How about some Vaccine with your Rice?

How about some Vaccine with your Rice?
Japanese scientists have manufactured an oral vaccine against cholera that will be encased in a rice protein.

Japanese scientists have manufactured an oral vaccine against cholera that will be encased in a rice protein.

Rice is the staple food of Japan and of other Asian countries. What could be simpler for scientists to do to spread the use of a vaccine they would like to see almost as common as rice, than for them to propagate it along with the grain? It will be cost-effective and easier to distribute. This is what Japanese scientists have done. They have manufactured an oral vaccine against cholera that will be encased in a rice protein. It has proven to be effective with mice and the scientists now hope that it will prove to be equally effective, if not more effective, against the disease in the case of humans.

The results of this work have been published in the Proceedings of the National Academy of Sciences by Immunologist Dr. Hiroshi Kiyono from the Tokyo's University's Department of Microbiology and Immunology and his team.

Cholera, which is caused by the Vibrio cholerae bacterium is a severe intestinal infection. There are about 200,000 cases reported each year in Asia, Russia, Latin America, Africa, and other places. Its incubation period is short, lasting from a few hours up to five days at the maximum. The infection results in vomiting and plenty of watery diarrhea, which if not treated immediately with oral rehydration salts, could result in acute dehydration and even in death.

In their experiment the team took genetic material from the microbe that produces the cholera toxin B and inserted it into a rice plant, Kitaake, with a recently sequenced genome. About 30 micrograms of the subunit were introduced into each grain of rice. Mice were then administered this rice in powder form. It was found that this 'vaccine' brought on a superior "two-tier" immunity, that of normal resistance from the body and also that of producing antibodies in the nose's, mouth's and urinary tract's "mucosal" surfaces.

To be taken in the form of a capsule the newly engineered vaccine will have several other advantages over, not only vaccines that need to be injected, but also over other oral vaccines against cholera.

Both, injectable and oral cholera vaccines are available in the market but then not very convenient as they are required to be kept at lower temperatures and refrigeration is not always possible in hot and humid places where it is needed the most.

Rice, therefore, has several advantages over traditional vaccines in that it does not need to be injected, purified or refrigerated. In fact, the vaccine was found to be as effective after being stored for a year and a half at room temperature. Besides this, it does not dissolve in the stomach and lasts until it reaches the intestine where it performs the necessary task of setting up an immune response that will fight the cholera bacteria.

Kiyono and his team now wish to test their vaccine on primates. They however and not very sure as to when they would be able to try it on humans but they are of the opinion that rice protein is an ideal means of delivering other vaccines too.

"Most infectious diseases occur during inhalation, ingestion and sexual contact, it can be applied for anthrax, influenza, HIV as well," says Kiyono.