Characterizing the Behavior of Healthcare Experts Towards COVID-19 Vaccine on Twitter

Spreading vaccine misinformation can have severe consequences for public health, including the increased risk of disease outbreaks. Even though experts with specialized knowl-edge can play a crucial role in combating vaccine misinformation, there is a lack of sufficient understanding on how healthcare experts communicated over social media during the early stages of the COVID-19 pandemic. Therefore, this study uses large-scale Twitter data in Japanese to examine how healthcare experts participated in key discussions about vaccines in 2020. Specifically, we identify healthcare expert users utilizing the Term Frequency - Inverse Document Frequency (TF-IDF) algorithm on social media profiles and analyze their distinctive behaviors in vaccine communication. Our findings indicate that healthcare experts were more likely to be pro-vaccine and less likely to be on the political right or neutral. We also find that these users received more replies and had more followers than the non-healthcare professional users, and that they tended to use different types of information sources compared to non-professionals. These findings highlight the unique position of healthcare professional users in the social media realm. Our study thus contributes to a better understanding of the role played by healthcare experts in public health policymaking, where social media has been increasing its presence.