort 2 (PCV20), participant 18-49 years of age

PCV21 BIOLOGICAL

0.5 mL of the 21 valent pneumococcal conjugate vaccine will be administered into the deltoid muscle

Also known as: Capvaxive

Cohort 1 (PCV21), participant ≥ 50 years of age

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Male or female ≥18 years of age (inclusive) at the time of randomization into the study.
• Able and willing to complete the informed consent process.
• Available for clinical follow-up through the last study visit.
• In good general health or with stable underlying chronic condition(s), as determined by medical history, oral temperature, physical examination, and clinical judgment of the Investigator (ongoing chronic conditions must be documented as stable per Investigator).
• Willing to have blood samples collected and used for research purposes.
• Able to provide proof of identity to the satisfaction of the site personnel completing the enrollment process.
• Female participants of childbearing potential, defined as premenopausal females capable of becoming pregnant, must have a negative urine pregnancy test immediately prior to randomization and agree to use acceptable contraception. Male subjects with partners of childbearing potential must agree to practice an acceptable contraception method.
• Able to access and use a device connected to Wi-Fi or cellular network for completion of an electronic diary (eDiary).

You may not qualify if:

• History of invasive pneumococcal disease (IPD) or pneumococcal pneumonia (either confirmed or self-reported) at any age.
• Previous receipt of any licensed or investigational pneumococcal vaccine at any age.
• Receipt of any investigational product within 30 days prior to Day 1, currently participating in another interventional investigational study, or having plans to receive another investigational product(s) while on study.
• Receipt of any live vaccine within 30 days prior to Day 1, or receipt of any non-live (including inactivated) vaccine within 14 days prior to Day 1.
• Body temperature \>38.0°C (\>100.4°F) or acute illness within 3 days prior to study vaccination (subject may be rescreened).
• Current diagnosis of human immunodeficiency virus, Hepatitis B, or Hepatitis C.
• History of severe allergic reaction with generalized urticaria, angioedema, or anaphylaxis to any previous vaccination.
• Individual who is pregnant, breastfeeding, or planning to become pregnant during study participation.
• Has a known or suspected immunocompromising condition, including, but not limited to, leukemia, lymphoma, chronic renal failure, or congenital or acquired immunodeficiency.
• Bleeding disorder diagnosed by a doctor (e.g., factor deficiency, coagulopathy, or platelet disorder requiring special precautions) resulting in clinically significant bruising or bleeding difficulties with IM injections or blood draws.
• Receipt of blood or blood product (including polyclonal intravenous immunoglobulin) within 60 days prior to enrollment into the study.
• Is currently receiving immunosuppressive or immune-modifying therapy, including systemic corticosteroids (this includes ≥3 months of prednisone equivalent from 5 to \<10 mg/day and ≥2 weeks of prednisone equivalent ≥10 mg/day).
• Received any part of a ≥14-day course of systemic corticosteroids (prednisone equivalent \>10 mg/day) within 14 days of study vaccination.
• History of malignancy ≤5 years before enrollment, except for adequately treated basal cell or squamous cell skin cancer or in situ cervical cancer.
• Any medical, psychiatric, or social condition that in the judgment of the Investigator is a contraindication to protocol participation or impairs a subject's ability to give informed consent.

Sponsors & Collaborators

• Vaxcyte, Inc.: lead

Study Sites (30)

Accel Research Site - Achieve - Birmingham - ERN

Birmingham, Alabama, 35216, United States

Location

Center for Indigenous Health - Chinle - Johns Hopkins Project

Chinle, Arizona, 86503, United States

Location

Center for Indigineous Health - Whiteriver - John Hopkins Project

Whiteriver, Arizona, 85941, United States

Location

Clinical Innovations Trials - Riverside - CenExel

Riverside, California, 92506, United States

Location

Research Centers of America - Hollywood - CenExel

Hollywood, Florida, 33024, United States

Location

Health Awareness - Jupiter - ERN

Jupiter, Florida, 33458, United States

Location

Suncoast Research Group LLC

Miami, Florida, 33135, United States

Location

Precision Clinical Research - Sunrise

Sunrise, Florida, 33351, United States

Location

Clinical Research Atlanta - Headlands

Stockbridge, Georgia, 30281, United States

Location

Velocity Clinical Research - Valparaiso (Buynak Clinical Research)

Valparaiso, Indiana, 46383, United States

Location

Johnson County Clin-Trials - JCCT

Lenexa, Kansas, 66219, United States

Location

Alliance for Multispecialty Research, LLC - West Wichita

Wichita, Kansas, 67207, United States

Location

DelRicht Clinical Research, LLC - New Orleans

New Orleans, Louisiana, 70115, United States

Location

Headlands Research - Detroit - Headlands

Southfield, Michigan, 48034, United States

Location

DelRicht Research, LLC - Gulfport

Gulfport, Mississippi, 39503, United States

Location

Sky Integrative Medical Center - SKYCRNG

Ridgeland, Mississippi, 39157, United States

Location

Alliance for Multispecialty Research, LLC - Kansas City

Kansas City, Missouri, 64114, United States

Location

Velocity Clinical Research

Omaha, Nebraska, 68134, United States

Location

Advanced Memory Research Institute - CenExe

Toms River, New Jersey, 08755, United States

Location

Center for Indigineous Health - Gallup - John Hopkins Project

Gallup, New Mexico, 87301, United States

Location

Center for Indigineous Health - Shiprock - John Hopkins Project

Shiprock, New Mexico, 87420, United States

Location

Rochester Clinical Research - ATLAS - Rochester

Rochester, New York, 14609, United States

Location

CTI Clinical Research Center

Cincinnati, Ohio, 45212, United States

Location

Lynn Institute of Norman

Norman, Oklahoma, 73072, United States

Location

DM Clinical Research - Philadelphia

Philadelphia, Pennsylvania, 19107, United States

Location

Coastal Carolina Research Center - Alcanza - HyperCore

North Charleston, South Carolina, 29405, United States

Location

Flourish Research - San Antonio

San Antonio, Texas, 78229, United States

Location

DM Clinical Research - Sugarland

Sugar Land, Texas, 77478, United States

Location

JBR Clinical Research - CenExel JBR

Salt Lake City, Utah, 84107, United States

Location

Charlottesville Medical Research Center - Alcanza - HyperCore

Charlottesville, Virginia, 22911, United States

Location

MeSH Terms

Conditions

Pneumonia; Pneumococcal Infections

Condition Hierarchy (Ancestors)

Respiratory Tract Infections; Infections; Lung Diseases; Respiratory Tract Diseases; Streptococcal Infections; Gram-Positive Bacterial Infections; Bacterial Infections; Bacterial Infections and Mycoses

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: December 8, 2025
• First Posted: December 16, 2025
• Study Start: December 1, 2025
• Primary Completion (Estimated): January 1, 2027
• Study Completion (Estimated): January 1, 2027
• Last Updated: March 31, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL
• Time Frame: Individual participant data will be shared after deidentification and made available starting 6 months after initial product approval.
• 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.

Locations

US (30)