The present study also analyzed plasma cytokines and chemokines to assess the state of immune balance after recovery, focusing on IL-18, CXCL9, and CCL3 as Th1 cytokines, IL-6 and IL-10 as Th2 cytokines, and VEGF as a fibrosis marker; significant results have been observed earlier in the analyses of plasma from patients with COVID-19 in the acute phase of infection15. Here, IL18 is linked to COVID-19.