“…High efficiency particulate air filters (HEPA) and fine filters have been reported to disinfect 83% and 54% SARS-CoV-2 containing aerosols, respectively, and have a high filtration efficiency for 0.3 µm - 10 µm particles ( Zhang, 2020 ; Zhao et al, 2020a ). Air purifiers with HEPA can be portable, are inexpensive for richer developing countries such as China, and have been recommended to be specially used in healthcare facilities ( Lednicky et al, 2020 ; Yeo et al, 2020 ; Zhao et al, 2020a ; Rodríguez et al, 2021 ; Settimo and Avino, 2021 ; WHO, 2021a). Air filters have been recommended to be positioned to face less cleaner air, regularly disinfected or discarded with medical waste, replaced according to expert or manufacturer advice, and to be used with UV lamps, face masks and ventilation ( Zhao et al, 2020b ; Cilhoroz and DeRuisseau, 2021 ; Curtius et al, 2021 ; Feng et al, 2021b ; Lindsley et al, 2021 ; WHO, 2021a).…”