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 antibody, and transmit that antibody through their milk to newborn piglets. It is intended to protect the piglets against PEDv.
The vaccine, called “iPED,” was developed by Harrisvaccines, Ames, Iowa. Since its introduction, approximately 2 million doses of the vaccine have been prescribed by veterinarians. The 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 immune level” beyond what natural exposure achieves, he said, noting that the vaccine used in combination with natural exposure has proven to boost immune levels significantly.
USDA issues conditional licenses based on full safety, purity testing and an expectation of efficacy. Preliminary studies have been promising, and they've shown sufficient data that we think the vaccine will be effective, USDA 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, said USDA.
PEDv, first seen in the U.S. in the spring of 2013, is not harmful to humans nor 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 its vaccine is predominately being used in herds that are already affected by the virus. The pigs have either already been exposed to the virus or it is being used when bringing in animals where the virus 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 opens up the availability of the vaccine for veterinarians to buy and distribute without the direct involvement of the company and allows producers to buy direct if they so wish. Harris said it also opens up opportunities to export the vaccine on a larger scale.
The 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. Harrisvaccines has received USDA licensure in the past using SirraVaxSM technology for its Swine Influenza vaccine (September 2012) and an Autogenous Vaccine, RNA for Rotavirus C (January 2013).
Essentially the process used by Harrisvaccines is that of taking data from the virus (RNA) to develop what look like virus particles using the gene sequence from the RNA. Once injected, the particles target the pig’s cells to replicate the RNA to 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 this 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 these diseases and issued a Federal Order requiring the reporting of new detections of PEDv and other new swine enteric coronavirus disease to APHIS or state animal health officials. The Federal Order also requires that operations reporting these viruses work with their veterinarian or 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 to reduce virus shed in affected animals, prevent further spread of the disease, and enable continued movement of animals for production and processing, said USDA.