Experimental Evaluation of the Efficacy of Air-Sanitizing Equipment in Neutralizing Airborne SARS-CoV-2 Virus

Air-sanitizing equipment is a collection of protective devices using filtration and/or UV irradiation to entrap aerosol and kill viruses, to prevent the spread of airborne infective diseases in indoor environments. The aim of the herein reported experimental study was to evaluate the possibility of attenuating the environmental spread of the SARS-CoV-2 virus by sanitizing indoor air. Aerosols were generated from human throat swab samples containing viable wild-type SARS-CoV-2. These samples were introduced into a controlled airflow channel and collected in buffered saline, with or without air sanitization. The viral presence was evaluated by antigenic test and qPCR. 34 different types of air- sanitizers were tested for their ability to neutralize viral aerosols. All devices neutralized viral infectivity as evaluated by a antigen test, qPCR, and cell infectivity, except for the unit without filtration and using LED-UV instead of bulbs, which was ineffective at 5 min but effective after 10 min of treatment. The obtained results provide evidence that 97% of the tested sanitizing devices are effective in breaking down the airborne viral load of wild human SARS-CoV-2 virus, even at a very high concentration, with a single passage of air. These results provide evidence that high-quality air-sanitizing devices may be used as a preventive tool to prevent the risk of airborne infections in indoor environments.