Elena Mitsi is an Associate Professor of Infection and Mucosal Immunity at the University of Oxford, UK. Her research focuses on viruses and bacteria, such as RSV and Streptococcus pneumoniae, that primarily affect mucosal sites in the human body, using controlled human infection models (CHIM) and natural infection cohort studies. Her work integrates CHIMs, advanced mucosal sampling methods, and in vitro infection models (3D human airway models, organoids) to investigate host–pathogen interactions, transmission dynamics, and their underpinning mechanisms, aiming to inform the development of new vaccines and novel therapeutic strategies.