THE U.S. Department of Agriculture has extended a conditional license on a vaccine for porcine epidemic diarrhea virus (PEDV).
The vaccine is the first to be licensed for PEDV and will be used to vaccinate sows with the intent that they build antibodies and transmit those antibodies through their milk to newborn piglets in order to protect the piglets from PEDV.
The vaccine, called iPED, was developed by Harrisvaccines in Ames, Iowa. Since its introduction, veterinarians have prescribed around 2 million doses of the vaccine. The USDA approval, issued June 16, widens the marketing and distribution channels for the product and acknowledges that the technology offers a reasonable expectation of efficacy.
"The approval validates our product and our technology," said Joel Harris, head of sales and marketing for Harrisvaccines.
"There's still a lot to learn about PEDV, but we know that we're increasing an immunity level" beyond what natural exposure achieves, he said, noting that using the vaccine in combination with natural exposure has been shown to boost immunity levels significantly.
USDA generally grants conditional licenses in order to meet an emergency or unmet need. A conditionally licensed product must show a reasonable expectation of efficacy, and all safety and purity requirements must be met.
Preliminary studies have been promising, and Harrisvaccines has provided sufficient data for USDA to believe that the vaccine will be effective, the agency said in its press statement.
The company will continue working toward completing the requirements for a full license. In the meantime, there are no restrictions on vaccine use under the conditional license, USDA said.
PEDV, first seen in the U.S. in the spring of 2013, is not harmful to people and does not pose a food safety risk but causes diarrhea, vomiting and dehydration in hogs and can result in death, particularly in piglets. To date, the virus is estimated to have killed some 7 million pigs in the U.S. It has been found in 30 states as well as in Canada, Mexico, Japan and South Korea.
At the World Pork Expo in early June, Agriculture Secretary Tom Vilsack called the virus a "tremendous hardship for many American pork producers."
Harris said the vaccine is predominately being used in previously affected herds in which the pigs have already been exposed to the virus or is being administered when bringing in animals to farms where PEDV is already present.
"What we've seen is there is a statistically higher antibody level in those vaccinated sows versus non-vaccinated ones," he said.
The USDA conditional licensing allows veterinarians to buy and distribute the vaccine without the direct involvement of the company and allows producers to also buy directly if they wish. Harris said it also opens up opportunities to export the vaccine on a larger scale.
Harrisvaccines has received USDA licensure in the past using SirraVax technology for its swine influenza vaccine (September 2012) and its RNA for Rotavirus C autogenous vaccine (January 2013).
Essentially, the process Harrisvaccines uses is to take data from the virus (RNA) to develop what looks like virus particles using the gene sequence from the RNA. Once injected, the particles target the pig's cells to replicate the RNA and generate an immune response inside the animal that is very targeted. When the pigs then encounter the actual live virus in the field, they already have a strong immunity against it.
The company now plans to move forward to receive full USDA approval so it can market the vaccine even more broadly to distributors and veterinarians.
Licensing of the vaccine is another step USDA is taking to continue to help the hog industry and producers. Recently, USDA announced the availability of $26.2 million in funding to combat PEDV and similar swine diseases and issued a federal order requiring the reporting of new detections of PEDV and other new swine enteric coronavirus diseases to federal or state animal health officials.
The federal order also requires operations reporting these viruses to work with their veterinarian, USDA or state animal health officials to develop and implement a reasonable management plan to address the detected virus and prevent its spread.
Plans will be based on industry-recommended best practices and include disease monitoring through testing and biosecurity measures. These steps will help reduce virus shedding in affected animals, prevent further spread of the disease and enable continued movement of animals for production and processing, USDA said.