Navigating the evolutionary routes of influenza viruses

ended

Seasonal influenza viruses re-infect us repeatedly, escaping antibody recognition, due to the evolution of the virus itself. Being able to predict when and how the virus will evolve would be transformative for influenza virus control. Problematically, we have only observed one of the likely many possible routes of virus evolution. We do not know how many viable routes may have existed or about the repeatability of the observed evolution. These knowledge gaps limit the predictability of influenza virus evolution. NaviFlu will fill these gaps by rigorously assessing the repeatability of influenza virus evolution and the diversity of routes the virus can explore. Recent work has shown that prolonged influenza virus infections can result in substantial virus evolution and occasionally portend virus mutational patterns on a global scale. However, observing large numbers of such infections is challenging. We will use an innovative ex-vivo human airway epithelium culture system to artificially create and study prolonged human infections. Together with cutting-edge next generation sequencing and new analysis tools, we will quantify the evolutionary landscape of seasonal influenza viruses. The project has three objectives, each building in complexity: 1–Quantify the evolutionary dynamics of seasonal influenza viruses in the absence of antibody-mediated selection. 2–Determine how the antibody complexity of immune sera shape the evolutionary trajectories of virus antigenic evolution. 3–Quantify the impact of differences in selection pressures by site of infection and underlying host variation on virus evolution. Through these objectives we will “play evolution forwards”, revealing the relative roles of different factors governing the mode and tempo of influenza virus evolution and quantify the predictability of virus evolution. This will improve the design of influenza vaccines, enhance prospects for influenza control, and lay new groundwork for exploring virus evolution.