biostudies-literatureMdluli TNIAID NIH HHS114344https://www.ebi.ac.uk/biostudies/studies/S-EPMC11298786biostudies-literatureUnknown43(6)A heterologous Ad26/MVA vaccine was given prior to an analytic treatment interruption (ATI) in people living with HIV-1 (mainly CRF01_AE) who initiated antiretroviral treatment (ART) during acute HIV-1. We investigate the impact of Ad26/MVA vaccination on antibody (Ab)-mediated immune responses and their effect on time to viral rebound. The vaccine mainly triggers vaccine-matched binding Abs while, upon viral rebound post ATI, infection-specific CRF01_AE binding Abs increase in all participants. Binding Abs are not associated with time to viral rebound. The Ad26/MVA mosaic vaccine profile consists of correlated non-CRF01_AE binding Ab and Fc effector features, with strong Ab-dependent cellular phagocytosis (ADCP) responses. CRF01_AE-specific ADCP responses (measured either prior to or postCell reportsMosaic vaccine-induced antibody-dependent cellular phagocytosis associated with delayed HIV-1 viral load rebound post treatment interruption.PMC11298786UM1 AI126603Kroon EPinyakorn SRolland MPhanupak NVasan STran USchuitemaker HHsu DCTrautmann LDussupt VStieh DJSlike BMde Souza MAke JAColby DJAnanworanich JPau MGShubin ZMdluli TMendez-Rivera LSacdalan CCurtis DJLi YTomaka FLRobb MLKrebs SJPaquin-Proulx DfalseMosaic vaccine-induced antibody-dependent cellular phagocytosis associated with delayed HIV-1 viral load rebound post treatment interruption.A heterologous Ad26/MVA vaccine was given prior to an analytic treatment interruption (ATI) in people living with HIV-1 (mainly CRF01_AE) who initiated antiretroviral treatment (ART) during acute HIV-1. We investigate the impact of Ad26/MVA vaccination on antibody (Ab)-mediated immune responses and their effect on time to viral rebound. The vaccine mainly triggers vaccine-matched binding Abs while, upon viral rebound post ATI, infection-specific CRF01_AE binding Abs increase in all participants. Binding Abs are not associated with time to viral rebound. The Ad26/MVA mosaic vaccine profile consists of correlated non-CRF01_AE binding Ab and Fc effector features, with strong Ab-dependent cellular phagocytosis (ADCP) responses. CRF01_AE-specific ADCP responses (measured either prior to or post2024-01-01T00:00:00Z2024 Jun2026-06-01T15:24:59.777Z2025-02-19T04:40:53.562ZS-EPMC112987863885052910.1016/j.celrep.2024.114344