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Vaccine misinformation on Facebook — published study

During the COVID-19 pandemic, Facebook had a policy of removing users who repeatedly posted COVID-19 vaccine misinformation. Though it may have reduced the number of posts on anti-vaccine pages and groups, a new peer-reviewed study showed that it did not lead to a sustained reduction in engagement with anti-vaccine content.

As someone who engaged with pro-vaccine advocacy on Facebook throughout the COVID-19 pandemic, I was constantly shocked by the amount of false information about the COVID-19 vaccines on the social platform. Sometimes, it felt like Facebook was doing nothing at all to control false narratives.

And this new paper seems to support what I was experiencing online. Let’s take a look at the paper and see what it tells us about the COVID-19 vaccine disinformation campaign on Facebook.

Photo by Artem Podrez on

Facebook and COVID-19 vaccine misinformation paper

In a paper published on 15 September 2023 in ScienceAdvances, Ph.D., of George Washington University in Washington, DC, and colleagues used CrowdTangle to pull data from public Facebook pages and groups.

In December 2020, Facebook announced a new policy whereby it would remove accounts and pages that repeatedly posted misinformation about COVID-19 vaccines, although it was later extended to general vaccine misinformation.

The pre-policy change search came up with 216 vaccine-related pages (114 anti-vaccine and 102 pro-vaccine) as well as 100 groups (92 anti-vaccine and 8 pro-vaccine). Within those were 119,091 posts to pages (73% anti-vaccine) and 168,419 posts to groups (97% anti-vaccine) that were created from Nov. 15, 2019, to Nov. 15, 2020.

There were 177,615 posts to those same pages (62% anti-vaccine) and 244,981 posts to those same groups (95% anti-vaccine) that were created from Nov. 16, 2020, to Feb. 28, 2022. Around 5% of public anti-vaccine groups switched to private, which evaded CrowdTangle analysis.

Here are some key results from the researchers’ analyses:

  • Explicitly anti-vaccine pages and groups were 2.13 times more likely to be removed than their pro-vaccine counterparts
  • Anti-vaccine post volumes decreased 1.47 times more than pro-vaccine post volumes.
  • Posts to anti-vaccine groups also decreased relative to pre-policy trends, and anti-vaccine group post volumes decreased 3.57 times more than pro-vaccine group post volumes.
  • After the change in Facebook policy, there were no significant changes in engagement with content on anti-vaccine pages. Anti-vaccine Facebook groups actually grew in engagement — they were 33% higher than what would be expected prior to changes in policy.
  • Of the posts that pushed COVID-19 vaccine misinformation, the largest increase (41%) was those that alleged severe adverse reactions to the vaccine.
  • Reports of hospitalizations and deaths from the vaccines increased 23%.
  • Posts promoting alternative medicine to vaccines increased 32%.
  • Posts alleging the negative effects of the COVID-19 vaccines on immunity (as a result of toxic ingredients) increased by 24%


The social media response to COVID-19 vaccines was a very frustrating time. Prior to the pandemic, vaccine misinformation was loud, but it didn’t feel like there was a lot of momentum in the social media world. I noticed because I was pushing the pro-vaccine narrative, but I doubt that it was broadly followed outside of a small group of people. In other words, I just thought they were noisy people that didn’t have much power.

But the COVID-19 vaccines changed that. Anti-vaccine views, although still not mainstream, became much more noisy. And this research bears that out.

I think Facebook (and at the time, Twitter) tried to get rid of anti-vaccine content, but they could only do so much. And I think the misinformation got out to the public, and people began to think the claims were facts.

And that’s why so many people spend their time trying to make sure that the actual vaccine facts are used to push against the disinformation campaigns on social media.


Michael Simpson

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