The ideal vaccine.

The ideal vaccine is discussed under three headings. 1. The major requirements of the vaccine. This includes primarlly safety and efficacy and a number of other desirable features if the vaccine is to control a disease of global importance. These include cost, easy administration (e.g. orally), thermal stability, multivalency and long-lived immunlty 2. The nature and persistence of the immune responses which, as judged by model systems, are probably generated by the most effective viral vaccines in current human usage. 3. Approaches for developing future 'simplified" vaccines with similar levels of safety and efficacy so that these objectives are achieved.