The new rice vaccine, which is tested only in mice, causes immune reactions both systemwide in the body and in mucosal tissues such as in the mouth, nose and genital tract. Standard vaccines delivered by needle do not cause immune responses in the mucosal areas.
Developed by a team of researchers led by Hiroshi Kiyono of the division of mucosal immunology at the University of Tokyo, the new discovery was reported in Tuesday's issue of Proceedings of the National Academy of Sciences.
According to AP reports, the new vaccine also has an advantage against pathogens that typically infect these membranes, such as cholera, E. coli, human immunodeficiency virus, influenza virus and the SARS virus.
However scientists have warned that getting a good response to orally delivered material is difficult in the harsh environment of the digestive system and more study is needed on ways to protect it from the degradation of the stomach.
Also, the Japanese researchers were able to generate a protective immune response in the mice while avoiding any allergic reaction to the rice itself. The ability to store the transgenic rice at room temperature doesn't have the risks of infection from an injection.
However, scientists have stressed that the use of rice engineered to produce a vaccine reaction doesn't mean it's an edible vaccine. Instead, the vaccine is delivered in a capsule or pill containing rice powder and should be treated as a drug, not food.
