Our results showed that EOS (OR 1.34, p = 0.006), CD8 T cell (OR 0.999, p = 0.024) and CD4 T cell (OR 0.995, p = 0.016) were independent risk factors for disease severity in patients with SARS-CoV-2 Omicron BA.2 variant infection. The gene discussed is CD8A; the disease is infection.