In contrast, significantly lower frequencies of CCCs/SARS-CoV-2 cross-reactive functional IFN-γ-producing CD8+ T cells were detected in the two groups of unvaccinated severely ill symptomatic COVID-19 patients (i.e., severity 3 and 4, mean SFCs < 50) and the unvaccinated COVID-19 patients with fatal outcomes (i.e., severity 5, mean SFCs < 25). This evidence concerns the gene CD8A and COVID-19.