Is a 'twindemic' on the horizon? Experts warn of brutal flu season as COVID-19 still spreads

Medical experts warn the approaching flu season could be particularly severe, renewing fears of a potential "twindemic," with COVID-19 still spreading.

In preparation, health officials are urging the public to get vaccinated against the flu as soon as possible. Here are eight things to know about the upcoming flu season and getting your annual flu shot during the pandemic:

1. After a profoundly mild flu season last year, this one might be rough.

Influenza was at record low levels last year across the United States, mostly due to masking and social distance protocols amid the pandemic.

But that means many people weren't exposed to the flu last season and didn't have the opportunity to boost their immunity. At the same time, some pandemic restrictions have been loosened or dropped, but COVID-19 is still circulating, said Dr. Jacqueline Korpics, the Cook County Department of Public Health's medical director for COVID-19.

"There is concern this will be an especially bad flu season due to loosening of mitigations, the fact that many of us were not exposed last year due to COVID mitigations and because influenza will be circulating simultaneously with COVID," she said. "So individuals could potentially get both at the same time, which could lead to more severe illness and more deaths."

The recent surge in local cases of another respiratory illness—respiratory syncytial virus or RSV—might also be a harbinger of an impending bad flu season, said Dr. Kelly Michelson, professor of pediatrics and director of the Center for Bioethics and Medical Humanities at Northwestern University's Feinberg School of Medicine.

"If flu behaves like RSV, we should prepare for lots of illness," she said.

2. Now is a good time to get the flu shot.

Ideally, everyone would be vaccinated against the flu by the end of October, according to the Centers for Disease Control and Prevention.

Korpics said September—now—is a great time to get vaccinated against influenza.

"Don't wait," she said.

Michelson agreed.

"Flu vaccines are currently available," she said. "Go get your annual flu vaccine now."

3. The COVID-19 shot and flu vaccine can be administered at the same time.

"You can get a COVID-19 vaccine and other vaccines at the same visit," the CDC says on its website. "You no longer need to wait 14 days between vaccinations."

The agency adds that side effects after COVID-19 vaccination are generally the same when given alone or with other immunizations.

"You can get (vaccines) on the same day," Korpics said. "We want you to be protected and to protect those around you who are especially vulnerable to influenza and COVID. Don't let yourself or those around you suffer from a preventable illness. Both vaccines are safe and, in general, there are few people with contraindications to either vaccine."

4. It's important to get these vaccines to protect yourself—and to help those who can't get vaccinated.

Although children under 12 can't get the COVID-19 vaccine yet, most can get immunized against the flu, and health experts say it's important to protect them against any virus possible to minimize potential illness during the pandemic.

For those over 12, it's important to get vaccinated against COVID-19 and the flu, to keep both illnesses to a minimum.

"Please get vaccinated for the flu and COVID-19—please," Michelson said. "It is important for you, for the children and for everyone."

She added that babies under 6 months old can't get flu shots, so it's important that adults and children do so to help keep infants healthy.

"So the more adults who get vaccinated, the less likely it will be for vulnerable babies under 6 months to get the flu," she said. "So another reason why everyone should get vaccinated is to help protect infants (under) 6 months old."

5. Flu vaccines are particularly important this season to keep from overwhelming hospitals.

In many parts of the country, hospitals are already overwhelmed with COVID-19 patients. The southernmost region in Illinois this week reported no available ICU beds this week, due to surging COVID-19 rates.

"We are hearing reports that people are not able to get the care they need," Michelson said. "Anything we can do to keep people out of the hospital will be helpful. This is another important reason for people to get the flu vaccine."

6. Flu vaccination rates are generally not that great.

Fewer than half of American adults typically get the flu shot each year, according to the National Foundation for Infectious Diseases. The nonprofit organization commissioned a survey last year, and found that 59% of adults polled planned to get the influenza vaccine during the 2020-2021 flu season, an increase from 52% the previous year.

Of those who were unsure or not planning to get vaccinated, 34% did not believe the flu vaccine worked well, 32% said they never got the flu, 29% were concerned about potential side effects and 22% said they were worried about catching the flu from the immunization—though that's not possible. Flu shots are made from either the inactivated virus or a single protein from the virus, and cannot cause illness, according to the CDC.

7. There's been a spotlight on vaccines—and vaccine hesitancy—during the pandemic, but experts aren't sure how this might impact flu shot uptake this season.

"I can only hope it will encourage more people to get vaccinated against influenza," Korpics said. "Influenza, like COVID, is a preventable illness due to our ability to vaccinate. As a physician, it is incredibly sad to see patients who come to the hospital and die from influenza or COVID, which could have been prevented by the vaccine."

She noted that even patients who get the flu or COVID-19 after vaccination generally have a much more mild illness and are still protected from hospitalization, severe illness and death.

Michelson said that an April study in the journal JMIR Public Health and Surveillance found that among a sample of people in the United Kingdom "COVID-19 has increased acceptance of influenza vaccination in previously eligible but unvaccinated people and has motivated substantial uptake in newly eligible people."

But she added the caveat that the United Kingdom has a different population and culture than the United States, so it's hard to forecast how many people will get the flu shot here this season.

"I really think this is hard to predict," she said. "I hope that people will realize that COVID vaccines are literally saving millions of lives every day and that flu vaccines can do the same."

8. While it's hard to tell the flu and COVID-19 apart, there are some differences in symptoms.

A stuffy nose is common with the flu but rare with COVID-19; loss of taste or smell is often associated with COVID-19 but unlikely with the flu, health experts say. But body aches, fevers, headaches and fatigue are symptoms of both viruses. Health officials advise getting tested for COVID-19 whenever symptomatic.