Problems and Opportunities Biotechnology and Animal Vaccines W. Ivan Morrison Supplies of livestock products in developing countries must increase to meet growing demand from burgeoning populations and rapid urbanization. Because of competition for land use, the necessary growth in livestock output will have to come in great part from improvement in the efficiency of production systems. Disease is one of the major factors contributing to poor livestock productivity in developing countries. Therapeutic agents are available for some of these diseases, but problems remain. Chemotherapy, for example, is impractical as a primary means of disease control, because costs are high and intensive application can create drug-resistant organisms.
Vaccination offers a potentially more effective and sustainable method of disease control.
But there are many other important diseases, notably parasitic diseases, for which attempts to develop vaccines have been unsuccessful. Rapid advances in biotechnology and immunology over the last two decades have created new opportunities to develop vaccines for parasitic diseases. Initial optimism in the early 1980s that vaccine products would quickly emerge from applications of recombinant DNA technology has not been fully realized. Subsequent experience has demonstrated that, unlike traditional approaches to vaccine development, effective exploitation of recombinant DNA technology requires knowledge of the target pathogens and the immune responses they induce, and an understanding of how immune responses can be manipulated. Since the early 1980s a series of fundamental discoveries in immunology have led to a detailed understanding of how the immune system processes and recognizes pathogenic organisms, and the different ways that immune responses control infections.