The hypothesis is that higher dose of antigen can increase the intensity and the quality of innate immunity, as the adaptive humoral and cellular responses.~In this study, the objectif is to evaluate innate and adaptive immunity following QIV-HD vaccination compared to QIV-SD vaccination in people 65 years of age and older.~Modifications of early blood molecular (transcriptome) and cellular (blood phenotyping) signatures within the first 24 hours following vaccination will be investigated. The association between early gene signature and late influenza-specific humoral immune responses weeks/months after vaccination will be also assessed.~This study is a hase IV, randomized, open-label, active-controlled, multi-center study comparing the immune response induced by QIV-HD vaccine (intervention) and QIV-SD vaccine (control).
The purpose of the study is to evaluate innate and adaptive immunity following QIV-HD vaccination compared to QIV-SD vaccination in people 65 years of age and older.