Understanding why susceptibility to respiratory viral infection varies across the human lifespan requires experimental systems that faithfully reproduce age‑dependent epithelial and immune behaviour. Recent advances in primary human airway culture, including donor‑specific air–liquid interface (ALI) models, and organoid-derived epithelia now make it possible to capture this heterogeneity ex vivo. In this presentation, I will discuss how my group uses primary ALI cultures from paediatric and adult donors to study epithelial differentiation, innate immune signalling, and viral replication dynamics. A particular focus will be on our co-culture work integrating primary neutrophils into these epithelial systems to model early innate responses to respiratory virus infection. By combining real‑time imaging and controlled viral challenge we are uncovering how neutrophil recruitment, activation, and effector function differ with age and influence epithelial antiviral responses. These studies reveal age‑dependent variation in neutrophil–epithelium crosstalk, with consequences for inflammation, interferon signalling, and viral control.