RT Journal Article SR Electronic T1 Inactivated trivalent influenza vaccination is associated with lower mortality among patients with COVID-19 in Brazil JF BMJ Evidence-Based Medicine JO BMJ EBM FD BMJ Publishing Group Ltd SP 192 OP 193 DO 10.1136/bmjebm-2020-111549 VO 26 IS 4 A1 Günther Fink A1 Nina Orlova-Fink A1 Tobias Schindler A1 Sandra Grisi A1 Ana Paula S Ferrer A1 Claudia Daubenberger A1 Alexandra Brentani YR 2021 UL http://ebm.bmj.com/content/26/4/192.abstract AB Objective To estimate associations between trivalent influenza vaccination and COVID-19 mortality as well as severe clinical outcomes among hospitalised patients.Design Retrospective observational study.Setting This study was conducted among hospitalised patients with COVID-19 in Brazil.Participants We analysed all hospitalised patients with COVID-19 with available vaccination information captured in Brazil’s national electronic respiratory infection data system between 1 January 2020 and 23 June 2020.Main outcome measures The primary outcomes were age-specific mortality rates of hospitalised patients with COVID-19 with and without recent inactivated trivalent influenza vaccination.Results A total of 53 752 clinically confirmed COVID-19 cases were analysed. Controlling for health facility of treatment, comorbidities as well as an extensive range of sociodemographic factors, patients who received a recent influenza vaccine experienced on average 7% lower odds of needing intensive care treatment (95% CI 0.87 to 0.98), 17% lower odds of requiring invasive respiratory support (95% CI 0.77 to 0.88) and 16% lower odds of death (95% CI 0.78 to 0.90). Protective effects were larger when the vaccine was administered after onset of symptoms as well as among younger patients.Conclusion Patients with COVID-19 with recent inactivated influenza vaccination experience significantly better health outcomes than non-vaccinated patients in Brazil. Beneficial off-target effects of influenza vaccination through trained innate immune responses seem plausible and need to be further explored. Large-scale promotion of influenza vaccines seems advisable, especially in populations at high risk for severe COVID-19 disease progression.Data are publicly available at the Brazilian Ministry of Health website.