Sequencing of humor and risk information in social media public service announcements on vaccines: the moderating role of vaccination calculation

Purpose: In vaccination-promoting public service announcements (PSAs), humor and risk information can be used together for more effective persuasion. However, little is known about how to sequence these message elements in social media multi-page posts. By focusing on humor’s role in buffering negative side effects of risk information, this study aims to examine the optimal placement of humor along with risk information for individuals with varying levels of vaccination calculation to enhance the persuasive impacts of health social media PSAs. Design/methodology/approach: An online experiment was conducted with a one-factor, two-condition (humor order: humor first vs humor second) design with vaccination calculation as a measured moderator and perceived vaccine effectiveness and attitude toward COVID-19 vaccination as serial mediators. Findings: For individuals with higher (lower) levels of vaccination calculation, placing humor on the first (second) page led to greater perceived vaccine effectiveness. In addition, placing humor first indirectly increased COVID-19 vaccination intention via an increase in perceived vaccine effectiveness and positive attitudes toward vaccination for individuals with higher vaccination calculation levels. Originality/value: This study extends the current humor literature by demonstrating the strategic sequencing of humor and risk information on social media. It highlights that humor may serve as a positive buffer differently for people with varying levels of vaccination calculation. Moreover, this study provides practical content guidelines for social marketers by applying a multi-page post type, which social marketers most commonly use, rather than a single-page post type.