Facebook issued a press release on Thursday addressing mounting criticism over its role in spreading anti-vaccination propaganda. “We are working to tackle vaccine misinformation on Facebook by reducing its distribution and providing people with authoritative information on the topic,” wrote Monika Bickert, vice president of Global Policy Management. Facebook’s advertising platform is used to spread anti-vaccine conspiracy theories and misinformation, with little oversight from the company.

The company said one step it’s taking is rejecting advertisers that “include misinformation about vaccinations,” and reducing “the ranking of groups” that spread these conspiracies in Facebook’s news feed and search functions. “These groups and Pages will not be included in recommendations or in predictions when you type into Search,” Bickert wrote. Facebook also says it will stop showing recommended content that contains vaccine misinformation, and is “exploring ways to share educational information about vaccines when people come across misinformation on this topic.” In order to accomplish these changes, Facebook says it will “take action” against “verifiable vaccine hoaxes” that leading health organizations, such as the World Health Organization, have previously identified.