Scientists at Kansas State University have proven they can build protection against avian influenza into an existing vaccine for Newcastle disease--another flu-like illness that affects poultry. Since most chickens are routinely vaccinated for Newcastle, the development could aid future efforts to control and prevent outbreaks of avian influenza, such as the one that has caused the loss of millions of chickens on Midwest farms.
By adding genetic material from avian influenza to the Newcastle vaccine formulation, the researchers showed they could stimulate immune protection against both illnesses, said Jurgen Richt, professor of veterinary medicine and director of the U.S. Department of Homeland Security's Center of Excellence for Emerging and Zoonotic Animal Diseases, in an interview with the Topeka Capital-Journal. So far they have tried the approach with two strains of avian influenza, H5N1 and H7N9, both of which originate in birds but can cross to people.
The Kansas State team's combination vaccines are already approved in Mexico, and the researchers are now weighing the feasibility of applying for USDA approval, Richt said. The scientists are also working on a vaccine that would combine Newcastle with H5N2, the deadly strain that's currently spreading in the U.S.
The demand for effective avian-influenza vaccines is rising as the U.S. battles the worst outbreak of the disease in history. More than 14 states have reported cases of avian influenza, recently prompting the U.S. government to pour an additional $330 million into fighting the disease. After the virus began spreading last year, several countries banned or restricted imports of poultry from affected states, including Canada, the European Union, and South Korea.
The Kansas State approach may prove useful beyond avian influenza. Combining the Newcastle vaccine with genetic material from other diseases to create vaccines may work in other animals, as well as people--even though most other species are not susceptible to Newcastle--Richt said. The virus, which is used in a weakened form, would merely serve as a way to deliver the genetic material that would produce the immune response. The Kansas State team has already shown that combining Newcastle with a strain of swine flu works. They're now using the method to develop a vaccine against the deadly porcine epidemic diarrhea virus.
"In mammalian species, it's not a 'two-birds-one-stone' concept, but it's a delivery platform that's safe," Richt said.
- here's the Capital-Journal story