Vaccine fights pervasive swine menace

Saskatoon, Sask., May 15, 2001

A new vaccine under commercial development could significantly decrease piglet mortality caused by Streptococcus suis. Research scientists at the Veterinary Infectious Disease Organization (VIDO) in Saskatoon developed the vaccine.

S. suis is a widespread disease found in 90 percent of hog herds surveyed in Western Canada, says Dr. Phil Willson, VIDO Bacteriology Program Co-ordinator. “This pathogen can cause disease in several different phases of production. The most disturbing is when newly-weaned piglets contract the disease at about six weeks of age.”

Currently, the only remedy is antibiotics. “However, antibiotic treatments have had mixed results and this disease is hard to manage with the high levels of antibiotics and quick treatments that are required,” he says. “So we decided on an immunological approach – a vaccine that prevents the disease from spreading by using the animal’s natural defences.”

A highly potent conventional vaccine was developed. “We administered it to sows in a field study and it increased the amount of antibodies in their bloodstreams. They then had a higher level of the antibody in their colostrum, which they passed on to their piglets,” says Willson. Those field tests demonstrated a 50 percent reduction in piglet mortality.

VIDO has partnered with the Alberta Research Council Inc. (ARC) to further develop the vaccine for licensing. “At this time we’re working on the vaccine production issues, ensuring that the changes in scale required to produce enough of the vaccine for licensing trials, does not change the vaccine’s makeup or its efficacy.” ARC develops and commercializes technologies to give its customers a competitive advantage.

Future vaccine enhancement could include a second-generation vaccine using recombinant antigens to provide a broader line of defence against the disease. “We are trying to identify the proteins involved in virulence that could become the basis of an improved vaccine,” says Willson.

The economic impact of the disease is considerable, as 25 percent of the operations with carriers of the S. suis pathogen have persistent problems with the disease, he says

“That’s a large number of hog operations with major problems. If the vaccine is as effective as demonstrated so far and proves commercially viable to produce, it will certainly help producers combat the disease and the production losses that go with it.”

VIDO is a wholly-owned University of Saskatchewan not-for-profit institute that is a global leader in food animal and poultry vaccine research for the control of infectious diseases. Significant ongoing support is received from the Governments of Saskatchewan, Alberta and Manitoba. Producer support for the project came from the B.C. Hog Producers Marketing Board, Alberta Pork, Saskatchewan Pork, Manitoba Pork Council and Ontario Pork.

For more information, contact:

Stuart Bond
Associate Director, Producer Relations
Veterinary Infectious Disease Organization
Phone: (306) 966-7474
Fax: (306) 966-7478