CD8A and COVID-19: When we analyzed the concomitant expression of HLA-DR and CD57 between hospitalized and non-hospitalized COVID-19 patients, we observed a higher median proportion of double positive cells in hospitalized patients in both CD4+: 1.5% (0.5–2.6) vs. 0.7% (0.3–1.5) (p = 0.007, Figure 3J) and CD8+: 8.35% (3.4–13.7) vs. 5% (2–8) (p = 0.02, Figure 3Q).