ABSTRACT Core E: Immunogenicity and Immune Correlates Core (Correlates) The goal of Core E-Correlates will be to provide support to the projects by conducting various technical measurements of immunogenicity to enable the establishment of immune correlates of protection for each prototype virus. We will conduct a comprehensive series of assays to quantitate both humoral and cellular immune responses in humans and animals for Projects 1-4. Working closely with Core D-Antibody we will assessing neutralizing antibody responses to down selected monoclonal antibodies. Finally, we will use predictive and interpretable machine learning to identify immune correlates of protection. Importantly, an overarching goal of this project is to use these prototype pathogens to identify immune correlates that could be applied to emerging viruses in the same family with pandemic potential, so we'll assess for similarities in immune correlates between viruses in the same family and across families for viruses in the same order.