Who's fuelling Twitter disinformation on the COVID-19 vaccination campaign? Evidence from a computational analysis of the green pass debate

The COVID-19 health emergency increased disinformation's role and fostered a growing fragmentation between conflicting opinions on COVID-19 causes, vaccination policies, and government measures to deal with the pandemic. Studies have found that disinformation sources included private citizens, independent organizations, mainstream online newspapers and even public figures such as politicians, commentators, bloggers etc. In Italy, the Twitter debate ignited a conflict between mainstream positions in favour of restrictions, and more libertarian opinions extremely critical of government measures. Our research investigates, through a computational approach based on digital methods and social network analysis (SNA), opinion leaders' roles in the Italian green pass debate on Twitter that surfaced in the second half of 2021. Drawing on the classic two-step model of communication, our essay identifies the Italian opinion leaders on Twitter and their content dissemination strategies. Our analysis reveals a limited number of dominant voices interacting in segregated networks of users. These networks can be considered echo chambers given the verbose and self-referential tweeting activity of their opinion leaders. Moreover, such activity involves spreading disinformation and conspiracy theories through a dissemination strategy aimed at diverting the audience from Twitter, towards 'below-the-radar' environments (e.g. Rumble), where political views are more radical.