RSVPreF3OA vaccine responses in kidney transplant recipients and dialysis patients versus healthy controls

BACKGROUND: Respiratory syncytial virus (RSV) causes severe respiratory illness in vulnerable populations, including kidney transplant recipients (KTRs) and dialysis patients (DPs). Despite the availability of RSV prefusion F protein-based vaccines, immune phenotyping of vaccine-specific B and T cells in KTRs and DPs remains limited. We hypothesized that RSVPreF3OA vaccination induces distinct immune signatures in KTRs and DPs compared with healthy controls (HCs), reflecting the impact of immunosuppression and uraemia on vaccine-induced B and T cell responses. METHODS: In this observational cohort, we analysed humoral and cellular responses following routine vaccination with the adjuvanted prefusion F protein-based RSVPreF3OA vaccine in 23 KTRs, 14 DPs and 24 HCs. Blood and saliva were collected at baseline and on days 30 and 90 post-vaccination. RSV-specific serum immunoglobulin G/immunoglobulin A, salivary antibodies and antigen-specific B and T cells were quantified by enzyme-linked immunosorbent assay and spectral flow cytometry, with tetanus- and severe acute respiratory syndrome coronavirus 2-specific responses assessed in parallel. RESULTS: In KTRs, vaccination induced increases in serum and salivary antibodies, expansion of RSV-specific B cells with enrichment of a switched memory phenotype unique to RSV-specific B cells and induction of RSV-A- and RSV-B-specific T cells with effector cytokine production. These signatures resembled those observed in HCs, whereas responses in DPs were delayed and attenuated. Across cohorts, RSV-specific B and T cells showed comparable phenotypic and functional characteristics. CONCLUSIONS: This study provides detailed immunophenotyping of RSVPreF3OA vaccine responses in KTRs, DPs and HCs over 90 days, showing that RSVPreF3OA vaccination induces protective RSV responses among KTRs comparable to HCs while DPs mount modestly lower cellular and humoral responses.