AMES, Iowa — A vaccine that is being administered to sow populations in six states may hold promise in U.S. pork producers’ battle against Porcine Epidemic Diarrhea Virus.

“We are very confident that we are developing the kind of immune response that we are targeting,” said Dr. Mark Mogler, head of research at Harris Vaccines, based in Ames.

Harris Vaccines developed iPED, a vaccine that is given to the pre-farrow sow one to three weeks before farrowing.

“The idea behind the vaccine is to increase the level of immunity in the sow herself and also the level of immunity she transfers to the suckling piglet,” said Joel Harris, son of Harris Vaccines founder Dr. Hank Harris and the head of sales and marketing for the company.

The company has shipped close to 800,000 doses of iPED to Iowa, Kansas, North Carolina, South Carolina, Oklahoma and Texas.

The vaccine became available only through veterinary prescription in August. Harris Vaccines is working with the Center for Veterinary Biologics in Ames to take the steps to license and sell the vaccine commercially.

“It’s held under a code of federal regulation called the VCP or veterinary-client patient relationship. We released it in August and at the same time are making strides with the (U.S. Department of Agriculture) to get a conditional USDA-approved product to make it easier to distribute both domestically and, hopefully, internationally,” Harris said.

The vaccine is based on the Harris Vaccines RNA Particle Platform technology. Harris said the company is working on a second-generation vaccine, known as iPED+, which is expected to be available soon.

Mogler said since the vaccine hasn’t received any official licensing, information about effectiveness is limited. He said that since PEDV is new to the U.S., much remains unknown about the disease.

“We’re still learning a lot about this virus since its introduction into the U.S.,” he said.

Work on the vaccine began almost immediately after the virus was first detected in the U.S. in April 2013.

“We started working on iPED right when it was first identified in the U.S. Some of the work that our collaborator companies did on SARS coronavirus was the baseline work that we looked to. SARS is a coronavirus like PEDV, so some of the strategies that we would use for the vaccine part are similar. We did preliminary studies during the summer, and by the time we were ready to release the vaccine for sale, we’d completed a number of studies here in our facilities in Ames,” Mogler said.

Harris said the company works with swine veterinarians and producers to maximize the effectiveness of the vaccine.

“Typically, we encourage vets to contact us. We try to be really involved with the producers, as well, arranging meetings with producers and their vets to come up with the best vaccination protocol,” he said.

The company was founded in 2006 by Joel Harris’s father, Dr. Hank Harris, a veterinarian and professor in the departments of animal science, veterinary diagnostic, and production animal medicine departments at Iowa State University.

Joel Harris said it’s satisfying for the company, which specializes in swine diseases, to develop a vaccine that could potentially provide some relief for PEDV.

“It’s really what makes Harris Vaccines unique and differentiates us from other vaccine companies, our ability to respond rapidly against emerging or mutating diseases, the ones that are difficult to grow, like PEDV or rotovirus C or ones that mutate constantly like swine influenza, that is really our forte,” he said.

PEDV, first detected in the U.S. hog herd in April, has been spreading across the nation seemingly unchecked. In the last USDA hogs and pigs report, for the final quarter of 2013, analysts said death losses from PEDV could be starting to appear in USDA numbers.

Analyst Alton Kahlo of Steiner Consulting in New Hampshire said the death loss for the fourth quarter is closer to 4 percent than the standard 2.5 percent used by analysts. He said that would equate to a loss of about 1.451 million pigs that normally would have come to market, but did not.

“I think that number is consistent with other estimates that are put out there, that various models are suggesting as far as the impact of the disease,” Kahlo said during the National Pork Board-sponsored post-report media call.

He added that the pigs saved per litter number for the fourth quarter, at 10.16, was flat, another indicator that the disease is taking a toll on the U.S. hog herd.

“It’s flat right now, and our thinking is it’s probably going to be flat for the next couple of quarters, as well, given that the disease is only spreading,” he said.

Four days prior to the USDA report, Smithfield Foods held its fourth-quarter earnings conference call.

Bo Manly, executive vice president and chief synergy officer, said the disease has impacted the Murphy-Brown production herds.

“We do have it in our Midwest and East Coast herds. Based on industry numbers of current infected herds, the potential impact could be as many as 500,000 to 1 million sows industrywide. This translates to a loss of industry pig production of 2 million to 3 million head or 2 percent to 3 percent in calendar 2014. Murphy-Brown pig production will likely be impacted similarly,” Manly said.