- Pig populations carry important data on future flu trends because they can be infected by both bird flu and human flu.
- By swabbing pigs’ noses, researchers are able to predict flu strains that may pose a threat to human health.
- Creating effective flu vaccines is a challenge because they need to be developed months before they’re administered.
- The annual flu vaccine is the best bet against getting sick.
Predicting the next influenza (flu) pandemic is an ongoing task, carried out by researchers around the globe.
Some of the most valuable data, though, comes from a place that may seem a bit unexpected: the pigs at county fairs.
For the past decade, researchers from Ohio State University’s College of Veterinary Medicine have used fair season to travel to local fairs and take swabs from the noses of swine.
This ongoing project was instituted after the 2009 flu pandemic that hospitalized more than a quarter million people in the United States, killing 12,000.
“In 2009, there was very little surveillance being done in the pig populations, and then we had the 2009 pandemic occur,” said Andrew Bowman, DVM, a research leader on the project and an associate professor of veterinary preventive medicine at the university.
“The virus came out of pigs, so there was an awful lot of interest in having better surveillance in the pig population,” he said.
The data gathered can serve as an early warning of flu strains that could be harmful to humans.
That, in turn, helps guide international health organizations as they develop their annual flu vaccines.
Dr. William Schaffner, a professor of preventive medicine health policy and professor in Vanderbilt University’s division of infectious diseases in Tennessee, told Healthline that pigs are important when it comes to predicting future flu outbreaks.
“There are many influenza viruses in animals, particularly birds. Sometimes, those bird viruses can get together with human viruses and exchange genes to create new influenza viral strains,” he said. “The place this mixing often occurs between bird flu and human flu is in swine because that animal happens to be susceptible to both bird flu and human flu strains.”
Schaffner says pigs can be seen as a living test tube in which two different flu strains can comingle, exchange genes, and possibly create a new flu strain that could be harmful to humans.
Often, the first humans to be infected with these new flu strains are people who work closely with animals.
When researchers detect a new strain of interest in the pig population, they pass that knowledge along the pipeline.
“We’ll share it with colleagues within the flu community, the CDC [Centers for Disease Control and Prevention] being one of them, along with other researchers, so that they can characterize them through multiple pathways,” Bowman told Healthline. “Various groups around the world might characterize different pieces and parts of that virus and do various tests to determine what its potential is to threaten human health.”
Ongoing flu surveillance, whether it’s in human or animal populations, is a necessity because influenza is ever-changing.
This necessitates an annual vaccine that will be effective against whatever the current strain is.
Flu season encompasses the winter months – roughly November through March in the Northern Hemisphere. It’s May to September in the Southern Hemisphere.
Coordinating effective vaccines for both hemispheres requires international cooperation — especially considering that the flu vaccine has to be decided on months before it’s administered.
“The influenza virus is very wily. It likes to change. And so we have to predict what will be happening six to nine months in the future because it takes that long to develop the vaccine,” Schaffner said. “Sometimes we’re right on target. Sometimes we’re a little off target because the influenza virus has changed during that interval.”
Schaffner said that researchers compensate for the unpredictability of the virus by creating vaccines that target various strains.
“We don’t really make one influenza vaccine. We make one that protects against either three or four different viral strains. The vaccine is really not a rifle — it’s more like a shotgun,” he said.
The flu vaccine is the best way to protect human populations against the flu. Despite this, less than 50 percent of people in the United States have gotten their flu shots in recent years.
While experts acknowledge that the flu vaccine is imperfect due to the adaptable nature of the virus, they say it’s still the best protection we have.
“Even if you get the vaccine and then get flu, the important thing is you’re likely to have a less severe infection,” Schaffner said. “That’s huge and hugely under-appreciated. You’re less likely to get the complications of pneumonia, be hospitalized, and to die.”
Because older people tend to bear the brunt of the most severe complications of influenza, it’s especially important that they get vaccinated.
To avoid the serious complications that the flu can bring, it’s crucial not to just get vaccinated, but to also to seek medical attention if you do get sick, Schaffner said.
“There are now antiviral medications, Tamiflu being one of them, that can shorten the duration of illness and make it less severe,” he explained. “Don’t try to tough it out. The longer you wait, the less effective the treatment. If you do get sick, medication is available.”