CD8A and COVID-19: The proportions of CD8 T cells and NK cells were significantly different between severe vs. mild COVID-19 (CD8 T cell p-value = 1.11 × 10–03, NK cell p-value = 0.02) and severe vs. moderate COVID-19 (CD8 T cell p-value = 0.04, monocyte p-value = 1.59 × 10–03, NK cell p-value = 0.02).