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Author(s): Yee Man Margaret, Katherine Hoffmann and Miguel Luengo-Oroz


Throughout the COVID-19 pandemic, there has been a concern that social media may contribute to vaccine hesitancy due to the wide availability of antivaccine content on social media platforms. YouTube has stated its commitment to removing content that contains misinformation on vaccination. Nevertheless, such claims are difficult to audit. There is a need for more empirical research to evaluate the actual prevalence of antivaccine sentiment on the internet.

This study examines recommendations made by YouTube’s algorithms in order to investigate whether the platform may facilitate the spread of antivaccine sentiment on the internet. We assess the prevalence of antivaccine sentiment in recommended videos and evaluate how real-world users’ experiences are different from the personalized recommendations obtained by using synthetic data collection methods, which are often used to study YouTube’s recommendation systems.