The AstraZeneca affair. A litmus test of information disorder in the Italian hybrid media ecosystem
In this paper we seek to demonstrate how a variety of information disorder phenomena comes to be at the intersection of legacy and social media interaction. To do so, we collected more than 750.000 tweets and 30.000 news articles related to the adoption of AstraZeneca vaccine in Italy for a period of six months (1st January 2021 - 30th June 2021). Initially, using timestamps of publications and tweets, we tracked the pace of public debate. Then, using a mixed methods approach, we investigated Twitter reaction during the climax of attention toward AstraZeneca. Acting as a litmus test, our study reveals three different but intertwined information disorder phenomena: first, the vaccine debate exhibit a flat progression with few condensed peaks of attention (acceleration phenomenon); second, the two main peaks that involve both journalistic coverage and Twitter discussion generate from news of suspect deaths related to AstraZeneca (sensationalisation phenomenon); and finally, the report of suspect deaths news by mainstream media accounts on Twitter correlates with a polarized and ideological reaction of the connected publics (fragmentation phenomenon). These results highlight how a direct implication of the hybrid media ecosystem's actual configuration could be a resistance in the formation of a public arena capable of sustaining a prolonged and effective debate, particularly with respect to controversial societal issues such as those related to the covid-19 vaccination campaign.