We want to understand why common pediatric respiratory virus infections cause severe disease in some people. Currently we focus on enterovirus D68, which typically causes colds but rarely causes acute flaccid myelitis, a polio-like paralyzing illness in children. We study both the pathogen and the host immune response, as both can contribute to pathogenesis. Projects focus on use of reverse genetic systems to create reporter viruses to infect both human respiratory epithelial cultures and small animal models such as mice. Human monoclonal antibody effects on pathogenesis are also of interest.