Covid-19, vaccines, and controversies on Twitter

This article investigates online debates about COVID-19 vaccination by focusing on controversies surrounding vaccine hesitancy, which has itself become a topic of mainstream debate. We are interested not only in Twitter users who opposed or were skeptical of vaccination, but also, and even more so, in users who were active and influential in the fight against anti-vaccination. Combining visual network analysis with a qualitative analysis of 8,667 tweets posted by 7,234 users collected between December 2020 and August 2021, we investigate the positioning and communicative strategies of a group of actors which we propose to call the ‘anti-anti-vaxxers’. Our findings demonstrate that, despite existing scholarship suggesting that extreme anti-vaccine misinformation was not the main driver of vaccine hesitancy, influential anti-anti-vaxxers concentrated on rebutting extreme anti-vaccination claims and failed to engage with the diverse concerns underlying vaccine hesitancy. We argue that the fact-checking, debunking, and delegitimization strategies employed by anti-anti-vaxxers may have had counterproductive effects by increasing the visibility and circulation of false information and alienating vaccine-hesitant individuals. Viewed in light of political developments through 2025, these findings highlight how well-intentioned social media interventions may inadvertently contribute to the mainstream visibility of anti-vaccine discourse and reinforce the appeal of anti-elite and populist movements.