Flu season is coming, and it could be a doozy this year.

After two winters of taking a backseat to COVID-19, the flu is something to be worried about again, thanks to what The Atlantic’s Katherine J. Wu is calling “an unnerving flu season in the Southern Hemisphere” that saw countries like Australia hit with the highest number of flu cases in years over that country’s just-ended winter.

“After skipping two seasons in the Southern Hemisphere, flu spent 2022 hopping across the planet’s lower half with more fervor than it’s had since the COVID crisis began. And of the three years of the pandemic that have played out so far, this one is previewing the strongest signs yet of a rough flu season ahead,” Wu writes.

Is it too soon to get a flu shot? 3 things you need to know

Flu was pretty much absent during the first winter of the COVID-19 pandemic as people masked up and took other precautions to prevent its spread, steps that also helped stop influenza in its tracks. Last year, some flu cases emerged and lingered into the spring, but a severe outbreak never came.

This year might be very different north of the equator.

“It’s been a really, really bad influenza season down in Australia. We have potential for a pretty bad (season),” Dr. Tamara Sheffield, medical director of preventative medicine for Intermountain Healthcare, said recently, stressing the need for Utahns to start planning for their annual flu shot.

She said there is some good news about this year’s flu vaccine.

“The nice thing is, the one that’s circulating in Australia, that made so many people sick, is in the vaccine, the current vaccine that we’re going to get. So we’re matched to what’s been running around,” Sheffield said. “That wasn’t the case last year.”

How bad will the flu season be and when should folks be vaccinated?

Timing a flu shot can be tricky, though. The rule of thumb, the doctor said, is to not get the shot more than 100 days before the flu season is expected to peak, to ensure the vaccine provides enough protection against infection when it’s needed most.

The peak usually comes in January or February, but Sheffield said it happened later last winter because the flu was pushed out for a while by the highly transmissible COVID-19 omicron variant that sent coronavirus cases spiraling to record levels at the start of the year.

When omicron cases started dropping, the doctor said, “all of a sudden, we had influenza pop up again that next month,” before another strain of omicron surfaced. Flu and COVID-19 “kind of compete with each other, of who’s going to make you sick,” she said.

The Centers for Disease Control and Prevention recommends that ideally, everyone should have a flu shot by Halloween, noting that, “For most people who need only one dose for the season, September and October are generally good times to get vaccinated.”

Flu shots can be given at the same time as the new, updated COVID-19 booster shot that’s targeted at the current versions of omicron circulating, including the dominant BA.5 subvariant. Health experts have advised getting the new COVID -19 booster, now available to anyone 12 and older, as soon as possible.

Here’s how you can get the new omicron-specific COVID-19 booster shot

Despite the dire predictions for the coming flu season, there is always the chance that it won’t be so bad.

“It’s still very possible that the flu will fizzle into mildness for the third year in a row, making experts’ gloomier suspicions welcomingly wrong,” Wu said in her article in The Atlantic. “Then again, this year is, virologically, nothing like the last.”

Asked whether Utahns might finally see an especially tough flu season, Sheffield answered, “Definitely.” Then she added, “But you can never predict flu. You don’t know when it’s going to come. You don’t know how bad it’s going to be.”