Examination of the requirements for powered air-purifying respirator (PAPR) utilization as an alternative to lockdown

With the emergence of COVID-19 variants and new viruses, it remains uncertain when the next pandemic will occur. A lockdown is considered the last resort to halt the spread of infection; however, it causes significant economic and social damage. Therefore, exploring less harmful alternatives during such scenarios is crucial. This study explores the feasibility of using a powered air-purifying respirator (PAPR) as an alternative to lockdowns and as a strategy for infection control. Specifically, the study examines the potential impact of the PAPR wearing rate and PAPR aerosol shielding performance on the controllability of the spread of infections. The study investigated the necessary PAPR wearing rate and aerosol shielding performance to control infections as an alternative to the lockdown, using a simple simulation under limited conditions. When using a PAPR with 100% aerosol shielding capability in air supply, only 55% of the population needs to consistently wear the PAPR to reduce the effective reproduction number from a critical level (R_t = 2) to a target level (R_t = 0.9). Furthermore, if everyone consistently wears PAPR, only 55% the reduction ratio in the probability of becoming infected by PAPR supplying air I_{r_in} is enough for reducing the effective reproduction number from a critical level (R_t = 2) to a target level (R_t = 0.9). This study demonstrates the potential for utilizing PAPR as an alternative to lockdowns.