Vaccine research and development is advancing at an unprecedented pace, with an increasing emphasis on rational design based upon a fundamental und- standing of the underlying molecular mechanisms. The aim of this volume is to provide a selection of contemporary protocols that will be useful to both novice and advanced practitioner alike. The variety of procedures required to design, develop, produce, and assess a vaccine is immense and covers aspects of ch- istry, biochemistry, molecular biology, cell biology, and immunology. No single volume can hope to cover these topics exclusively. Rather, here we attempt to provide a methods sourcebook focusing on hands-on practical advice. Comp- mentary and background information may be found in other volumes in the Me- ods in Molecular Medicine series. Of particular interest are volumes on Dendritic Cell Protocols, Interleukin Protocols, Vaccine Adjuvants, and DNA Vaccines. Since the publication of the first edition of Vaccine Protocols there have been major advances, particularly in the areas of bacterial genomics, antig- specific T-cell quantification, genetic manipulation of vaccine vectors, the h- nessing of natural molecules concerned with the regulation of immune responses, and the burgeoning field of DNA vaccinology. Hence, the extensive revision of this edition with new chapters on live viral vaccine vectors, atte- ated bacterial vectors, immunomodulators, MHC-peptide tetrameric complexes, and the identification of vaccine candidates by genomic analysis. Additionally, chapters from the first edition have been updated to accommodate state-of-t- art methods in vaccinology.