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.
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
- Type of treatment
- Vaccines, Injection or infusion
- 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
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.
- Conditions
- Pneumococcal Vaccines
- 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 group | Role | What they receive |
|---|---|---|
| Cohort 1 (VAX-31): Prior PPSV23 | Experimental | Participants 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 PPSV23 | Active comparator | Participants will receive a single dose of PCV20 (Prevnar 20) administered via intramuscular injection at Day 1 Receives: Biological: PCV20 |
| Cohort 2 (VAX-31): Prior PCV20 | Experimental | Participants 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 PCV20 | Active comparator | Participants 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 combination | Experimental | Participants 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 combination | Active comparator | Participants 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.
Serotype-specific OPA geometric mean titers (GMT)
Measured: 1 month after VAX-31 vaccination
Serotype-specific OPA geometric mean fold rise (GMFR) from baseline
Measured: 1 month after VAX-31 vaccination
Percentage of subjects reporting solicited local adverse events (AE) (redness, swelling, and pain at injection site)
Measured: up to 7 days after vaccination
Percentage of subjects reporting solicited systemic AE (fever, headache, fatigue, muscle pain, and joint pain)
Measured: up to 7 days after vaccination
Percentage of subjects reporting unsolicited AE
Measured: up to 31 days after vaccination
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)
Serotype-specific IgG geometric mean concentration (GMC)
Measured: 1 month after VAX-31 vaccination
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.
- First posted20 Feb 2026
- Study start9 Feb 2026
- Primary completionMar 2027 (estimated)
- Study completionMar 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Pneumococcal VaccinesStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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)
Sponsor and investigators
- Lead sponsor
- Vaxcyte, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
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
Study at a glance
From the registry record, last updated by the sponsor on 30 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- 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
- ClinicalTrials.gov ID
- NCT07425392
- Acronym / sponsor ID
- VAX31-105
- Conditions
- Pneumococcal Vaccines
- Keywords
- Pneumonia, Pneumococcal Infection, 31-Valent PCV
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 752 participants (actual)
- Lead sponsor
- Vaxcyte, Inc.Industry (pharma, biotech, devices)
- Study start
- 9 Feb 2026 (actual)
- Primary completion
- Mar 2027 (estimated)
- Study completion
- Mar 2027 (estimated)
- First posted
- 20 Feb 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The study will evaluate the safety, tolerability, and immunogenicity of VAX-31 in adults ≥50 years of age.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 6
| Arm | Type | Receives |
|---|---|---|
| Cohort 1 (VAX-31): Prior PPSV23 | Experimental | Biological: 31-valent pneumococcal conjugate vaccineParticipants will receive a single dose of VAX-31 administered via intramuscular injection at Day 1 |
| Cohort 1 (PCV20): Prior PPSV23 | Active comparator | Biological: PCV20Participants will receive a single dose of PCV20 (Prevnar 20) administered via intramuscular injection at Day 1 |
| Cohort 2 (VAX-31): Prior PCV20 | Experimental | Biological: 31-valent pneumococcal conjugate vaccineParticipants will receive a single dose of VAX-31 administered via intramuscular injection at Day 1 |
| Cohort 2 (PCV20): Prior PCV20 | Active comparator | Biological: PCV20Participants will receive a single dose of PCV20 (Prevnar 20) administered via intramuscular injection at Day 1 |
| Cohort 3 (VAX-31): Other prior licensed pneumococcal vaccine or combination | Experimental | Biological: 31-valent pneumococcal conjugate vaccineParticipants will receive a single dose of VAX-31 administered via intramuscular injection at Day 1 |
| Cohort 3 (PCV20): Other prior licensed pneumococcal vaccine or combination | Active comparator | Biological: PCV20Participants will receive a single dose of PCV20 (Prevnar 20) administered via intramuscular injection at Day 1 |
Who may qualify
- Ages
- 50 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (9 listed)
- 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).
Key exclusion criteria (16 listed)
- 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).
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| 31-valent pneumococcal conjugate vaccine0.5 mL of VAX-31 will be administered into the deltoid muscle | Biological | Cohort 1 (VAX-31): Prior PPSV23, Cohort 2 (VAX-31): Prior PCV20, Cohort 3 (VAX-31): Other prior licensed pneumococcal vaccine or combination |
| PCV200.5 mL of the 20-valent pneumococcal conjugate vaccine will be administered into the deltoid muscle | Biological | Cohort 1 (PCV20): Prior PPSV23, Cohort 2 (PCV20): Prior PCV20, Cohort 3 (PCV20): Other prior licensed pneumococcal vaccine or combination |
Primary outcome
Serotype-specific OPA geometric mean titers (GMT)
Time frame: 1 month after VAX-31 vaccination
Serotype-specific OPA geometric mean fold rise (GMFR) from baseline
Time frame: 1 month after VAX-31 vaccination
Percentage of subjects reporting solicited local adverse events (AE) (redness, swelling, and pain at injection site)
Time frame: up to 7 days after vaccination
Percentage of subjects reporting solicited systemic AE (fever, headache, fatigue, muscle pain, and joint pain)
Time frame: up to 7 days after vaccination
Percentage of subjects reporting unsolicited AE
Time frame: up to 31 days after vaccination
Percentage of subjects reporting new onset of chronic illness (NOCI), medically attended AE (MAAE), and serious adverse events (SAE)
Time frame: up to 6 months after vaccination
2 secondary outcomes
Serotype-specific IgG geometric mean concentration (GMC)
Time frame: 1 month after VAX-31 vaccination
Serotype-specific IgG geometric mean fold-rise (GMFR) from baseline
Time frame: 1 month after VAX-31 vaccination
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 30 Jun 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
30 sites in 1 country: see every site and its status.
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.