Design: Phase 3, randomised, double-blind, placebo-controlled; stopped for futility
Population: 17,701 adults aged 60 or over with UTI in the previous 2 years
Primary outcome: First invasive E. coli disease caused by vaccine serotypes
Effect: 11 vs 13 cases; vaccine efficacy 14.6% (95% CI -106.6 to 65.4)

The E.mbrace trial, published in Lancet Infectious Diseases on 12 October 2026, randomised 17,701 adults aged 60 or over with a urinary tract infection in the previous two years, at 332 sites in 20 countries, to a single dose of a nine-valent extraintestinal E. coli conjugate vaccine or placebo.

A planned futility analysis stopped the trial early. There were 24 invasive infections caused by vaccine serotypes: 11 in the vaccine group and 13 with placebo, a vaccine efficacy of 14.6% (95% CI -106.6 to 65.4). The vaccine produced strong and lasting antibody responses and had an acceptable safety profile, but this did not translate into protection. Development has been discontinued.

The result matters beyond one product. E. coli bloodstream infection in older adults, often from a urinary source, remains a leading cause of sepsis, and there is no vaccine in prospect. Antibody response alone was not a reliable guide to protection here.

No vaccine against invasive E. coli disease is available or near approval.
Prevention in older adults still rests on UTI management, catheter care and prompt treatment of urosepsis.
Treat antibody results from early vaccine trials with caution; here they did not predict protection.
Recurrent UTI in older adults remains a sepsis risk worth active follow-up.

Why it matters

Strong antibody responses did not prevent disease, which tempers hopes pinned on immunogenicity data.

The statistics, in plain English

With only 24 events, the confidence interval for efficacy runs from about -107% to 65%, which is compatible with harm, no effect or moderate benefit. The futility analysis judged a useful effect unlikely enough to stop.