Needle-free vaccine may stop Montezuma's Revenge

By Maggie Fox, Health and Science Editor

WASHINGTON (Reuters) - A needle-free vaccine protected more than 70 percent of visitors to Mexico and Guatemala from traveler's diarrhea, popularly known as Montezuma's Revenge, researchers reported on Wednesday.

Even if travelers did get infected with the stomach bug, Iomai Corp.'s experimental vaccine patch prevented severe illness, the researchers reported in the Lancet medical journal.

"I think it's one of the most exciting new developments in travel medicine," said Dr. Herbert DuPont of the University of Texas in Houston, who helped test the vaccine.

"People could buy this and put it on themselves whenever they take a trip. It is the most convenient form of immunization I have ever seen," DuPont said in a telephone interview.

The vaccine protects against Escherichia coli bacteria -- specifically a strain known as Enterotoxigenic E. coli or

ETEC.

It is the leading cause of diarrhea in travelers to certain areas, causing four to five days of misery including nausea and cramps.

Iomai's team, along with DuPont's independent team and a group at Johns Hopkins University in Baltimore, tested the patches in a Phase II safety and efficacy trial. They got data back from 170 adults traveling to areas known to be hot spots of tummy trouble in Guatemala and Mexico.