- The flu is back this winter, after an unusually mild season last year.
- Flu season, which runs from October through May, usually results in millions of infections and thousands of deaths.
- Doctors explain how COVID-19 prevention efforts have diminished flu-related deaths this year.
For nearly two years, the world has obsessively pored over news and statistics on COVID-19. While cases of COVID-19 have risen and fallen over time, we saw a pretty mild flu season last year. This year, numbers are already trending much higher.
Last fall, epidemiologists warned of an oncoming “twindemic” of COVID-19 and seasonal influenza. Now, cases of COVID-19 are exploding this winter, and there is also increased flu activity happening across the country.
It’s still flu season in the U.S., which runs from October through May, according to the Centers for Disease Control and Prevention (CDC). And like COVID-19, the flu can cause unpleasant symptoms, have lingering side effects, and even be deadly. While there were shockingly few confirmed cases of the flu last year, case counts are definitely up this year over the last. Here’s everything you need to know about the flu’s mortality rate, plus how it’s spreading this year.
How many people die from the flu each year?
The answer is slightly complicated: The CDC doesn’t have an exact count of the number of people who die from influenza each year. Instead, the federal agency develops estimates based on rates of confirmed hospitalizations from the flu.
For that reason, it’s difficult to compare flu deaths with those of COVID-19, which are actual documented deaths, says Mark Hicar, M.D., Ph.D., associate professor of infectious disease at the University at Buffalo in New York. In fact, COVID-19 deaths are being tracked by confirmed cases, “but there are still going to be numbers of unconfirmed cases so the deaths from COVID-19 are probably higher then what is being reported,” Dr. Hicar says. So far, nearly 51 million Americans have been infected with COVID-19, resulting in more than more than 803,000 deaths, per the latest data from the CDC.
Compared to the 2019-2020 flu season, for example, the CDC estimated that more than 38 million became sick with influenza, leading to 400,000 hospitalizations and 22,000 deaths. That’s slightly lower than the 2018-2019 season (34,200 deaths) and significantly less than the 2017-2018 season (61,000 deaths).
Why can the flu be so deadly?
The flu is a contagious respiratory illness that’s caused by influenza viruses that infect the nose, throat, and lungs, the CDC explains. There are two main types—influenza A and B—that regularly circulate each year. While plenty of people get the flu, have a miserable period of illness, and then recover, others can actually die of the virus.
“Influenza is a respiratory virus that has the ability to kill at a very high rate, even in the modern era,” says infectious disease expert Amesh A. Adalja, M.D., a senior scholar at the Johns Hopkins Center for Health Security. “In severe cases, it causes pneumonia that can be complicated with a secondary bacterial infection.”
Other possible serious complications triggered by the flu, per the CDC, can include:
- inflammation of the heart (myocarditis)
- inflammation of the brain (encephalitis)
- inflammation of the muscle tissues (myositis, rhabdomyolysis)
- multi-organ failure (like respiratory and kidney failure)
- Sepsis, a life-threatening response to an infection
Who is most at risk of dying from the flu?
The CDC has a list of people who are at a higher-than-average risk of getting seriously ill with the flu and even dying of it:
- Adults 65 and up
- Pregnant people
- Young children
- Young children with neurological disease
Certain health conditions can also put people at a higher risk of severe flu, the CDC says, including:
- Heart disease and stroke
- Chronic kidney disease
“The flu tends to kill people at the extremes of age: very young and very old,” Dr. Adalja says. “The very young and the old may have very low physiological reserve when it comes to fighting influenza off.”
How many total flu-related deaths are expected for the 2021-2022 season?
The numbers are higher than last year, which isn’t shocking, says William Schaffner, M.D., an infectious disease specialist and professor at the Vanderbilt University School of Medicine. “People are getting out more and taking less precautions” than they did last flu season, he says.
Still, the same disease-prevention practices we’ve mastered to slow the spread of COVID-19 can also impact impacted flu transmission, says David Cennimo, M.D., assistant professor of medicine-pediatrics infectious disease at Rutgers New Jersey Medical School. While flu rates are higher than last year’s extraordinarily low numbers, they’re still lower than your average flu season. That’s “a byproduct” of efforts like masking, hand-washing, and social distancing, Dr. Cennimo says.
Flu deaths have also “depend on how many people get the flu vaccine,” says Richard Watkins, M.D., infectious disease physician and professor of medicine at the Northeast Ohio Medical University. Millions more doses than usual were distributed this winter, hinting at a higher rate of flu vaccination among the COVID-19 vaccine rollout.
How to protect yourself from the flu
If you haven’t already gotten your flu shot, Dr. Schaffner recommends doing it ASAP, as it takes time to build immunity. Flu season continues through May, after all. “It’s still not too late to get vaccinated,” he says.
The following precautions can also protect you from the flu:
- Avoid close contact with people who are sick.
- Wash your hands often with soap and water for at least 20 seconds.
- If soap and water aren’t available, use an alcohol-based hand sanitizer.
- Avoid touching your eyes, nose, and mouth.
- Clean and disinfect high-touch surfaces and objects.
Methods that help prevent the spread of COVID-19, like wearing a mask when you’re around people who aren’t in your household and practicing social distancing, can also help you prevent a cold, flu, and other respiratory illnesses. “The flu’s impact on deaths in the U.S. may well be blunted by our behaviors in trying to avoid COVID-19,” Dr. Schaffner says.
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