SARS-CoV-2 spike-directed T cells and anti-receptor-binding-domain antibodies in hematological patients receiving three mRNA COVID-19 vaccine doses
Introduction: Studies assessing SARS-CoV-2 antibodies and functional T-cell responses in hematological patients following receipt of a three-dose mRNA vaccine schedule have yielded conflicting results. Methods: We conducted a retrospective observational study in which we measured SARS-CoV-2-S-direct...
| Autores: | , , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2026 |
| País: | España |
| Institución: | INCLIVA |
| Repositorio: | r-INCLIVA. Repositorio Institucional de Producción Científica de INCLIVA |
| OAI Identifier: | oai:dnet:incliva_____::004e046d2cc42f242f6ef274c7d8b05e |
| Acceso en línea: | https://incliva.portalinvestigacion.com/publicaciones/20799 |
| Access Level: | acceso abierto |
| Palabra clave: | SARS-CoV-2 COVID-19 vaccine T-cell immunity Anti-RBD antibodies Booster |
| Sumario: | Introduction: Studies assessing SARS-CoV-2 antibodies and functional T-cell responses in hematological patients following receipt of a three-dose mRNA vaccine schedule have yielded conflicting results. Methods: We conducted a retrospective observational study in which we measured SARS-CoV-2-S-directed cytokine-producing CD8+ and CD4+ T cells by flow cytometry and anti-receptor-binding domain (RBD) total antibodies in 32 hematological patients, including 10 allogeneic hematopoietic stem cell transplant (allo-HCT) recipients and 22 non-transplanted individuals. Immunological testing was performed after the second COVID-19 mRNA vaccine dose (Post-2D), prior to the third dose (Pre-3D), and after the third dose (Post-3D). Results: At Post-2D, 72.4%, 44.8%, and 37.9% of participants had detectable IFN-gamma-, TNF-alpha-, and IFN-gamma/TNF-alpha producing CD8+T cells, respectively. A decrease in the rate of detectable and frequencies of monofunctional and bifunctional SARS-CoV-2-S CD8+ T-cell responses was observed at Pre-3D. By contrast, the number of participants displaying detectable cytokine-producing CD4+ T-cell responses and their frequencies were rather conserved at all testing times. Receiving a 3D had no significant impact on the rate of detection and frequencies of monofun ctional and bifunctional SARS-CoV-2-S-directed T-cell subsets. Anti-RBD total antibody responses were detected in approximately half of participants at all time points. Overall, anti-RBD antibody levels decreased at Pre-3D and then increased following the 3D. Conclusion: Administration of the 3D may have a limited impact on both cellular and humoral immune responses in a substantial proportion of hematological patients. These findings highlight the heterogeneity of vaccine-induced immunity and support the role of combined immune monitoring and alternative protective strategies for selected patients. |
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