There's plenty of misinformation circulating about COVID-19 and the virus that causes it. Some is deliberate — disinformation designed to mislead. But most is simply mistaken, though it can be every bit as wrong and just as dangerous.

A study that traced the spread of one mistaken story offers a case study in how misinformation can take hold. Earlier this year, a story made its way through Europe that ibuprofen was harmful to people with COVID-19. It had no basis in fact. A close look at how this happened just might lead you to question who is a reliable source of information when it comes to COVID-19, and that might not be a bad thing.

In France, the media generally reproduced the Minister's tweet without fact checking, adding an extra layer of credibility to it. Yet nobody took the story seriously in Germany.

The message spread chiefly because of the involvement of the French Minister of Health, a person many would take to be a reliable source of COVID-related information. In March, he warned in a tweet that taking ibuprofen could make COVID-19 symptoms worse and that people with a fever should take paracetamol (acetaminophen) instead.

Because he was a government official, his statement was taken seriously enough that the World Health Organization briefly echoed the message, advising people with COVID-19 symptoms to avoid taking ibuprofen and to take paracetamol, though they backed away from that recommendation a few days later.

There's a grain of truth in every myth. The warning was based on preliminary research suggesting that an enzyme that increased when ibuprofen was taken (ACE2) might possibly worsen COVID-19 infections. Unlike the U.S. experience with hydroxychloroquine, this wasn't even based on a study of the drug but on information about people who had severe COVID-19 — many of whom also had conditions that are often treated with medications that raise the ACE2 level.

That research was published as a letter in The Lancet Respiratory Medicine. Even if its speculations eventually prove true, it offers no evidence that people should change their behavior right now.

When Spanish researchers analyzed how the story of ibuprofen and COVID spread throughout Europe, they found that while it did make its way across the continent, it wasn't taken as seriously in some places as others. It had its greatest impact in France and very little impact in Germany.

There's a grain of truth in every myth.

In France, the media generally reproduced the Minister's tweet without fact checking, spreading it far and wide and adding an extra layer of credibility to it. Comments refuting the tweet were virtually non-existent.

Yet nobody took the story seriously in Germany, the researchers found. There the message spread not as a tweet, but mostly as an anonymous voice message. Since it was not possible to identify who originally recorded it, the voice message had very little credibility and people generally debunked it or made jokes about it. This incident suggests the important roles the local media and officials play in both promoting and preventing false stories from taking hold.

“Misinformation is counteracted most effectively by local sources. When a false narrative starts to circulate in a region, it is the local channels that must help in checking the information and exposing it as fake when necessary,” says lead author, Sergi Xaudiera, a doctoral candidate at the Universitat Oberta de Catalunya (Catalonia) in Spain.

There is no magic bullet for misinformation. Being cautious about what you accept as fact, especially about COVID-19, should help. And it's imperative that social media platforms do more to prevent misinformation from circulating on their platforms, according to the study authors.

For more details, see the article in the Harvard Kennedy School Misinformation Review.