In the majority of COVID-19-recovering individuals (COVID-19+), larger overall SARS-CoV-2-specific CD4+ and CD8+ T-cell responses were observed with severe disease, yet an increase in polyfunctional CD8+ T cells was noted in mild cases (Kared et al., 2020; Rydyznski Moderbacher et al., 2020; Sattler et al., 2020). Here, CD4 is linked to COVID-19.