Pre-Pandemic history of a health controversy. Ten years of vaccine hesitancy on the Italian Twitter

The discursive politicization of vaccine-sceptic positions on Twitter following related legislative interventions. The Covid-19 pandemic underlined the complex ways in which social media and public health intertwine. This led to a newfound focus on the role of digital platforms in structuring public discourse around health and public health policies. In this context, one of the most addressed topics is vaccination, as research focused on how vaccine hesitancy is structured and received on social media in relation to the broader climate of a pandemic. However, the pervasiveness of the pandemic made it difficult to unpack social and political factors, and to gauge the effects on the conversation of legislative interventions concerning the pandemic vis a vis acts concerning vaccines specifically. To this end, the effects of a comparable legislative act on social media conversations have been measured. Specifically, the focus is on the discourse surrounding vaccines on Twitter in the 10 years leading to, and including, the aftermath of the Lorenzin Decree, a legislative intervention addressing immunization practices in Italy. The present research shows how the issuing of a decree involving vaccination practices led to a broader politicization of the issue, enhancing the visibility of vaccine sceptic positions, and radically altering the morphology of the conversation. This underlines how events and their subsequent discursive platformisation can affect the tone and frames of a conversation.