ABSTRACT-PROJECT 2 The SARS-CoV-2 pandemic has established beyond doubt that animal coronaviruses are a major potential threat to human health. Although vaccines and antibodies to prevent and treat SARS-CoV-2 infection have been developed at unprecedented speed, the recurrent emergence of coronaviruses from bat and other animal reservoirs underlines the need for preparedness to prevent future pandemics. Current vaccines have been designed to combat SARS-CoV-2, but it is unclear how effective they will be in the future against emergent variants in circulating SARS-CoV-2 populations and, importantly, against other potentially zoonotic coronaviruses. To generate immunogens that can elicit broad neutralizing antibodies targeting multiple, distinct coronaviruses we need first to understand what epitopes on the coronavirus envelope glycoprotein spike constitute targets for neutralizing antibodies. Therefore, the first aim of this project will be to deploy an array of VSV-based and HIV-1 based pseudotyped and viruses to identify SARS-CoV-2 epitopes targeted by human neutralizing antibodies found in SARS-CoV-2 convalescent or vaccinee plasma. Additionally, we will determine to what extent these epitopes are functionally preserved in progressively more divergent coronaviruses. In the second aim, we will use this and other information to design immunogens and immunization strategies. We will employ a variety of multivalent immunogens and delivery methods aimed to prolong antigen exposure and maximize antibody somatic mutation. The goal of these experiments will be to elicit production of neutralizing antibodies with the maximum possible breadth, and test their ability to protect against infection by pandemic threat coronaviruses.