Although most of immune cell types (except natural killer cells) were comparable in the circulation between control and COVID-19 convalescents (Fig. 2A), there was an increase in the frequency of γ/δ T cells, B cells, and CD8+ T cells within the respiratory compartment of the COVID-19 convalescent cohort compared with those of control (Fig. 2B). Here, CD8A is linked to COVID-19.