AirTRAC: The effect of air composition on the respiratory virus transmission chain

This research proposal aims to elucidate the role of air composition on the efficacy of respiratory virus transmission via the airborne route. Despite the importance of airborne transmission for respiratory viruses our current understanding of the physicochemical processes that affect the infectivity of respiratory viruses in the aerosol and the susceptibility of the next host to airborne infection are limited. Recent research has revealed an important impact of air composition on virus transmission, though its effects on the different elements of the respiratory transmission chain remain poorly defined. AirTRAC will unravel the effects of air composition on the entire airborne transmission chain of respiratory viruses, ranging from airborne virus stability to host cell susceptibility to pre-clinical infection models. The project will focus on influenza A virus (IAV), a candidate virus for the next pandemic, but will also include other respiratory viruses of high relevance to public health. As the process of respiratory virus transmission sits at the interface of aerosol science and virology, an interdisciplinary approach is required to reveal the factors that govern virus infectivity and susceptibility of the host. Our team brings together the necessary expertise in the areas of aerosol physics and chemistry, environmental and molecular virology to tackle this timely and important task. In our previous collaboration we combined experiments conducted in bulk solutions and in a novel, large-scale aerosol chamber with a unique biophysical aerosol model, "ReSAM", to demonstrate an important role of aerosol pH and salinity in the inactivation of IAV and two coronaviruses. Here, we propose to build upon this work and uncover the effect of air composition on the efficacy of respiratory virus transmission via the airborne route. Specifically, we aim to-reveal how exposure to particulate air pollutants, inflammatory conditions and differences in host genetics impact the susceptibility of airway epithelia to respiratory virus infection (work package 2), -assess the impact of air composition on IAV transmission in the guinea pig transmission model by acidifying air via ammonia removal or addition of oxalic acid (work package 3), -generate an experimentally validated biophysical aerosol model to simulate the inactivation of four important respiratory viruses (influenza A virus, human 229E coronavirus, respiratory syncytial virus and rhinovirus) under different air compositions and make this accessible via a public version of ReSAM (work package 1).We expect to unravel the interplay between air composition, virus infectivity and host susceptibility, which can provide the intellectual framework for developing targeted strategies to curb disease transmission in indoor environments.