ThePigsite.com, UK

11-20-07

Pork board grant could yeild next Circovirus vaccine, says researcher

US - When the National Pork Board wanted to research how to eradicate the latest strain of porcine circovirus, Kansas State University's Richard Hesse stepped forward.

As K-State's director of diagnostic virology, Hesse has had the chance to identify and characterize a number of diseases, including porcine circovirus. He is one of a group of K-State researchers who have conducted clinical trials on a vaccine now used by pork producers nationwide to ward off the effects of the disease.

Given that expertise, Hesse and fellow researchers from K-State, Iowa State University and South Dakota State University were recently awarded a $200,875 grant from the National Pork Board to delve deeper into how the disease affects the immune system of infected pigs. The multistate team will lead a national effort to develop the diagnostic tools to determine what viral strain a pig has been infected with, to tell the difference between antibodies produced in response to natural infection or vaccination, and to determine when the best time is to vaccinate.

Porcine circovirus is a disease that compromises a pig's immune system. Clinical signs of the disease include skin rashes, jaundice, fever, diarrhea, poor growth, weight loss and death, though not all pigs show signs of disease. The success of the vaccine used today is measured in its ability to resolve a pig's weight and growth issues, which impacts the producer's bottom line.

Hesse says that the circovirus isn't a new phenomenon, but in recent years a new pathogenic strain has made its way south from Canada. K-State researchers were the first to systematically test commercial circovirus vaccines, but Hesse said there is a lot more to learn about the disease.

"We're going to characterize exactly how the infection impairs immunity," Hesse said. "This research will give producers and veterinarians a keen understanding of what exactly is happening, and the diagnostic tools we develop along the way -- like a test to differentiate between a vaccinated pig and a naturally infected one - will be critical in the development of the next generation of vaccines against circovirus."

Armed to be effective

Hesse said this study will arm producers with the information they need to adhere to an effective vaccination program. Being able to better understand the mechanisms of porcine circovirus infection and control through vaccination will mean that producers may soon be able to say their pigs are disease free.

"Porcine circovirus is a devastating disease for both the animal and the producer," Hesse said. "The management practices used by producers will be critical to the health of the herd. This research will point us in the right direction when it comes to meeting the needs of both the animals and those raising them."

Hesse is the project's principal investigator. He is working closely with K-State's Bob Rowland, professor of diagnostic medicine and pathobiology, and Carol Wyatt, associate professor of diagnostic medicine and pathobiology, as well as Eileen Thacker of Iowa State University and Ying Fang of South Dakota State University. The National Pork Board grant will be funded as a yearlong research project.