Pneumococcal DiseasePhase 2NCT06524414
A Study to Learn About How a New Pneumococcal Vaccine Works in Infants
A Phase 2 study testing PG4, 20-valent pneumococcal conjugate vaccine (20vPnC) and 15-valent pneumococcal conjugate vaccine (PCV15) in people with Pneumococcal Disease, run by Pfizer at 67 sites in 2 countries.
Trial summary
The purpose of this study is to learn about the safety of a new pneumococcal vaccine and how the new pneumococcal vaccine helps to fight against germs in infants when compared to the pneumococcal vaccines that are currently in use, 20vPnC (Prevnar 20®) or another licensed pneumococcal vaccine. Read more about this study
- Who is it for?
- Ages 42 to 98 daysHealthy volunteers can take part
- Conditions the study is for
- Pneumococcal Disease
- What is being tested?
- PG4, 20-valent pneumococcal conjugate vaccine (20vPnC) and 15-valent pneumococcal conjugate vaccine (PCV15)
- Type of treatment
- Vaccines
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 605 participants
- Where
- 67 sitesin 2 countries
- Study dates
- 25 Jul 2024to 1 May 2027
- Phase
- Phase 2
- 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 42 to 98 days
- All sexes
- Healthy volunteers accepted
- Child
Who may be able to join
- Male or female infants born at >36 weeks of gestation and 2 months of age at the time of consent.
- Healthy infants determined by clinical assessment, including medical history and clinical judgment, to be eligible for the study.
Who cannot join
- History of severe adverse reaction associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis).
- Major known congenital malformation or serious chronic disorder.
- Other acute or chronic medical or psychiatric condition or laboratory abnormality that may increase the risk associated with study participation or investigational product administration or may interfere with the interpretation of study results and, in the judgment of the investigator, would make the participant inappropriate for entry into this study.
- Previous vaccination with any licensed or investigational pneumococcal vaccine, or planned receipt through study participation.
Trial locations and contacts
67 sites in 2 countries.
67 sites in 2 countries
United States60 sites
The Iowa Clinic
Ankeny, Iowa, 50023
University of Maryland
Baltimore, Maryland, 21201
Kentucky Pediatric/ Adult Research
Bardstown, Kentucky, 40004
Pediatric Research of Charlottesville, LLC
Charlottesville, Virginia, 22902
Javara Inc.
Dallas, Texas, 75230
Oak Cliff Research Company, LLC
Dallas, Texas, 75287
Dayton Clinical Research
Dayton, Ohio, 45409
Ohio Pediatric Research Assn.
Dayton, Ohio, 45414
Velocity Clinical Research Inc.
Durham, North Carolina, 27701
Duke Vaccine and Trials Unit
Durham, North Carolina, 27703
Durham Pediatrics at North Duke Street
Durham, North Carolina, 27704
Child Health Care Associates
East Syracuse, New York, 13057
PAS Research - McAllen
Edinburg, Texas, 78539
Allegheny Health and Wellness Pavilion
Erie, Pennsylvania, 16506
Square-1 Clincal Research
Erie, Pennsylvania, 16506
Pediatric Associates of Fall River
Fall River, Massachusetts, 02721
Northwest Arkansas Pediatric Clinic
Fayetteville, Arkansas, 72703
UMB/CVD
Frederick, Maryland, 21702
Boeson Research GTF
Great Falls, Montana, 59405
OBGYN Associates
Great Falls, Montana, 59405
Origin Health
Great Falls, Montana, 59405
Cyn3rgy Research
Gresham, Oregon, 97030
Mercury clinical research Inc.
Houston, Texas, 77054
Mercury Clinical Research - Pediatric Associates
Houston, Texas, 77087
Clinical Research Prime
Idaho Falls, Idaho, 83404
The Children's Clinic
Jonesboro, Arkansas, 72401
Boeson Research KAL
Kalispell, Montana, 59901
Heart and Hands Midwifery and Family Practice
Kalispell, Montana, 59901
POEM Healthcare
Kalispell, Montana, 59901
AMR Clinical
Kaysville, Utah, 84037
Tanner Clinic - Kaysville
Kaysville, Utah, 84037
Holston Medical Group
Kingsport, Tennessee, 37660
Los Ninos Children's Medical Clinic
La Puente, California, 91744
Alliance for Multispecialty Research, LLC
Layton, Utah, 84041
Tanner Clinic
Layton, Utah, 84041
Tanner Memorial Clinic
Layton, Utah, 84041
University of Texas Medical Branch
League City, Texas, 77573
Midwest Children's Health Research Institute
Lincoln, Nebraska, 68522
DCOL Center for Clinical Research
Longview, Texas, 75605
All Children Pediatrics
Louisville, Kentucky, 40243
Bluegrass Clinical Research, Inc.
Louisville, Kentucky, 40291
Riveldi Biomedical Research and Associates - Miami
Miami Lakes, Florida, 33014
Blue Moose Pediatrics
Missoula, Montana, 59804
Boeson Research Laboratory
Missoula, Montana, 59804
Boeson Research MSO
Missoula, Montana, 59804
AMR Clinical
Murray, Utah, 84107
AMR Clinical
Provo, Utah, 84604
University of Rochester
Rochester, New York, 14611
University of Rochester Medical Center
Rochester, New York, 14642
AMR Clinical
Roy, Utah, 84067
LSUHSC Clinical Trials Office
Shreveport, Louisiana, 71101
Louisiana State University Health Sciences Shreveport
Shreveport, Louisiana, 71103
Ochsner/LSU Health Ambulatory Care Center
Shreveport, Louisiana, 71103
Senders Pediatrics
South Euclid, Ohio, 44121
AMR Clinical
South Jordan, Utah, 84095
Coastal Pediatric Research
Summerville, South Carolina, 29486
AMR Clinical
Syracuse, Utah, 84075
Cotton O'Neil Pediatrics
Topeka, Kansas, 66604
Velocity Clinical Research, Washington DC
Washington D.C., District of Columbia, 20016
Los Ninos Children's Medical Clinic
West Covina, California, 91790
Puerto Rico7 sites
Clinical Research Puerto Rico
Guayama, 00784
Ponce Medical School Foundation Inc.
Ponce, 00716
BRCR Global Puerto Rico
San Juan, 00907-1509
CMRC Headlands, LLC
San Juan, 00918
University of Puerto Rico - Medical Sciences Campus
San Juan, 00935-6528
The Hispanic Alliance for Clinical and Translational Research
San Juan, 00935
San Miguel Medical
Trujillo Alto, PR, 00976
About this study
Official title: A Phase 2, Randomized, Double-Blind Trial to Evaluate the Safety, Tolerability, and Immunogenicity of a Multivalent Pneumococcal Conjugate Vaccine in Healthy Infants
The purpose of this study is to learn about the safety of a new pneumococcal vaccine and how the new pneumococcal vaccine helps to fight against germs in infants when compared to the pneumococcal vaccines that are currently in use, 20vPnC (Prevnar 20®) or another licensed pneumococcal vaccine.
To ensure that the new vaccine (PG4) stays stable, it is placed in a liquid mixture of sterile water and other substances (a solution). This study will also test if there is a difference in the safety and immune effects of the new pneumococcal vaccine when it is one type of solution compared to when it is in a different type of solution.
Read more
The immune response is how the body's cells; tissues and organs work together to protect the body from infection. Blood samples will be used to measure the amount of antibodies produced after the vaccination. Antibodies are proteins that protect you when an unwanted germ enters the body. This will help understand how well the new pneumococcal vaccine works. This vaccine can possibly provide protection against pneumococcal disease. Pneumococcal disease includes a variety of infections caused by a specific germ, Streptococcus pneumoniae.
This study is seeking participants who are:
- male or female infants who are 2 months of age,
- infants born at 36 weeks (about 8 and a half months) of pregnancy or later; and,
- said to be healthy by the study doctor
There are four groups in this study. All participants will be assigned to one of the four groups. All study vaccines will be given as a single shot into the left thigh muscle. Participants in the three groups will have 3 blood samples collected during the 1 and a half years they are in the study.
The first 400 participants who enter the study will be assigned to either Group 1 or Group 2. Half the participants in Group 1 and half the participants in Group 2 will receive 4 doses at 2, 4, 6, and 12 to 15 months of age of PG4 mixed in the first solution. The other half of the participants in Groups 1 and 2 will receive 4 doses of 20vPnC (Prevnar 20®) at 2, 4, 6, and 12 to 15 months of age. The main difference between Groups 1 and 2 is that participants in Group 2 will have the first blood sample collected at an earlier time than those in Group 1.
Once 400 participants have been assigned to Groups 1 and 2 then 100 new participants will be assigned to Group 3. Half the participants in Group 3 will receive PG4 in the second solution at 2, 4, 6, and 12 to 15 months of age. The other half of the participants in Groups 3 will receive 4 doses of 20vPnC (Prevnar 20®) at 2, 4, 6, and 12 to 15 months of age.
Once the 100 participants have been assigned to Group 3 then 300 new participants will be assigned to Group 4. Half the participants in Group 4 will receive PG4 in the first solution at 2, 4, 6, and 12 to 15 months of age. The other half of the participants in Group 4 will receive 4 doses of a licensed pneumococcal comparator vaccine at 2, 4, 6, and 12 to 15 months of age.
Participants will take part in this study for about 16 to 19 months (about 1 and a half years). During this time, participants will have 6 study clinic visits and 1 to 2 phone calls. At these study clinic visits, parent(s) or legal guardian(s) will be asked if the participant experienced any side effects. A side effect is an unintentional or unexpected reaction to a vaccine.
- Conditions
- Pneumococcal Disease
- Being tested
- PG4, 20-valent pneumococcal conjugate vaccine (20vPnC), 15-valent pneumococcal conjugate vaccine (PCV15)
- Medical subject headings
- Pneumococcal Infections
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PG4Biological
Multivalent pneumococcal conjugate vaccine
20-valent pneumococcal conjugate vaccine (20vPnC)Biological
Also called Prevnar 20
20-valent pneumococcal conjugate vaccine
15-valent pneumococcal conjugate vaccine (PCV15)Biological
Also called PCV15
15-valent pneumococcal conjugate vaccine
| Study group | Role | What they receive |
|---|---|---|
| Group 1 PG4 | Experimental | Multivalent Pneumococcal Vaccine Receives: Biological: PG4 |
| Group 1 20-valent pneumococcal conjugate vaccine (20vPnC) | Active comparator | 20-valent pneumococcal conjugate vaccine (20vPnC) Receives: Biological: 20-valent pneumococcal conjugate vaccine (20vPnC) |
| Group 2 PG4 | Experimental | Multivalent Pneumococcal Vaccine Receives: Biological: PG4 |
| Group 2 20-valent pneumococcal conjugate vaccine (20vPnC) | Active comparator | 20-valent pneumococcal conjugate vaccine (20vPnC) Receives: Biological: 20-valent pneumococcal conjugate vaccine (20vPnC) |
| Group 3 PG4 | Experimental | Multivalent Pneumococcal Vaccine Receives: Biological: PG4 |
| Group 3 20-valent pneumococcal conjugate vaccine (20vPnC) | Active comparator | 20-valent pneumococcal conjugate vaccine (20vPnC) Receives: Biological: 20-valent pneumococcal conjugate vaccine (20vPnC) |
| Group 4 PG4 | Experimental | Multivalent Pneumococcal Vaccine Receives: Biological: PG4 |
| Group 4 15-valent pneumococcal conjugate vaccine (PCV15) | Active comparator | 15-valent pneumococcal conjugate vaccine (PCV15) Receives: Biological: 15-valent pneumococcal conjugate vaccine (PCV15) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Percentage of participants reporting local reactions within 7 days after each dose
Prompted local reactions after each dose
Measured: Day 7
Percentage of participants reporting systemic events within 7 days after each dose
Prompted systemic reactions after each dose
Measured: Day 7
Percentage of participants reporting adverse events (AEs)
AEs occurring from Dose 1 to 1 month after Dose 2
Measured: Dose 1 to 1 month after Dose 3
Percentage of participants reporting AEs
AEs occurring from Dose 4 to 1 month after Dose 4
Measured: Dose 4 to 1 month after Dose 4
Percentage of participants reporting serious adverse events (SAEs)
SAEs occurring from Dose 1 to 6 months after Dose 4
Measured: Dose 1 to 6 months after Dose 4
Secondary outcomes (1)
Pneumococcal immunoglobulin G (IgG) geometric mean concentrations (GMCs)
Pneumococcal IgG GMCs 1 month after Dose 4
Measured: 1 month after Dose 4
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Jul 2024
- Study start25 Jul 2024
- Primary completion1 May 2027 (estimated)
- Study completion1 May 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Pneumococcal DiseaseStudies of the same condition, open and under way.
- More trials run by PfizerThe sponsor's other registered studies.
- 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 2
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Parallel assignment
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 605 participants (actual)
Sponsor and investigators
- Lead sponsor
- Pfizer
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Pfizer CT.gov Call Center, Study director, Pfizer
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06524414
- Sponsor's protocol ID
- C4931002
- Other IDs
- NCT06524414, 2025-000081-28, 2025
- Status last verified
- Oct 2026
- First submitted
- 23 Jul 2024
- Last updated
- 19 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.
Study at a glance
From the registry record, last updated by the sponsor on 19 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 2, Randomized, Double-Blind Trial to Evaluate the Safety, Tolerability, and Immunogenicity of a Multivalent Pneumococcal Conjugate Vaccine in Healthy Infants
- ClinicalTrials.gov ID
- NCT06524414
- Acronym / sponsor ID
- C4931002
- Conditions
- Pneumococcal Disease
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 605 participants (actual)
- Lead sponsor
- PfizerIndustry (pharma, biotech, devices)
- Study start
- 25 Jul 2024 (actual)
- Primary completion
- 1 May 2027 (estimated)
- Study completion
- 1 May 2027 (estimated)
- First posted
- 29 Jul 2024 (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 purpose of this study is to learn about the safety of a new pneumococcal vaccine and how the new pneumococcal vaccine helps to fight against germs in infants when compared to the pneumococcal vaccines that are currently in use, 20vPnC (Prevnar 20®) or another licensed pneumococcal vaccine.
To ensure that the new vaccine (PG4) stays stable, it is placed in a liquid mixture of sterile water and other substances (a solution). This study will also test if there is a difference in the safety and immune effects of the new pneumococcal vaccine when it is one type of solution compared to when it is in a different type of solution.
The immune response is how the body's cells; tissues and organs work together to protect the body from infection. Blood samples will be used to measure the amount of antibodies produced after the vaccination. Antibodies are proteins that protect you when an unwanted germ enters the body. This will help understand how well the new pneumococcal vaccine works. This vaccine can possibly provide protection against pneumococcal disease. Pneumococcal disease includes a variety of infections caused by a specific germ, Streptococcus pneumoniae.
This study is seeking participants who are:
- male or female infants who are 2 months of age,
- infants born at 36 weeks (about 8 and a half months) of pregnancy or later; and,
- said to be healthy by the study doctor
There are four groups in this study. All participants will be assigned to one of the four groups. All study vaccines will be given as a single shot into the left thigh muscle. Participants in the three groups will have 3 blood samples collected during the 1 and a half years they are in the study.
The first 400 participants who enter the study will be assigned to either Group 1 or Group 2. Half the participants in Group 1 and half the participants in Group 2 will receive 4 doses at 2, 4, 6, and 12 to 15 months of age of PG4 mixed in the first solution. The other half of the participants in Groups 1 and 2 will receive 4 doses of 20vPnC (Prevnar 20®) at 2, 4, 6, and 12 to 15 months of age. The main difference between Groups 1 and 2 is that participants in Group 2 will have the first blood sample collected at an earlier time than those in Group 1.
Once 400 participants have been assigned to Groups 1 and 2 then 100 new participants will be assigned to Group 3. Half the participants in Group 3 will receive PG4 in the second solution at 2, 4, 6, and 12 to 15 months of age. The other half of the participants in Groups 3 will receive 4 doses of 20vPnC (Prevnar 20®) at 2, 4, 6, and 12 to 15 months of age.
Once the 100 participants have been assigned to Group 3 then 300 new participants will be assigned to Group 4. Half the participants in Group 4 will receive PG4 in the first solution at 2, 4, 6, and 12 to 15 months of age. The other half of the participants in Group 4 will receive 4 doses of a licensed pneumococcal comparator vaccine at 2, 4, 6, and 12 to 15 months of age.
Participants will take part in this study for about 16 to 19 months (about 1 and a half years). During this time, participants will have 6 study clinic visits and 1 to 2 phone calls. At these study clinic visits, parent(s) or legal guardian(s) will be asked if the participant experienced any side effects. A side effect is an unintentional or unexpected reaction to a vaccine.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 8
- Model description
- Parallel assignment
| Arm | Type | Receives |
|---|---|---|
| Group 1 PG4 | Experimental | Biological: PG4Multivalent Pneumococcal Vaccine |
| Group 1 20-valent pneumococcal conjugate vaccine (20vPnC) | Active comparator | Biological: 20-valent pneumococcal conjugate vaccine (20vPnC)20-valent pneumococcal conjugate vaccine (20vPnC) |
| Group 2 PG4 | Experimental | Biological: PG4Multivalent Pneumococcal Vaccine |
| Group 2 20-valent pneumococcal conjugate vaccine (20vPnC) | Active comparator | Biological: 20-valent pneumococcal conjugate vaccine (20vPnC)20-valent pneumococcal conjugate vaccine (20vPnC) |
| Group 3 PG4 | Experimental | Biological: PG4Multivalent Pneumococcal Vaccine |
| Group 3 20-valent pneumococcal conjugate vaccine (20vPnC) | Active comparator | Biological: 20-valent pneumococcal conjugate vaccine (20vPnC)20-valent pneumococcal conjugate vaccine (20vPnC) |
| Group 4 PG4 | Experimental | Biological: PG4Multivalent Pneumococcal Vaccine |
| Group 4 15-valent pneumococcal conjugate vaccine (PCV15) | Active comparator | Biological: 15-valent pneumococcal conjugate vaccine (PCV15)15-valent pneumococcal conjugate vaccine (PCV15) |
Who may qualify
- Ages
- 42 to 98 days
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child
Key inclusion criteria (2 listed)
- Male or female infants born at >36 weeks of gestation and 2 months of age at the time of consent.
- Healthy infants determined by clinical assessment, including medical history and clinical judgment, to be eligible for the study.
Key exclusion criteria (4 listed)
- History of severe adverse reaction associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis).
- Major known congenital malformation or serious chronic disorder.
- Other acute or chronic medical or psychiatric condition or laboratory abnormality that may increase the risk associated with study participation or investigational product administration or may interfere with the interpretation of study results and, in the judgment of the investigator, would make the participant inappropriate for entry into this study.
- Previous vaccination with any licensed or investigational pneumococcal vaccine, or planned receipt through study participation.
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 |
|---|---|---|
| PG4Multivalent pneumococcal conjugate vaccine | Biological | Group 1 PG4, Group 2 PG4, Group 3 PG4, Group 4 PG4 |
| 20-valent pneumococcal conjugate vaccine (20vPnC)Also: Prevnar 2020-valent pneumococcal conjugate vaccine | Biological | Group 1 20-valent pneumococcal conjugate vaccine (20vPnC), Group 2 20-valent pneumococcal conjugate vaccine (20vPnC), Group 3 20-valent pneumococcal conjugate vaccine (20vPnC) |
| 15-valent pneumococcal conjugate vaccine (PCV15)Also: PCV1515-valent pneumococcal conjugate vaccine | Biological | Group 4 15-valent pneumococcal conjugate vaccine (PCV15) |
Primary outcome
Percentage of participants reporting local reactions within 7 days after each dose
Time frame: Day 7
Prompted local reactions after each dose
Percentage of participants reporting systemic events within 7 days after each dose
Time frame: Day 7
Prompted systemic reactions after each dose
Percentage of participants reporting adverse events (AEs)
Time frame: Dose 1 to 1 month after Dose 3
AEs occurring from Dose 1 to 1 month after Dose 2
Percentage of participants reporting AEs
Time frame: Dose 4 to 1 month after Dose 4
AEs occurring from Dose 4 to 1 month after Dose 4
Percentage of participants reporting serious adverse events (SAEs)
Time frame: Dose 1 to 6 months after Dose 4
SAEs occurring from Dose 1 to 6 months after Dose 4
1 secondary outcome
Pneumococcal immunoglobulin G (IgG) geometric mean concentrations (GMCs)
Time frame: 1 month after Dose 4
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 19 Oct 2026.
- To obtain contact information for a study center near you, click here.Link provided by the sponsor.
- Individual participant dataSharing planned: Yes. Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical_trials/trial_data_and_results/data_requests.
Related trials for Pneumococcal Disease
RecruitingPhase 3
A Study to Learn About the Safety of an Expanded Pneumococcal Vaccine in Healthy Infants
Pneumococcal Disease
RecruitingPhase 3
Study to Learn About Safety, Tolerability, and Immune Response of a Catch-up Pneumococcal Vaccine in Children and Adolescents
Pneumococcal Disease
Active, not recruitingPhase 1
A Study to Understand the Safety of the 20vPnC Vaccine in Healthy Chinese Adults, Children, and Infant
Pneumococcal Disease
Enrolling by invitation
Randomized Controlled Trial Of Text Messages To Increase Pneumococcal Vaccination In Adults In Chile.
Pneumococcal Infections, Immunization Programs
Not yet recruitingPhase 4
Preoperative Pneumococcal and Influenza Vaccination to Prevent Postoperative Pulmonary Infection in Patients Undergoing Lung Resection for Pulmonary Nodules or Lung Cancer
Pneumococcal Polysaccharide Vaccine, Influenza Vaccines
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.
Pfizer CT.gov Call Center study director
Pfizer
67 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing PG4, 20-valent pneumococcal conjugate vaccine (20vPnC) and 15-valent pneumococcal conjugate vaccine (PCV15) in people with Pneumococcal Disease, run by Pfizer at 67 sites in 2 countries.
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 2 inclusion and 4 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 19 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 67 sites in United States, Puerto Rico. 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 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
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?
Percentage of participants reporting local reactions within 7 days after each dose (time frame: Day 7). The study lists 5 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 19 Oct 2026.