One year of COVID-19 vaccine misinformation on Twitter

Abstract

We collected almost 300M English-language tweets related to COVID-19 vaccines using a list of over 80 relevant keywords over a period of 12 months. We then extracted and labeled news articles at the source level, based on third-party lists of low-credibility and mainstream news sources, and measured the prevalence of different kinds of information. We also considered suspicious YouTube videos shared on Twitter. To identify spreaders of vaccine misinformation, we focused on verified Twitter accounts and employed a bot detection algorithm to identify accounts that are likely automated. Our findings show a low prevalence of low-credibility information compared to mainstream news. However, most popular low-credibility sources had reshare volumes comparable to many mainstream sources, and larger volumes than authoritative sources such as the U.S. Centers for Disease Control and Prevention and the World Health Organization. Throughout the year, we observed an increasing trend in the prevalence of low-credibility news relative to mainstream news about vaccines. We also observed a considerable amount of suspicious YouTube videos shared on Twitter. We found that tweets by a small group of about 800 superspreaders verified by Twitter accounted for approximately 35% of all reshares of misinformation on the average day, with the top superspreader (RobertKennedyJr) being responsible for over 13% of retweets. We also found that low-credibility news and suspicious YouTube videos were more likely to be shared by automated accounts.