Mar 11, 2009 (CIDRAP News) The US Department of Agriculture (USDA) recently granted a conditional license for the nation's first Escherichia coli O157:H7 vaccine for cattle, allowing Epitopix LLC, a Willmar, Minn., company, to immediately offer the vaccine to the beef industry.
Epitopix announced the granting of the conditional license on Mar 5 at the Beef Industry Food Safety Council annual meeting in San Diego, according to a company press release. "It represents a significant breakthrough in the beef industry's ongoing effort to reduce E coli O157," said Jim Sandstrom, Epitopix' general manager, in the press release.
The company will conduct more potency and efficacy studies to gain full approval for the vaccine, which was developed by the company's scientists along with researchers from Kansas State University and West Texas A&M University. The vaccine uses "siderophore receptor and porin" (SRP) technology developed by Epitopix.
Dan Thompson, associate professor of clinical sciences at Kansas State University, said in a March 27, 2008, press release from the university that foodborne pathogens use siderophore receptors and porin proteins to acquire iron. "Iron is to bacteria as oxygen is to humans. Without iron consumption, the bacteria suffocate and can't grow or replicate," he said, adding that the vaccine keeps the pathogen from taking up iron.
Thompson said researchers conducted a challenge study, a natural infection trial, and two large-pen field studies of the SRP E coli vaccine at commercial feedlots. He said the trials demonstrated that the vaccine decreased the number of cattle shedding the bacteria, the concentration of the bacteria that was shed, and the number of "super shedder" cattle.
"We had a decrease in cattle shedding E coli by 54% in our first study," Thompson said in the press release. "However, we increased the amount of SRP exposure in the second field study and decreased the rate of shedding by 85%." The large-pen studies involved 20 pens and more than 1,200 head of cattle.
Sandstrom credited the USDA and the National Cattlemen's Beef Association for supporting several public and private E coli preharvest and postharvest interventions. "We are confident that our E coli O157:H7 SRP vaccine will play an important role for beef producers and packers as they work together to implement E coli O157:H7 control efforts," he said.
Though Epitopix is the first company to win conditional USDA approval, other groups are working on E coli vaccines for cattle. In February 2008, Bioniche, a Canadian company that developed Canada's first E coli vaccine for cattle, said it received word from the USDA that it was in a good position to secure conditional licensure. A conditional license would allow Bioniche to sell the vaccine in the United States if at least one step in the manufacturing process takes place on US soil and the company doesn't use a trademark name for the vaccine.
Also, GeneThera, Inc., based in Wheat Ridge, Colo., said in November 2008 that it had signed an agreement to license and distribute an E coli vaccine developed at the University of New Mexico Health Sciences Center, according to a previous report. A representative from the company said that the company would launch phase 2 clinical trials soon and take the vaccine to market as soon as possible.
E coli O157:H7 doesn't sicken cattle but is potentially fatal to humans. It produces a toxin that causes diarrhea, often bloody, but usually without fever. Though most patients with E coli O157:H7 infections recover in 5 to 10 days, 2% to 7% develop hemolytic uremic syndrome, a potentially fatal form of kidney failure.
Because the pathogen doesn't sicken cattle, it's unclear how vigorously cattle producers will embrace the vaccine, some industry experts have said. Sandstrom told CIDRAP News that Epitopix has not yet set a price for a course of its vaccine. Bioniche has said its vaccine would likely cost less than $10 per head of cattle.
Mar 27, 2008, K-State press release
Feb 2, 2008, CIDRAP News story "E coli cattle vaccine nearing US approval"
Nov 3, 2008, CIDRAP News story "Canada approves E coli vaccine for cattle"