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What to watch out for this flu season as omicron sweeps across the U.S.

Just as omicron is sweeping the U.S., there's another virus to watch out for: the flu. (Peter Hamlin/AP Illustration)
Just as omicron is sweeping the U.S., there's another virus to watch out for: the flu. (Peter Hamlin/AP Illustration)

As omicron sweeps across the U.S., there’s another virus Americans need to watch out for.

A bad flu season could claim more than 50,000 lives, according to the Centers for Disease Control and Prevention. And researchers say there’s reason to be concerned this year.

What to expect this flu season

Last year, the flu didn’t circulate because of social distancing, mask-wearing and international travel hitting an all-time low, says Scott Hensley, a professor of microbiology at the University of Pennsylvania who led a study into this year’s flu vaccine. That means immunity is low among the population this flu season as people are gathering again.

“In some ways, we’re kind of sitting ducks right now,” he says. “It’s certainly a good thing that flu didn’t circulate over the last two years. But what we’re left with are very low levels of immunity in many of us.”

Is it worth getting the flu shot?

This year’s flu vaccine doesn’t match the dominant strain, but Hensley encourages Americans to get the shot anyway.

Omicron is teaching people about antigenic drift, the process in which viruses change parts of themselves to evade human immune responses, he says.

What’s happening now with omicron happens with the flu every year. This year, there has been a major antigenic drift in the H3N2 variant of the flu, he says.

“Flu is a virus that is constantly changing. It’s sort of a master shapeshifter,” Hensley says. “And many times these changes are in the regions of viruses that are specifically targeted by human antibodies.

For both omicron and the flu, Hensley says to get vaccinated regardless of this antigenic drift.

“Even in years where we have these antigenic mismatches, what we see is incredibly good protection against severe disease and death,” he says.

Breakthrough omicron infections in vaccinated people display why folks should still get the shot, he says.

“Across the board, what we see are with these omicron infections, individuals that are vaccinated do not end up in the hospital,” he says. “That is almost certainly how it will end up this year with flu as well.”

Assessing the threat of a twin-demic

Flu season is picking up as omicron is breaking records for new daily infections. Hospitals are starting to get overwhelmed and a continued rise in flu cases could put more pressure on our strained health care system, Hensley says.

This year, the northern hemisphere is on track for a regular flu season — but experts like Hensley fear it could become severe because of the lack of population immunity. And he hopes omicron will decline as fast as it spiked, which other countries like South Africa have seen, but it’s not a guarantee.

“It seems to me that we are really in what I think might be the last days of the pandemic right now,” he says. “I think if we can just hold on for a few more months as a country, the worst may be over.”


Samantha Raphelson produced this interview and edited it for broadcast with Tinku Ray. Allison Hagan adapted it for the web.

This article was originally published on WBUR.org.

Copyright 2022 NPR. To see more, visit https://www.npr.org.