Publications de Shannon Christa David

Inactivation of SARS-CoV-2 at acidic pH is driven by partial unfolding of spike

Tamar Kohn, Aline Laetitia Schaub, Athanasios Nenes, Shannon Christa David

SARS-CoV-2, the causative agent of COVID-19, is predominantly transmitted by respiratory aerosol and contaminated surfaces. Recent studies demonstrated that aerosols can become acidic, and acidification has been proposed as decontamination method. Here, we ...

Springer Science and Business Media LLC2025

The early communication stages between serine proteases and enterovirus capsids in the race for viral disintegration

Diego Chiappe, Tamar Kohn, Shannon Christa David, Shotaro Torii

Serine proteases are important environmental contributors of enterovirus biocontrol. However, the structural features of molecular interaction accounting for the susceptibility of enteroviruses to proteases remains unexplained. Here, we describe the molecu ...

Springer Science and Business Media LLC2024

Dependence of aerosol-borne influenza A virus infectivity on relative humidity and aerosol composition

Tamar Kohn, Céline Terrettaz, Aline Laetitia Schaub, Athanasios Nenes, Kalliopi Violaki, Shannon Christa David, Ghislain Gilles Jean-Michel Motos, Walter Hugentobler, Laura José Costa Henriques

We describe a novel biosafety aerosol chamber equipped with state-of-theart instrumentation for bubble-bursting aerosol generation, size distribution measurement, and condensation-growth collection to minimize sampling artifacts when measuring virus infect ...

Frontiers Media SA2024

Stability of influenza A virus in droplets and aerosols is heightened by the presence of commensal respiratory bacteria

Tamar Kohn, Htet Kyi Wynn, Céline Terrettaz, Aline Laetitia Schaub, Athanasios Nenes, Kalliopi Violaki, Marta Augugliaro, Shannon Christa David, Ghislain Gilles Jean-Michel Motos, Walter Hugentobler, Laura José Costa Henriques, Daniel Scott Nolan

Aerosol transmission remains a major challenge for control of respiratory viruses, particularly those causing recurrent epidemics, like influenza A virus (IAV). These viruses are rarely expelled alone, but instead are embedded in a consortium of microorgan ...

American Society for Microbiology2024

Impact of organic compounds on the stability of influenza A virus in deposited 1-μL droplets

Tamar Kohn, Céline Terrettaz, Aline Laetitia Schaub, Athanasios Nenes, Kalliopi Violaki, Shannon Christa David, Ghislain Gilles Jean-Michel Motos, Walter Hugentobler

The composition of respiratory fluids influences the stability of viruses in exhaled aerosol particles and droplets, though the role of respiratory organics in modulating virus stability remains poorly understood. This study investigates the effect of orga ...

2024

A new chapter of healthy indoor air: antiviral air treatments

Shannon Christa David

Aerosol transmission remains a major challenge for the control of respiratory viruses. To date, prevention strategies include masks, vaccinations, physical distancing, travel restrictions, and lockdowns. Such measures are effective but come with heavy soci ...

Wiley2023

Inactivation mechanisms of influenza A virus under pH conditions encountered in aerosol particles as revealed by whole-virus HDX-MS

Tamar Kohn, Jonathan Paz Montoya, Aline Laetitia Schaub, Athanasios Nenes, Giovanni D'Angelo, Kalliopi Violaki, Shannon Christa David, Ghislain Gilles Jean-Michel Motos, Walter Hugentobler

Multiple respiratory viruses, including influenza A virus (IAV), can be transmitted via expiratory aerosol particles, and aerosol pH was recently identified as a major factor influencing airborne virus infectivity. Indoors, small exhaled aerosols undergo r ...

2023

Observed Kinetics of Enterovirus Inactivation by Free Chlorine Are Host Cell-Dependent

Tamar Kohn, Odile Marie Clotilde Hervás de Nalda-Larivé, Shannon Christa David, Federica Cariti, Shotaro Torii

Virucidal efficacies of disinfectants are typically assessed by infectivity assay utilizing a single type of host cell. Enteroviruses infect multiple host cells via various entry routes, and each entry route may be impaired differently by a given disinfect ...

2023

Expiratory Aerosol pH: The Overlooked Driver of Airborne Virus Inactivation

Tamar Kohn, Aline Laetitia Schaub, Athanasios Nenes, Kalliopi Violaki, Shannon Christa David, Ghislain Gilles Jean-Michel Motos, Walter Hugentobler

Respiratory viruses, including influenza virus and SARS-CoV-2, are transmitted by the airborne route. Air filtration and ventilation mechanically reduce the concentration of airborne viruses and are necessary tools for disease mitigation. However, they ign ...

2023

Expiratory aerosol pH is determined by indoor room trace gases and particle size

Tamar Kohn, Aline Laetitia Schaub, Athanasios Nenes, Kalliopi Violaki, Shannon Christa David, Ghislain Gilles Jean-Michel Motos, Walter Hugentobler

2022