When COVID-19 patients were categorized into recovered versus long-COVID-19 subgroups (Fig 4), we observed that IFN-γ (P<0.01), IP-10 (P<0.01), IL-8 (P<0.05), and IL-2 (P<0.01) S protein-specific levels were significantly higher in both subgroups compared to unexposed individuals. This evidence concerns the gene IFNG and COVID-19.