Influenza vaccine effectiveness in preventing hospitalizations among children: a retrospective population-based cohort study in Ribeirão Preto, São Paulo State, Brazil. SciELO Preprints, 2026. DOI: 10.1590/SciELOPreprints.18689. Disponível em: https://preprints.scielo.org/index.php/scielo/preprint/view/18689. Acesso em: 10 nov. 2026.