3.Y.1. PechaKucha: Vaccine hesitancy in European parents and adolescents: epidemiology, determinants, interventions

Abstract Vaccine hesitancy, defined as the delay in acceptance or outright refusal of vaccines despite their availability, represents a significant public health challenge by undermining immunization efforts and increasing the risk of outbreaks of vaccine-preventable diseases. Epidemiological studies consistently demonstrate the widespread presence of vaccine hesitancy, particularly among parents and adolescents. For instance, recent data (2022-23) from Europe indicate that 20.8% of adolescents and 20.4% of parents exhibit hesitancy toward vaccination, with key determinants including concerns over vaccine safety, fear of adverse events, and diminished trust in health authorities (Millat-Martínez et al., 2025). This phenomenon results in inadequate vaccination coverage and increased vulnerability to vaccine- preventable diseases, particularly within young populations. This scientific session aims to examine the complex nature of vaccine hesitancy by presenting epidemiological trends, socio-behavioral determinants, and barriers to vaccination among parents and adolescents. The workshop seeks to foster a comprehensive, evidence-based understanding among public health professionals and stakeholders, while promoting actionable strategies through interdisciplinary dialogue and meaningful engagement. The added value of this workshop lies in its integration of current research, policy perspectives, and practical experiences to address vaccine hesitancy in this important target group. The session will feature four presentations, each contributing to a coherent exploration of the topic. First, a systematic review of the primary literature will elucidate the relationship between vaccine hesitancy and vaccine uptake among adolescents. Second, a recent Italian representative survey on HPV vaccine acceptance, with a special focus on parents of children aged 12-18 and adult children (> 18 years) will be presented. Third, a large- scale investigation on vaccine hesitancy in Italy, within the larger INF-ACT project, will be presented focusing on parental attitudes and behaviors toward childhood immunization and related issues such accessibility to services, particularly for children and adolescents. Fourth, preliminary data from a study in the Netherlands will be presented, evaluating a web-based decision aid to inform and support decision-making about routine childhood vaccinations, targeting (prospective) parents from pregnancy onwards. The workshop will follow the Pecha Kucha Format: four presentations, each consisting of 15 slides that auto-advance every 15 seconds, followed by a 10-minute Q&A. The session aims to enhance delegates’ ability to address vaccine hesitancy among parents and adolescents, and to showcase actionable, innovative practices applicable across Europe. Key messages • Vaccine hesitancy is a widespread challenge in Europe driven primarily by safety concerns, fear of adverse events, and eroded trust in health authorities, heightening outbreak risks. • Multi-level, evidence-based interventions are essential to effectively address hesitancy and bolster vaccine acceptance among parents and adolescents.