Infectious diseases affect humans, animals and plants, sometimes with devastating outcomes and world-wide impact. Infectious agents comprise numerous viruses, bacteria and eukaryotic parasites. Yet, many pathogens and infectious diseases are insufficiently treated by vaccines or other therapeutics. This is in part due to the evasion of the well-known agents from immunity and therapy, and the emergence of unknown pathogens. The members of the network ‘Infection and Immunity Zurich’ strive to enhance our understanding of viral, bacterial and eukaryotic agents in the context of human and animal health. The research in this network sheds new light into disease mechanisms and immunity, and lays a foundation for the development of novel therapeutics.