In recent years, an increased number of zoonotic viruses and bacteria have crossed the species barrier to humans and caused or threatened to cause human pandemics with high morbidity and mortality. Because of our inability to predict the emergence of these pathogens, it is difficult to take preventive measures. It is known that zoonotic pathogens need to cross barriers at the animal-human interface, at the pathogen-host interface within humans, and at the human-human interface before they can cause a human pandemic. However, it is poorly understood which pathogen, host, arthropod vector, and environmental factors allow zoonotic pathogens to successfully cross these barriers. Therefore, our overall objective is to identify the key factors that render zoonotic pathogens prone to cross the species barrier and gain efficient transmissibility among humans. ANTIGONE has a two-pronged approach to reach this objective. First, we will perform primary research studies to fill important gaps in our understanding of how zoonotic pathogens can gain pandemic potential. These studies will focus on selected viruses and bacteria, including SARS coronavirus, , Crimean-Congo haemorrhagic fever virus, Nipah virus, Ebola virus, E. coli, M. bovis, B. burgdorferi, C. burnetii and S. suis. Integral to these activities will be a cross-disciplinary training programme for young scientists (Young ANTIGONE) and a web-based pathogen information sharing platform. Second, we will organize Dahlem studies where experts from the human and veterinary fields, from within and outside ANTIGONE, will discuss key issues in infectivity, pathogenicity, and transmissibility of zoonotic pathogens and determine general criteria to assess the risk of these pathogens to gain human pandemic potential. Together, the results of these activities will improve our ability to model and predict potential human pandemics of zoonotic origin and to develop effective and timely preventive measures.