The Scope and Effects of Vaccine Misinformation on Social Media

Vaccination is one topic where misinformation has been particularly problematic on social media. This chapter spotlights the role of social media in the spread of vaccine misinformation. It begins by defining key terms and considering existing theory on this topic. The chapter considers the scope and content of vaccine misinformation on social media, its effects, its politicization, beliefs in misinformation, and how it can be combatted. Vaccination behavior has been widely understood through the theory of planned behavior. It explains how people's attitudes, subjective norms, and perceived behavioral control influence whether or not they choose to engage in a particular behavior. A growing area in vaccine misinformation research concerns how people discuss vaccines and is explored by examining the psycholinguistic properties of relevant online messages using dictionary-based content analysis tools. One framework that can be used to understand the implications of political ideology for vaccine misinformation on social media is social identity theory.