Why flu shots are really important this year

It’s officially flu season, which means sniffles, coughs, fevers, and more. But this flu season is different because of the pandemic, and the continued circulation of the coronavirus.

Last year’s flu season was much lighter than usual, because of social distancing and mask wearing. Typically, millions of people are affected by the flu every year — and many die. The 2019-2020 flu season killed about 22,000 people in the United States, according to the Centers for Disease Control and Prevention. By comparison, during the 2020-2021 flu season it was about 700 people, Scientific American reports.

The low circulation of influenza last year caused the population to be what doctors call immunologically naive. Dr. Scott Hensley, a professor of microbiology at the University of Pennsylvania, explained that specifically in the case of influenza, many of us do not have robust immune responses because we have not been exposed to or infected with these viruses in quite some time.

“We’re not sure if the viruses will spread widely this year, but we’re afraid that once the viruses start spreading … that they will start spreading very widely. And that’s because so many of us have not seen these viruses in over a year-and-a-half,” Hensley said.

In addition, many families have missed doctor visits throughout the pandemic. That means missing the additional immunity that comes from the typical annual flu shot in children and adults alike, said Dr. Lori Handy, a pediatric infectious disease physician at Children’s Hospital of Philadelphia.

The lack of immunity has made this year’s flu season very unpredictable, she said.

“Typically, we see the flu season onset kind of November-December. It’s always a little bit challenging to predict, and then lasts potentially four to five months. All of that is now actually unpredictable, and for that reason, we are essentially informing families to prepare for the worst,” Handy said.

So how can we increase immunity among ourselves so that the worst never happens? The easiest way, Hensely and Handy agreed, is to get vaccinated.

“What the vaccine does is it gives your immune system the opportunity to see a version of the virus that won’t make you sick, so that it gets practice with fighting the virus. That means that when you actually are faced with the true live virus, your immune system is ready to go. It recognizes that it knows what to do,” Handy said.

Many people may think: But I’m healthy, why do I need to get a vaccine?

Handy said everyone should be vaccinated to minimize the impact of the flu on those we interact with and our community, as well as ourselves.

“Think about all the children born over the last year-and-a-half,” Hensley said. “Influenza has not circulated in the United States very widely, so most children who have been born over the last year and a half have no immunity to flu unless they’ve gotten a flu vaccine. And that’s a very important population that we worry about — these young children who have never seen the flu before. There are likely many, many more immunologically naive children this year than in previous years.”

Doctors are continuing to emphasize that, after almost two years of the pandemic, their offices are safer than ever — and that, especially if you missed appointments during this time, it is never too late to catch up.

The flu vaccine is also available at most local pharmacies, and often no appointments are necessary — you just walk in and get the shot.

Editor’s note: In a previous version of this story, Dr. Lori Handy’s name was misspelled. It has been corrected.