World Pork Expo: Start planning now for the fall season of influenza A in swine
Zoetis’ Dr. Micah Jansen explains how to stay ahead of this evolving virus
12 August 2025
3 minute read
By: Dr. Micah Jansen, managing technical services veterinarian with Zoetis, recently spoke to The Pig Site’s Sarah Mikesell at World Pork Expo in Des Moines, Iowa, USA, and highlighted strategies to protect against swine influenza.
Heading into the fall, influenza A for swine becomes a more persistent challenge. What is changing with flu from year to year?
I would say consistently the thing that changes with flu is the virus itself. The flu virus is exceptionally good at changing, and that makes it difficult for producers and for veterinarians because sometimes it's hard to keep up with what is circulating in the pig populations that they're looking at.
How do you help producers stay ahead of this evolving virus?
The first step is to make sure that they constantly understand what flu virus they are dealing with. Often that means doing diagnostics to understand:
- What is present in their herd?
- How does it compare to what they've dealt with in the past?
- How does it compare to what they're utilizing to vaccinate their pigs?
Early disease challenge is a big contributor to piglet mortality. How do strategies differ when protecting young pigs from influenza versus sows and gilts?
Sometimes, depending on the population that we're trying to protect, it might change our strategy and how we're vaccinating. For example, if we want to protect sows and pigs, we want to vaccinate the sows, and often that might be a whole herd vaccination that all female breeding animals in the herd receive at once. When it comes to protecting young pigs, it does help to vaccinate the sows and gilts because we reduce the virus transmission in the herd. We can also do things like administer vaccine to the sows and gilts before they farrow, and that will drive those antibodies up and the pigs will have a higher antibody level when they're weaned.
Are all vaccines created equal? How are they different?
There's a lot of variety when it comes to influenza vaccines. Some of it might be just the actual format of the vaccine. For example, FluSure XP® from Zoetis is a whole inactivated virus vaccine, which means we grow the entire whole virus and then inactivate it before we put it into the vaccine. We have four different strains of influenza that are contained in FluSure XP.
Other products might differ either in the strain that's included in the vaccine, or they might be different in the delivery of the antigen. Instead of having the whole virus, they may just have a portion of the genetic sequence.
Where can readers go to learn more?
They can visit the Zoetis website. We have resources there specific to influenza, or they can also reach out to their Zoetis representatives whether it's their sales person that they may know or even a tech services veterinarian, like me. We can collaborate with them and their herd veterinarian to develop a strategy around influenza.
Sarah Mikesell
Sarah Mikesell grew up on a five-generation family farming operation in Ohio, USA, where her family still farms. She feels extraordinarily lucky to get to do what she loves - write about livestock and crop agriculture. You can find her on LinkedIn.
