biostudies-literatureBonduelle OSANOFI PASTEUR S.A.e184128https://www.ebi.ac.uk/biostudies/studies/S-EPMC12016920biostudies-literatureUnknown10(8)BACKGROUNDThe high-dose quadrivalent influenza vaccine (QIV-HD) showed superior efficacy against laboratory-confirmed illness compared with the standard-dose quadrivalent influenza vaccine (QIV-SD) in randomized controlled trials with the elderly. However, specific underlying mechanism remains unclear.METHODSThis phase IV randomized controlled trial compared early innate responses induced by QIV-HD and QIV-SD in 59 individuals aged > 65 years. Systemic innate cells and gene signatures at day 0 (D0) and D1 as well as hemagglutinin inhibition antibody (HIA) titers at D0 and D21 after vaccination were assessed.RESULTSQIV-HD elicited robust humoral response with significantly higher antibody titers and seroconversion rates than QIV-SD. At D1 after vaccination, QIV-HD recipients showed significJCI insightBoosting effect of high-dose influenza vaccination on innate immunity among elderly.PMC12016920E003603032Bonduelle OBennacer SCombadiere BAlves KINFLUOMICS Study groupJanssen CRogeaux OGhidi MWokam MLenormand Mde Bernard SLina BPetrier MDelory TFranco-Moscardini INourikyan JfalseBoosting effect of high-dose influenza vaccination on innate immunity among elderly.BACKGROUNDThe high-dose quadrivalent influenza vaccine (QIV-HD) showed superior efficacy against laboratory-confirmed illness compared with the standard-dose quadrivalent influenza vaccine (QIV-SD) in randomized controlled trials with the elderly. However, specific underlying mechanism remains unclear.METHODSThis phase IV randomized controlled trial compared early innate responses induced by QIV-HD and QIV-SD in 59 individuals aged > 65 years. Systemic innate cells and gene signatures at day 0 (D0) and D1 as well as hemagglutinin inhibition antibody (HIA) titers at D0 and D21 after vaccination were assessed.RESULTSQIV-HD elicited robust humoral response with significantly higher antibody titers and seroconversion rates than QIV-SD. At D1 after vaccination, QIV-HD recipients showed signific2025-01-01T00:00:00Z2025 Apr2026-06-02T04:15:04.261Z2025-07-06T03:04:08.684ZS-EPMC120169204003607710.1172/jci.insight.184128