This flu season wasn’t pleasant. In fact, at times it has felt like everyone around us had either had it or knew someone close to them who got it. Sometimes it wasn’t even just one strain that people got, but two of the three that were going around.
While this season was highly contagious, it wasn’t considered a pandemic, just an epidemic, says Spencer Fox, a graduate student of computational biology at the University of Texas. “This seasonal flu was large because it was roughly the same flu subtype, but due to mutations and a variety of different factors, it became more transmittable,” Fox says. He’s been crunching numbers to see what trends since 1889 can be discovered when it comes to flu.
Specifically, he’s been looking at the 1918 pandemic, which celebrated its 100th birthday this week.
The 1918 virus, he says, was something new to humans, which is why doctors didn’t know how to fight it and why the number of deaths was so high. It’s estimated that that flu killed more than the number of people killed during World War I and World War II combined, he says.
World War I also helped spread the disease as large movements of people traveled across continents to fight in the war. It was also a mutation of three different types of flu: ones that started from bird, horse and swine. “It was a very novel virus,” Fox says. “It was a perfect storm to spread.”
Flu viruses tend to start in livestock and then become transmittable to humans. That’s why scientists become so interested in the avian flu viruses that emerge from Southeast Asia. They are looking for the next pandemic that will go from livestock to humans. For some reason, that area of the world appears to be a hotbed for new viruses, Fox says.Researchers aren’t sure why except that it might have to do with the amount of livestock encountered by a large percentage of that population. “For some biological reason, it has tended to be a source for flu diversity,” Fox says. “Viruses are spreading and mutating everywhere, but that’s where mutations are being sourced into the rest of the world. The ones that are occurring there tend to be dominate.”
Fox says we have experienced a pandemic in our lifetime. The 2009 swine flu was one, and it didn’t follow the typical pattern of emerging from Asia. It went from livestock in Mexico to humans in the rest of the world very quickly. Like all pandemic flues, it was new.
It also followed the typical pattern that many people don’t think about when it comes to flu. It started in spring with a second large wave in fall. We think of flu as a winter disease, which is true for the seasonal disease, like the one we have experienced this year. A true pandemic tends to emerge in spring, though. It’s a pattern that Fox found in his research looking at newspapers as well as journals from army generals who described strange illnesses infecting their troops.
The seasonal flu might actually be protecting people from a pandemic flu during the winter months, but when the immunity wears off a few weeks or a month after the seasonal flu has hit, a pandemic flu could emerge.
The swine flu of 2009 gives us some hope that we won’t experience another pandemic like 1918. Within five months of the swine flu hitting, a vaccine had been developed. We also had thought that with a pandemic no one would be immune, yet, in 2009 researchers found that not everyone exposed got the swine flu that year. This was also true with the Ebola outbreak of 2014.
One theory is that the flu virus that you are first exposed to tends to have give you some additional protection to that type of virus. “The things we don’t know yet is how that influences your chances of getting or transmitting the flu as far as strength and duration,” Fox says.
We also now have medical advances that can prevent the death toll from rising. Most flu deaths come from secondary infections. Antibiotics help to prevent those. With a true pandemic, we also might do things like shut down schools to stop the spread, start a hand-washing campaign, and wear face masks.
We also now have a flu vaccine, which even though not always as effective as we want every year, it does help diminish the amount of flu cases and seriousness of the cases. We also have antiviral drugs that also help diminish the strength of the flu.