A team of Japanese researchers has developed a type of rice that can carry a vaccine for cholera, a step that could one day ease delivery of vaccines in developing countries.While it is only the latest of several plants being tested as potential means of producing vaccines, the development is potentially important in medically under-served countries that lack refrigeration to store regular vaccines. However, the work is preliminary, having been tested only in mice.The team, led by Hiroshi Kiyono from the University of Tokyo, has reported the development of the new vaccine in Proceedings of the National Academy of Sciences published today.A major advantage of this approach, they said, it that it 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 spur immune responses in the mucosal areas.This means that the new vaccine could have an advantage against pathogens that typically infect these membranes, such as cholera, E. coli, human immuno-deficiency virus, influenza virus and the SARS virus.Attempts to alter plants to produce proteins that induce an immuneus diseases have been underway for years, but none has reached the state where it could be used in humans.
