A novel approach for vaccinating sows and gilts offers a new, potentially safe, effective method for protecting both the mother pig and her piglets from the disease.
Researchers with VIDO-InterVac are examining a new method of vaccination, which involves administering vaccines directly into the uterus of the pig during artificial insemination.
Dr. Heather Wilson, a research scientist with VIDO-InterVac, the Vaccine and Infectious Disease Organization at the University of Saskatchewan, said they developed the concept to fill a specific need.
“Most of the diseases that are important for the pig industry impact reproduction or they impact the newborn piglets,” said Dr. Wilson. “Why not try to develop a vaccine that targets the uterus, the site for reproduction; if we immunize the moms, then she can deliver passive immunity to the babies once they’re born through her colostrum. Another crucial point is that we wanted to work within current husbandry practices. The last thing is to ask producers to round up their animals, and change their workday to accommodate a new vaccination schedule.”
They realized they inseminate artificially 90 percent of their gilts and sows using AI. During this period, they undergo what’s called a lordosis response which means the sows will freeze up for about 10 minutes. So it’s a very safe time to immunize them, and it’s a time that is happening anyway, she said.
“You’re inseminating, why not administer the vaccine directly to the uterus along with the semen and go from there,” said Wilson. “Initial results suggest vaccines administered to the uterus provide a strong antibody response, and there appears to be no negative effects on the semen, the piglets or their mothers.”
She said VIDO-InterVac first did the work, but Dr. Murray Pettit and his team at the Prairie Swine Center are doing some at their facility. It’s going to take a couple of years obviously to get through all the trials and to try everything.

“If we can have it out as a barn setting, it’s more realistically following what’s going to happen in the field. That can only be a good thing,” she said. “The first steps in the project, to see if you can target a uterus to get a strong immune response. “We used rabbits first just as a cheaper model and found that when we administer a vaccine into a rabbit uterus, it gets a solid antibody response. The response isn’t to the uterus but found in the vagina, in the lung, which means it is at a distal site, so not just the site of immunization. Of course, we get blood antibodies produced, and this excited us much because this occurred after only a single dose, which is a bit unusual if you know mucosal vaccines.”
Dr. Wilson said the next step is to keep to vaccinating gilts one time, perhaps twice, so at different parodies, and then actually perform a challenge study.
“If we vaccinate and challenge with an infectious disease to show a vaccine administered into the uterus is very protective, confirm that semen and fertility aren’t affected, the kinetics of the growth of the piglets is perfectly fine, that is great,” she said. “Just to advance into challenge studies would be the next thing.”
Dr. Wilson said it’ll take a couple of years to answer all these questions.
“We’ll give talks at producer meetings such as Sask Pork Symposium, Banff Pork, that kind of thing so that we can talk directly to the producers. We’ll be publishing in academic journals, hopefully, present the work at conferences so that veterinarians can see as well as other PhDs and scientists,” she said. “The information will certainly be put onto our website at vido.org, and communicated to producers through help with our industry liaison person at VIDO-InterVac and hopefully with more interviews such as this one.”
“Anytime we can remove a needle is a good thing for the safety of the barn personnel. If we can show that administering a vaccine during artificial insemination, delivering it to the uterus, gives an outstanding immune response,” said Wilson. “We can show people how safe it is, especially if the animals undergo that freezing response. Then we would hope to communicate that to the veterinarians, to the pig barns, and maybe change the whole way that vaccination takes place during reproductive infectious diseases. Initially, we are targeting the pig industry, but we would like to look at any other models, any other animals that use AI. That could be in the cattle, beef, dairy, and definitely, turkey’s use quite a bit of AI. We’d look at expanding into those livestock species as well.” •
— By Harry Siemens