Fig. 2: Method for simulating transmission events.

a A computational model described the emission and subsequent dynamics of virus-containing particles following a single cough. We modelled the diffusion of particles of different sizes through space and time, accounting for evaporation, sedimentation, ventilation, and the inactivation of viruses within infectious particles. Our model describes the time- and location-dependent concentration of infectious material within an environment. b Our model facilitates the calculation of the cumulative volume of infectious material that we would expect for different individuals in an environment. Specifying an effective viral load, or alternatively the parameter R_env, which describes the expected number of infections to occur within an environment, generates viral exposures, which describe the expected number of infectious viruses that initiate infection within each person: The outcome of exposure, whether infection or non-infection, is characterised by this viral exposure.