Markers of T-cell dysfunction and not inflammaging predict the waning of humoral responses to SARS-CoV-2 mRNA booster vaccination in people with HIV.

In this prospective longitudinal study, we evaluated the durability of humoral responses to SARS-CoV-2 mRNA booster vaccination in 93 people with HIV, exploring the possible role of T-cell dysfunction and inflammaging biomarkers in predicting antibody waning. We found that, despite a negligible influence of the inflammaging milieu, low CD4/CD8 ratio and CD4+CD127+ percentage as well as high CD8+CD38+CD45RO+ percentage are associated with faster antibody waning, in turn contributing to our understanding of the determinants of COVID-19 vaccine-elicited immune response in this population.