A wider shield for babies: a 25-strain pneumonia vaccine candidate matched the best in class in Phase 2

Pneumonia bacteria (pneumococcus) remain a leading killer of young children worldwide, and vaccines protect against only some of the strains in circulation. Pfizer's experimental 25-valent vaccine — covering 25 strains, five more than the current 20-strain vaccine — was tested in infants in a Phase 2 study presented at IDWeek 2026 in Washington, D.C. A four-dose course produced robust immune responses against all 25 strains, with safety comparable to the existing vaccine. If Phase 3 confirms the results, the candidate could cover strains responsible for about 84% of serious pneumococcal disease in American children under five.

SDG 3 · Good health and well-being — Mechanism: tech innovation