CD4 and infection: We studied functional anti-viral immunity by assessing CD4+ and CD8+ T-cells secreting the canonical type 1 cytokines: IFN-γ, TNF-α and IL-2 upon stimulation with SARS-CoV-2 proteins16 in COVID-19 cases with a wide range of disease severity, collected up to eight months after diagnosis of infection, and compared them to uninfected controls.