Credit: Pixabay/CC0 Public Domain

More than 500 websites have promoted misinformation about the coronavirus—including debunked claims about vaccines, according to a firm that rates the credibility of websites.

NewsGuard announced Wednesday that, of the more than 6,700 websites it has analyzed, 519 have published about COVID-19. Some of the sites publish dubious health information or political conspiracy theories, while others were "created specifically to spread misinformation about COVID-19," the company says on its website.

"It's become virtually impossible for people to tell the difference between a generally reliable site and an untrustworthy site," Gordon Crovitz, co-founder of NewsGuard, told U.S. TODAY in an exclusive interview. "And that is why there is such a big business in publishing this information."

The findings come as new daily COVID-19 infections, hospitalizations and deaths remain high across much of the country. About 53% of Americans have been fully vaccinated against the virus, according to the Centers for Disease Control and Prevention.

Launched in spring 2018, NewsGuard employs experienced journalists to assess the credibility and transparency of the most popular news and information websites in the U.S., United Kingdom, Germany, France and Italy. The firm publishes "nutrition labels" that tell users whether a source adheres to or violates journalistic standards.

"We don't believe in blocking stuff and not letting people see things," said Steven Brill, co-founder of NewsGuard. "What we believe in is giving people information about what they're about to see so they can make their own decision."

In its Wednesday release, NewsGuard also identified 50 of the top COVID-19 vaccine myths spreading online. They include debunked claims that the vaccines alter people's DNA, cause infertility or create new variants of the virus.

"They're all hoaxes that have gained traction, and we know that because we see them spreading from website to website," said Matt Skibinski, NewsGuard's general manager.

Of the sites on NewsGuard's list, 339 have an audience predominantly based in the U.S. Several of them, including InfoWars and Mercola.com, have a track record of promoting conspiracy theories and dubious health claims. Others try to dupe people by using domain names close to those of credible news outlets, such as WashingtonPosted.news and Ussanews.com, mimicking washingtonpost.com and USNews.com, respectively.

Some of the websites NewsGuard identified have become more popular online than trustworthy sources of information about COVID-19.

For example, anti-vaccine advocacy group Children's Health Defense has received more engagement in the past 90 days than the CDC and the National Institutes of Health, according to NewsGuard. The site, which is run by anti-vaccine advocate Robert F. Kennedy Jr., has previously cast doubt on the safety of COVID-19 vaccines and promoted conspiracy theories about 5G technology.

NewsGuard uses NewsWhip, a social media analytics firm, to measure engagement, which includes social media interactions and traffic. Crovitz warned against underestimating the danger of websites that have published COVID-19 misinformation simply because they make up a relatively small portion of content.

"We've rated all the news and information sources that account for 97% of engagement in the U.S. Of those, 7% are publishing COVID misinformation," Crovitz said. "That's as if 7% of all contained strychnine and the cereal companies said, 'Well, it's only 7%.'"

NewsGuard's findings are the latest attempt to quantify misinformation about the coronavirus pandemic.

A March report from the Center for Countering Digital Hate, a London-based nonprofit organization, found that a dozen accounts were responsible for 65% of the anti-vaccine misinformation spreading on Facebook and Twitter. NewsGuard has also identified "super-spreaders" of COVID-19 vaccine misinformation.

Those kinds of reports have made waves in Washington, where lawmakers have introduced legislation aimed at holding social media companies responsible for health misinformation.

In July, White House press secretary Jen Psaki cited the 65% figure to criticize social media platforms' handling of COVID-19 misinformation. President Joe Biden said Facebook was "killing people" for allowing false information about the vaccines to spread, a statement he later softened. Surgeon General Vivek Murthy said misinformation "is still spreading like wildfire in our country, aided and abetted by technology platforms."

Biden later walked back his statement, and Facebook disputed the Center for Countering Digital Hate's findings.

"Focusing on these 12 individuals misses the forest for the trees," Monika Bickert, vice president of content policy at Facebook, wrote in an August press release. "Since the beginning of the pandemic across our entire platform, we have removed over 3,000 accounts, pages and groups for repeatedly violating our rules against spreading COVID-19 and vaccine and removed more than 20 million pieces of content for breaking these rules."

Still, websites that publish false claims about COVID-19—partially funded by advertisers who may not know the nature of the site they're connected with—continue to get traction online. And public health officials say that could have an effect on the ongoing vaccine rollout.

"What we've seen in the last 20 months is an erosion of trust, an erosion of science and an erosion of the truth," said Andy Pattison, team lead for digital channels at the World Health Organization's Digital Health and Innovation Department, which has partnered with NewsGuard since last year. "And I think that's really scary."