Designing future vaccines.

Vaccination is one of the major preventive measures against infectious diseases. With the exception of the hepatitis B vaccine, the vaccines in use today are produced from the infectious agents themselves, either by attenuation or inactivation. Although these products have been successful in controlling many diseases, there are several reasons why efforts are being made to improve their quality. In addition there are some infectious diseases for which vaccines are not available because the causal agents cannot be grown in sufficient quantities. New approaches will be required to obtain effective vaccines against these diseases. In this paper, these approaches to the design of new vaccines are described using hepatitis B, rabies and foot-and-mouth disease as examples.