Characterizing the Diffusion of Misinformation Regarding the CoronaVac Vaccine in Brazil

The start of the vaccination against COVID-19 was an essential step towards the end of the pandemic. In Brazil, CoronaVac was the first vaccine to be applied in the immunization campaign, and it is one of the most used today. Still, CoronaVac has specific components that have driven the spread of misinformation online. In this work, we compare the dissemination of misinformation on Twitter about the approval of such a vaccine for adults and children. The results show that misinformation is significant on Twitter and there has been a substantial change in the style of such content shared between 2021 and 2022, moving from a false narrative about the development of the vaccine to raising suspicions on the approval process by the health regulatory agency.