Vaccine may fight C. diff, too

By The Columbus Dispatch  • 
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Tom Dodge | Dispatch
OhioHealth Riverside Methodist Hospital microbiology supervisor Linda Hooper runs a bacterial DNA test to check for Clostridium difficile in a specimen.

A vaccine to prevent a sometimes-deadly intestinal illness could be a powerful tool to control the bacteria called Clostridium difficile, or C. diff.

Researchers, including some in Columbus, are testing the experimental three-shot vaccine and comparing it with a placebo in people considered to be at higher risk of C. diff infection.

Painful C. diff infections most commonly arise when the normal flora in the gut has been disrupted by antibiotics.

In a healthy person with a normal balance of bacteria, C. diff will typically come and go without incident. The trouble comes when the bacteria flourish unchecked and produce toxins that cause diarrhea, abdominal pain, cramps, inflammation and fever.

C. diff kills 14,000 people in the United States every year and is at a historical high, according to the Centers for Disease Control and Prevention, which has urged judicious use of antibiotics and other measures to try to control infections.

OhioHealth Riverside Methodist Hospital is among 200 research sites planning to recruit 15,000 people for the study of the vaccine made by Sanofi Pasteur. Two-thirds will get the vaccine. The study is to last three to five years.

The vaccine, Cdiffense, introduces an innocuous form of the toxin produced by C. diff bacteria into the gut in an attempt to prompt the immune system to make antibodies against it, said Dr. Ian Baird, a researcher and infectious-disease specialist at Riverside. Researchers already have seen that result in animals.

Cdiffense is based on the same principal as vaccines against tetanus and diphtheria, Baird said. It does not currently have a price tag, but new vaccines tend to come with a significant cost, at least to start.

Side effects have been minimal, limited to minor soreness at the injection site in the arm, said Baird, whose team had recruited five people to the study as of last week. Study participants are people whom doctors anticipate are likely to be hospitalized or need antibiotics within the next year.

Doctors treat C. diff infections with a handful of antibiotics, but they aren’t always effective.

“There are people who get better with therapy and then have a recurrence, and we don’t really understand why that is,” Baird said. “At the severe end of the spectrum, especially among elderly people, the death rate is as high as 8 to 10 percent.”

In about a quarter of cases, a person who has an infection will become ill again with C. diff, said Dr. Jane Emerick, an infectious-disease specialist at Mount Carmel St. Ann’s hospital, which is not participating in the vaccine trial. Ohio State University’s Wexner Medical Center also is not part of the study but is considering joining it.

The most-severe infections usually happen to people who’ve recently taken antibiotics and have underlying health problems, Emerick said. Chemotherapy and anti-fungal medications can also make the bowel more hospitable to infection, she said.

“Anytime we can prevent rather than treat and go through the expense, that’s a huge advantage,” Emerick said about the potential for a vaccine.

Linda Jenkins, a Columbus woman who had three bouts of C. diff infection in 2012, said she’d welcome news that there was a way to prevent the illness, which was so severe she was hospitalized.

“It’s debilitating. You can’t do anything, and you’re just so tired afterwards,” said Jenkins, who is 67 and lives on the Northwest Side. “It does take awhile for you to build yourself back up again.”