Primary endpoints across both cohorts included safety, serotype-specific OPA GMTs 30 days post-vaccination, and percentage of participants with greater than or equal to a four-fold rise from baseline in serotype-specific OPAs. Cohort 1 enrolled participants 50 and older (n=2,362) who were randomized 1:1 to receive a single dose of either V116 or the comparator, PCV20. Key findings from primary endpoints include:

V116 was non-inferior to PCV20 for the ten serotypes common to both vaccines (3, 6A, 7F, 8, 10A, 11A, 12F, 19A, 22F, 33F), as assessed by serotype-specific OPA GMTs 30 days post-vaccination.

V116 was superior to PCV20 for 10 of 11 serotypes included in V116 but not in PCV20 (9N, 15A, 16F, 17, 20A, 23A, 23B, 24F, 31, 35B), as assessed by serotype-specific OPA GMTs 30 days post-vaccination and the proportions of patients with a greater than or equal to four-fold increase in OPA from Day 1 to Day 30.

Immune responses were observed for serotype 15C in participants receiving V116, but these did not meet the criteria for statistical superiority.

Cohort 2 enrolled participants 18-49 years of age (n=301) who were randomized 2:1 to receive a single dose of either V116 or comparator, PCV20. Results from primary endpoints showed immune responses elicited by V116 in participants 18-49 years of age were non-inferior (immunobridged) compared to participants 50-64 years of age for all 21 serotypes, as assessed by serotype-specific OPA GMTs 30 days post-vaccination.

Across both cohorts, V116 had a safety profile comparable to PCV20. Participants administered V116 and PCV20 who reported at least one adverse event (AE) were 61.7% and 67.2%, respectively. There were no vaccine-related serious AEs or vaccine-related deaths in the study.