Vaccine in a potato
An edible vaccine for hepatitis B is in the final stages of development. Once ready, it will work just as the existing vaccine that is injected and used widely around the world does. The current hepatitis B vaccine is based on an antigen (a protein) that stimulates the body to produce antibodies produced in yeast. Researchers have produced the same antigen in genetically modified potato that produces the vaccine in its flesh. For years scientists have known that a protein, known as HBsAg, can act as an antigen. They insert the gene from this protein into yeast, which then produces the protein used to make the vaccine. But the process is expensive. The new edible vaccine may give a cheap solution ( Nature Biotechnology , Vol 18, No 11).