Immune responses to infections and vaccinations are typically measured in blood. However, this does not reflect what is going on at the mucosal sites of infection or in the lymphoid tissues were immune memory is generated. We apply minimally-invasive sampling methods to collect samples from the airway mucosa and vaccine-draining lymph nodes. We use state of the art immunological and computational tools to study immune responses in such samples following infection and vaccination. Our aim is to understand how protective immunity is induced and maintained in the respiratory mucosa after infection and vaccination.