Sanofi Pasteur’s vaccine division has started a Phase III clinical trial to evaluate the safety and efficacy of a vaccine for Clostridium difficile.

The Cdiffense Phase III clinical program started recruiting volunteers in Canada for a randomized multi-national trial that is expected to include up to 15,000 adults at 200 sites in 17 countries. Volunteers must be at least age 50 and planning an upcoming hospitalization, or have had at least two hospital stays and received antibiotics in the past year. 

Participants will either receive the vaccine or a placebo. The trial is expected to take three years. 

A C. diff vaccine would be good news to long-term care providers, as complications from the disease kill tens of thousands of people each year. Its estimated cost to the U.S. healthcare system is $3.2 billion a year, according to Sanofi. 

In 2010, the Food and Drug Administration gave fast-track designation to Sanofi Pasteur for an investigation into a C. diff vaccine.

In other recent C. diff news, an August analysis in GIE: Gastrointestinal Endoscopy found fecal microbiotia transplants could be one of the most effective treatments for patients who have had recurrences. While the first option is to stop the “culprit antibiotic” and treat with metronidazole, vancomycin or fidaxomicin, up to 35% of C. diff patients will have a recurrence.