Abstract
BACKGROUND: The 2019 Coronavirus disease (COVID-19) pandemic has affected hundreds of millions globally, resulting in millions of deaths. People living with HIV (PLWH) typically exhibit significantly lower antibody titers after vaccination compared to healthy individuals, and are particularly vulnerable to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) due to their compromised immune system. Given the continuous emergence of SARS-CoV-2 variants, monitoring immune responses in this high-risk population is crucial. This study aims to investigate SARS-CoV-2 antibody dynamics in PLWH during the Omicron BA.5 and XBB.1.5 waves in China, with a focus of vaccination and antibody detection kits. METHODS: In December 2022, we recruited 147 PLWH who were initially infected with the Omicron variant during the BA.5 wave. They were unvaccinated, fully vaccinated, or received a dose of booster immunization. A four-month follow-up was conducted during the XBB.1.5 wave. At both time points, information related to basic demographic, HIV, and COVID-19 were collected. Peripheral blood samples were obtained to measure SARS-CoV-2 antibody levels and HIV viral loads. SARS-CoV-2 antibody levels were measured using eight serological kits against wild-type S strain, and two kits against BA.4/5 and XBB.1.5 strains, respectively. RESULTS: Booster vaccination was associated with the highest antibody levels after breakthrough infection, followed by full vaccination, and unvaccination. The differences in antibody levels between three groups diminished by the second follow-up in the reinfected PLWH. Those with HIV viral load higher than 30 IU/mL exhibited reduced antibody responses. Spearman correlation analysis showed that in the vaccinated individuals with Omicron reinfection, the kits against wild-type strain showed poorer correlation with BA.4/5 and XBB.1.5 kits than unvaccinated individuals, confirming antibody repertoire alterations after repeated exposure. CONCLUSIONS: Our findings show the importance of vaccination in enhancing SARS-CoV-2 immunity among PLWH, with the diminishing differences in antibody levels in repeated Omicron reinfections. The results emphasize the need for continuous monitoring using variant-specific serological kits and adaptation of vaccination strategies.