This project is an applied clinical study aimed at analyzing different patterns in responder and non-responder following influenza vaccination.. Distinct immunological and molecular signatures underpinning influenza vaccine responsiveness in the elderly

Seasonal influenza outbreaks, especially in high-risk groups such as the elderly, represent an important public health problem. The prevailing inadequate efficacy of seasonal vaccines, both conventional and elderly-tailored, is a crucial bottleneck. Understanding the immunological and molecular mechanisms underpinning differential influenza vaccine responsiveness is thus important in improving vaccination strategies. Here we perform a comprehensive characterization of the immune response of randomly selected elderly participants (≥ 65 years), triple immunized with adjuvanted influenza vaccine (Fluad), across two seasons. In-depth analyses by serology, multi-parametric flow cytometry, microbiome, multiplex and transcriptome (bulk and single cell) analysis, coupled to bioinformatics and mathematical modelling are applied to reveal distinguishing features between responders and non-responders defined by vaccine-induced seroconversion status. The generated comprehensive high dimensional dataset enables the identification of putative mechanisms and nodes responsible for vaccine non-responsiveness independent of confounding age-dependent related effects, with the potential to facilitate development of tailored vaccination strategies.