Gaio, VâniaSaraiva, Ana LeonorSantos, Ana JoãoAmaral, PalmiraMachado, Ausenda2026-03-032026-03-032025-11http://hdl.handle.net/10400.18/11068Background: Healthcare workers (HCWs) play a critical role in vaccination uptake, both through personal adherence and by promoting immunisation among patients. Low vaccine confidence among HCWs can undermine public health efforts by reducing personal vaccination rates, but also impacting vaccine recommendations. This study aimed to assess psychosocial determinants influencing vaccine confidence among HCWs in Portugal. Methods: A cross-sectional study was conducted between October and November 2024 among doctors and nurses from a Portuguese healthcare unit. An online questionnaire incorporating an adapted short version of the Professionals Vaccine Confidence and Behaviors (Pro-VC-Be) scale was applied. Exploratory factor analysis (EFA) was conducted to assess the scale’s unidimensionality. Descriptive statistics, bivariate analyses (vaccinated vs. non-vaccinated) using Fisher’s exact and Pearson’s Chi-squared tests were performed to identify key psychosocial dimensions of vaccine confidence. Results: Among 112 HCWs (82% female; 71% nurses), 67% were vaccinated against COVID-19 in the 2024/25 season. EFA suggested an unidimensional structure, with one dominant factor (eigenvalue=1.90) explaining 56% of the variance. Vaccinated HCWs showed significantly higher confidence scores (mean=42.9 vs. 40.8; p=0.003). Trust in vaccine safety (p=0.027), belief in vaccine benefits (p=0.011), and complacency (p=0.048) were positively associated with COVID-19 vaccination status. Conclusions: This exploratory study highlights key psychosocial determinants of vaccine confidence among Portuguese HCWs, notably perceived safety and effectiveness. Given the small sample size, results should be interpreted with caution. Applying the scale to a larger and more diverse population of HCWs is essential to validate these findings and support the development of targeted strategies focusing on building trust and combating misinformation to enhance vaccine uptake.engVaccine ConfidencePsychosocial FactorsHealthcare WorkersEstados de Saúde e de DoençaDeterminantes da Saúde e da Doençaconference object