Vaccinology Group

Traditional approaches to vaccination, which have relied on the delivery of inactivated or attenuated organisms, have had a major impact on the control of livestock diseases. However, there remain many important diseases for which vaccines are either not available or for which the current vaccines are only partially effective. Traditional vaccination approaches utilising inactivated organisms or attenuated strains, selected by passage in vitro or in an unnatural host, have a number of shortcomings. Thus, inactivated organisms may induce inappropriate immune responses or immunity may be of short duration; incomplete attenuation or inactivation of organisms can result in disease; and it is not always possible to produce stable attenuated organisms or "marker vaccines" by in vitro or in vivo passage.

Developments in DNA technology have created new opportunities for vaccine production, both through genetic manipulation of pathogens and by enabling the identification of defined antigens that induce protective immune responses. These opportunities, together with a detailed understanding of the components of the immune response that mediate protection, and knowledge of how these responses can be induced and regulated at an appropriate location in vivo, provide a conceptual framework for the rational development of new vaccines.

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