Social media networks are working to remove or stop the spread of a viral pandemic conspiracy video that contains false, misleading or unproven claims about Covid-19.

The roughly 26-minute “Plandemic Movie” video claims to be an excerpt of a larger documentary to be released this summer and contains claims about the origins of the virus and how it spreads. The video tries to argue that the coronavirus pandemic was created to make profits off vaccines. Among other claims that defy advice of medical experts, it suggests that sheltering in place harms consumers’ immune systems and that masks can make people sicker. 

As of midweek, it had been viewed and shared widely across Alphabet‘s YouTube, Twitter, Facebook and IAC-owned Vimeo. People were also sharing clips of the video on Twitter.

It comes as health-care professionals are confronted with a bombardment of misinformation and harassment from conspiracy theorists, some of whom have moved beyond posting online to pressing doctors for proof of the severity of the pandemic. Earlier this year, the World Health Organization hosted a meeting with tech leaders from Google, Facebook, Twitter and other tech platforms, in part to discuss what they’re doing to prevent the mounting spread of coronavirus-related misinformation.

One video, shared on Facebook by someone claiming to be one of the filmmakers behind the film, had received more than 1.7 million views as of Thursday and been shared more than 140,000 times. He encouraged viewers to download the video on the film’s website and share it to “all your favorite platforms.”

One of the YouTube videos had received more than 1 million views before it was removed, according to the MIT Technology Review. 

Facebook originally declined to comment on whether the video violated its policies, with a spokeswoman saying the video “is eligible for fact-checkers to review and rate.” Later Thursday, a spokeswoman said “Suggesting that wearing a mask can make you sick could lead to imminent harm, so we’re removing the video.” That video, along with other identical videos on Facebook, was still live midafternoon Thursday. 

A YouTube spokeswoman said the platform quickly removes flagged content that violates its community guidelines, including content that includes medically unsubstantiated diagnostic advice for Covid-19. According to the company, the video was removed for making claims about a cure for Covid-19 that has not been backed by health organizations. 

Vimeo said it “stands firm in keeping [its] platform safe from content that spreads harmful and misleading health information.” It said the video had been removed for violating those policies and added that it will be constantly monitoring and will continue to remove similar videos uploaded. 

Twitter, where users were sharing video links and clips, said it has blocked the hashtags “#PlagueofCorruption” and #PlandemicMovie” from trends and search. According to the company, a video shared on Twitter by Judy Mikovits, who is featured in the video, is not in violation of its misinformation policy. In the video, Mikovits claims that masks are dangerous and “literally killing people.” Twitter did say the URL of the video has been marked as “unsafe.”