A National Early Warning Score 2 >2 (OR:41.4; CI:10.38–167.0), ferritin >583 pg/mL (OR:16.3; CI: 3.88–69.9), neutrophil/lymphocyte ratio >3 (OR: 3.5; CI: 1.08–12.0), sIL-2rα (sCD25) >512 pg/mL (OR: 3.3; CI: 1.48–7.9), IL-1Ra >94 pg/mL (OR: 3.2; IC: 1.4–7.3), and IL-18 >125 pg/mL (OR: 2.4; CI: 1.1–5.0) were associated with severe/critical COVID-19 in the multivariate models used. Here, IL18 is linked to COVID-19.