THURSDAY JUNE 12, 2008 (foodconsumer.org) -- A needle-free vaccine seems to be effective at preventing traveler's diarrhea or reducing the severity of destined-to-occur diarrhea, according to a phase II trial.

The trial showed the vaccine patches designed to protect against Enterotoxigenic E. coli or ETEC which causes diarrhea protected more than 70 percent of visitors to Mexico and Guatemala from moderate to severe diarrhea known as Montesuma Revenge.

In the trial, Dr. Herbert DuPont of the University of Texas in Houston and colleagues tested the vaccine made by Maryland-based Iomai in 70 adults traveling to Guatemala and Mexico.

Reports from the travelers showed during and after travel, 15 percent of those given the vaccine had diarrhea of any type, and 5 percent had ETEC induced diarrhea.   In comparison, 22 percent of travelers experienced diarrhea of any type and 10 percent of whom had ETEC diarrhea.

"It looked like it prevented more than 70 percent of the episodes of moderate or severe traveler's diarrhea," DuPont was quoted by Reuters as saying. "This vaccine is among the best we have for these kinds of diseases."

Travelers' diarrhea is the most common illness affecting travelers. Each year between 20%-50% of international travelers, an estimated 10 million persons, develop diarrhea, according to the Centers for Disease Control and Prevention.

The CDC says that to minimize the risk of  travellers’ diarrhea, one should not eat foods or drink beverages purchased from street vendors or other establishments where unhygienic conditions are present , and should not eat raw or undercooked meat and seafood and raw fruits (e.g., oranges, bananas, avocados) and vegetables unless the traveler peels them.