WILLINGNESS AND ADHERENCE TOWARDS SEASONAL VACCINATIONS AGAINST RESPIRATORY VIRUSES AMONG HEALTHCARE WORKERS IN A SOUTHERN ITALIAN UNIVERSITY HOSPITAL

Healthcare workers (HCWs) represent a priority group for vaccination against vaccine-preventable diseases (VPDs), particularly those transmitted by airborne routes, due to both occupational exposure and their potential role in transmitting infections to vulnerable patients. Nevertheless, in many countries, including Italy, where regional disparities persist, vaccination coverage among HCWs remains suboptimal. While vaccine hesitancy is often cited as a barrier, changes in risk perception following the pandemic – and, potentially, vaccine fatigue regarding COVID-19 vaccines – could contribute to a further decline in adherence rates. The objective of this study was to assess willingness and adherence toward vaccination against respiratory viruses among HCWs at the main university hospital of Western Sicily (Italy) and to evaluate adherence to seasonal influenza and COVID-19 vaccines over two consecutive winter seasons (2023-24 and 2024-25). To this end, a cross-sectional survey was conducted among HCWs at the University Hospital of Palermo in the two seasons (n=52 and n=59, respectively). The questionnaire collected socio-demographic and professional data, vaccination uptake (influenza and COVID-19), and items from the validated Vaccine Hesitancy Scale (VHS). Trends in VHS scores and vaccination coverage were compared across seasons. Logistic regression was used to identify predictors of uptake. Participants in 2023-24 were 63% women (mean age 43.7±14.0), while in 2024-25 they were 61% women (mean age 39.0±12.9). VHS scores indicated low and stable levels of hesitancy (2023-24: 2.14±0.85; 2024-25: 2.04±0.83), with no significant differences between vaccinated and unvaccinated respondents. Nonetheless, influenza vaccine uptake declined from 59.6% (31/52) to 35.6% (21/59) (χ²=5.27; p=0.058), and COVID-19 uptake decreased from 21.1% (11/52) to 6.8% (4/59) (χ²=3.28; p=0.036). Despite stable and favorable attitudes, uptake of both influenza and COVID-19 vaccines among HCWs at a major referral hospital declined across the two seasons studied. This trend could reflect a phenomenon of vaccine fatigue, possibly linked to reduced salience and trust in COVID-19 vaccination, which in turn may have influenced adherence to influenza vaccination. These findings highlight the need for strategies that address not only attitudes but also organizational and contextual barriers.