Pfizer Advances Pneumonia Shot After Positive Study in Children

Pfizer Inc. said a new version of its bestselling Prevnar vaccine may provide infants with better protection against common strains of pneumonia than currently available immunizations.

The experimental shot was designed to protect against 25 strains of a bacteria that causes pneumonia, five more than the company’s current vaccine. In a mid-stage trial, Pfizer tested it against Prevnar 20, which has been approved for kids since 2023.

After four doses, the newer shot triggered strong immune responses in children up to age 15 months across bacterial strains, Pfizer said on Wednesday. Notably, it also led to a 15-fold higher antibody ...