Sanofi has begun a major late-stage trial on a vaccine against Clostridium difficile infections.

The French drugmaker's Sanofi Pasteur division says a Phase III programme has just started recruiting for a trial that will include up to 15,000 adults at 200 sites across 17 countries. Volunteers should be aged 50 or older and planning an upcoming hospitalisation or have had at least two hospital stays and have received systemic antibiotics in the past year.

The risk of C diff, a spore-forming bacterium that causes intestinal disease, increases with age, antibiotic treatment and time spent in hospitals or nursing homes. C diff toxins cause gastrointestinal disease that can lead to death in 8%-15% of infected people and since 20%-30% of patients experience recurrences of CDI and re-hospitalisations.

Sanofi's vaccine is designed to produce an immune response that targets the toxins generated by C diff bacteria and may help prevent a future infection from occurring. John Shiver, head of R&D at Sanofi Pasteur, said that “vaccination could be an efficacious, cost-effective and important public-health measure to protect individuals from C diff.”