TNFRSF9 and COVID-19: In the present study, we investigate in vitro the putative impact of helminth co-infection on the activation of SARS-CoV-2-specific T cells in COVID-19 patients by monitoring ex vivo the expression of SARS-CoV-2-induced CD69 and CD137 expression on CD4+ and CD8+ T cells in the presence or absence of helminth antigens.