Ex vivo mucosal cultures: an emerging player in vaccine development

Increased awareness of pathogens with pandemic potential, especially respiratory viruses, is driving research on next-generation mucosal vaccines. However, clinical translation is still hampered by the lack of relevant experimental systems. Here, we review advances in human mucosal <i>ex vivo</i> cultures and their eligibility for vaccine development as an alternative to animal models. Ranging from organotypic air-liquid interface cultures to lymphoid organoids and microfluidics-based co-cultures, several breakthroughs occurred in recent years in modeling mucosa architecture and physiology, as well as adaptive immune responses. Advancing recent progress for clinical developments may require high-throughput approaches to validate the representativeness of the immune response within models, benchmark best practices for regulatory standardization, and investigate the influence of microbiota on mucosal immune responses.