And vaccines delivered in food trigger a two-way immune response. This is the systemic response created by injected vaccines. Antigens trip the immune system's red alert signals, launching the body's disease-fighting regiments. To build these pharmaceutical factories, researchers take cells from plants and coax them to multiply like bacteria cultures. Many plants could carry antigens, but the final vaccine must be produced in fruits or vegetables that can be processed and eaten raw.
Cooking breaks down the proteins that provoke the needed immune response.
And although raw potatoes may not make the most delectable snack, volunteers have willingly eaten diced transgenic potatoes in clinical trials. Last year, another group of volunteers ate potatoes engineered to fight the Norwalk virus. This is proof that plant-based edible vaccines work. And last summer, Thanavala began human trials with potatoes engineered to carry a vaccine for Hepatitis B, a killer virus, which is also a major cause of liver cancer. At Loma Linda University, California, William Langridge and his research team successfully vaccinated mice with a cholera vaccine.