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| Volume 9, Number 2 | September 7, 2001 |
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VIDO pursuing more vaccines to provide tools for safer food
By Michael Robin As food safety gains more attention in the public eye, a research institution on campus works quietly to develop tools to keep the food supply free of lethal microbes. The Veterinary Infectious Disease Organization (VIDO) is a not-for-profit institute wholly owned by the University of Saskatchewan. It is a global leader in food animal and poultry vaccine research for the control of infectious diseases. According to Dr. Andrew Potter, Associate Director for Science, vaccines are not only critical for the health of food animals, they are essential to produce products safe for us to eat. One example is ‘E. coli O157:H7’ — the bug responsible for wreaking havoc with the water supply in Walkerton, Ont., sickening and killing the townspeople. This microbe also causes that bane of backyard barbeques, ‘hamburger disease’. “Why aren’t we vaccinating animals to prevent that?” Potter asks. “It doesn’t cause any disease in animals, but the principle is still there, and in fact there are a number of vaccines under development, including ones at VIDO.” In fact, a collaborative effort between Potter and Dr. Brett Finlay at the University of British Columbia may have yielded one of the first vaccines to control E. coli O157:H7 in cattle. “We’ve been able to demonstrate that by using technology developed by Finlay, it’s possible to substantially reduce the levels of (the bacteria) in vaccinated cattle,” Potter says. Field trials of the vaccine are slated to begin in September, 2001. Hoof and mouth disease is also an area where VIDO work may play an indirect role, in providing more doses of vaccine than current manufacturing methods. Currently, there is no good way to contain hoof and mouth once it takes hold. The response has been “scorched earth”, as seen with the recent outbreak in the United Kingdom. All animals infected or suspected of being infected are slaughtered, burned and buried. Another strategy is to vaccinate all animals, but vaccines cause the same immune response as the disease. Tests can’t tell the difference between an infected animal and a vaccinated one, and they cannot be exported. Potter explains that one strategy being considered in the U.K. is “perimeter vaccination”, that is, destroy all infected animals, then vaccinate those within a given area around the infection site. In either case, manufacturing enough doses is a challenge. “There’s simply not enough of it.,” Potter says. “If there was an outbreak in Europe, in North America, there wouldn’t be enough vaccine to vaccinate the animals.” VIDO is collaborating with Saskatoon-based PharmaDerm to increase efficacy of vaccines and multiply dose manufacture. While this technology hasn’t been applied to foot and mouth, it has potential for wide application in animal and human health. “What we were able to show at VIDO is, we took a vaccine that was in use and were able to reduce the dose 10 times,” Potter says. VIDO is also working on delivery systems that would make needles obsolete. According to Potter, needle technology is as old as Pasteur: you find something that induces an immune response, mix it with an oil, and inject it. Eliminating needles would be a boon to animals, farmers and exporters. Potter explains that despite the best efforts of animal husbandry, needles occasionally break off inside the animal. One exporter was warned by a Japanese customer that a needle had been found in their meat, and that if it happened again, they would take their business elsewhere. A needle showed up in a later shipment, and the exporter hasn’t sold into the Japanese market since. VIDO’s approach is to develop oral, nasal and even suppository vaccines to induce an immune response right where diseases attack — at the mucous membranes. Ultimately, vaccination is about healthier animals, and, according to Potter, that means safer food. “I would rather, as a consumer, eat food from a vaccinated animal, than one that had been exposed and had diseases caused by any number of viruses or bacteria,” he says.
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