Vaccine fights pervasive swine menace

Posted May 18, 2001


For Immediate Release:

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 further information contact:

Stuart Bond
Associate Director (Marketing and Business Development)
Veterinary Infectious Disease Organization
Phone: (306) 966-7474
Fax: (306) 966-7478
E-mail: bonds@sask.usask.ca