Response to BNT162b2 mRNA COVID-19 vaccine of ART-experienced people living with HIV: a prospective analysis from a single-center study in Rome, Italy

Objectives: We aimed to assess the immunologic response to BNT162b2 mRNA COVID-19 vaccine in ART-experienced people living with HIV (PLWH). Methods: In this pilot prospective study, we enrolled 20 PLWH (all on effective ART, 80% with CD4 cells count >500) and 52 immunocompetent health-care workers, as control. All subjects received two doses of vaccine 21 days apart. Serum samples were collected at different time points, immediately before first administration (BL) and 21 days after each dose (T1 and T2) and 45-50 days after second dose (T3). We evaluated the immune response in terms of frequency of responders and antibody titers against SARS-CoV-2 at each timepoint. The viro-immunological parameters of PLWH were also monitored. Results: We found that the participants displayed an immune response after the first dose that increased markedly at T2. At T3 a significantly descending trend of IgG levels was observed in both groups. No difference in humoral immune response assessed in terms of percentage of responders after first and second dose and in terms of IgG titers over time and at each time point was found between groups. Any significant variation in terms of viremia and immunological parameters was observed in PLWH. Conclusions: BNT162b2 mRNA COVID-19 vaccine appears immunogenic in this setting of PLWH eliciting an immune response comparable to that of healthy donors.