JMIR Publications

ABSTRACT

Pandemic responses to COVID-19 largely followed a two-stage framework: reliance on behavior change and immunity acquisition, and, when control became difficult, the use of lockdowns to buy time at substantial social cost. However, this framework has not institutionally incorporated interventions that act directly on the physical process of infection establishment—namely, individual-level engineering interventions capable of reducing inhalation exposure by orders of magnitude—as independent objects of public health evaluation. Powered air-purifying respirators (PAPRs) suppress the inflow of unfiltered ambient air into the breathing zone by maintaining positive pressure, a mechanism fundamentally different from passive face masks whose effectiveness depends on fit and user behavior under negative pressure. From a mechanistic perspective, positive-pressure exposure control acts directly on the physical process of infection establishment by reducing inhalation exposure. This Viewpoint does not advocate adoption or immediate implementation of PAPRs for the general public. Instead, it examines whether individual-level positive-pressure exposure control, including population-oriented PAPR use, has reached the stage at which it should be subjected to systematic and formal evaluation within public health preparedness frameworks.