by SUSAN MANN
Just a handful of Ontario farmers are using the United States-developed porcine epidemic diarrhea virus vaccine that has recently received a conditional license from the United States Department of Agriculture.
Developed by Harrisvaccines Inc. of Ames, Iowa, the vaccine has been available to Canadian producers since February, when the Canadian Food Inspection Agency approved its importation into Canada under an emergency permit through a veterinarian.
The vaccine is for sows, says Joel Harris, Harrisvaccines head of sales and marketing. “It’s given seven to 10 days prior to farrowing so that the sow’s immunity is increased and those virus neutralizing antibodies are passed down to the piglets through the colostrum or milk. The goal of the vaccine is to get piglets to survive the first few days or weeks of life.”
Porcine epidemic diarrhea virus is a highly contagious swine disease that first showed up in the United States in April 2013 and in Ontario in January of this year. There are 62 cases in Ontario. The virus isn’t a human health or food safety risk and doesn’t pose a threat to other livestock besides pigs. But it causes vomiting and diarrhea in older animals and extreme dehydration along with mortality of up to 100 per cent in piglets less than one week old. Since entering the U.S. the disease has spread to 30 states.
Harris says the conditional approval “is a way to get USDA approval faster when there’s either an emergency situation or there’s no other products available on the market. Basically what it means is we’ve proven or presented enough data and information that the vaccine is safe, its purity has been checked and confirmed and there’s what they say is a reasonable expectation for efficacy.”
The company’s June 16 press release says the conditional license will allow it to sell the vaccine directly to veterinarians and swine producers. Some states restrict producers to only being able to buy the vaccine through their veterinarians, he says. But having the conditional approval “makes it a lot easier for swine producers to get ahold of the vaccine.”
So far, the vaccine doesn’t have a marketed name. It’s currently being called porcine epidemic diarrhea vaccine, RNA, he says, adding the RNA is the classification of the technology they use to make the vaccine.
Mike DeGroot, Ontario Pork’s national biosecurity coordinator, says the vaccine has been used in “a small number of herds” in Ontario. Asked if it helps, DeGroot says he doesn’t know for sure because he doesn’t have direct feedback from veterinarians who have experience with it. Based on information from the United States “it helps to provide immunity across the herd and stop shedding of the virus. But it doesn’t necessarily stop animals from becoming sick from the virus.”
The vaccine won’t necessarily stop pigs that are negative for porcine epidemic diarrhea virus from getting sick if they’re exposed to the virus and the herd was vaccinated. But “in a positive site it may be a tool that’s used to provide better immunity across the herd and less shedding of the virus,” DeGroot says, adding “it will be a tool that hopefully will be able to help control the disease a little bit and help in some of our elimination strategies. It’s hard to say. I don’t know if it will be something that is widely used right now.”
DeGroot says farmers should continue to maintain their heightened biosecurity protocols. “The vaccine is not really going to be a tool to stop the virus from coming into a herd as much as controlling the virus once it’s in a herd.”
In Ontario, the vaccine is likely to be used by veterinarians to control virus shedding or “in their elimination plans on farms but not necessarily on herds that don’t have the virus,” he says. In Canada, veterinarians are the ones that must import the vaccine. But producers can inject their own animals under instructions from their veterinarians.
Harris says since February they have exported more than 150,000 doses to two Canadian provinces, including in Ontario.
The USDA conditional license is approved for two years, Harris says. “You can’t get extensions on it but in the meantime we’re working to get what they call full USDA approval.” The company is doing experiments internally and in the field to “satisfy all those requirements. But because the virus is really difficult to grow in the laboratory it will take anywhere from six to 18 months before we have enough data to submit to the USDA.” BF