biostudies-literatureJackson SBritish Heart FoundationMedical Research CouncilNational Institute for Health Research (NIHR)Wellcome Trust655-668https://www.ebi.ac.uk/biostudies/studies/S-EPMC7616636biostudies-literatureUnknown5(7)<h4>Background</h4>A SARS-CoV-2 controlled human infection model (CHIM) has been successfully established in seronegative individuals using a dose of 1×10¹ 50% tissue culture infectious dose (TCID₅₀) pre-alpha SARS-CoV-2 virus. Given the increasing prevalence of seropositivity to SARS-CoV-2, a CHIM that could be used for vaccine development will need to induce infection in those with pre-existing immunity. Our aim was to find a dose of pre-alpha SARS-CoV-2 virus that induced infection in previously infected individuals.<h4>Methods</h4>Healthy, UK volunteers aged 18-30 years, with proven (quantitative RT-PCR or lateral flow antigen test) previous SARS-CoV-2 infection (with or without vaccination) were inoculated intranasally in a stepwise dose escalation CHIM with eithThe Lancet. MicrobeSafety, tolerability, viral kinetics, and immune correlates of protection in healthy, seropositive UK adults inoculated with SARS-CoV-2: a single-centre, open-label, phase 1 controlled human infection study.PMC7616636MR/X009297/1222305/Z/21/ZNIHR300791CH/16/1/32013222305Fredsgaard-Jones TPWSodipo VLonget SSette ACarroll MPatel BPollard AJCatchpole AConway OLuciw MCOV-CHIM01 study teamHarris SAParvelikudy BMarshall JLHughes EBenamore RAlparaque MTipton TVoaides AOrobiyi-Rieba MPlatt ALaidlaw SMujadidi YValmores MAMorrison HCabrera Puig IBreuer JLopez-Ramon RTanner RBarnes EGleeson FQuaddy JVuddamalay GStone HPreston-Jones HByard NTurner CCrowther CDoherty RPRapeport GFerreira VMMawer ANehiweze ANyamunda SAteere ASatti IPswarayi DBharti NJackson SMcShane HMitchell RChiu CSrijith PDunachie SJStylianou EWu MSSamuel BEBurns AJose JCooper CAnid LJohnstone TfalseSafety, tolerability, viral kinetics, and immune correlates of protection in healthy, seropositive UK adults inoculated with SARS-CoV-2: a single-centre, open-label, phase 1 controlled human infection study.<h4>Background</h4>A SARS-CoV-2 controlled human infection model (CHIM) has been successfully established in seronegative individuals using a dose of 1×10¹ 50% tissue culture infectious dose (TCID₅₀) pre-alpha SARS-CoV-2 virus. Given the increasing prevalence of seropositivity to SARS-CoV-2, a CHIM that could be used for vaccine development will need to induce infection in those with pre-existing immunity. Our aim was to find a dose of pre-alpha SARS-CoV-2 virus that induced infection in previously infected individuals.<h4>Methods</h4>Healthy, UK volunteers aged 18-30 years, with proven (quantitative RT-PCR or lateral flow antigen test) previous SARS-CoV-2 infection (with or without vaccination) were inoculated intranasally in a stepwise dose escalation CHIM with eith2024-01-01T00:00:00Z2024 Jul2026-06-01T07:33:18.135Z2025-04-04T23:48:22.669ZS-EPMC76166363870378210.1016/S2666-5247(24)00025-9