Physics of pathogen transmission

Aerosols exchanged between asymptomatic carriers are one of the most significant transmission routes for many viral pathogens. Understanding the coupling between the biology of successful transmission and the physico-chemistry involved in aerosols is key to defining a more general concept of infectivity. This, in turn, helps to define the spatiotemporal aspects of transmission risks and inform effective prevention and control strategies for the health response. However, studying the whole chain of events underlying airborne transmission presents strong technical and conceptual challenges that go beyond the discipline of virology alone, and requires complementary knowledge and approaches from soft matter and biochemistry to fluid mechanics. Our work is an ambitious and synergistic interdisciplinary approach that deciphers, recapitulate and dissect with advanced analytical tools, the biophysical constraints faced by airborne pathogens such as viral particles and bacteria, from their encapsulation in saliva aerosol droplets generated by phonation and the great desiccation stresses they undergo during air transport, to their successful deposition and internalization on the epithelial cell layers of the respiratory tract.