ABSTRACT: Abstract The goal of this core is to provide centralized influenza virology support to enhance the overall structure- function analysis and immunogen discovery activities of the program. Specifically, Core B, housed in the NIAID-constructed Regional Biocontainment Laboratory (RBL) at Duke, will provide comprehensive influenza virus stock propagation, HAI and neutralization assays, and small animal influenza virus challenge models. The Duke RBL is fully approved for BSL2, BSL3, Select Agent and highly pathogenic avian influenza Risk Group 3 work and is as a multi-disiplanary research support facility at Duke constructed with federal funds to support the NIAID biodefense agenda or other NIAID approved biomedical research activities. These unique services are not available through other facilities at Duke or Harvard. Core B activities will be specifically utilized by all projects in this renewal P01. The aims of the Virology Core are: 1) Influenza Strain Collections: Maintain a broad panel of purified influenza viruses for in vitro assays and animal model challenge; 2) Influenza Humoral Response Monitoring: Perform centralized influenza HAI and neutralization assays (human, mouse, and NHP specimens) on purified antibodies, culture supernatants and plasma/serum samples; and 3) Influenza Small Animal Challenge Models. Provide harmonized mouse infection/challenge studies. The inclusion of this Virology Core will provide a common set of reagents and assays for mechanistic analysis of host immune response for three projects. Critical to the Core aims and overall goal is an ongoing commitment to development of new assays, quality control monitoring and consultation with all project leaders to anticipate and meet the needs of the investigative teams in a safe, compliant and efficient manner.