A Phase 3 interventional study of 20vPnC and 13vPnC in Pneumococcal Diseases, sponsored by Pfizer. Recruiting at 4 sites in China. Open to participants aged 42 Days to 98 Days, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-08-10.
Sponsored by Pfizer · Phase 3, Interventional, and Prevention
The purpose of this study is to evaluate a study vaccine called 20-valent pneumococcal conjugate vaccine (20vPnC). The study will assess whether the study vaccine is safe to use in healthy infants. It will also evaluate if the study vaccine can help the body make antibodies (known as immune response). These antibodies help protect against 20 types of pneumococcal bacteria. The study will compare 20vPnC with 13vPnC (control vaccine), which is approved for use in infants.
The study is seeking participants who:
Infants will receive either 20vPnC or 13vPnC. Doses will be given at approximately 2, 4, and 6 months of age (Doses 1 through 3). A fourth dose will be given at 12 to 15 months of age. Infants will receive the same vaccine (20vPnC or 13vPnC) for all 4 doses.
The total time of the study will be about 16 to 19 months. A subset of infants will be asked to stay in the study for longer.
298 studies on the registry are indexed under Pneumococcal Infections; 26 are open to participants now.
This study's planned enrollment of 1,250 is above the median of 373 across 253 interventional studies indexed under Pneumococcal Infections.
Browse Pneumococcal Infections studies →Pfizer is the lead sponsor of 3,334 studies on the registry; 149 are open to participants now.
Of its 601 completed or terminated interventional studies of FDA-regulated products, 391 (65%) have results posted.
Counted across the registry records on this site, refreshed daily.
Key Inclusion Criteria:
- Healthy male or female infants born at ≥37 weeks of gestation and who are approximately 2 months of age (≥42 to ≤98 days) at the time of consent (the day of birth is considered Day 1 of life) will be enrolled.
Key Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants receive 13vPnC at approximately 2, 4, and 6 months of age (Doses 1 through 3) and 12 through 15 months of age (Dose 4)
Biological: 13vPnC
Participants receive 20vPnC at approximately 2, 4, and 6 months of age (Doses 1 through 3) and 12 through 15 months of age (Dose 4)
Biological: 20vPnC
Percentage of participants reporting prespecified local reactions
Time frame: From Day 1 (the day of vaccination) through Day 7 following Vaccinations 1, 2, 3, and 4
Percentage of participants reporting prespecified systemic events
Time frame: From Day 1 (the day of vaccination) through Day 7 following Vaccinations 1, 2, 3, and 4
Percentage of participants reporting Adverse Events (AEs) from the first study vaccination through 1 month following the third study vaccination.
Time frame: From the first study vaccination to 1 month after the third study vaccination
Percentage of participants reporting AEs from the fourth study vaccination to 1 month following the fourth study vaccination.
Time frame: From the fourth study vaccination to 1 month after the fourth study vaccination
Percentage of participants reporting serious adverse events (SAEs) through 6 months post last vaccination
Time frame: From the first study vaccination to 6 months after the last study vaccination
The percentages of participants with predefined serotype-specific immunoglobulin G (IgG) concentrations in 20vPnC group compared to 13vPnC group at 1 month after Dose 3
Time frame: At 1 month after Dose 3
The serotype-specific IgG geometric mean concentrations (GMCs) in 20vPnC group compared to 13vPnC group at 1 month after Dose 3
Time frame: At 1 month after Dose 3
The percentages of participants with predefined serotype-specific immunoglobulin G (IgG) concentrations in 20vPnC group compared to 13vPnC group at 1 month after Dose 4
Time frame: At 1 month after Dose 4
The serotype-specific IgG geometric mean concentrations (GMCs) in 20vPnC group compared to 13vPnC group at 1 month after Dose 4
Time frame: At 1 month after Dose 4
To further describe the immune response of 20vPnC
Serotype-specific Opsonophagocytic Activity (OPA) Geometric Mean Titers (GMTs)
Time frame: At prior to Dose 1, 1 months after Dose 3, prior to Dose 4 and 1 month after Dose 4
Plan to share: 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.
Data sharing details ↗ · www.pfizer.com
Started Jul 2026 (actual). Primary completion is estimated for Nov 2028, 28 months after the start.
Of 81 industry-sponsored phase 3 interventional studies under Pneumococcal Infections, half reached primary completion within 13 months of starting (the median), counting those still running; a quarter within 9 and three quarters within 23. This study's planned 28 months is above that.
Counting every sponsor, half of 82 studies reached it within 13 months; a quarter within 9 and three quarters within 23.
How these figures are worked out, and which studies are left out of them.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Studies of the drug tested here: Pneumococcal 20-Valent Conjugate Vaccine