The COVID-19 pandemic has brought a new appreciation of the importance of airborne disease transmission. Airborne transmission is caused by the inhalation of pathogen-containing aerosols that are produced by an infected person.1 Before the pandemic, the main accepted airborne diseases were tuberculosis, measles, and chickenpox. In principle, surface touch (fomites) can also lead to infection, although with low probability.6 THE EMISSION PLUS DILUTION DOMAINS OF AIRBORNE TRANSMISSION There are four spatial domains of airborne transmission: Indoors in close proximity, where the respiratory jet of the infected is inhaled by the susceptible with limited dilution. In terms of characterizing a new potentially airborne disease, the attack rate of different superspreading events can be plotted versus I H i SB r sb similar to Figure 1A. This provides a rapid empirical characterization of the potential of a given disease for shared-room airborne transmission. [Extracted from the article]