Illustration of C. difficile bacteria. (image courtesy of CDC/Jennifer Oosthuizen)
Investigators at Vanderbilt Health are enrolling participants in a Phase 3 clinical trial testing an investigational vaccine against Clostridioides difficile, or C. diff, a contagious bacterial infection of the colon.
C. diff is a leading cause of health care-associated infection in the United States. The Centers for Disease Control and Prevention estimates it affects almost 500,000 people in the U.S. each year. A 2015 study in The New England Journal of Medicine, based on 2011 laboratory surveillance in 10 U.S. regions, estimated the infection caused 453,000 illnesses and 29,300 deaths across the U.S. that year.
Symptoms include watery diarrhea, fever, nausea and abdominal pain. Complications can include severe inflammation of the colon, perforation of the colon, and sepsis. Recent antibiotic use and frequent health care exposures are the chief risk factors, and people ages 65 and older are at greatest risk.
There is no licensed vaccine to prevent the infection.
“C. diff is one of those infections that turns a routine hospital stay or a course of antibiotics into something far more serious, and older adults bear the brunt of it,” said C. Buddy Creech, MD, MPH, the Edie Carell Johnson Professor of Pediatrics and Director of the Vanderbilt Vaccine Research Program. “We have gotten better at treating C. diff, but preventing it altogether would be a fundamentally different kind of win — for patients, their families and for the health care system. That is what makes this trial worth doing, and it is why we are asking our community in Middle Tennessee to help answer the question.”
The study is open to people ages 65 and older who have had recent or planned contact with the health care system or who have recently received antibiotics. People who have had C. diff before, who have had part of the small or large intestine surgically removed, or who have certain other health conditions may not be eligible; study staff will review the full criteria with interested volunteers.
Participants will be randomly assigned to receive two doses of either the investigational vaccine or a saline placebo, given as an injection in the upper arm. Neither participants nor the study team will know which they received. Volunteers will be followed for symptoms for up to three and a half years through a combination of telephone and in-person visits on the Vanderbilt Health Main Campus. Participants will be compensated for their participation.
The trial is sponsored and funded by Pfizer, an American multinational pharmaceutical and biotechnology corporation headquartered in New York City. Vanderbilt Health’s participation is led by Creech and Maribeth Nicholson, MD, MPH, Associate Professor of Pediatrics in the Division of Gastroenterology, Hepatology and Nutrition. In all, the study aims to enroll approximately 32,000 people at 174 sites in four countries, including 135 U.S. sites across 29 states and the District of Columbia.
For more information or to enroll, contact the study team at vaccineresearch@vumc.org. Additional details are available at ClinicalTrials.gov under identifier NCT07282665.
