Booster dose reshapes SARS-CoV-2 RBD-specific B cell immunity in people living with HIV

Le résumé fourni par la source

Long-term persistence of spike-specific memory B cells (MBC) upon mRNA SARS-CoV-2 vaccination remains poorly explored in people living with HIV (PLWH). We previously observed that the primary two-dose immunization elicited a B cell response quantitatively similar but phenotypically different compared to healthy participants (HC), with higher prevalence of CD27 - IgD - double-negative cells and lower proportion of CD27 + Ig-switched MBC. The PatoVac_COV longitudinal prospective single-centre study included 74 PLWH vaccinated with mRNA SARS-CoV-2 vaccines. Building upon our previous findings, blood samples were collected before and after the third and fourth doses, and two years after the first dose. PBMC were analysed for the RBD-specific MBC response by multidimensional flow cytometry, while spike-specific IgG were tested in plasma samples by ELISA and by surrogate virus neutralization assay. A supervised decision tree model was used to identify clinical and demographic predictors of RBD-specific MBC persistence. The third vaccine dose robustly recalled RBD-specific MBC, driving their differentiation into Ig-switched resting MBC, a subset undetectable before boosting and dominant also in HC. The fourth vaccine dose minimally impacted on the MBC response. IgG + resting MBC, recognizing both wild type and Omicron BA.2 strains, were still present two years after vaccination. Clinical and demographic factors associated to the persistence of IgG + resting RBD-specific MBC were time since initiation of current ART, BMI, CD8 + cells count, granulocytes count and blood creatinine levels. These findings highlight the impact of boosting, particularly the third dose, in enhancing and shaping the RBD-specific MBC in PLWH. Clinical and demographic variables associated with long-term MBC persistence may serve as potential biomarkers for predicting durable vaccine responses in PLWH.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.