The online competition between pro- and anti-vaccination views.

Area of Science:

• Social science
• Network analysis
• Public health communication

Background:

• Distrust in scientific expertise poses significant public health risks, exemplified by vaccine hesitancy during the COVID-19 pandemic.
• The spread of misinformation and dismissal of expert advice online exacerbates outbreaks and hinders public health efforts.

Purpose of the Study:

• To map the complex landscape of vaccine-related contention on a global scale using social media data.
• To understand the system-level evolution of distrust in scientific expertise and its impact on vaccination attitudes.

Main Methods:

• Analysis of approximately three billion Facebook users to map vaccine-related contention.
• Identification and analysis of interconnected clusters representing pro-vaccination, anti-vaccination, and undecided individuals.
• Development of a theoretical framework to model the dynamics of online discourse surrounding vaccines.

Main Results:

• A complex, multi-sided network of nearly 100 million individuals across diverse geographic and linguistic clusters was identified.
• Anti-vaccination clusters are highly integrated with undecided clusters, while pro-vaccination clusters remain more peripheral.
• The theoretical framework successfully reproduced the recent surge in anti-vaccination sentiment and predicts its future dominance.

Conclusions:

• Network cluster dynamics play a crucial role in the spread of health-related information and misinformation.
• Conventional understanding of undecided individuals in health debates needs reevaluation.
• Insights can inform new strategies to counter vaccine hesitancy and combat the spread of health misinformation.