Rotavirus Vaccines at 20 Years: Success, Challenges, and the Road Ahead.

Twenty years after the introduction of rotavirus vaccines, the 15th International Rotavirus Symposium convened researchers, clinicians, immunization program managers, and policymakers to review advances in rotavirus epidemiology, immunology, vaccine development, and implementation. Rotavirus vaccination has contributed to sustained reductions in severe rotavirus hospitalizations and child mortality, yet population-level benefits remain heterogeneous and are constrained by gaps in coverage, supply-related program disruptions, and context-specific vaccine performance. Presenters highlighted evidence from multi-pathogen surveillance confirming that rotavirus remains a leading cause of pediatric diarrhea requiring hospitalization despite widespread vaccine introduction. Accumulating evidence implicates maternally derived antibodies, environmental enteric dysfunction, and early-life microbiome development as contributors to reduced oral vaccine performance in low- and middle-income communities, while recent studies of next-generation vaccine candidates underscore the need for improved correlates of protection and clinically meaningful efficacy endpoints. Collectively, the symposium emphasized that further reductions in rotavirus morbidity and mortality will require strengthening delivery of existing vaccines-including improving coverage, minimizing supply interruptions, and reaching zero-dose and under-immunized children-while sustaining surveillance and investing in integrated enteric disease prevention and next-generation vaccines to optimize protection in high-burden settings.