Novel antigen delivery technologies: a review

Over the past few years, new insights into immunobiology and delivery systems have allowed the development of better vaccines and for a wider range of diseases. Currently available vaccines represent outstanding success story in modern medicine and have had a dramatic effect on morbidity and mortality worldwide. Conventional vaccines have been based on live attenuated, or killed, viruses or bacteria, or recombinant proteins from these organisms. The design of live attenuated vaccines depended to some extent on serendipity and resulted in low success rates. Both live attenuated and killed vaccines require handling of live pathogens and are associated with safety problems. Despite the success of vaccines, there is a clear need for novel antigen delivery technologies to improve vaccine efficacy and safety. Antigen stability, safety, and immunogenicity are the key hurdles in development of novel antigen delivery technologies. Nowadays, various novel drug delivery systems are becoming one of the fastest growing sectors in the pharmaceutical and biotechnological industries. Delivery of vaccines via oral, intranasal, transcutaneous, and intradermal routes will decrease the risk of needle-borne diseases and may eliminate the need for trained personnel and sterile equipment. Currently, various techniques involving DNA vaccines, adjuvants, nanoparticles, liposome, microneedle, and NanoMAP technology are being developed and evaluated. This review focuses on the current development of some novel vaccine delivery systems and will explore the non-parenteral routes of vaccine administrations.