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BackgroundPeople with HIV on antiretroviral therapy with good CD4 T cell counts make effective immune responses following vaccination against SARS-CoV-2. There are few data on longer term responses and the impact of a booster dose.MethodsAdults with HIV were enrolled into a single arm open label study. Two doses of ChAdOx1 nCoV-19 were followed twelve months later by a third heterologous vaccine dose. Participants had undetectable viraemia on ART and CD4 counts >350 cells/µl. Immune responses to the ancestral strain and variants of concern were measured by anti-spike IgG ELISA, MesoScale Discovery (MSD) anti-spike platform, ACE-2 inhibition, Activation Induced Marker (AIM) assay and T cell proliferation.Findings54 participants received two doses of ChAdOx1 nCoV-19. 43 received a third dose (42 with BNT162b2; 1 with mRNA-1273) one year after the first dose. After the third dose, total anti-SARS-CoV-2 spike IgG titres (MSD), ACE-2 inhibition and IgG ELISA results were significantly higher compared to Day 182 titres (P ConclusionsIn PWH receiving a third vaccine dose, there were significant increases in B and T cell immunity, including to known VOCs.

Original publication





Clinical infectious diseases : an official publication of the Infectious Diseases Society of America

Publication Date



Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, UK.