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SciCheck’s COVID-19/Vaccination Project

Fewer Cases of Flu Due to Pandemic Precautions, Contrary to Viral Claim

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SciCheck Digest

Public health organizations have explained that the reason there were far fewer cases of the flu in 2020 and 2021 was likely due to measures adopted to slow the spread of the virus that causes COVID-19, such as handwashing and social distancing. But a post on social media has spread the false claim that the dip in flu cases suggests that COVID-19 was a hoax.

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Measures adopted to slow the spread of COVID-19 — such as wearing masks, keeping six feet apart, washing hands frequently and staying home — also slowed the spread of viruses that cause the flu.

That’s likely the reason that recorded cases of influenza dropped dramatically in 2020 and 2021, as explained by the U.S. Centers for Disease Control and Prevention, the World Health Organization, and many other researchers and scientists.

The flu is caused by influenza viruses that spread mostly through respiratory droplets, similar to the way the virus that causes COVID-19 spreads. Since the 2012-2013 flu season, the average number of flu cases in the U.S. has been around 30 million each year with roughly about 40,000 deaths, according to the CDC, which did not give estimates for the 2020-2021 season because of the low rates of infection.

But a post has gone viral on social media showing a graph from the WHO that demonstrates the dip in cases of the flu. The post includes text that references a well-worn but false claim that COVID-19 was a hoax, saying, “One of the greatest mysteries of COVID-19: Where did the flu go in 2020 and 2021?”

Social media users responded with comments such as, “Pretty much they repackaged that year’s flu strain as the rona & took away your civil liberties & destroyed the lives and businesses of thousands, if not millions of people.”

The post originated on Twitter, where it has amassed more than 7 million views, according to the site, and elicited a comment — “good question” — from Twitter CEO Elon Musk. It then spread as a screenshot meme to other platforms, including Facebook and Instagram, where it generated such inaccurate comments as “COVID is basically the influenza Flu.”

We’ve already addressed similar claims that have spun the falsehood that cases of the flu were wrongly counted as or confused with COVID-19.

A WHO spokesperson told us in an email on April 12 that the current claim is also “not accurate,” adding, “the surveillance systems/testing for the two are entirely different.”

That’s because the flu and COVID-19 are different illnesses caused by different viruses. As we said, the flu is caused by various types of influenza viruses. COVID-19, however, is caused by a specific type of coronavirus that was first identified at the end of 2019 — SARS-CoV-2. That virus spreads more easily than viruses that cause the flu, and COVID-19 has killed 1.1 million people in the U.S. since it emerged just over three years ago, which dwarfs the annual average of roughly 40,000 killed by the flu.

COVID-19 killed more than 260,000 people in the U.S. in 2022, according to the CDC. In 2021 it killed more than 470,000 and in 2020 it killed more than 354,000, making it the third-leading cause of death in both years — behind heart disease and cancer — according to the National Institutes of Health. It’s likely to be the third leading cause of death again in 2022, according to the Kaiser Family Foundation, although official figures haven’t yet been released.

The WHO spokesperson also reiterated the point that’s been made widely by public health organizations and scientists for years: “One of the postulated reasons for the low levels of influenza activity was the effect of lockdowns and travel restrictions during that period.”

In fact, the level of recorded influenza cases for one strain of flu virus was so low in that period that researchers thought it may have disappeared entirely.

So, it’s wrong to suggest that the dip in recorded cases of the flu during the pandemic is a mystery or that COVID-19 is a hoax. The reduction in flu cases isn’t a mystery, and it’s been explained as the result of widely adopted measures that affect the spread of viruses.

Editor’s note: SciCheck’s articles providing accurate health information and correcting health misinformation are made possible by a grant from the Robert Wood Johnson Foundation. The foundation has no control over FactCheck.org’s editorial decisions, and the views expressed in our articles do not necessarily reflect the views of the foundation.


Centers for Disease Control and Prevention. Coronavirus Disease 2019 (COVID-19) — How to Protect Yourself & Others. Archived 22 Oct 2020.

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