This is a Phase 3, randomized, double-blind study with a 4-arm parallel design. Adults 18 through 49 years of age with no history of pneumococcal vaccination will be randomized in a 2:2:2:1 ratio to receive a single dose of: 20vPnC Lot 1; 20vPnC Lot 2; 20vPnC Lot 3; or 13vPnC.

The 13vPnC arm was included in the study as a control group for safety assessments.

Results

Pfizer announced top-line results which described the safety and evaluated the consistency of immune responses elicited across three different lots of its 20-valent pneumococcal polysaccharide conjugate vaccine (20vPnC) candidate in adults 18 through 49 years of age not previously vaccinated against pneumococcal disease.

Responses elicited by 20vPnC for all 20 serotypes were equivalent across all three lots, meeting the primary immunogenicity objective of the study. In this study, the 20vPnC safety profile was similar to the Prevnar 13® (pneumococcal 13-valent Conjugate Vaccine control group.

This clinical lot consistency study is expected to satisfy licensure requirements for manufacturing consistency by the U.S. Food and Drug Administration, and other countries’ regulatory agencies.