. . . "You may need vaccinations.??? Guard against infection by washing your hands often, especially after you???ve been on a plane, train or bus.??? If you are in a country where traveler???s diarrhea is common, avoid street vendors, uncooked food, unpasteurized dairy products, tap water and ice.??? To battle jet lag, drink a lot of water on your flight.??? Get up and walk on a plane or train to protect" . .