K-State Researcher Makes Inroads in Fighting Classical Swine Fever

Jishu Shi, professor of vaccine immunology and director of the U.S.-China Center for Animal Health, ( Kansas State University )

A Kansas State University researcher has licensed a new vaccine to an animal health company to fight a highly contagious swine disease overseas, according to a news release from the university. In addition, a second discovery by the researcher could improve vaccines for the disease and help protect the U.S. from an outbreak.

The release states that Jishu Shi, professor of vaccine immunology and director of the U.S.-China Center for Animal Health in the university's College of Veterinary Medicine, has developed a method of producing a classical swine fever vaccine safely and inexpensively. The disease can cause devastating epidemics among pigs if left unchecked.

Shi's vaccine “uses a protein from the virus rather than a live or attenuated virus, which means the vaccine poses no biosecurity risk to produce in the U.S., where classical swine fever was eradicated in 1978,” the news report said.

The new subunit vaccine is licensed to an animal health company in China, which will continue to study its field efficacy, according to the report. Classical swine fever has not been eliminated in China, and each of the 700 million pigs raised annually in the country currently receives two doses of vaccine against the virulent disease. Shi's version requires only one dose.

"We need to test the vaccine in the field to prove it will work," Shi said in the release. "If it does, we can help China eradicate the disease, which further secures the U.S. by ensuring the disease doesn't spread to our shores."

A Test that Differentiates
Pigs given the current modified live virus classical swine fever vaccine test positive for the disease. Shi's other discovery will help develop a test to differentiate infected from vaccinated animals, known as a “DIVA” strategy, the release said.

“Shi and his collaborators identified two specific antibodies that can be used to differentiate whether pigs are infected or vaccinated, and he is working with colleagues at the U.S. Department of Agriculture, in Europe and in China to conduct more trials and gain full validation,” the release stated.

"This exciting discovery could result in solving an economic and trade problem in China — vaccines are expensive, and countries with classical swine fever can't export pork — and a security problem for the U.S.," Shi said.