With the previous edition of Immunization in Practice (IIP) having been translated and used throughout the world, we realized the tremendous responsibility we had when we embarked on this new version. This new edition has seven modules instead of eight as we concluded that merging target diseases and vaccines would make the flow more useful for our readers. Several new vaccines that have become more readily available and used in recent years have been added. Also the section on integration with other health interventions has been expanded as exciting opportunities and experiences have become evident in the years following the previous edition.