A stronger pneumonia shot for older adults clears its biggest test

The bacteria that cause pneumonia are one of the biggest infection threats to people over 50 — they can lead to pneumonia, meningitis, and dangerous bloodstream infections. Today, California vaccine company Vaxcyte announced its new shot, VAX-31, passed the biggest trial of its life. The vaccine protects against 31 strains of the bacteria — more than any shot available today — and in the late-stage OPUS-1 trial it triggered immune responses at least as strong as the current leading vaccines (Pfizer's Prevnar 20 and Merck's Capvaxive) on the 28 strains they have in common. It even did better on three strains only VAX-31 covers. Safety looked clean, with no serious side effects tied to the vaccine. Two more late-stage trials report in the first half of 2027, and the company plans to seek US approval in the first half of 2028.