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Experts warn of a ‘twindemic’ of both flu and COVID-19 this upcoming cold season. Bryan R. Smith/AFP/Getty Images
  • Although there was very little flu activity last year, experts are concerned that the 2021–2022 flu season may be more difficult.
  • The relaxation of pandemic safety measures that also inhibited the spread of other respiratory viruses, such as influenza, may encourage flu infections.
  • Experts know little about treating people who have COVID-19 and the flu at the same time, but there is reason to think that it might lead to more severe outcomes.

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As we enter this year’s flu season, experts are strongly encouraging people to get vaccinated against influenza. There are reasons to anticipate a difficult flu season occurring alongside the ongoing COVID-19 pandemic. Such a “twindemic” could lead to more severe illnesses and a higher death rate.

Although COVID-19 vaccinations make COVID-19 more survivable, medical professionals are concerned about the potential amplifying effect of a simultaneous flu infection.

Infectious disease and international health expert Dr. Patrick E. H. Jackson of the University of Virginia told Medical News Today: “There have been relatively few studies of COVID-19 and influenza co-infection in humans. However, there is some data to suggest that outcomes could be worse if a patient has both viruses at the same time. Co-infection would also complicate treatment for hospitalized patients.”

“Steroids are a mainstay of COVID-19 treatment in patients who need supplemental oxygen, but prior research indicates that steroids can actually increase mortality in influenza infection. It would be a challenge to figure out how best to manage [people with both infections].”

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Although experts were concerned about a possible twindemic last year, the 2020–2021 flu season was unusually quiet, with the number of cases lower than expected. The Centers for Disease Control and Prevention (CDC) report that in the United States, there were fewer confirmed cases of hospitalization due to flu than in any other year since the collection of such data began in 2005.

As the flu — like COVID-19 — is a respiratory disease, experts suspect that the prevention measures that people took to avoid SARS-CoV-2 infections also proved effective in preventing the flu.

Wearing masks, practicing physical distancing, washing the hands regularly, disinfecting surfaces, reducing travel, and closing schools all served to limit the flu’s ability to infect people.

However, the relaxation of such mitigation measures in many places in the U.S. means that the environment is now becoming more inviting to non-COVID-19 respiratory diseases.

There is already a surge in cases of respiratory syncytial virus (RSV) that experts fear is a foreshadowing of a difficult flu season.

Dr. Jackson said:

“We saw an extremely low level of influenza last year, which is fantastic. However, that means that there are fewer people in the population that are relatively protected due to natural infection, and the virus may have an easier time spreading among the unvaccinated. On a population level, both vaccinated people and people who have immunity after having recovered from previous infections help to limit the spread of the virus.”

The best way to avoid serious health consequences is to be vaccinated against COVID-19 and to get a flu shot as soon as possible.

According to the CDC, you can safely get both a COVID-19 vaccination and a flu shot at the same time.

Getting vaccinated for both illnesses is the best way to protect other people, particularly children too young to get a COVID-19 vaccine and older people.

Children older than 6 months can get a flu shot, which should help them avoid at least one-half of the twindemic, should it occur.

Dr. Jackson said that it would also be advisable to continue some pandemic habits:

“Some practices — like washing your hands frequently and avoiding exposing other people when you’re feeling ill — just make good sense and should continue indefinitely. I also think that wearing a mask in public when rates of influenza or COVID-19 are high continues to be a good idea — particularly for medically vulnerable people.”

Another concern is that adding flu hospitalizations to the COVID-19 cases currently overwhelming many hospitals would exacerbate what is already verging on a critical shortage of hospital beds for anyone who requires hospitalization for any reason.

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