For volume 2: A broad-ranging collection of cutting-edge techniques for the study of HBV and HDV infections and for the development of therapies to treat them. In this second of two volumes, Immunology, Model Systems, and Clinical Studies, the authors focus on protocols for the study of host immune responses to infection, in vitro and in vivo models of infection, and the development of antivirals. Each fully tested protocol is described in step-by-step detail by an established expert in the field and includes a background introduction outlining the principle underlying the technique, equipment and reagent lists, and tips on troubleshooting and avoiding known pitfalls. An accompanying first volume, Detection, Genotypes, and Characterization, contains user-friendly protocols for the identification and quantification of viral markers, the detection and impact of viral variants, and the study of the viral life cycle. For both volumes: A broad-ranging collection of core techniques for the study of HBV and HDV infections and for the development of therapies to treat them. The first volume Detection, Genotypes, and Characterization, the authors focus on readily reproducible molecular methods for the identification and quantification of viral markers, the detection and impact of viral variants, and the study of the viral life cycle. The second volume, Immunology, Model Systems, and Clinical Studies, contains user-friendly protocols for the study of host immune responses to infection, in vitro and in vivo models of infection, and the development of antivirals. Each fully tested protocol is described in step-by-step detail by an established expert in the field and includes a background introduction outlining the principle underlying the technique, equipment and reagent lists, and tips on troubleshooting and avoiding known pitfalls. The set offers both new and experienced investigators an encyclopedic collection of powerful tools for studying HBV and HDV infections, an essential resource for finding new therapies to treat chronically infected patients.