CD8A and COVID-19: Recent research showed marked reductions in counts and percentages of total lymphocytes, total T cells, CD4+ T cells, CD8+ T cells, B cells, and natural killer cells (NK) without changes in the typical TCD4:TCD8 ratio of approximately 1:1 in healthy subjects whether vaccinated or unvaccinated, who are COVID-19 survivors (324) (Figure 1).