Defining the contribution of variable microbial factors and host immunity to pertussis severity – PERT-SEVEREII

Pertussis resurgence is associated strain vaccine-escape evolution driven by acellular vaccines, with a possible impact on vaccine effectiveness and clinical presentation in children. The mechanisms responsible for this clinical variability and the development of its most severe form, fulminant pertussis, have not been well characterized. We will deploy an integrative strategy that combines clinical, microbiological, immunological, and omics approaches based on a prospective clinical cohort of pediatric pertussis infections, to 1) identify gene expression profiles of current Bp according to clinical outcome, integrating recent microbial evolution changes, and 2) profile the immune responses at the systemic and mucosal levels of children infected by Bp. This study is a prerequisite for the identification of new candidate vaccine antigens, adapted to pathogen evolution and specific immune responses in children.