Skin Patch May Stop Montezuma’s Revenge
Novel Vaccine Cuts Risk of Travelers’ Diarrhea by 75%
Sept. 19, 2007 (Chicago) -- Researchers have developed a skin patch that
prevents the curse of many trips abroad: travelers’ diarrhea.
In a study of more than 150 travelers to Mexico and Guatemala, the novel
vaccine cut the risk of moderate to severe diarrhea by 75%. Those who did get
sick had a shorter, milder course of illness, says researcher Herbert DuPont,
MD, director of the Center for Infectious Diseases at the University of Texas
School of Public Health in Houston.
The vaccine, which looks like a large bandage, goes on your arm or leg, he
“The idea of putting a Band-Aid on yourself and immunizing yourself when you
travel is truly novel and exciting,” DuPont tells WebMD.
The research was presented at a meeting of the American Society for
17 Million Travelers Struck Each Year
Intestinal illness caused by contaminated food and drink is the most common
malady afflicting international travelers, particularly in developing
Seventeen million travelers are struck each year, typically suffering
agonizing bouts of vomiting and diarrhea that last about three to five days,
says Gregory Glenn, MD, chief scientific officer of Iomai Corp., which is
developing the patch and funded the study.
The illness also raises the risk of developing irritable bowel syndrome, or
IBS, a chronic disorder of the intestines that causes belly pain, cramping or
bloating, and diarrhea or constipation by 10% to 30%, Glenn says.
“Travelers’ diarrhea is a bigger deal than we thought, causing this syndrome
that can last for years, even decades,” DuPont says.
How It Works
He says that the patch contains a toxin that causes traveler’s diarrhea.
Once it’s absorbed through the skin, the body makes antibodies against the
Then, if you eat food that contains the strain of E. coli bacterium
that causes the diarrhea, the antibodies evoke an immune reaction that prevents
the toxin from causing disease, DuPont explains.
The new study included 170 volunteers who put on two patches containing
either the vaccine or a placebo, two to three weeks apart, with the second
patch administered at least a week before travel.
The volunteers stayed in Mexico or Guatemala for at least five days, during
which they kept detailed diaries and received checkups.
Risk of Severe Diarrhea Cut by 84%
Among the findings:
- Only 3 of 59 people who got the vaccine suffered moderate or severe
diarrhea, compared with 23 of the 111 who received a placebo. This translates
to a 75% reduction in risk.
- 1 of the 59 volunteers in the vaccine group reported severe diarrhea,
compared with 12 of the 111 in the placebo group, an 84% reduction in
- Of the vaccinated patients who did get sick, the diarrhea lasted only half
a day on average. Those in the placebo group endured two days of illness.
- Three times as many people who got placebo developed IBS, compared with
those who got the vaccine. But the numbers were so small they could have been
due to chance.
There were no serious side effects.
The patch, which would be available by prescription only, is scheduled to
undergo further testing, with FDA approval expected by 2011, DuPont says.
Randall Holmes, MD, PhD, chief of microbiology at the University of Colorado
School of Medicine in Aurora, says the ease of administration is a real
“There are no injections, which makes this very attractive,” he tells WebMD.
Holmes is also developing a vaccine against travelers’ diarrhea, which would be
administered orally. It’s in early development, he says.