Lot-to-lot Consistency Study of a 21-valent Pneumococcal Conjugate Vaccine in Healthy Infants From 2 Months of Age

This is a phase 3 randomized, modified double-blind study whose purpose is to measure whether 3 lots of the investigational pneumococcal vaccine PCV21 can help the body to develop germ-fighting agents called "antibodies" (immunogenicity) in a similar way (ie, same immune response) when they are given to infants aged from approximately 2 months (42 to 89 days) and are safe compared to a licensed 20-valent pneumococcal vaccine (20vPCV) (Prevnar 20™). The study duration per participant will be up to approximately 17 months. The study vaccines (either PCV21 or 20vPCV) will be administered at approximately 2, 4, 6 and 12 months of age. Cohort A will include randomization to three PCV21 formulation groups or one 20vPCV comparator group (Group 1-4, approximately 896 total participants), whereas Cohort B will include randomization to three PCV21 formulation groups only (Groups 1-3, approximately 1299 total participants). Routine pediatric vaccines will be given as per local recommendations. There will be 6 study visits: Visit (V)01, V02 separated from V01 by 60 days, V03 separated from V02 by 60 days, V04 separated from V03 by 30 days, V05 at 12 months of age, V06 separated from V05 by 30 days

NCT Number	NCT07348692
Lead Sponsor	Sanofi
Conditions	Pneumococcal Immunization, Healthy Volunteers
Enrollment	2,195 participants
Start Date	2026-01-20
Primary Completion	2027-06-07 (estimated)
Study Completion	2028-05-29 (estimated)
Updated on ClinicalTrials.gov	2026-05-22