Humoral immune response in people living with HIV after administration of SARS-CoV-2 vaccine CoronaVac or BNT162b2 or CoronaVac/BNT162b2 booster sequence: A cross-sectional study

Background: The evidence of SARS-CoV-2 vaccine effectiveness in people living with HIV (PLWH) is limited. This study evaluated the humoral immune response to CoronaVac (TM) (virus inactivated) and BNT162b2 (mRNAbased) vaccines in PLWH and HIV-negative controls, with and without a booster sequence. Methods: We conducted a cross-sectional study on PLWH and HIV-negative controls who received CoronaVac or BNT162b2, with a subgroup receiving a CoronaVac/BNT162b2 booster. Blood samples were collected 4-6 months after primary vaccination and tested for anti-SARS-CoV-2 protein S (aSAb) and neutralizing antibodies (NtAb) using validated assays. Immune response was evaluated by age, sex, previous COVID-19 history, and CD4 + cell count. Findings: One hundred and eighty nine participants were enrolled with 161 (85%) being PLWH. Among participants without previous known COVID-19, median aSAb levels were significantly lower in PLWH who received CoronaVac compared to BNT162b2 (32 U/mL vs. 587 U/mL, p < 0.001), with similar results in HIV-negative controls. NtAb presence was also significantly lower after CoronaVac compared to BNT162b2 (30% vs. 93%, p < 0.001). The booster sequence group showed a significant increase in aSAb titers in both PLWH and HIVnegative controls (from 33 U/ml to 2500 U/ml, p < 0.001), and NtAb positivity increased from 20% to 95 % in PLWH, and 27% to 100% in HIV-negative controls. Prior COVID-19 led to significantly higher post-vaccine antibody titers particularly in the BNT162b2 group. PLWH with CD4 + count < 200 cells/mL showed a weaker immune response to both vaccines. Interpretation: CoronaVac resulted in a weaker immune response in both PLWH and HIV-negative controls compared to BNT162b2, particularly in immunosuppressed PLWH without prior COVID-19. Hybrid immunity and heterologous booster vaccination increased antibody levels. Funding: Local funding.