C. Diff vaccine moves to next phase of clinical trial

Aug 24, 2017

Credit By CDC/ James Archer

Clostridium difficile is a common bacteria that can be harmless. But for some – especially older adults taking antibiotics who visit hospitals or nursing homes – it can cause serious infections. A vaccine being studied to prevent these infections is making headway.

The vaccine developed by the pharmaceutical company Pfizer is moving into its third phase of clinical trial. That means it’s one stage away from the Food and Drug Administration potentially considering it for approval. Pfizer expects to enroll 16,000 participants from around the world in the trial. Rochester Clinical Research is one of 231 sites involved in the study.

“C. Diff is a very common organism. I think they estimate three percent of the population is colonized with it. But the problem gets worst when you get into a hospital environment – people are already sicker, and people are using powerful, strong antibiotics that alter your normal defenses against it. Then you can get really sick,” says Dr. Matthew Davis, medical director of Rochester Clinical Research and principal investigator for the local site.

Researchers are seeking participants who are considered at risk for a C. diff infection — people over 50 years old who have a certain degree of interaction with hospitals or nursing facilities. During the course of the study, participants will receive either the actual vaccine or a placebo. Researchers will then track participants over a few years to see whether they develop an infection or not.

“They’re looking to see who develops a C. diff infection. They’re trying to show that if you get the vaccine it will basically prevent you from getting a C. diff infection, if you’re exposed to it,” Davis says.

The Centers for Disease Control and Prevention found that in one year almost half a million Americans developed an infection from Clostridium difficile. Of that group about 29,000 patients died within 30 days of the initial diagnosis.

Davis says results from this phase of the study are expected in four or five years.