ABSTRACT

The development of vaccines using genetic engineering technology has the potential to provide additional and safer products for controlling certain diseases. This technology, which is being applied to some animal diseases that occur in the US, promises more effective, less-expensive products through genetic engineering. The potential for application of genetic engineering is highest for use in controlling animal diseases caused by viruses. This is possibly because more viruses have been studied at the molecular level; these viruses also cause some of the more important infectious diseases. Vaccinia virus has been bioengineered to act as an expression vector for cloning foreign genes in tissue cultures and animals. Tissue-culture cells infected with vaccinia virus that carry the gene for hepatitis B surface antigen, permit the cells or the rabbits vaccinated with such a virus to express the immunizing protein for hepatitis B virus. The use of genetically programmed bacteria is a promising avenue to vaccine manufacturing.