(Mis)perceptions and engagement on Twitter: COVID-19 vaccine rumors on efficacy and mass immunization effort

This paper reports the findings of a 606-participant study analyzing the perception of, and engagement with, COVID-19 vaccine rumors on efficacy and mass immunization effort on Twitter. Misperceptions were successfully induced through simple content alterations and the addition of popular anti-COVID-19 hashtags such as #COVIDIOT and #covidhoax to otherwise valid Twitter content. Twitter's soft moderation warning label helped the majority of our participants to dismiss the rumors about mass immunization. However, for the skeptic, vaccine-hesitant minority, the soft moderation caused a “backfire effect” i.e., make them perceive the rumor as accurate. While the majority of the participants staunchly refrain from engaging with the COVID-19 rumors, the hesitant and skeptic minority was open to comment, retweet, like and share the vaccine efficacy rumors. Based on these findings, we recommend misinformation label designs to prevent the “backfire effect” of COVID-19 vaccine rumors on Twitter.