Manuela Dingeldey

TL;DR: CD4 + T cells that are reactive against the spike glycoprotein of SARS-CoV-2 in the peripheral blood of patients with COVID-19 and healthy donors are found, indicating that spike-protein cross-reactive T cells are present and probably generated during previous encounters with endemic coronaviruses.

TL;DR: This study is the first to directly measure SARS-CoV-2-reactive T cell responses providing critical tools for large scale testing, in depth epitope mapping and characterization of potential cross-reacting cellular immunity to SARS, as well as larger scale prospective cohort studies needed to assess whether their presence is a correlate of protection or pathology.

TL;DR: In this article, the functional relevance of preexisting cross-immunity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a subject of intense debate.

TL;DR: Pre-existing SARS-CoV-2 cross-reactive CD4+ T cells in the elderly are suggested as a predictor of an efficient COVID-19 vaccine-induced humoral immune response in old individuals.

TL;DR: The absence of humoral and T cell responses suggests that fingolimod-treated patients with MS are at risk for severe SARS-CoV-2 infections despite booster vaccinations, which is highly relevant for clinical decision-making and adapted protective measures, particularly considering additional recently approved sphingosine-1-phosphate receptor antagonists for MS treatment.