A new inactivated virus vaccine for porcine reproductive and respiratory syndrome (PRRS) is offering improved efficacy and protection over current live virus vaccines based on early tests. This difference eliminates adverse reactions in pigs, such as abortion, sick piglets and further spread of the disease, says Renukaradhya (Aradhya) Gourapura, an associate professor in the university's Food Animal Health Research Program (FAHRP), part of the Ohio Agricultural Research and Development Center (OARDC).

The new vaccine is also enclosed in biodegradable nanoparticles, which improves its efficacy and its absorption by a pig's immune system.

“Our tests have shown that two doses of this vaccine, administered intranasally along with a potent mucosal adjuvant, achieve 100% protection in pigs against genetically variant PRRS virus," says Gourapura, who started working on this project in 2009.

A patented technology, the nanoparticle-based PRRS virus vaccine is made from a biodegradable polymer of lactic acid and glycolic acid, known as PLGA. PLGA is an agent approved by the U.S. Food and Drug Administration for use in human vaccines and cancer drug-delivery systems. This is the first time the PLGA-based nanotechnology is being used with food animals.

“Our vaccine has proven to be completely safe in tests so far, with no side effects associated with it,” Gourapura says. “The use of nanoparticles allows the vaccine to stay in the pig's system for four to eight weeks without being degraded. The vaccine is also shelf-stable. We have tested it for one year without showing any loss of quality.”

Gourapura says the vaccine has been successfully tested in a small number of animals at Ohio State. The next step involves extensive field trials in hundreds of pigs in commercial herds.

Gourapura says his vaccine could also become a model for the development of similar nanoparticle-encapsulated vaccines for other diseases affecting pigs and other food-producing animals.

This research project has been supported by several grants from the National Pork Board, the U.S. Department of Agriculture's PRRS CAP2 project and OARDC, totaling over $500,000.

This report appeared this week in the American Association of Swine Veterinarians newsletter (http://www.aasv.org/news).