Taiwanese scientists' research on an oral vaccine for animals that will use an enteric-coating dosage system will soon enable farmers to better care for the health of their pigs. Scientists at the National Science Council (NSC) yesterday said the breakthrough product will be available by 2005.
The Animal Technology Institute of Taiwan yesterday revealed the results of an NSC-sponsored research project on the development of an enteric-coating-dosage form of the oral vaccine, saying that experiments on pigs demonstrated that the new form of the vaccine is more effective than injected vaccines.
Taiwan's most prevalent pig diseases are caused by many different bacteria, including E. coli and salmonella.
The nation's efforts to prevent epidemics rely on both drugs and farm management because of the limited effectiveness of injection vaccines.
Yesterday, NSC scientists said that six kinds of oral vaccines for pigs were developed to combat diseases caused by common bacteria.
Due to the vaccines' effectiveness, scientists said, three local vaccine companies had worked with the institute to commercialize the drug at acceptable prices, making it only one-fourth to one-fifth the price of similar vaccines available at present.
"We predict that our new bacterial vaccines will have an annual market value of NT$225 million in Taiwan," Weng Chung-nan (
Weng said the Taiwan market would need around 18 million doses annually. Taiwan raises 9 million pigs a year. On average, each Taiwanese consumes 41kg of pork annually.
On average, Weng said, each dose will cost only NT$25 once the vaccine hits the market in 2005.
* The Animal Technology Institute is developing oral vaccines for pigs that cost less than a quarter of injected vaccines.
* Taiwan's pigs are affected by several diseases, including E. coli and salmonella.
* The scientists have been using nanotechnology to produce a coating material that allows the antigens to be released into the small intestines of the pig rather than the stomach.
* The oral vaccine is also being tested on cows.
Some foreign pharmaceutical companies have expressed interest in working with the institute to market the vaccine, Weng said.
Liao Chao-wei (廖朝暐), the convener of the research project, said that his team had tried to solve nanotechnology-related problems involved in the procedure since 1998. He said they have now succeeded in solving the problems.
Liao said the team was applying for patent rights in Taiwan, the US and the EU for some of the technologies they had developed.
Scientists put antigens into a special capsule by using a cellulose derivative as a coating material, of which the thickness is about 300nm.
Liao said the antigens inside the oral vaccine can easily be absorbed by animals. The immunoreaction, however, is only induced in the small intestines rather than in the stomach, because the reaction requires higher pH levels.
The reaction will effectively prevent enteric infections and thus enhance the pigs' immunity.
"It's more convenient than injections. The vaccine's effectiveness is about 10 times that of traditional injected ones," Liao said.
Liao said that the use of the oral vaccine will result in lower costs for livestock producers, fewer cases of disease and increased food safety.
Apart from pigs, Liao said, researchers had also tested the drug on cows. In the future, Liao said, researchers would focus on developing oral vaccines for high-priced water-based products, such as shrimps, by using similar technologies.
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