Safety and immunogenicity of the ChAdOx1 nCoV-19 (AZD1222) vaccine against SARS-CoV-2 in HIV infection: a single-arm substudy of a phase 2/3 clinical trial


Data on vaccine immunogenicity against SARS-CoV-2 are needed for the 40 million people globally living with HIV who might have less functional immunity and more associated comorbidities than the general population. We aimed to explore safety and immunogenicity of the ChAdOx1 nCoV-19 (AZD1222) vaccine in people with HIV.


In this single-arm open-label vaccination substudy within the protocol of the larger phase 2/3 trial COV002, adults aged 18–55 years with HIV were enrolled at two HIV clinics in London, UK. Eligible participants were required to be on antiretroviral therapy (ART), with undetectable plasma HIV viral loads (<50 copies per mL), and CD4 counts of more than 350 cells per μL. A prime-boost regimen of ChAdOx1 nCoV-19, with two doses was given 4–6 weeks apart. The primary outcomes for this substudy were safety and reactogenicity of the vaccine, as determined by serious adverse events and solicited local and systemic reactions. Humoral responses were measured by anti-spike IgG ELISA and antibody-mediated live virus neutralisation. Cell-mediated immune responses were measured by ex-vivo IFN-γ enzyme-linked immunospot assay (ELISpot) and T-cell proliferation. All outcomes were compared with an HIV-uninfected group from the main COV002 study within the same age group and dosing strategy and are reported until day 56 after prime vaccination. Outcomes were analysed in all participants who received both doses and with available samples. The COV002 study is registered with, NCT04400838, and is ongoing.


Between Nov 5 and Nov 24, 2020, 54 participants with HIV (all male, median age 42·5 years [IQR 37·2–49·8]) were enrolled and received two doses of ChAdOx1 nCoV-19. Median CD4 count at enrolment was 694·0 cells per μL (IQR 573·5–859·5). No serious adverse events occurred. Local and systemic reactions occurring during the first 7 days after prime vaccination included pain at the injection site (26 [49%] of 53 participants with available data), fatigue (25 [47%]), headache (25 [47%]), malaise (18 [34%]), chills (12 [23%]), muscle ache (19 [36%]), joint pain (five [9%]), and nausea (four [8%]), the frequencies of which were similar to the HIV-negative participants. Anti-spike IgG responses by ELISA peaked at day 42 (median 1440 ELISA units [EUs; IQR 704–2728]; n=50) and were sustained until day 56 (median 941 EUs [531–1445]; n=49). We found no correlation between the magnitude of the anti-spike IgG response at day 56 and CD4 cell count (p=0·93) or age (p=0·48). ELISpot and T-cell proliferative responses peaked at day 14 and 28 after prime dose and were sustained to day 56. Compared with participants without HIV, we found no difference in magnitude or persistence of SARS-CoV-2 spike-specific humoral or cellular responses (p>0·05 for all analyses).


In this study of people with HIV, ChAdOx1 nCoV-19 was safe and immunogenic, supporting vaccination for those well controlled on ART.

Author list


Prof John Frater, PhD  †

Katie J Ewer, PhD †

Ane Ogbe, PhD †

Mathew Pace, PhD †

Sandra Adele, MSc 

Emily Adland, DPhil 

Jasmini Alagaratnam, MBBS 

Parvinder K Aley, PhD 

Mohammad Ali, MD 

M Azim Ansari, DPhil 

Anna Bara, MPhil 

Mustapha Bittaye, PhD 

Samantha Broadhead, BSc 

Anthony Brown, BSc 

Helen Brown, BSc 

Federica Cappuccini, PhD 

Enya Cooney, MBBS 

Wanwisa Dejnirattisai, PhD 

Christina Dold, PhD 

Cassandra Fairhead, MBBS 

Henry Fok, PhD 

Pedro M Folegatti, MD 

Jamie Fowler, BA 

Charlotte Gibbs

Anna L Goodman, FRCP 

Daniel Jenkin, MRCP 

Mathew Jones, DPhil 

Rebecca Makinson, MBiol 

Natalie G Marchevsky, MSc 

Yama F Mujadidi, MSc 

Hanna Nguyen, MBBS 

Lucia Parolini, PhD 

Claire Petersen, MSc 

Emma Plested

Katrina M Pollock, PhD 

Maheshi N Ramasamy, DPhil 

Sarah Rhead, MBChB 

Hannah Robinson, RN 

Nicola Robinson, MSc 

Patpong Rongkard, MSc 

Fiona Ryan, MBBch 

Sonia Serrano, BSc 

Timothy Tipoe, MBChB 

Merryn Voysey, DPhil 

Anele Waters, MRes 

Panagiota Zacharopoulou, MSc 

Prof Eleanor Barnes, PhD 

Prof Susanna Dunachie, PhD 

Prof Philip Goulder, DPhil 

Prof Paul Klenerman, FMedSci 

Prof Gavin R Screaton, PhD 

Prof Alan Winston, MD 

Prof Adrian V S Hill, FMedSci †

Prof Sarah C Gilbert, PhD †

Prof Andrew J Pollard, FMedSci †

Prof Sarah Fidler, PhD †

Julie Fox, MD †

Prof Teresa Lambe, PhD †

for the

Oxford COVID Vaccine Trial Group

Novel Coronavirus SARS-CoV-2


The Lancet - HIV