The development of subunit and synthetic vaccines using recombinant DNA technology

Vaccination of humans and animals against invasion by pathogenic organisms is an effective and integral component of preventive medicine. Traditionally, vaccines have been prepared from various forms of killed or attenuated whole organisms. Such killed or attenuated vaccines presumably retain some of the important antigenic determinants of the organism which can elicit an effective immune response in the vaccinated host. Major drawbacks encountered with these types of vaccines include the introduction of undesirable side-effects after vaccination, as well as induction of only partial protection in some cases. In addition to killed or attenuated vaccines, partially purified antigenic determinants from the whole organism have been used as vaccines. However, the cost and difficulties involved in preparation of the purified antigen often make this an uneconomical approach. Within the last decade, the advent of recombinant DNA technology has brought about a new approach in the preparation of vaccines. In this review, some of the recent developments in several research areas leading to the production of effective vaccines will be presented to demonstrate the promising future of this new approach to vaccine development.