Safety and Immunogenicity of the ChAdOx1 nCoV-19 Vaccine in People with HIV

23 Jun, 21

Introduction

Vaccination against SARS-CoV-2 reduces morbidity and mortality associated with COVID-19. Mortality due to COVID-19 has been speculated to be higher in people with HIV, and particularly those from black and minority ethnic groups or with comorbidities, than in general population. Limited data exist on immune responses to vaccination against SARS-CoV-2 in people with HIV.

Aim

To evaluate safety and immunogenicity of the ChAdOx1 nCoV-19 (AZD1222) vaccine in PLHIV on ART with CD4 counts >350 cells/µl.

Patient Population

HIV adults aged 18–55 years on antiretroviral therapy (ART)
With undetectable plasma HIV viral loads (<50 copies per mL)
CD4 counts of more than 350 cells per ?L

Methods

Single-arm open-label vaccination substudy within the larger multicentre phase 2/3 COV002 trial
54 participants with HIV received ChAdOx1 nCoV-19 prime and boost vaccinations between 4–6 weeks
Humoral responses were measured using a standardised total IgG ELISA against trimeric SARS-CoV-2 spike protein
Antibody neutralisation was measured in a randomly selected subset of participants by use of a focus reduction neutralisation test (FRNT)
Cell-mediated immune responses were measured by ex-vivo IFN-? enzyme-linked immunospot assay (ELISpot).
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.

Endpoints

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
The secondary outcome of interest in this cohort was the immunogenicity profile of ChAdOx1 nCoV-19 in people living with HIV

Results

All participants were male with a median age of 42.5 Years
No serious adverse events were reported

Table 1: Local and systemic reactions occurring during the first 7 days after prime and boost vaccination

Adverse events	No of patients (%)
Adverse events	Prime Vaccination (n=53)	Boost Vaccination (n=51)
pain at the injection site	49%	20%
fatigue	47%	29%
headache	47%	24%
malaise	34%	18%
chills	23%	8%
muscle ache	36%	14%
Feverish	19%	6%
joint pain	9%	10%
nausea	8%	8%

The frequencies of local and systemic reactions occurring during the first 7 days after prime vaccination were similar to the HIV-negative participants

Anti-spike IgG responses by ELISA peaked at day 42 and were sustained until day 56
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)
Summed IFN-? ELISpot responses across 12 pools of SARS-CoV-2 spike peptides peaked on day 14 after prime dose and were sustained at a lower level until day 56
At all timepoints, responses were significantly increased compared with baseline
No difference in magnitude or persistence of SARS-CoV-2 spike-specific humoral or cellular responses (p>0·05 for all analyses) were observed in patients with HIV compared to without HIV

Conclusion

ChAdOx1 nCoV-19 was safe and immunogenic, supporting vaccination for those HIV patients on well controlled on ART
The findings suggested that ChAdOx1 nCoV-19 is likely to be protective and efficacious against COVID-19 for people with HIV and emphasizes that this population should be supported to receive vaccination against SARS-CoV-2

Reference

Lancet HIV. June 18, 2021 https://doi.org/10.1016/ S2352-3018(21)00103-X