Avoiding the cost of complacency: barriers and solutions to ending the HIV epidemic in Europe.

Introduction: Despite significant advances in antiretroviral therapy and prevention strategies, Europe remains off track to meet the UNAIDS 2030 targets of ending HIV as a public health threat. This study explores the implications of failing to meet these targets by quantifying the associated costs and identifying pathways to get back on track. Methods: We adopted a mixed-methods approach across eight European countries. Targeted literature reviews estimated annual and lifetime HIV costs, identified barriers and solutions, and assessed evidence on long-acting injectables (LAIs). Epidemiological data from UNAIDS and ECDC informed projections of HIV prevalence and diagnoses to 2030 under three scenarios. Semi-structured stakeholder consultations validated and expanded the evidence base, and an expert roundtable prioritized solutions and evaluated LAIs' potential impact. Results: If current trends persist, over 98,000 new HIV diagnoses are projected between 2025-2030, adding more than €4 billion in healthcare costs and nearly €36 billion in lifetime costs. Prevalence-related costs across five countries could reach €66.3 billion by 2030. Barriers occur at multiple levels, including individual (low risk perception, treatment adherence), societal (stigma, limited community engagement), healthcare (restricted service accessibility), and policy (insufficient funding and fragmented surveillance). LAIs emerged as a promising strategy to overcome adherence challenges and reduce stigma. Conclusion: Without intensified action, Europe faces escalating costs and rising diagnoses. Tackling structural barriers and diversifying treatment options is essential to altering current trajectories. LAIs offer a potentially transformative addition to the HIV care landscape, but achieving their impact requires equitable access, sufficient healthcare capacity, and sustained political commitment.