Novel Vaccine Strategies

Andy Potter, Vaccine & Infectious Disease Organization

Vaccination was introduced over 200 years ago in Western society by Jenner, and since that time, immunization has since proven to be the single-most effective means of preventing infectious diseases in both humans and animals. However, most of the advances made in the field of vaccine development have been accomplished without an understanding of microbial pathogenesis or the host response to infection. Thus, the true potential of vaccination as a disease control technology has not been realized. Advances made over the past two decades have provided a wealth of tools in the areas of molecular biology, immunology, vaccine formulation and delivery, and genomics which have the potential to revolutionize the way we view the use of vaccines.

Contemporary targets for vaccination include not only infectious diseases, but modification of non-disease targets such as reproduction, behavior and production enhancement. There has also been considerable interest in the use of vaccination as a means of enhancing food safety through the control of colonization of animals by human pathogens such as Escherichia coli O157:H7 and Campylobacter jejuni. Since these organisms do not cause disease in their animal hosts, new strategies for vaccine development are required. Advances in the area of antigen identification have made it relatively easy to choose components of microbe which will confer protective immunity. However, we still formulate and deliver these antigens using century-old invasive technology which does not efficiently induce immunity at the site(s) of infection, most often the mucosal surface. In addition, these practices also result in tissue damage at injection sites. New vaccine formulation and delivery strategies designed to enhance the quality and quantity of immune responses to vaccination will be described, including the use of novel synthetic adjuvants and immunomodulators as well as routes of administration. These new formulations are compatible with both new as well as conventional vaccines and promise to result in vaccines which not only show improved efficacy, but are also easier to use in a variety of management situations.