CD8A and COVID-19: Conversely, the immune cells subsets, such as lymphocytes (HR 0.220, 95% CI 0.161–0.302, P < 0.0001), B cells (HR 0.994, 95% CI 0.990–0.998, P = 0.002), NK cells (HR 0.985, 95% CI 0.981–0.990, P < 0.0001), CD3+CD19− T cells (HR 0.996, 95% CI 0.995–0.997, P < 0.0001) and CD3+CD8+ T cells (HR 0.989, 95% CI 0.985–0.992, P < 0.0001), were significantly associated with the lower death risk of COVID-19.