Syracuse, NY — Upstate Medical University is looking for 1,000 volunteers — its largest clinical trial to date — to test a vaccine against a deadly infection that primarily afflicts people in healthcare settings.
The effort, led by pharmaceutical giant Pfizer, is aimed at preventing bacterial infections caused by Clostridioides difficile, commonly known as c. diff.
C. diff is most common in people who have recently had antibiotics in a hospital, nursing home or other health facility.
It causes typically causes diarrhea, abdominal pain and fever. But severe cases can be deadly.
Roughly half a million Americans contract a C. diff infection each year, causing anywhere from 15,000 to 50,000 deaths.
“People who need to take antibiotics for one reason or another is the greatest risk factor for C. diff,” said lead researcher, Upstate’s Dr. Stephen Thomas. “Antibiotics can disrupt the balance of good and bad bacteria in the gut and when this occurs the C. diff bacteria (bad) can rise up and cause disease.”
The Upstate Institute for Global Health is organizing the effort locally. Worldwide, the goal is to enroll 32,000 people for the study.
To qualify, participants must have never had C. diff and meet one of the following criteria:
65 years or olderReceived antibiotics in the last three monthsBeen hospitalized at least once or had two ER visits in the last yearHad 10 or more healthcare visits in the last yearAre scheduled to be hospitalized or have elective surgery
Upstate researchers will be available to discuss the trial in person between 10 a.m. and 11 a.m. Thursday, Jan. 22, 2026, at the Upstate Institute for Global Health.
The institute is located at 5010 Campuswood Drive, Suite 100, East Syracuse.
Those who can attend can contact the Global Health Institute at trials@upstate.edu or (315) 464-9869.