Designing Interventions to Address the Spread of Anti Vaccine Views Online

This month we are discussing what is a timely and growing concern–the spread of anti vaccine views online, after a hiatus of several months due to COVID-19 .  During our Twitter chat on July 14th at 6pm (PDT), we will be discussing the recently published article, “The Online Competition Between Pro- and Anti-Vaccination Views,” by Neil F. Johnson, et al.  Below is a brief summary in case you don’t have time to read the full article in between all those Zoom calls.

Poster for Twitter chat on july 14th 2020

Anti vaccine views -Article Summary

Opposition to vaccination with a future vaccine against SARS-CoV-2 could increase outbreaks and prolong the pandemic.  On a smaller scale, opposition to vaccination led to outbreaks of measles in 2019.  The authors examine the critical question of how distrust around vaccines evolves on social media. Anti-vaccination sentiments are only one kind of the plethora of misinformation and dismissals of expert advice that are spread via the Internet.  This study provides a system-level analysis of vaccine views expressed on Facebook.


Individuals come together into interlinked clusters (Facebook pages), where members of a given page share, interact, and subscribe to the information and narrative(s) presented on that page. The information spreads when members of one Facebook page recommend another Facebook page to its members.  Anti-vaccine and pro-vaccine pages, as well as pages focused around vaccines along with other topics (e.g., parent teacher association pages) where the stance on vaccines is undecided, are included in the analysis. 


The authors identify seven features of the cluster network and its evolution to explain why anti-vaccine views have become so prominent and resilient, despite news reports, information, and attempts to quell anti-vaccination sentiments.

  1. Although anti-vaccination clusters are numerically smaller and express opinions that are held by a minority of the public, such views have become centrally positioned within the Facebook network.  Anti-vaccination clusters are heavily entangled with undecided clusters, while pro-vaccination clusters are confined to the 2-3 smallest network patches within the broader network. Thus, pro-vaccination clusters may remain unaware of the main conflict and have a false impression that they are “winning” the vaccination debate.
  2. Contrary to the assumption that undecided populations are passive, undecided populations are highly active and have the highest growth of out-of-network links.  
  3. Anti-vaccination clusters form more than twice as many clusters, compared to pro-vaccine clusters.  This provides more opportunities to engage in anti-vaccination information and allows these pages to become more entangled and centralized in the Facebook network.
  4. Anti-vaccination clusters include attractive narratives that blend safety concerns, conspiracy theories, alternative health and medicine, and causes and cures for COVID-19.  Anti-vaccine narratives are diverse compared to pro-vaccine group narratives, allowing anti-vaccination supporters to form into smaller clusters that each provide their own nuanced opinion.
  5. Anti-vaccination clusters showed the highest growth during the 2019 measles outbreak, while pro-vaccination clusters showed the lowest growth.  Some anti-vaccination clusters grew approximately three times as much as any pro-vaccine cluster.  Anti-vaccination clusters may attract undecided clusters with diverse narratives, which is attributed to their growth.
  6. Medium-sized anti-vaccination clusters grow the most, as they go unnoticed by pro-vaccination proponents, who are distracted by the larger anti-vaccination clusters.
  7. Anti-vaccination clusters tend to self-locate within cities, states, countries, or stay global.  Local clusters are typically interconnected through global clusters, so they feel part of a local and global campaign.

Predicting the Future?

This study highlights the complex dynamics between anti-vaccine, pro-vaccine, and undecided clusters and presents some surprising findings. With such a large pro-vaccination majority, one would expect that “anti-vaccination clusters should shrink relative to pro-vaccination clusters under attrition (232).” However, the opposite happened in 2019. Additionally, the model predicts that anti-vaccine views will dominate in approximately ten years under present conditions (without new interventions).

Thinking About Interventions

This study suggests a new theoretical framework to describe how anti-vaccination views interact and evolve on social media. These findings can be used to inform policies and approaches for intervening in the online spread of health-related misinformation, falsehoods, conspiracy theories, and the like. Be sure to join us on July 14th at 6pm (PDT) for a discussion about how the science communication community can design interventions to reduce the spread of anti-vaccination information online.

Citation: Johnson, N.F., Velásquez, N., Restrepo, N.J. et al. The online competition between pro- and anti-vaccination views. Nature (2020).