Vaccination of animals for the prevention of infectious diseases has b
een practised for a number of years with little change in product comp
osition. Recent advances in molecular biology, pathogenesis and immuno
logy have laid the groundwork for the development of a new generation
of veterinary vaccines based on pure subunits as well as live vectored
bacteria and viruses. Along with novel methods of antigen preparation
, the use of new adjuvants and delivery systems will permit targeting
of the appropriate immune response as well as offering flexibility in
terms of vaccination protocols. These new technologies are also being
applied to the development of vaccines to enhance animal productivity
and to control reproduction.