Apr 30, 2020 - Science

How to avoid dueling outbreaks of coronavirus and flu

Illustration of two hands in medical gloves engaged in a thumb war

Illustration: Sarah Grillo/Axios

The seasonal return of influenza in the fall and winter is set to further complicate the ongoing response to the COVID-19 pandemic — but it doesn't have to be a double disaster.

The big picture: Influenza kills tens of thousands of Americans each year, with symptoms similar to COVID-19 that make it easy to mistake one for the another. But the flu has a vaccine — and a dedicated plan to increase vaccination rates could avert a magnified disease crisis.

The same social distancing put in place to slow the spread of COVID-19 also seems to have brought an early end to this year's flu season. If those efforts continue into the fall and winter, "it's likely to help us somewhat with the flu as well," says William Schaffner, an infectious disease specialist at Vanderbilt University Medical Center.

The catch: If social distancing in some form remains in place — as many experts believe it will — it may prove difficult to distribute the flu vaccine.

  • Health officials have reported drastic drops in childhood immunization rates this spring, with uptake for some vaccines falling by more than 70%. That's due to many doctor's offices temporarily closing because of COVID-19, along with fears from parents that bringing children to open health clinics could expose them to the coronavirus.
  • "As states look to reopen their economies, it is crucial that they open up healthcare services as well for vaccinations," says Besser.

Regardless, it's almost certain COVID-19 and flu will be circulating at the same time this fall, says Richard Besser, CEO of the Robert Wood Johnson Foundation. "That makes it important to plan now for how we will deal with both outbreaks simultaneously."

  • The flu on its own puts tremendous pressure on hospitals each year — last year's season resulted in nearly 500,000 hospitalizations, especially among the same elderly cohort that is most at risk from COVID-19. "We must use this time to prepare for that," says Tom Frieden, former U.S. Centers for Disease Control and Prevention director and president and CEO of Resolve to Save Lives.
  • The most important step Americans can take is to ensure they get vaccinated for the flu this year, which will offer them some individual protection and reduce the strain on the health care system.

Background: Each year from roughly November to April, circulating influenza strains infect people in the Northern Hemisphere. (The flu season timing is reversed in the Southern Hemisphere.)

  • A new flu vaccine is produced each season because flu strains mutate, but the vaccine is never a perfect match for the virus. This season's flu vaccine was 45% effective, according to an interim report from the CDC, on the low end of its usual range.
  • In part because the seasonal flu vaccine is imperfect, and in part because less than half of American adults get vaccinated, influenza takes a major toll on health — the CDC estimates more than 35 million people were sickened and more than 34,000 died in the 2018-19 season.

What to watch: Assuming an effective COVID-19 vaccine can be developed, the world will need to produce hundreds of millions of doses, if not far more.

  • Some experts are worried vaccine manufacturers may hit production limits that force them to choose between a new COVID-19 vaccine and existing vaccines for diseases like the flu.

The bottom line: The annual misery of the flu season is the closest thing medicine has to a sure thing. Doctors will need to be on guard — and Americans will need to get their flu shot — to ensure that influenza doesn't make a bad COVID-19 pandemic even worse.


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