Facebook is to clamp down on anti-vaccination groups on the site, announcing it will reduce the ranking of pages that “spread misinformation” on the subject.
The social network said it will also reject any adverts it finds include false information on the topic and will not show or recommend any content from Facebook and Instagram it deems to be spreading misinformation.
It comes after criticism of the platform over the way its algorithm highlighted content that promotes anti-vaccination ideas.
Last week the head of NHS England warned “vaccination deniers” were gaining traction on social media as part of a “fake news” movement.
In an official blog post, Facebook’s vice president of global policy management Monika Bickert said: “We are working to tackle vaccine misinformation on Facebook by reducing its distribution and providing people with authoritative information on the topic.
“Leading global health organisations, such as the World Health Organisation and the US Centers for Disease Control and Prevention, have publicly identified verifiable vaccine hoaxes. If these vaccine hoaxes appear on Facebook, we will take action against them.”
The social network previously said it was looking into how it approached the issue in a way that enabled freedom of expression but also supported the safety of users.
Other platforms have also taken action on the subject – YouTube has removed adverts from anti-vaccination videos and Pinterest has taken action to block vaccination searches.
Ms Bickert said the social network was also looking into ways of providing more information on the topic to users of Facebook.
“We also believe in providing people with additional context so they can decide whether to read, share or engage in conversations about information they see on Facebook,” she said.
“We are exploring ways to give people more accurate information from expert organisations about vaccines at the top of results for related searches, on pages discussing the topic, and on invitations to join groups about the topic. We will have an update on this soon.”
In January, a study by the Royal Society for Public Health (RSPH) warned social media was a “breeding ground for misleading information and negative messaging around vaccination” and more action needed to be taken to challenge claims made against vaccines.