'The benefits of the vaccine outweigh the risks… they say'

This study aims to analyse Italian Internet users' comments on two posts that appeared on the Facebook page of the Italian newspaper Il Corriere della Sera during a particularly critical phase of the COVID-19 pandemic (specifically, March 2021). At that time, the AstraZeneca vaccine had been temporarily suspended in some European countries due to confirmed reports of blood clots but subsequently declared "safe and effective" by the European Medicines Agency. Two datasets of comments were collected and analysed by combining automatic and manual, as well as quantitative and qualitative, methods. The main findings shed light on the orientation (agreement vs disagreement), construction of consensus and dissent, and epistemic positioning of Facebook users when they are confronted and engaged in dialogue with uncertain news about public health issues.