Flu cases have been dropping in the United States after a post-Thanksgiving peak.

But that doesn’t mean there can’t be another flu surge in the coming months. Since the winter of 1982-83, February is the month that the flu has most often hit the hardest, according to Centers for Disease Control and Prevention shows.

“There’s two things that can happen,” said Dr. Tamara Sheffield, senior medical director of preventative medicine for Intermountain Healthcare. “One is, we’ve hit our peak and we’re done for the season.”

The other possibility, she said, is that the current flu season could be another big jump in cases. That’s what happened last winter in Utah, when flu cases hit a high in December 2021 before falling in January, as the omicron variant of COVID-19 was raging through the state.

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By February, though, the flu “came right back and it was a very long influenza season through the spring,” Sheffield said, even though it turned out to be milder than what’s already happening now.

Nationwide, the CDC estimates that so far this flu season, the influenza virus has caused at least 24 million illnesses, 260,000 hospitalizations and 16,000 deaths, including five children.

There’s been 79 pediatric flu deaths reported in the U.S. this season, a number Sheffield said is “shocking,” especially since there were almost none at the height of the COVID-19 pandemic. The flu typically claims more than 100 children nationwide each season.

Cumulative hospitalizations for the first week of January were the highest for that time period since 2010-11, the CDC said, although still lower than end-of-season hospitalization rates for all but four of those flu seasons before the COVID-19 pandemic.

The spread of flu as well as other viruses, including RSV or respiratory syncytial virus, were curbed significantly by masking, social distancing and other measures taken during the COVID-19 pandemic that began in March 2020.

With many people no longer practicing pandemic precautions, the seasons for both the flu and RSV started earlier than usual, with cases filling hospitals already bracing for a possible COVID-19 surge.

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But the country’s weekly case counts have been going down since early December, according to the CDC, which says in its latest update that “seasonal influenza activity continues but is declining in most areas.”

That’s the situation in Utah, where Intermountain Healthcare’s GermWatch website says there’s high activity for influenza throughout the state except for in Grand and San Juan counties, but the virus is decreasing in the state.

In the last week, Sheffield said Intermountain Healthcare facilities throughout Utah recorded 151 flu cases among people who tested positive for the virus after seeking medical care.

That’s about a third of what the region’s largest health care provider saw in Utah the previous week, and a “dramatic decline” from a high of more than 1,100 flu cases the week before Christmas, she said.

The time off many people including school children had over the holidays may be a factor in the slowing spread of the flu, she said, adding it can be harder to keep passing around a virus once there’s been a break in routines.

The latest omicron subvariant, XBB.1.5, also known as “Kraken,” may also have a role, Sheffield said. Believed to be the most transmissible version of COVID-19 yet, she said the subvariant could push out the flu just as the original omicron did last January.

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The CDC continues to recommend that everyone 6 months and older get a flu shot, but the federal agency’s data shows more than 2.5 million fewer doses of influenza vaccine had been distributed as of the end of 2022 compared to a year earlier.

CNN reported in mid-December that only about 40% of adults and 46% of children had gotten this season’s flu shot despite climbing cases and warnings for months that the U.S. faced a “tripledemic” of flu, RSV and COVID-19 cases.

Utahns were slow to get their flu shots in the fall, Sheffield said, blaming warmer than normal temperatures. Cold weather is usually the cue that it’s time for a flu vaccine, she said, estimated 15% to 20% fewer people have gotten the shots this season.

“It’s not too late to do it because we could see another peak, just like we did last year,” the doctor said, describing the decline in cases as “telling us we’ve got a reprieve. It’s possible we won’t see a resurgence but that didn’t happen last year.”