Objective: The main objective of this study was to estimate the efficacy of influenza vaccination in reducing influenza-attributable hospitalization and emergency room (ER) admission for severe complications and influenza-attributable excess mortality in individuals ≥65 years of age.
Methods: We analyzed the ≥65 years-old community (n = 952,822) afferent to the Brescia (Northern Italy) Health Protection Agency, considered an Italian population reference, to evaluate the efficacy of influenza vaccination (seasons 2014-17) in reducing deaths, ER-admissions, and hospitalizations for influenza-related complications in the elderly.
Results: A protective effect of influenza vaccination emerged in reducing hospitalization and ER admission for diseases of the respiratory system and for death from all causes in people ≥65 years. The major effect of influenza vaccination was the reduction in risk of death from all causes, increasing with age and comorbidity.
Conclusion: Influenza vaccination has reduced the number of ER admissions and hospitalizations caused by influenza-related complications and has prevented death among high-risk groups in elderly ≥65 years, resulting in social and public health cost savings. Stronger or new vaccination strategies are needed to improve vaccination rates among the elderly.
Keywords: Efficacy of influenza vaccination; cardiac disease and stroke; death from all causes; diseases of the respiratory system; elderly.