Bridging the Gap: identifying factors impacting mRNA SARS-CoV-2 vaccine booster response in people living with HIV-1.

OBJECTIVES This study aimed to investigate the association of demographic and clinical characteristics, including HIV-specific parameters with the antibody response to a third dose of a SARS-CoV-2 mRNA vaccine in people living with HIV-1 (PWH). DESIGN Post-hoc analysis of data collected during the observational extension of the COrona VaccinE tRiAL pLatform trial (COVERALL-2) nested into the Swiss HIV Cohort Study. METHODS Serological measurements were conducted on a total of 439 PWH who had received a third dose of either mRNA-1273 (Moderna) or BNT162b2 (Pfizer-BioNTech) SARS-CoV-2 vaccine. Antibody reactivity was assessed using the multifactorial ABCORA immunoassay that defines SARS-CoV-2 seroconversion and predicts neutralization activity. The association between log transformed antibody reactivity and various baseline factors, including vaccine type, demographics, immune and viral status, smoking status, co-morbidities, infection history, and co-medication with chemotherapy and immunosuppressive drugs, was investigated using a multivariable linear regression model. RESULTS Antibody response against SARS-CoV-2 after a third vaccination was significantly lower among PWH with CD4 cell count