ABSTRACT CORE B: RSV to Asthma Cooperative Clinical Ascertainment, Biospecimen, and Data Management Research Core Core B is designed as the clinical ascertainment and data management core. The INSPIRE (Infant Susceptibility to Pulmonary Infections and Asthma Following RSV Exposure) birth cohort successfully enrolled over 1900 term healthy infants and will have followed them to approximately 4 years of age during the first funding cycle. This core extends the longitudinal follow-up to age 6-8 years at which time the cumulative incidence of asthma will be defined, and include physiologic testing as well as additional biospecimens, thus providing resources directly to Projects 1 and 2. The core will coordinate the data to address the fundamental questions about the causal role of asthmagenic strains of RSV on childhood asthma through scientific projects that focus on interactive pathways of the viral strain and host on asthma development (Project 1), and the mechanisms through which specific RSV strains cause asthma (Project 2). Our specific aims are to 1) facilitate longitudinal follow-up of the INSPIRE cohort, with biospecimen and data management for Projects 1 and 2; and 2) integrate clinical, physiological, immunologic, microbiome and viral sequencing data from collaborating sites and provide analytic support to address research questions across projects. This core assembles a complementary research team of epidemiologists, virologists, immunologists, biostatisticians, and research personnel experienced in cohort retention, biospecimen acquisition and processing, and data management. As bronchiolitis and asthma are the most common, serious, acute and chronic conditions of infancy and childhood, respectively, and are diseases that disproportionately burden vulnerable populations, this core and supported projects will have major, long-lasting impact by improving our understanding of RSV- mediated asthma.