A PHASE 3, RANDOMIZED, DOUBLE-BLIND TRIAL TO EVALUATE THE SAFETY, TOLERABILITY, AND IMMUNOGENICITY OF A MULTIVALENT PNEUMOCOCCAL CONJUGATE VACCINE IN HEALTHY INFANTS
A Study to Learn About How a New Pneumococcal Vaccine Works in Infants.
Kawai Norisuke
Pfizer R&D Japan G.K.
Shinjuku Bunka Quint Bldg., 3-22-7 Yoyogi, Shibuya-ku, Tokyo
+81-3-5309-7000
clinical-trials@pfizer.com
Clinical Trials Information Desk
Pfizer R&D Japan G.K.
Shinjuku Bunka Quint Bldg., 3-22-7 Yoyogi, Shibuya-ku, Tokyo
+81-3-5309-7000
clinical-trials@pfizer.com
Recruiting
June. 17, 2026
June. 10, 2026
3230
Interventional
randomized controlled trial
double blind
active control
parallel assignment
prevention purpose
Inclusion Criteria:
* infants who are 2 months of age in Group 1.
* infants who are 2 to 6 months of age in Groups 2 and 3.
* Healthy infants determined by clinical assessment, including medical history and clinical judgment, to be eligible for the study.
Exclusion Criteria:
* 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.
* Percentage of participants reporting local reactions within 7 days after each dose [Time Frame: Day 7]
o Prompted local reactions after each dose
* Percentage of participants reporting systemic events within 7 days after each dose [Time Frame: Day 7]
o Prompted systemic events after each dose
* Percentage of participants reporting adverse events (AEs) from Dose 1 to 1 month after Dose 3 [Time Frame: Dose 1 to 1 month after Dose 3]
o AEs occurring from Dose 1 to 1 month after Dose 3
* Percentage of participants reporting AEs from Dose 4 to 1 month after Dose 4 [Time Frame: Dose 4 to 1 month after Dose 4]
o 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]
o SAEs occurring from Dose 1 to 6 months after Dose 4
* Differences in percentages of participants with predefined pneumococcal specific immunoglobulin G (IgG) concentrations 1 month after Dose 3 [Time Frame: 1 month after Dose 3]
o Differences in pneumococcal immunoglobulin G (IgG) concentrations 1 month after Dose 3
* Pneumococcal IgG geometric mean concentrations (GMCs) 1 month after Dose 4 [Time Frame: 1 month after Dose 4]
o Pneumococcal IgG GMCs 1 month after Dose 4
* Pneumococcal IgG GMCs 1 month after Dose 3 [Time Frame: 1 month after Dose 3]
o Pneumococcal IgG GMCs 1 month after Dose 3
* Percentage of participants with serotype 3 specific predefined pneumococcal IgG concentrations 1 month after Dose 3 [Time Frame: 1 month after Dose 3]
o Pneumococcal serotype 3 IgG concentrations 1 month after Dose 3
* Pneumococcal serotype 3 IgG GMCs 1 month after Dose 4 [Time Frame: 1 month after Dose 4]
o Pneumococcal serotype 3 IgG GMCs 1 month after Dose 4
* Differences in percentages of participants with predefined pneumococcal serotype 6C and 15C immunoglobulin G (IgG) concentrations 1 month after Dose 3 [Time Frame: 1 month after Dose 3]
o Differences in pneumococcal serotype 6C and 15C immunoglobulin G (IgG) concentrations 1 month after Dose 3
* Pneumococcal serotype 6C and 15C IgG GMCs and GMRs 1 month after Dose 4 [Time Frame: 1 month after Dose 4]
o Pneumococcal serotype 6C and 15C IgG GMCs and GMRs 1 month after Dose 4
* Pneumococcal opsonophagocytic activity (OPA) titers 1 month after Dose 3 [Time Frame: 1 month after Dose 3]
o Pneumococcal OPA titers 1 month after Dose 3
* Pneumococcal OPA titers prior to Dose 4 [Time Frame: Prior to Dose 4]
o Pneumococcal OPA titers prior to Dose 4
* Pneumococcal OPA titers 1 month after Dose 4 [Time Frame: 1 month after Dose 4]
o Pneumococcal OPA titers 1 month after Dose 4
* Percentage of participants with predefined pneumococcal specific IgG concentrations 1 month after Dose 4 [Time Frame: 1 month after Dose 4]
o Percentage of participants with predefined pneumococcal specific IgG concentrations 1 month after Dose 4
* Pneumococcal IgG concentrations 1 month after Dose 3 [Time Frame: 1 month after Dose 3]
o Pneumococcal IgG concentrations 1 month after Dose 3
* Pneumococcal IgG concentrations prior to Dose 4 [Time Frame: Prior to Dose 4]
o Pneumococcal IgG concentrations prior to Dose 4
* Pneumococcal IgG concentrations 1 month after Dose 4 [Time Frame: 1 month after Dose 4]
o Pneumococcal IgG concentrations 1 month after Dose 4
* IgG geometric mean fold rise (GMFR) from before Dose 4 to 1 month after Dose 4 [Time Frame: Before Dose 4 to 1 month after Dose 4]
o IgG GMFR from before Dose 4 to 1 month after Dose 4
* IgG GMFR from 1 month after Dose 3 to 1 month after Dose 4 [Time Frame: From 1 month after Dose 3 to 1 month after Dose 4]
o IgG GMFR from 1 month after Dose 3 to 1 month after Dose 4
* Percentages of participants with prespecified antibody levels to specific concomitant vaccine antigens 1 month after Dose 3 [Time Frame: 1 month after Dose 3]
o Prespecified antibody levels to specific concomitant vaccine antigens 1 month after Dose 3
* Geometric mean of antibody levels to measles, mumps, rubella, varicella, and hepatitis A virus antigens 1 month after Dose 4 [Time Frame: 1 month after Dose 4]
o Geometric mean of antibody levels to measles, mumps, rubella, varicella, and hepatitis A virus antigens 1 month after Dose 4
* Geometric mean of immunoglobulin A (IgA) antibody levels to rotavirus 1 month after Dose 3 [Time Frame: 1 month after Dose 3]
o Geometric mean of IgA antibody levels to rotavirus 1 month after Dose 3
Pfizer Japan Inc.
Japan Conference of Clinical Research Single IRB
1-13-23 Minami-Ikebukuro, Toshima-ku, Tokyo
+81-3-6868-7022
jccr-info@jccr.jp
Approval
May. 14, 2026
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.
