The quest for edible vaccines -- and a reason to eat your vegetables that mother never imagined -- got a booster shot.

Researchers reported that they have genetically modified potatoes to carry a vaccine against Hepatitis B and successfully tested it in humans.

More than 60% of the volunteers tested showed signs of increased immunity after eating bite-sized pieces of transgenic potatoes.

University of Arizona biologist Charles Arntzen, who is also developing edible vaccines in bananas and tomatoes, says the findings "provide compelling evidence" that edible vaccines could help combat a disease that annually kills more than 1 million people worldwide.