[New vaccines and new veterinary therapies derived from biotechnologies: examples of applications].

The last ten years have seen the development of vaccines derived from deoxyribonucleic acid (DNA) recombination, which, when used in association with appropriate diagnostic kits, make it possible to distinguish vaccinated from infected animals. This article describes the general principles behind these vaccines, provides examples of different applications, e.g. vaccines against Aujeszky's disease, classical swine fever, rabies, avian diseases and rinderpest, and discusses the role of this type of vaccine in certain control plans. Deoxyribonucleic acid vaccines constitute a revolution in the concept of vaccination, which was previously based on the injection of a protein or a medium expressing a protein. It is now possible, however, to induce immunisation by direct injection of the gene that codes for the immunogenic antigen. Examples of such vaccines are described. Finally, the production of biological molecules used for therapeutic purposes thanks to genetic engineering techniques is illustrated by some examples concerning, in particular, animal bioreactors (transgenic animals).