As a deadly outbreak of a rare form of E. coli ravages Europe, the latest in a string of similar health scares over the years, scientists are in a race to come up with ways to eliminate the often deadly bacteria from the food system. Now, a made-in-Canada solution is about to hit the mass market in the form of a vaccine that would inoculate cows for the most common strain.
Canada's Bioniche Life Sciences Inc. holds the patent to the world's first E. coli vaccine. Trademarked Econiche, the vaccine works by enabling a treated cow to produce antibodies that block proteins secreted by the dangerous strain of bacteria as it attempts to take up residence in the intestinal wall. Because the bacteria are blocked from attaching to the cell wall, they die, rather than congregate and multiply. The theory behind reducing E. coli levels in cows is that it will reduce the amount an animal "sheds" into the environment, in turn making E. coli contamination less likely in the food chain.
Bovines carry a cocktail of E. coli strains in their intestinal tracts, none of which is harmful to the animals. Released into water, soil or onto crops via contaminated manure, the bacteria can be picked up by other animals and transferred to people. Several strains are dangerous and even fatal to humans because they produce Shiga toxins, which trigger symptoms ranging from diarrhea to untreatable kidney and liver failure. Those include O157:H7, which the new vaccine targets, and the more rare strain O104 at the centre of Germany's outbreak.
In 2000, seven people died and hundreds more were sickened by water contaminated with O157:H7 in the small town of Walkerton, Ont., and in 1993, hundreds became ill and four died after an outbreak of the same strain in Washington state caused by contaminated beef patties at Jack in the Box restaurants. Other outbreaks of it were linked to meat at Welsh schools and fresh spinach in California.
Food companies around the world have made huge investments in technologies that allow them to detect harmful E. coli or refine their packing processes to reduce risks. Treating cattle with a vaccine would ideally nip much of the problem at its source.
"Canada is clearly a leader in this field," said Graeme McRae, president of Bioniche, who secured permission from the Canadian government to disseminate the vaccine back in 2008 and is waiting on licensing in the United States. It was developed by University of British Columbia microbiologist Brett Finlay to tackle E. coli O157:H7 and licensed to the company Bioniche.
Peer-reviewed studies conducted with the vaccine have proven it can effectively reduce the amount of O157:H7 E. coli in a cow's digestive tract by 99 per cent, Mr. McRae said.
But widespread dissemination of the vaccine has been hampered by lack of facilities to mass-produce it.
Mr. McRae said Canada has scant production capacity for veterinary vaccines and imports most of its treatments from the United States. With $25-million in loans from the provincial and federal governments, Bioniche recently built a state-of-the-art facility that, at capacity, will churn out 500 million doses annually of the vaccine. By year's end, it will be producing 100 million doses - enough to vaccinate all of Canada's 12.5 million cattle and nearly all of the 92.6 million that U.S. officials say are in the United States.
Two companies in the United States are also working on similar vaccines and have been granted conditional licences to produce them while continuing studies on efficacy. Canadian researchers with the federal Department of Agriculture and Agri-Food based in Guelph, Ont., are working on a means of reducing E. coli counts in animal intestines via application of antimicrobial essential oils. Early results have shown that carvacrol (from wild oregano) and cinnamaldehyde (cinnamon oil) have some effect, although trials are still under way.
While officials have yet to pinpoint the cause of the outbreak in Germany that has killed at least 14 people and sickened more than 1,000 others, scientists have long pointed to cows as the true source of E. coli-related food illness epidemics worldwide. There are not yet any guarantees that the vaccine Mr. McRae's company is producing would be effective against other strains, although it is considering conducting tests to determine that.
Each vaccine costs about $10 a head plus extra for the veterinarian required to supervise its delivery. The frequency required to keep E. coli counts under control depends on a given cow's situation. Beef cows should be vaccinated at six weeks of age and then twice more while at feed lots, which are notorious for spreading the bacteria because animals are packed into close quarters. Cows and bulls used for breeding in both beef and dairy should be vaccinated annually.
Now the company needs to persuade farmers - or governments - to buy it. Some Canadian farmers have had access to the vaccine, and several thousand cows have been inoculated, but Mr. McRae suspects the cost will be a problem.
Outbreaks like the one in Germany may convince governments around the world of the need to subsidize the vaccine to protect trading markets and public health. More research is needed to understand whether this vaccine is effective against more than one strain of E. coli. Dr. Finlay, Econiche's creator, said he doesn't know whether it would work against O104, the destructive strain sweeping Germany.
In fact, very little is known about the bacteria, which is in only its second food-borne outbreak. Keith Warriner, a University of Guelph food scientist, applied for a grant to study the strain just before the German outbreak struck.
"The main problem with this group of bacteria is that nobody has done any research," he said. "We had a notion of it 30 years ago and we knew [E. coli]was evolving very rapidly. We knew this was a problem. We didn't think it was going to hit us this hard this soon," he said, adding: "This is a consequence of not acting on the information we had."
With a report from Adrian Morrow