A decrease in the activities of the ecSOD, TrxR, GPx, GST GR, (p = 0 ≤ 0.1), and the GSH, TAC, thiols, and NO2– (p ≤ 0.001) concentrations and an increase in LPO and 3-NT (p = 0.001) concentrations were found in COVID-19 patients vs. healthy subjects. The gene discussed is SOD3; the disease is COVID-19.