Interdisciplinary symposium on challenges and opportunities for vaccines: A comprehensive approach of current and future vaccine strategies to improve vaccine effectiveness in complex chronic infectious contexts

Vaccination is a key public health intervention, but vaccine immunogenicity, efficacy, and effectiveness vary geographically. These variations are not yet fully understood but are likely influenced by factors such as chronic infections, environmental and genetic differences, social and behavioral factors, and operational challenges, particularly in low- and middle-income countries (LMICs). To address these issues, the “International Symposium on Global Challenges and Opportunities for Vaccines” was held in Kloster Bernried, Germany, bringing together international scientists and stakeholders. Key discussions included: (1) Compromised vaccine immunogenicity due to helminth infections, (2) new vaccine approaches in vaccine development, (3) new frontiers in therapeutic vaccination, (4) challenges of vaccine trials, especially in low-resource settings, and (5) conceptualizing vaccine confidence in low and high resource contexts. The symposium highlighted the challenges of conducting vaccine trials in LMICs, such as participant follow-up, logistics, resources, and building trust. The main recommendation was to improve future vaccine trial designs through a comprehensive, interdisciplinary approach, including tools to evaluate vaccine immunogenicity, efficacy, and effectiveness.