Published online by Cambridge University Press: 14 October 2009
Molecular biology and, in particular, knowledge of the immune response at the molecular level provide the research community with the opportunity to design vaccines that will elicit the appropriate responses for many diseases. The critical issue is to identify the immune response that correlates with protection. It is remarkable how well the empirical approach has worked; it is essential, therefore, not to ignore the lessons to be learned from these successes. It is particularly essential that each disease and the immune response that affords protection be studied individually so that the appropriate responses can be induced.