CD8A and COVID-19: We observed higher median proportion of effector CD8+ T cells in COVID-19 X-ray (+) patients than in COVID-19 X-ray (−) patients and healthy control, without significant differences between COVID-19 X-ray (+) patients and COVID-19 X-ray (−) patients (45.0 vs. 20.3 vs. 7.8%, p = 0.0001).