Entering the twenty-first century
Scarcely a day passes without mention in the news media of another exciting biotechnological discovery made in this nation's research laboratories. Genetic engineering is being applied to human and animal health, agricultural production, and many other vital aspects of the human existence. These advances are especially relevant to Third World countries where the problems are compounded by conditions often mentioned only in the history texts of the developed countries.
Several speakers addressed the subject of biotechnology at this symposium. They described briefly how the relatively young disciplines of molecular biology and genetic engineering have affected humans, plants, and animals worldwide, and how the many amazing accomplishments made thus far are likely to affect the developing countries. They also assessed what the future holds in these fields.
Biomedical breakthroughs using the techniques of biotechnology are contributing to human health in the diagnosis, treatment, and prevention of disease. In the diagnosis of both infectious and genetic diseases there is widespread interest in using simple, rapid diagnostic tests based on nucleic acid hybridization and monoclonal antibodies. In the treatment of disease, molecular biology can help isolate and determine the complete chemical and three-dimensional structure of, for example, receptors for drugs, the key parasitic enzymes, and the folic acid system. And in the prevention of disease, molecular biology and biotechnology are of particular interest in vaccine development, a subject that is well known to Dr. Kenneth S. Warren, director of health sciences at the Rockefeller Foundation.
Approximately 20 vaccines have been discovered over the last 200 years, many of which are inferior and most of which are not used today. Only six vaccines are being used by the World Health Organization's immunization program - BCG (tuberculosis), diphtheria, pertussis, tetanus, measles, and polio - and a few others are also being used in the United States (particularly mumps and rubella) and elsewhere (the yellow fever, cholera, and typhoid vaccines, for example).
Tragically, however, children are still dying - 5 million in 1980 alone - from diseases for which vaccines are available, and the toll is the highest, of course, in the developing countries. According to Warren, the major causes of childhood deaths worldwide are diarrhea and malnutrition, measles, lower respiratory infection, tetanus, and malaria. For the great killers like the diarrheas there are no effective vaccines. Likewise, there are no vaccines for malaria nor for any of the other major parasitic infections such as trypanosomiasis, leishmaniasis, amebiasis, schistosomiasis, filariasis (especially river blindness), and all the helminth infections (roundworm and tapeworm).
Added to this shortage of vaccines is the inadequacy of many of the key vaccines. For example, BCG vaccine has been controversial for years, and studies in southern India have questioned whether it can prevent pulmonary tuberculosis. The side effects of the pertussis vaccine are so severe that England, Japan, and some of the Scandinavian countries no longer use it, despite the fact that an epidemic of the disease is worse than the vaccine.
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