The flu season that isn't
Thanks largely to social distancing and mask-wearing — as well as higher uptake of the flu vaccine — influenza deaths this season are almost nonexistent.
Why it matters: The drastic drop in infections of influenza and other circulating respiratory viruses has given the U.S. health care system a welcome respite at a time when COVID-19 is rampaging.
By the numbers: According to the CDC, the U.S. recorded just five flu deaths in the 52nd week of 2020, a period that usually represents the height of the influenza season.
- That is 40-fold fewer deaths than the same week in 2019, and more than 130-fold fewer deaths than during the bad flu season of 2017.
- According to data from BioFire Diagnostics, levels of nearly every common respiratory and gastrointestinal virus are currently all but undetectable.
How it works: It turns out if you drastically reduce global travel, close public workplaces and schools, and promote mask-wearing and handwashing, you'll cut off opportunities for common pathogens to spread.
- It also helps that a record number of flu vaccine doses have been shipped this season, and an estimated 53–54% of American adults had gotten a shot by the end of December, significantly higher than the same time last year.
The big picture: Historically low levels of flu and other common viruses are happening at the same time the COVID-19 pandemic in the U.S. is at its worst.
- That's not surprising: While common viruses have circulated for years and there is a base level of resistance in the population, no one had encountered SARS-CoV-2 before it emerged in China a year ago, and the virus continues to spread rapidly through the vulnerable population.
What to watch: With each week that passes with unusually low levels of flu, susceptibility to the virus will rise, potentially setting up the U.S. for a harsh rebound in the future.
- That may be what's happening in Australia, where flu cases during its winter season were virtually nonexistent, only to bounce back this December, when the flu is usually absent in the Southern Hemisphere.
The bottom line: While it's good to see fewer deaths from influenza, SARS-CoV-2 is ravaging the U.S. at an entirely different magnitude, with more Americans dying of COVID-19 last week than the entire number of flu deaths last season.