PITTSBURGH — Health experts are calling it a potential "twindemic".
First, rising cases of COVID-19 fueled by the Delta variant and now with winter on the horizon, influenza is likely on its way.
Experts warn those flu cases may be particularly serious.
"Much of our immunity to influenza comes from people who had it last year and a lot of that is gone," warned Dr. Mark Roberts of the University of Pittsburgh Graduate School of Public Health.
Dr. Roberts and his colleagues ran two separate computer analyses.
"The likelihood is that there could be 20% or 30% more cases," he said of the 2021-2022 flu season.
"The mathematical model that we use said as many as 400,000 extra hospitalizations."
Experts are concerned flu could crush healthcare systems that are already straining to keep up with the demands of COVID.
They say the best way to avoid a worst-case scenario is a flu vaccine.
"Even though the flu vaccine is not as effective as the COVID vaccine is, it is still effective at preventing serious disease, and it's more effective than not," he explained.
According to one model, if 75% of Americans get vaccinated against the flu as compared to 50% in a typical year, many of those additional hospitalizations could be avoided.
Dr. Roberts says for people who have been immunized against COVID, there is no concern that the flu shot would cause an interaction.
He says you can get both a COVID booster and a flu shot together.
Last year was almost flu-free
In 2020-2021, for the first time in recent history, the CDC reported almost no cases of flu.
And of the 818,939 specimens tested for influenza from late September 2020 through late May 2021, only 0.2% came back positive, compared to 26% to 30% during a normal season.
Check current CDC flu reports by clicking here.
The CDC says having lower than normal numbers recorded last flu season is more than likely due to COVID-19 precautions such as wearing face masks, social distancing and people staying home from work and school.
In addition, about 52% of American adults got the flu shot last year.
With coronavirus cases spiking, the CDC is again recommending wearing face masks indoors, social distancing and avoiding crowds, even for those fully vaccinated against COVID-19.