Evaluating Modes of Influenza Transmission using a Randomized Controlled Trial (EMIT-2-RCT)

Project Summary/Abstract – Evaluating Modes of Influenza Transmission using a Randomized Controlled Trial The “Evaluating Modes of Influenza Transmission using a Randomized Controlled Trial (EMIT-2-RCT)” research project addresses a key knowledge gap, the lack of definitive evidence regarding the mechanisms of transmission, in particular the importance of viral aerosols (airborne or aerosol transmission) as compared with contact - fomite and sprayborne (also called droplet) transmission. The overall objective of this project is to evaluate how viral aerosol shedding and ventilation interact to facilitate human-to-human influenza transmission and provide insights into correlates of protection in the setting of absent or low hemagglutination inhibiting (HI) antibodies using a novel study design. In doing so, we directly address objective 1.1 of the NIAID strategic plan. Our central hypothesis is that infectious aerosols are a major contributor to influenza transmission and that ventilation and reduced aerosol exposure are associated with reduction of both attack rates and disease severity. We are uniquely positioned to quantify infectious exhaled breath aerosols with the Gesundheit-II previously developed in the PI’s lab and to extend these measurements in collaboration with a highly multidisciplinary team. We will comprehensively evaluate exposure via direct contact, fomites, sprayborne drops, and aerosols as factors facilitating transmission by conducting a novel randomized controlled trial of seven groups with 4 naturally infected Donors and 18 Recipients per group. The Clinical and Biostatistics Core will provide the infrastructure to recruit and screen the participants and the clinical oversight of the quarantine facility. Within each group, we will randomize half of the Recipients to a hand hygiene–face shield intervention. The first group in year-1 will be in a low ventilation environment. In years 2-4 we will conduct two exposure groups per year, one in a low ventilation environment and one in a high ventilation environment with upper-room germicidal UV air sanitation. Specifically, we will: (1) Identify the dominant mode of transmission using naturally infected Donors with community acquired infection in a randomized controlled trial of air sanitation-ventilation and hand hygiene–face shield interventions; (2) Determine the impact of aerosol exposure on disease severity; and (3) Investigate the impact of serologic and mucosal antibody levels on influenza transmission, susceptibility and immunologic response to infection in the setting of absent or very low levels of hemagglutination inhibiting antibodies. This unique randomized controlled trial will provide a definitive assessment of the role of aerosols in transmission and provide critical data on which to build effective non-pharmaceutical interventions and assess efficacy of vaccine and therapeutic impacts on transmission.