biostudies-literatureUnknownRiou CEuropean & Developing Countries Clinical Trials Partnership (EDCTP)NIAID NIH HHSWellcome Trust<h4>Background</h4>We report the safety and immunogenicity of fractional and full dose Ad26.COV2.S and BNT162b2 in an open label phase 2 trial of participants previously vaccinated with a single dose of Ad26.COV2.S, with 91.4% showing evidence of previous SARS-CoV-2 infection.<h4>Methods</h4>A total of 286 adults (with or without HIV) were enrolled >4 months after an Ad26.COV2.S prime and randomized 1:1:1:1 to receive either a full or half-dose booster of Ad26.COV2.S or BNT162b2 vaccine. B cell responses (binding, neutralization and antibody dependent cellular cytotoxicity-ADCC), and spike-specific T-cell responses were evaluated at baseline, 2, 12 and 24 weeks post-boost. Antibody and T-cell immunity targeting the Ad26 vector was also evaluated.<h4>Results</h4>No vaccine-associated serioumedRxiv : the preprint server for health sciences2023.11.20.23298785https://www.ebi.ac.uk/biostudies/studies/S-EPMC10690356biostudies-literatureSafety and immunogenicity of booster vaccination and fractional dosing with Ad26.COV2.S or BNT162b2 in Ad26.COV2.S-vaccinated participants.PMC1069035675N93021C0001696833UM1 AI068614TMA2016SF-1535226137/Z/22/Z75N93019C00065TMA2017SF-1951Sette AMoyo-Gwete TRees HRiou CAyres FGill KNgomti APanchia RSigal AMadzivhandila MPatel FSingh UBenede NMosala PHermanus TBalla SRGrifoni AVenter EMDhar MNesamari RBesethi ASMkhize QManamela NPGarrett NNkayi AABekker LGBernstein MWalters ANana AKaldine HMzindle NBKgagudi PCrowther CNkosi TPMoore PLFairlie LMakhado ZGeyer SGanga YBhiman JNMotlou TPBurgers WAKeeton RSBaguma RLazarus EOmondi MAvan Graan SLustig GSawry SRichardson SIRoux JLMagugu SFMutavhatsindi HGray GKhan KCele SfalseSafety and immunogenicity of booster vaccination and fractional dosing with Ad26.COV2.S or BNT162b2 in Ad26.COV2.S-vaccinated participants.<h4>Background</h4>We report the safety and immunogenicity of fractional and full dose Ad26.COV2.S and BNT162b2 in an open label phase 2 trial of participants previously vaccinated with a single dose of Ad26.COV2.S, with 91.4% showing evidence of previous SARS-CoV-2 infection.<h4>Methods</h4>A total of 286 adults (with or without HIV) were enrolled >4 months after an Ad26.COV2.S prime and randomized 1:1:1:1 to receive either a full or half-dose booster of Ad26.COV2.S or BNT162b2 vaccine. B cell responses (binding, neutralization and antibody dependent cellular cytotoxicity-ADCC), and spike-specific T-cell responses were evaluated at baseline, 2, 12 and 24 weeks post-boost. Antibody and T-cell immunity targeting the Ad26 vector was also evaluated.<h4>Results</h4>No vaccine-associated seriou2023-01-01T00:00:00Z2023 Nov2026-05-14T03:15:44.795Z2025-04-05T11:15:17.504ZS-EPMC106903563804532110.1101/2023.11.20.23298785