Vaccines based on viral vectors
Much progress has been made towards the development of novel vaccines and vaccination approaches. Viral vectors have been studied as potential tools to deliver vaccines as they present advantages over traditional vaccines in that they stimulate a broad range of immune responses including cell mediated immunity. Viral vectors have been extensively studied in animal models, and many of them have entered clinical evaluation. Some of the most promising approaches include combining "prime-boost" (different vaccine types used in the first and the subsequent doses) strategies with other types of vaccines such as recombinant antigens or DNA vaccines. Thus, although the use of viral vectors is a promising system for developing effective and safe vaccines against many important diseases, more studies are needed before the ideal vector is developed and licensed for use in humans.