What is a twindemic, and how deadly could it be?

twindemic what is it coronavirus flu
Photo via Paul Swansen/Flickr (CC BY ND 2.0)
  • It’s when the coronavirus pandemic overlaps with flu season
  • Even a mild flu season can overwhelm hospitals during normal times
  • You should get your flu vaccine before the end of October

Health experts warn that Americans should prepare for a “twindemic”—or, an overlap of the annual flu season with the COVID-19 pandemic—this fall and winter. 

The term “twindemic” was popularized by the New York Times on Aug. 16, in an article that warned things could worsen in the final stretch of 2020 if Americans resist a flu vaccine.  

According to the newspaper, even a mild flu season typically overwhelms hospitals and the medical system. In the 2019-2020 flu season, the Centers for Disease Control and Prevention recorded 39 million-56 million influenza infections, up to 740,000 hospitalizations, and 24,000-62,000 flu-related deaths. That was considered a “mild” flu season. 

Combine those numbers with the thousands of COVID-19 infections recorded daily across the country, and it is easy to see how things could become dire this winter. Additionally, it’s possible to have both infections at the same time and experience more severe symptoms. 

Doctors told Health they worry about overwhelming hospitals and the challenge of distinguishing the two viral infections from one another (even Dr. Anthony Fauci, the nation’s top infectious disease expert, said he’s concerned). The flu and COVID-19 share similar symptoms—like fever, headache, cough, sore throat, muscle aches, and fatigue—but doctors treat them differently. They are also caused by different viruses. 

“Even if we have to deal with a moderate-sized flu epidemic—which all by itself can stress hospital facilities—at the same time as the pandemic, we may be in for a quite rough winter,” Dr. William Schaffner, an infectious disease specialist, told Health.

Health experts say the best way Americans can protect themselves and each other is by getting the flu vaccine as soon as it becomes available. The CDC recommends Americans get vaccinated by the end of October, but not sooner than September to optimize protection against the flu. But a national survey released at the end of September revealed that one in three parents said they would not vaccinate their child for the flu. Potentially causing more problems was that a massive surge in people getting flu vaccines had caused a shortage in China in October.

No one is certain how deadly a “twindemic” could be—though one forecaster said in late September that pandemic deaths in the U.S. could rise to 3,000 per day by December and could top 400,000 by the end of 2020, and by late October, there was worry that the U.S. was entering a third wave of the pandemic. Even by mid-November, doctors were saying that it’s not too late to get your flu shot.

But experts observed how the 2020 flu season on the other side of the world shaped up.  The Australian flu season coincides with its winter season, June through August. According to the New York Times, demand for the vaccine was much higher this year, and consequently, reported flu cases dropped by 99%. 

“Australia’s milder-than-usual flu season is likely the result of a number of factors—strong flu vaccination uptake, social distancing, but also severely decreased movement of people,” Dr. Jonathan Anderson, a spokesman for flu vaccine supplier Seqirus, told the Times

Health experts don’t believe that trend will extend to the U.S., thanks to a combination of resistance to social distancing and a distrust of vaccines. During the 2018-2019 flu season, only 45.3% of adults over the age of 18 got the vaccine, according to the newspaper. 

“We probably won’t get the same level of control of influenza as countries like Australia,” Dr. Amesh A. Adalja, a senior scholar at the Johns Hopkins Center for Health Security, told Health. “We have to prepare for a challenging flu season.”

Plus, the lack of rapid testing in the U.S. could also be a hindrance.

“My main fear is we will see cases of maybe influenza, maybe COVID, maybe some of the other respiratory viruses, and because rapid testing is not available on a widespread basis, we will be in front of the people and we won’t know what they have,’’ Dr. Julita Mir, a Boston physician, told USA Today.

The CDC and other health professionals urge everyone to get the flu vaccine annually, because immunity from the shot the year prior wears off and because the vaccine is continuously updated to cover mutated versions of the virus. 

The CDC also recommends getting the vaccine before community spread begins, which starts by the end of October. It takes two weeks after the vaccine is administered for antibodies to develop in the body and provide protection. 

Even if you believe you have a strong immune system, doctors recommend the vaccine because it prevents you from unknowingly spreading the virus to immunocompromised people and and because it could lessen the effect of a possible twindemic.  

Or as the Houston Chronicle editorial board recently wrote, “Fortunately, there is a simple way to avoid this dose of double trouble: Get a flu shot. It’s that easy. It could save thousands of lives, including your own and all those who benefit from treatment in an ICU bed you won’t need.”

On Sept. 10, Fauci continued to sound the alarm, saying, “We need to hunker down and get through this fall and winter because it’s not going to be easy … Don’t ever, ever underestimate the potential of the pandemic. And don’t try and look at the rosy side of things.”

But President Trump has done exactly that. Even after he was infected by COVID-19, he tweeted comparisons between the coronavirus and the seasonal flu and that Americans would have to learn to live with both. Even into mid-October, Trump was tweeting that COVID-19 is less lethal than the flu, a statement that is demonstrably false.

Americans can get the flu shot in most doctor’s offices, clinics, health departments, pharmacies, and college health centers. Your employer or school district might provide it, too. Check the HealthMap Vaccine Finder to see where you can get vaccinated locally. 

Sources: New York Times, CDC, Health, HeathMap Vaccine Finder

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