Experimental E. coli Vaccine Trial Was Discontinued
A large clinical trial for an E. coli vaccine ended early after researchers found it did not provide protection against disease.
Updated on Oct. 14, 2026 in COVID-19
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Johnson & Johnson has ended development of its experimental ExPEC9V vaccine after the phase III E.mbrace trial failed to show a protective effect against invasive E. coli disease. The study, which included over 17,000 older adults, was stopped early following disappointing efficacy results.
Why it matters
The trial was unable to prove that the vaccine successfully prevented invasive disease compared to a placebo. This development ends the development of this specific candidate, impacting the pipeline of preventative treatments for vulnerable populations with recurrent urinary tract infections.
In a phase III trial of over 17,000 participants aged 60 and older, the ExPEC9V vaccine demonstrated a 14.6% efficacy rate, with 11 cases of invasive E. coli disease in the vaccine group versus 13 in the placebo group. These findings were deemed insufficient to justify continued development.
The players
Johnson & Johnson
A global pharmaceutical and medical technology company that manages research and development for various vaccine and therapeutic programs.
The details
The ExPEC9V vaccine was administered as a single intramuscular injection designed to trigger an immune response against targeted E. coli strains. While antibody titers were observed to rise in the vaccine group within 30 days and remained elevated for 366 days, this did not translate into clinical protection. Participants in the vaccine arm experienced higher rates of local and systemic adverse events compared to those who received a placebo.
Timeline
Participants required a history of urinary tract infections over the prior 2 years.
Antibody titers rose in the vaccine group 30 days after administration.
Antibody levels remained higher than placebo after 366 days.
The E.mbrace trial was officially discontinued on October 14, 2026.
Health Landscape
The discontinuation of the E.mbrace trial follows a trend of narrowing participant criteria to capture specific disease-risk populations in late-stage clinical research. It highlights the challenges in translating immune-marker responses into meaningful clinical protection for invasive bacterial diseases.
Because this vaccine will not be moving forward, it remains unavailable for clinical use. If you have been managing recurrent urinary tract infections, it is worth discussing current evidence-based prevention and treatment strategies with your physician.
The takeaway
The E.mbrace trial results underscore that immune markers do not always correlate with clinical protection against infection. Individuals with frequent urinary tract infections should continue to focus on established preventive care and discuss any new management plans with their primary care provider.
Further reading
For broader context on vaccine research and disease prevention, visit COVID-19.
Source note: This article includes information reported by MedPage Today.
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