CD8A and COVID-19: In many COVID-19 convalescents, broad CD8+ T-cell response against multiple SARS-CoV-2 proteins mediated by effector and memory T cell populations were detected, suggesting a key role for T cells in protective immunity in recovered patients (Dan et al., 2021; Grifoni et al., 2020; Oxford Immunology Network Covid-19 Response T cell Consortium et al., 2020).