Preparing for a “Twindemic”

Last year, more than 35 million people in the U.S. came down with the flu. They suffered symptoms like fever, body aches, a cough, and a runny nose. About 30,000 of those individuals died from serious complications caused by the illness. Scientists worry that flu season, which peaks between December and February, could be even more deadly this year. That’s because it will coincide with the coronavirus pandemic, leading to what some call a “twindemic.”

“Influenza and Covid-19 could happen at the same time this year, in the fall and winter months,” says Dr. Sumon Chakrabarti, an infectious-diseases physician from Trillium Hospital in Toronto, Canada. “Right now, we are much more prepared for Covid-19 than we were in March. But if you have a bunch of cases happening at the same time, there is the chance that hospitals could get overwhelmed with patients.” That’s why it’s important for everyone to get a yearly flu vaccine, which helps prevent people from getting infected with the influenza virus. (To learn more, check out “Battling the Flu,” Science World, November 19, 2018)

With the threat of a twindemic, there’s another good reason to get your flu shot: People who receive it may be less likely to contract Covid-19. Recently, scientists at the Radboud University Medical Center in the Netherlands studied hospital employees who got the flu shot in 2019. The researchers found that these essential workers were 39 percent less likely to become infected with the coronavirus that causes Covid-19 than their unvacccinated colleagues.

The scientists acknowledge that individuals who got their flu shot might also be more likely to follow Covid-19 prevention guidelines, like social distancing and wearing a mask. But they believe this research supports the hypothesis that vaccines that target specific diseases, like the one for the flu, might also trigger the body’s disease-fighting immune system to fight off a range of other infections—including the coronavirus.