Study: Facebook policy blocked vaccine misinformation

A 2019 Facebook policy to stop the spread of misinformation about vaccines actually worked, according to a new study. In addition, the researchers called for rigorous evaluation to ensure social media policies are effective.

The study, “The impact of Facebook’s vaccine misinformation policy on user endorsements of vaccine content: An interrupted time series analysis,” was published in Vaccine and announced by George Washington University (GWU) in a news release.

Researchers there found the Facebook policy about vaccines did reduce people’s interactions with vaccine misinformation.

Following years of growing vaccine opposition and several outbreaks of measles -- a vaccine-preventable disease -- Facebook established in 2019 its first policy to stop the spread of misinformation about vaccines, according to the study.

The GWU researchers wondered if the new policies were effective at stopping the spread of misinformation.

The researchers identified 172 anti- and pro-vaccine Facebook pages and collected posts from these pages for six months before and after the policy went into effect.

They found that Facebook’s March 2019 vaccine misinformation policy moderately curtailed the number of “likes” of anti-vaccine content on pages on its platform, according to the announcement.

“There is a growing consensus that health misinformation on social media platforms presents a critical challenge for public health, especially during the COVID-19 pandemic,” Lorien Abroms, professor of prevention and community health, said in the news release. “While new policies by social media companies are an important first step to stopping the spread of misinformation, it is also necessary to rigorously evaluate these policies to ensure they are effective.”

The researchers concluded that social media companies can take measures to limit the popularity of anti-vaccine content.

“This research is a good first step in developing a process to evaluate the effectiveness of social media policies that are created to stop the spread of misinformation,” PhD student Jiayan Gu said in the news release. “We are excited to continue this work and grow our understanding of how social media policy interventions can positively change online information sharing ecosystems.”