COVID-19 boosters restore virus-specific immune responses in kidney transplant recipients unresponsive to primary vaccination
den Hartog, Yvette van Sleen, Yannick Gommers, Lennert Zaeck, Luca M Geers, Daryl Messchendorp, A Lianne Sanders, Jan-Stephan F Baan, Carla C van Baarle, Debbie de Vries, Rory D
den Hartog, Yvette
van Sleen, Yannick
Gommers, Lennert
Zaeck, Luca M
Geers, Daryl
Messchendorp, A Lianne
Sanders, Jan-Stephan F
Baan, Carla C
van Baarle, Debbie
de Vries, Rory D
Series / Report no.
Open Access
Type
Journal Article
Article
Article
Language
en
Date of publication
2026-02-27
Year of publication
Research Projects
Organizational Units
Journal Issue
Title
COVID-19 boosters restore virus-specific immune responses in kidney transplant recipients unresponsive to primary vaccination
Translated Title
Published in
Npj Viruses 2026; 4(1):14
Abstract
Kidney transplant recipients (KTRs) often exhibit impaired immune responses to vaccination, necessitating multiple doses to obtain sufficient protection from severe disease. This study compared immunological mechanisms underlying the vaccine-induced response between KTRs who responded to primary vaccination (primary responders) and those who only responded to a booster vaccination (booster responders). Humoral immune responses, including binding and Fc-mediated functionalities, and T cell responses, were generally comparable in primary and booster responders. More in-depth analyses revealed that booster responders had an expanded memory B cell pool and stronger omicron BA.1 neutralization, while primary responders had more IL-21-producing T cells and a distinct SARS-CoV-2-specific CD4 T cell phenotype. Principal component analysis demonstrated that booster responders exhibited a more refined immune network integration. These results suggest that the delayed immune response of booster responders is not functionally impaired and that repeated vaccination is an effective strategy to achieve adequate protection in this population.