[Vaccines and social media: a debate around vaccines on Instagram and Facebook during the COVID-19 pandemic (2020-2021)].

Considering that the Internet and especially social media work as a locus for the circulation of information on COVID-19, this study aimed to assess the attention given to the vaccine theme on Instagram and Facebook in posts throughout two years of pandemic, identifying the temporality in which discussion about the different immunizing agents in social media and highlighting the actors who permeated the discussions on the subject. Data were collected using the CrowdTangle graphical interface, based on search terms in Portuguese related to vaccines approved for use in Brazil and it included posts from public Facebook pages and open Instagram profiles made from January 1st, 2020, to December 31st, 2021. The database included 3,876,408 posts (2,901,457 on Facebook and 974,952 on Instagram). The results showed an alternation of Pfizer, CoronaVac, AstraZeneca, and Janssen vaccines as the focus of discussion, following the public debate established in the country around the dilemmas and advances related to the development, production, distribution, and application of immunizing agents. References to institutions involved in the acquisition and production of immunizing agents were also identified, such as the Brazilian Ministry of Health, the Butantan Institute, and the Oswaldo Cruz Foundation, present among the thousand social actors that most generated comments from users in both networks. It was evidenced that the debate on immunizing agents, in the analyzed channels and period, was permeated by social media related to journalism and politicians and celebrities' pages and profiles.