A preventive influenza vaccine for pigs was launched in Ontario last year. Now, new data supports anecdotal evidence from the industry that the regional vaccine is making a difference in managing an increasingly virulent disease.
Piglets born to vaccinated sows showed higher average daily gain, lower mortality and fewer clinical signs of disease, according to results from a field experience study by South West Ontario Veterinary Services (South West).
Why it matters: Although only a small number of pigs die from influenza itself, the virus makes them more vulnerable to diseases like streptococcus suis, mycoplasma and Porcine Reproductive and Respiratory Syndrome (PRRS), which have high mortality rates and require costly treatments.
South West worked with Kitchener’s Gallant Custom Laboratories Inc. to develop the regional vaccine, which includes five Influenza A strains that have been most common in Ontario swine herds in the last several years.
The idea, according South West veterinarian Dr. Kevin Vilaca, came from human medicine where an annual seasonal flu shot helps protect people against the most common influenza strains likely to be prevalent that year.
“Why not apply that same principle to pigs and vaccinate sows before they get influenza instead of trying to rid a herd of the disease after an outbreak?” he says.
Influenza itself isn’t new to Ontario’s swine industry, but new strains that have emerged in recent years are much more virulent. It started in 2005 with H3N2, followed by pandemic H1N1 in 2009, and the worst so far, H1N2, which first showed up in Ontario in 2016.
Since then, influenza in Ontario has been more frequent, more serious and longer-lasting, and according to Vilaca, commercial vaccines weren’t effective as the viruses change rapidly. As well, Ontario’s dominant influenza viruses appeared to be different from those circulating in other parts of Canada and the U.S, pointing to the need for a made-in-Ontario solution.
With the collaboration of the Ontario Ministry of Agriculture, Food and Rural Affairs and the Animal Health Lab at University of Guelph, South West has developed an influenza database that includes more than 500 genetic sequences of strains isolated from Ontario swine farms to date.
This has made it possible to make some predictions about key strains and use that information to move ahead with an Ontario-focused solution.
The Canadian Food Inspection Agency granted permission for South West and Gallant to proceed with development of a regional vaccine and provided final approval for the new product in spring 2019.
Jeff Balfour of Jena Farms Inc., south of Mitchell, has welcomed the regional vaccine. With 1,100 sows, he finishes half of his pigs to market weight and sells the rest as weaners.
“Any time we can vaccinate, it reduces our drug usage, so we prefer to go that route – especially from an animal welfare perspective,” Balfour says.
He had previously tried to deal with consistent influenza flare-ups through medication before vaccinating his sows last fall, and although he didn’t notice much of a change in the sows themselves, he did in their piglets.
“We saw a remarkable difference in the piglets in the nursery after weaning. They weren’t sick or in bad shape before, but now they are a little fuller, have a nicer shine to their coat and are just better,” he says. “Flu hurts you a little bit all the time, so it’s hard to measure, but anytime you can move the average up, it’s an improvement.”
That is supported by data from South West’s most recent field experience summary that followed three batches of pigs born to vaccinated sows on a continuous flow, high health farm over a six-month period. Pigs were weaned an average of one kilogram heavier and had a 50 gram per day higher average daily gain while in the nursery.
“What’s important here is that even in a high health herd with low mortality, the pigs did better and weren’t coughing or breathing heavily,” Vilaca says, adding that a herd with significant health challenges would see even better results.
Producers interested in the influenza vaccine should contact their veterinarian.