There is a possibility of a edible vaccine against Hepatitis B virus. A virus that infects billions of people. It causes many deaths every year because of chronic liver disease and liver cancer.
     Researchers have genetically engineered a potato that produces the vaccine in its flesh.
     The hepatitis B vaccine currently in use is based on an antigen produced in yeast.  Hugh Mason, who led the research at Cornell University’s Boyce Thompson Institute for Plant Research, said "We have shown we can produce the same antigen in plants,”
     Antigens are proteins on a virus or bacteria that stimulate the body to produce antibodies to fight diseases.