Regarding the immunologic features, longitudinal studies have shown that high levels of pro-inflammatory cytokines are maintained for over 30 days in patients with severe COVID-19.29 IL-8, a biomarker of COVID-19 severity,30 has been related to a longer disease duration31 and is inversely correlated with the time from admission to death.32 Furthermore, high levels of IL-8 are associated with elevated D-dimer and decreased PaO2/FiO2 ratio. Here, CXCL8 is linked to COVID-19.