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Pneumococcal VaccinesPhase 3NCT07425392

Safety, Tolerability, and Immunogenicity of VAX-31 in Adults ≥50 Years With Prior Pneumococcal Vaccination

A Phase 3 study testing 31-valent pneumococcal conjugate vaccine and PCV20 in people with Pneumococcal Vaccines, run by Vaxcyte, Inc. at 30 sites in United States.

Active, not recruiting

Under way, not looking for participants. Everyone needed has enrolled. The study is still running.

Official record
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Trial summary

The study will evaluate the safety, tolerability, and immunogenicity of VAX-31 in adults ≥50 years of age. Read more about this study

Who is it for?
Ages 50 years and olderHealthy volunteers can take part
Conditions the study is for
Pneumococcal Vaccines
What is being tested?
31-valent pneumococcal conjugate vaccine and PCV20
Could I receive a placebo?
No, everyone receives an active treatment
How many people
752 participants
Where
30 sitesUnited States
Study dates
9 Feb 2026to Mar 2027
Phase
Phase 3
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 50 years and older
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • Male or female ≥50 years of age (inclusive) at the time of randomization into the study.
  • Previous receipt of a licensed pneumococcal vaccine or combination of licensed vaccines, with most recent vaccination ≥1 year prior to randomization; the exception is PCV21, which may have been received ≥6 months prior to randomization (confirmed).
  • 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.
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  • 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).

Who cannot join

  • Previous invasive pneumococcal disease (IPD) or pneumococcal pneumonia (either confirmed or self-reported) at any age.
  • Previous receipt of an 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.
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  • 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.
  • Employee of, or first-degree relative of, any person employed by the Sponsor, the contract research organization (CRO), the Investigator, site personnel, or site

Trial locations and contacts

30 sites in 1 country.

30 sites in 1 country

United States30 sites
  • Tekton Research

    Austin, Texas, 78745

  • REX Clinical Trials

    Beaumont, Texas, 77701

  • Alcanza (Charlottesville Medical Research)

    Charlottesville, Virginia, 22911

  • Chinle Center for Indigenous Health

    Chinle, Arizona, 86503

  • Tekton Research

    Edmond, Oklahoma, 73013

  • Center of American Indian Health

    Gallup, New Mexico, 87301

  • DelRicht Research

    Hendersonville, Tennessee, 37075

  • CenExel (RCA)

    Hollywood, Florida, 33024

  • Eximia (Health Awareness)

    Jupiter, Florida, 33458

  • AMR

    Kansas City, Missouri, 64114

  • Johnson County Clin-Trials, LLC

    Lenexa, Kansas, 66219

  • DelRicht Clinical Research

    New Orleans, Louisiana, 70115

  • Health Research of Hampton Roads, Inc.

    Newport News, Virginia, 23606

  • Quality Clinical Research

    Omaha, Nebraska, 68114

  • Avacare (CCT Research)

    Phoenix, Arizona, 85044

  • Eximia (Health Awareness)

    Port Saint Lucie, Florida, 34952

  • Rochester Clinical Research, Inc.

    Rochester, New York, 14609

  • Velocity (Meridian Clinical Research)

    Rockville, Maryland, 20854

  • Flourish Research

    San Antonio, Texas, 78229

  • Shiprock Center for Indigenous Health

    Shiprock, New Mexico, 87420

  • DM Clinical Research-Detroit

    Southfield, Michigan, 48076

  • DelRicht Research (Command Family Medicine)

    Springfield, Missouri, 65807

  • DelRicht Clinical Research

    Stockbridge, Georgia, 30281

  • DM Clinical Research

    Sugar Land, Texas, 77478

  • Precision Clinical Research

    Sunrise, Florida, 33351

  • The Villages

    The Villages, Florida, 32162

  • Velocity Clinical Valparaiso

    Valparaiso, Indiana, 46383

  • Chase Medical Research

    Waterbury, Connecticut, 06708

  • Whiteriver Center for Indigenous Health

    Whiteriver, Arizona, 85941

  • Headlands (Trial Management Associates)

    Wilmington, North Carolina, 28403

Other trials in United States

About this study

Official title: A Phase 3, Randomized, Double-Blind, Active-Controlled Clinical Study to Evaluate the Safety, Tolerability, and Immunogenicity of VAX-31 in Healthy Subjects 50 Years of Age and Older With Prior Pneumococcal Vaccination

The study will evaluate the safety, tolerability, and immunogenicity of VAX-31 in adults ≥50 years of age.

Being tested
31-valent pneumococcal conjugate vaccine, PCV20
Keywords
Pneumonia, Pneumococcal Infection, 31-Valent PCV
Medical subject headings
Pneumonia, Pneumococcal Infections

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • 31-valent pneumococcal conjugate vaccineBiological

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

  • PCV20Biological

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

Study groups in NCT07425392
Study groupRoleWhat they receive
Cohort 1 (VAX-31): Prior PPSV23ExperimentalParticipants will receive a single dose of VAX-31 administered via intramuscular injection at Day 1
Receives: Biological: 31-valent pneumococcal conjugate vaccine
Cohort 1 (PCV20): Prior PPSV23Active comparatorParticipants will receive a single dose of PCV20 (Prevnar 20) administered via intramuscular injection at Day 1
Receives: Biological: PCV20
Cohort 2 (VAX-31): Prior PCV20ExperimentalParticipants will receive a single dose of VAX-31 administered via intramuscular injection at Day 1
Receives: Biological: 31-valent pneumococcal conjugate vaccine
Cohort 2 (PCV20): Prior PCV20Active comparatorParticipants will receive a single dose of PCV20 (Prevnar 20) administered via intramuscular injection at Day 1
Receives: Biological: PCV20
Cohort 3 (VAX-31): Other prior licensed pneumococcal vaccine or combinationExperimentalParticipants will receive a single dose of VAX-31 administered via intramuscular injection at Day 1
Receives: Biological: 31-valent pneumococcal conjugate vaccine
Cohort 3 (PCV20): Other prior licensed pneumococcal vaccine or combinationActive comparatorParticipants will receive a single dose of PCV20 (Prevnar 20) administered via intramuscular injection at Day 1
Receives: Biological: PCV20

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Serotype-specific OPA geometric mean titers (GMT)

    Measured: 1 month after VAX-31 vaccination

  2. Serotype-specific OPA geometric mean fold rise (GMFR) from baseline

    Measured: 1 month after VAX-31 vaccination

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

    Measured: up to 7 days after vaccination

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

    Measured: up to 7 days after vaccination

  5. Percentage of subjects reporting unsolicited AE

    Measured: up to 31 days after vaccination

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

    Measured: up to 6 months after vaccination

Secondary outcomes (2)
  1. Serotype-specific IgG geometric mean concentration (GMC)

    Measured: 1 month after VAX-31 vaccination

  2. Serotype-specific IgG geometric mean fold-rise (GMFR) from baseline

    Measured: 1 month after VAX-31 vaccination

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted20 Feb 2026
  2. Study start9 Feb 2026
  3. Primary completionMar 2027 (estimated)
  4. Study completionMar 2027 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 3
Primary purpose
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Masking
Quadruple blind
Who is masked
Participant, Care provider, Investigator, Outcomes assessor
Enrolment
752 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07425392
Sponsor's protocol ID
VAX31-105
Status last verified
Jun 2026
First submitted
11 Feb 2026
Last updated
30 Jun 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No

Questions about this trial

What is this clinical trial studying?

A Phase 3 study testing 31-valent pneumococcal conjugate vaccine and PCV20 in people with Pneumococcal Vaccines, run by Vaxcyte, Inc. at 30 sites in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 9 inclusion and 16 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: under way, not looking for participants, as of the sponsor's last update on 30 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 30 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Serotype-specific OPA geometric mean titers (GMT) (time frame: 1 month after VAX-31 vaccination). The study lists 6 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 30 Jun 2026.

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