Immunogenicity of AZD1222 (ChAdOx1) SARS-CoV-2 vaccine in people living with HIV

Background: People living with HIV (PLWHIV) are at increased risk for severe COVID-19 [1]. We aimed to evaluate the serological response after two doses of AZD1222 (ChAdOx1) SARS-CoV-2 vaccination in PLWHIV. Materials and methods: Participants were evaluated before the first dose (baseline) and 3 months after the second dose of the ChAdOx1 vaccine. Patient's sera were analysed using the SARS-CoV-2 IgG II Quant Architect Abbott assay [2]. An antibody concentration ≥50 arbitrary units per milliliter (AU/mL) was defined as positive (seroconversion) [2]. We also compared the immunogenicity of AZD1222 in PLWHIV to sex-matched healthcare workers (controls) who received two doses of the BNT162b2 vaccine. The study measurements were done from April to December 2021. Results: Fifty-nine PLWHIV were included: 57 men, median age 45.0 years, all receiving antiretroviral treatment and with controlled viral loads (58 with HIV RNA 200 CD4+ cells/μL, and the median CD4 cell count was 722 (IQR 520 to 878) cells/μL (Table 1). Eight (13.6%) PLWHIV were obese (≥30.0 kg/m2), and 31 (52.5%) were overweight (excluding obese). At baseline 56 PLWHIV had an antibody concentration