Facebook's parent company Meta said Wednesday it had derailed an anti-vaccine campaign that harassed medical workers, journalists and elected officials, in a signal of the ongoing pressure from coronavirus pandemic-tied misinformation.

The social media giant took down accounts in France and Italy that were linked to a conspiracy movement called "V_V", which inundated pro-vaccine posts with potentially tens of thousands of comments.

"V-V" supporters also "mass-harassed" people on YouTube, Twitter, VKontakte and other online platforms, using swastikas or other images as well as calling doctors and media workers "Nazi supporters" for backing vaccines, Meta said.

The company's update regarding efforts to counter misinformation and harassment on its platform comes as the tech giant battles accusations that it puts profit over user safety.

The firm changed its parent company name to "Meta" in October as it tries to move past the reputation of Facebook as a scandal-plagued social network to the company's virtual reality vision for the future.

A report by social network analysis firm Graphika offered additional information on "V_V," which it says touts itself as engaged in guerilla "psychological warfare" that targets vaccine supporters.

Graphika estimates that "V_V" has about 20,000 followers and said the group has been linked to vandalism of hospitals and efforts to disrupt vaccination programs by repeatedly booking and canceling medical appointments.

The group's campaign used messaging service Telegram to train recruits and spread word of who to target, according to Meta head of emerging harms investigations Mike Dvilyanski.

Using media to spread misinformation

"While we aren't banning all V_V content, we're continuing to monitor the situation and will take action if we find additional violations," Meta said.

Since the start of the pandemic, misinformation has taken many forms, from false and dangerous health advice to so-called miracle cures, conspiracy theories, racist rhetoric and online scams.

The United States in March denounced what it called a Russian disinformation campaign against US-made Covid-19 vaccines, saying Moscow was putting lives at risk.

Meta also reported taking down a "sprawling and unsuccessful" network out of China that used fake accounts to promote a bogus claim that a Swiss biologist contended the United States was putting pressure on World Health Organization scientists to blame China for the pandemic.

Investigators on the Meta security team equated the campaign to a "hall of mirrors, endlessly reflecting a single fake persona" with even Chinese state media citing the fabricated claim.

"Clusters of fake accounts attempted post-amplification, which only took root when media picked up the stories," Meta head of security policy Nathaniel Gleicher said in the briefing.

"But, that was quickly debunked and fizzled out quickly," he added.

The tactic reflected a trend of trying to get legitimate news outlets to spread misinformation promoted by networks of fake accounts, Gleicher noted.

"Operations like these will also target media, marketers and influencers, who need defenses against these kinds of campaigns," he said.

Meta found links to employees of people associated with Chinese state infrastructure companies based around the world.

"This is the first time we have observed an operation that included a coordinated cluster of state employees to amplify itself in this way," Meta said.

"Our investigation also found that a number of Chinese government officials began interacting with the operation's content less than an hour after it first posted."