Using the resulting K-ML2 (AT) clone 35 for SARS-CoV-2-infection or its subclone 35–40 for IL-6 productivity, it was possible to evaluate the potential of sera from severe COVID-19 patients to cause ADE and to stimulate IL-6 production upon infection with SARS-CoV-2. This evidence concerns the gene IL6 and acute disseminated encephalomyelitis.