Background: The lack of specific vaccines or drugs against coronavirus disease 2019 (COVID-19) warrants studies focusing on alternative clinical approaches to reduce the spread of this pandemic disease In this study, we investigated whether anti-influenza vaccination plays a role in minimizing the diffusion of COVID-19 in the Italian population aged 65 and over Methods: Four COVID-19 outcomes were used: severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence, hospitalizations for COVID-19 symptoms, admissions to intensive care units for reasons related to SARS-CoV-2, and deaths attributable to COVID-19 Results: At univariate analyses, the influenza vaccination coverage rates correlated negatively with all COVID-19 outcomes (Beta ranging from &minus;134 to &minus;0 61;all p &lt;0 01) At multivariable analyses, influenza vaccination coverage rates correlated independently with SARS-CoV-2 seroprevalence (Beta (95% C I ): &minus;130 (&minus;198, &minus;62);p = 0 001), hospitalizations for COVID-19 symptoms (Beta (95% C I ): &minus;4 16 (&minus;6 27, &minus;2 05);p = 0 001), admission to intensive care units for reasons related to SARS-CoV-2 (Beta (95% C I ): &minus;0 58 (&minus;1 05, &minus;0 12);p = 0 017), and number of deaths attributable to COVID-19 (Beta (95% C I ): &minus;3 29 (&minus;5 66, &minus;0 93);p = 0 010) The R2 observed in the unadjusted analysis increased from 82% to 159% for all the considered outcomes after multivariable analyses Conclusions: In the Italian population, the coverage rate of the influenza vaccination in people aged 65 and over is associated with a reduced spread and a less severe clinical expression of COVID-19 This finding warrants ad hoc studies to investigate the role of influenza vaccination in preventing the spread of COVID-19
Relationship between Influenza Vaccination Coverage Rate and COVID-19 Outbreak: An Italian Ecological Study