New approaches in viral vaccine development.

With the exception of the vaccine against hepatitis B the principles involved in the production of the viral vaccines in use today have not changed since Jenner (1) first developed the vaccine which was so important in the control and eventual eradication of smallpox in 1977. All have relied on the presentation of the live attenuated or inactivated virus to the host, either orally or by injection, so that it elicited the formation of antibody and primed memory cells for a rapid response to the subsequent invasion of the virus. With the discovery that protective immunity could be obtained with isolated individual proteins from virus particles and the development of methods for the expression of these proteins, both in vivo and in vitro, there is now considerable promise that immunity can be induced without the need to use the disease agent itself. Moreover, the molecular basis of the immune response is now beginning to be understood, thus allowing a more rational approach to the design of vaccines for individual diseases.