Cattle Vaccine Could Reduce E. Coli Outbreaks

Pfizer will market promising new vaccine; beef producers cautious.

February 18, 2011, 5:25 PM

Feb. 23, 2011— -- The battle against E. coli contamination in the nation's food supply has a new weapon, but consumers are not likely to see its benefit anytime soon.

Epitopix, a Minnesota-based veterinary vaccine company, recently released a vaccine that promises to help prevent cattle from carrying E. coli O157 -- a bacteria strain that, although harmless to livestock, can be deadly to humans.

Yet critical barriers stand in the way of implementation -- the need for additional research and a high price tag.

Labeled as "E. coli Bacterial Extract," the vaccine is now available under a conditional license from the USDA, but beef industry leaders want to perform their own independent studies before moving forward with wide-scale implementation -- a common practice for newly released vaccines.

"A lot of basic research needs to occur before a technology like this is developed," said Michelle Rossman, senior director of beef safety research at the National Cattlemen's Beef Association.

At least 63,000 Americans acquire the foodborne pathogen every year after consuming contaminated foods such as ground beef or raw vegetables according to the most recent data from the Centers for Disease Control and Prevention. As a result, the CDC estimates 2,138 require hospitalization and 20 will die.

A separate CDC study found that a third of all known E. Coli outbreaks from 1998-2002 were traced back to beef products, and 35 percent were from an unknown origin.

Cargill Meat Solutions, one of the nation's largest beef producers, ran a large-scale test with the vaccine last summer on more than 85,000 animals. Initial results of the study showed promise, but the findings were ultimately thrown out.

As it turned out, that summer was an exceptional year for E. coli. The cattle carried an unusually low amount of the bacteria, even those that did not receive the vaccine. In fact, so few cattle carried the bacteria that it invalidated the entire study.

"At the end of the day, that was the deal with Cargill," said Dan Thomsen, a veterinary epidemiologist at Kansas State University who was involved with the project. "We just didn't have a challenge."

Cargill intends to repeat the study this summer for more definitive results, which could be viewed as a show of optimism in the vaccine's effectiveness.

"There were some encouraging signs, and it could turn out to be another tool in our toolbox of measures that we use to ensure food safety," said Cargill spokesman Mike Martin.

If the Cargill study can show that the vaccine works as advertised, that would create one clear signal that wider use of the product could be on the horizon. And last month, Pfizer, Inc. sent another large signal to the industry when it reached a marketing agreement with Epitopix.

David Smith, a professor of veterinary and biomedical science at the University of Nebraska-Lincoln, has been researching E. coli since 2002. The amount of interest shown by such key players in the industry could mean that wide implementation is a distinct possibility, particularly with the addition of Pfizer, he said.

"Here's a very large company that says we're willing to invest in pre-harvest interventions because we think there's a future there," Smith said.

Even so, cost could pose a problem for the industry, said Jim Sandstrom, Epitopix general manager.

"The food chain has to bear the responsibility, but nobody's really figured out how to do that yet," he said.

Pfizer will sell it for $2.35 per injection, and it could take two to four doses to inoculate each animal. A two-dose regimen is most likely.

Estimates put the cost to suppliers from about $5 to as much as $15, depending on the added logistical costs of administering the injections. While it may seem a trifle to outsiders, even the lower range of the estimate could be significant added expense. Steve Kay, publisher of Cattle Buyers Weekly since 1986, said it doesn't take much to change the fortunes of those in the cattle industry.

"That's a tremendous cost that somebody would have to bear," he said. "Even if it was shared between the feeders and packers, that might be the difference between profit and loss for them."

Adding to the cost, Kay said, are the logistical concerns of keeping vaccinated cattle segregated from the non-vaccinated cattle.But the cost of another E. coli outbreak in the beef market could be greater. Using data collected from industry reports and academic researchers, Kay estimated that E. coli cost the industry $2.671 billion during a 10-year span beginning in 1993.

The vaccine admittedly does nothing for the cattle, which makes it a hard sell for ranchers. The sole function is to protect humans from a strain of E. coli that lives as a harmless hitchhiker in the intestines of infected livestock, deer and other wild animals.

"Spending the money before it's proved to be effective is not a brilliant move," said rancher Bill Rishel, 66, former president of the Nebraska Cattlemen's Association. "If it's proved to be effective, I think you can rest-assured this industry will absolutely adopt it."

The Epitopix vaccine is not alone in the fight against E. coli in cattle. The first commercially available E. coli vaccine was made by Bioniche, and is now available on the Canadian market. That vaccine, labeled Econiche, is currently pursuing approval from the USDA for use in the United States.

UNL researcher David Smith conducted in 2002 the first trials on the Bioniche vaccine. He said the two vaccines were similar in that they both provoke an immune response in the animal to fight the bacteria.

"Actually, I would have to admit that I was pretty surprised when we did get positive results, and that we continued to get positive results," he said.

Smith said the biggest distinction between the two vaccines is in how they work. The Epitopix vaccine blocks the bacteria's ability to absorb iron, essentially starving it. The Bioniche vaccine, however, blocks the bacteria's ability to stick to the intestinal wall, which is necessary for colonization. But more importantly both are effective, he said.

Bioniche CEO Graeme McRae expects to have USDA approval before the end of the year, and is building a $37 million manufacturing facility that can meet global-scale demand. He wasn't familiar with the Epitopix vaccine, but hopes claims of its effectiveness prove to be true with further testing.

"I hope it works, because there's room in this marketplace for several vaccines," he said. "And one vaccine that proves it doesn't work very well, that will affect the sale of everybody's vaccine."

Even if E. coli vaccines do come into wide use, researchers caution that it will not be a "silver bullet" that entirely eliminates the dangers of E. coli and its effects which, in extreme cases, can lead to kidney failure and even death.

Contracting the bacteria typically comes from ingesting contaminated food or water.

Because E. coli lives and thrives in the intestines, it enters the environment through fecal matter like cow manure. Meat can be contaminated when it comes into contact with even microscopic amounts of that manure. Just 10 E. coli bacteria are enough to make a person sick

Under the right conditions it can survive for months, but extreme heat and cold, or even direct sunlight is enough to kill it. Cooking meat to the recommended temperature also kills the bacteria, but for people who enjoy rare beef undercooking is common.

"I think we've given up on the concept that we're going to cook our meat to 165 degrees," said Dan Thomson, a veterinary epidemiologist at Kansas State University. "If people would wash their hands, not contaminate raw meat with other food, and cook it to the proper temperature, this would be a non-issue." contributor Charlie Litton is a member of the ABC News on Campus bureau in Lincoln, Neb.

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