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 CoronaVac effectiveness in people living with HIV (PLWH) is limited. This study evaluated the immune response to CoronaVac and BNT162b2 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 comercial assays. Immune response was evaluated by age, sex, previous COVID-19 history, and CD4+ cell count.Findings: 189 participants were enrolled with 161 (85%) being PLWH. Among participants without previous 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 HIV-negative 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.