Rapid Inactivation of SARS-CoV-2 Variants by Continuous and Intermittent Irradiation with a Deep-Ultraviolet Light-Emitting Diode (DUV-LED) Device

More than 1 year has passed since social activities have been restricted due to the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). recently, novel SARS-CoV-2 variants spreading around world, and there is growing concern that they may higher transmissibility protective efficacy vaccines be weaker against them. Immediate measures are needed reduce human exposure virus. In this study, antiviral deep-ultraviolet light-emitting diode (DUV-LED) irradiation (280 ± 5 nm, 3.75 mW/cm2) three was evaluated. For B.1.1.7, B.1.351, P.1 variant strains, virus stocks for s resulted in infectious titer reduction rates 96.3%, 94.6%, 91.9%, respectively, with s, increased 99.9%, 99.8%, respectively. We also tested effect pulsed DUV-LED (7.5 mW/cm2, duty rate: 50%, frequency: kHz) under same output conditions as continuous found same. These findings suggest by further developing optimizing device increase its output, it possible instantly inactivate irradiation.