Monitoring influenza vaccination coverage among healthcare workers during the COVID-19 pandemic: a three-year survey in a large university hospital in North-Western Italy.

Introduction: Healthcare workers (HCWs) are one of the highest priority groups recommended for seasonal influenza vaccination (SIV). Greater awareness of the importance of influenza vaccination was observed among HCWs after the start of the COVID-19 pandemic. The aim of this study was to analyze SIV coverage rates in the 2019-2020, 2020-2021 and 2021-2022 seasons among HCWs employed at the IRCCS Ospedale Policlinico San Martino in Genoa, in order to observe how coverage has changed since the COVID-19 pandemic began. Methods: A retrospective, single-center study was conducted among HCWs working at the IRCCS Ospedale Policlinico San Martino in Genoa. The vaccinated population was stratified by gender, age, qualification and area of activity, and the characteristics of vaccinated HCWs were analyzed. Results: While SIV coverage was below the recommended target in all seasons, a sharp increase was observed in 2020/2021 (12.8%; 40.9% and 23% in 2019/2020, 2020/2021 and 2021/2022, respectively). The mean and median age of vaccinees also increased during the 2020/2021 vaccination campaign (46.7 and 49 years, respectively) in comparison with the 2019/2020 season (43.5 and 45, respectively). In the 2019/2020 and 2021/2022 seasons, a higher proportion of vaccinees were physicians. Vaccinated females outnumbered males, but the coverage rate resulted greater in males than females in all three seasons. While a higher proportion of vaccinated subjects worked in medical areas, the most evident increase over the three years was seen among subjects working in the services area. Conclusions: This survey highlights the importance of studying the determinants that influence vaccination adherence and how the COVID-19 pandemic has affected SIV coverage.