Biotechnology in the development of vaccines for animal parasites.

Attempts to develop vaccines for protozoan and helminth parasites of livestock have been generally unproductive. Difficulties have been encountered in identifying antigens which induce protective immune responses and in obtaining sufficient quantities of antigens for vaccine trials. Use of monoclonal antibody and genetic engineering technologies provides the necessary tools to overcome these problems. Application of these technologies in animal parasitology should provide for significant breakthroughs in vaccine development.