WASHINGTON — Facebook launched an offensive on Thursday to suppress the spread of misinformation about vaccines on the 2.3-billion-member social network.

The company has faced pressure in recent weeks to tackle the problem, amid outbreaks of measles around the United States attributed to growing numbers of parents who refuse to vaccinate their children.

US lawmakers have decried the higher incidences of preventable diseases in the wake of a movement against child vaccination, in large part due to rumours they can cause health or developmental issues.

Monika Bickert, Facebook’s vice president for global policy management, said the social media network would reduce the distribution of false data and provide users with authoritative information about vaccinations.

"We will reduce the ranking of groups and pages that spread misinformation about vaccinations in news feed and search," Bickert said in a statement.

Facebook also will remove the misleading content from search recommendations and predictions, reject advertisements found to contain misinformation about vaccines, and disable accounts that continue to violate company policies on vaccine information, she said.

The company no longer allows targeting based on users’ interest in "vaccine controversies" and will share educational materials with users that come across such misinformation.

The World Health Organisation and US Centers for Disease Control and Prevention have identified "verifiable vaccine hoaxes," Bickert said, and, "If these vaccine hoaxes appear on Facebook, we will take action against them."

WHO in February listed "vaccine hesitancy" among its top 10 most pressing global health threats for 2019 and the UN last week warned against "complacency" as measles cases soared worldwide.

The resurgence in some countries has been linked to debunked claims that vaccines cause autism. Prior to taking office, US President Donald Trump promoted this claim.

New research published this week, which followed 650,000 Danish children for more than a decade, again concluded that vaccination for measles, mumps and rubella did not increase the risk of autism. — AFP