CD8A and COVID-19: In the memory CD8+ compartment we observed a significant reduction in CM CD8+ T cells in HD patients compared to HC that was further aggravated in HD + COVID-19 patients, as well as a significant increase in TEMRA and CD8+ T cells positive for the activation marker human leukocyte antigen-DR (HLA-DR) in both HD and HD + COVID-19 patients compared to HC (Figure 2B).