Facebook announced on Monday that the company would take action against users and groups on Facebook and Instagram that spread misinformation about the coronavirus disease 2019 (Covid-19) vaccine or vaccines in general.

“We will begin enforcing this policy immediately,” the company said on a blog post, “Groups, pages and accounts on Facebook and Instagram that repeatedly share these debunked claims may be removed altogether.”

Facebook already has banned advertisements that spread misinformation about vaccines.

In December, the company announced that on the advice of its oversight board, posts that spread misinformation about Covid-19 would be labeled as inaccurate, with links to correct information.

The new policy was developed in consultation with the World Health Organization expanding a list of debunked claims to include those that Covid-19 was man-made in a lab; that vaccines are not effective, toxic, dangerous or cause autism; or that “it’s safer to get the disease than to get the vaccination.”

Anti-vaccine activists have used social media to undermine the public’s confidence in the vaccines, including anti-vaxxer Robert Kennedy Jr., whose January Facebook post, perpetuating the hoax that baseball legend Hank Aaron  died of Covid-19 after being vaccinated, remains on the site, although it is tagged by reviewers.

The Fulton County, Georgia medical examiner refuted  the rumors and said Aaron died of natural causes.

The false Internet rumors about Aaron’s death were the inspiration for some anti-vaccine protesters who attacked a mass vaccination site in Dodger Stadium last week, they told a leading US daily.

But plenty of anti-vaccine groups have been active since before the pandemic. An October 2020 article in The Lancet showed that 31 million people followed anti-vaccine pages on Facebook in 2019, with the number of followers growing by more than 7 million in one year.

Waves of online disinformation about Covid-19 were traced to Russia and China  last year.

A January study that anti-vaccine social media posts were correlated with an increased public resistance to vaccines for HPV, which researchers said could be relevant in how the public will accept Covid-19 vaccines.

Facebook said Monday the company would “continue to review content on our platforms, assess trends in language and engage with experts to provide additional policy guidance to keep people safe during this crisis.”