Authors: Matthias Reinscheid, Hendrik Luxenburger, Vivien Karl, Anne Graeser, Sebastian Giese, Kevin Ciminski, David B. Reeg, Valerie Oberhardt, Natascha Roehlen, Julia Lang-Meli, Kathrin Heim, Nina Gross, Christina Baum, Siegbert Rieg, Claudius Speer, Florian Emmerich, Susanne Breisinger, Daniel Steinmann, Bertram Bengsch, Tobias Boettler, Georg Kochs, Martin Schwemmle, Robert Thimme, Christoph Neumann-Haefelin, Maike Hofmann
Published: 2022-08-08
DOI: 10.1038/s41467-022-32324-x
Source: Full article
AbstractImmunization with two mRNA vaccine doses elicits robust spike-specific CD8+ T cell responses, but reports of waning immunity after COVID-19 vaccination prompt the introduction of booster vaccination campaigns. However, the effect of mRNA booster vaccination on the spike-specific CD8+ T cell response remains unclear. Here we show that spike-specific CD8+ T cells are activated and expanded in all analyzed individuals receiving the 3rd and 4th mRNA vaccine shots. This CD8+ T cell boost response is followed by a contraction phase and lasts only for about 30-60 days. The spike-specific CD8+ T memory stem cell pool is not affected by the 3rd vaccination. Both 4th vaccination and breakthrough infections with Delta and Omicron rapidly reactivate CD8+ T memory cells. In contrast, neutralizing antibody responses display little boost effect towards Omicron. Thus, COVID-19 mRNA booster vaccination elicits a transient T effector cell response while long-term spike-specific CD8+ T cell immunity is conserved to mount robust memory recall targeting emerging variants of concern.