or both jaws. There is also anecdotal evidence that, when several adjacent teeth are lost, they can be replaced by implant-supported partial dentures. On the other hand, there are essentially no data on the use of implants for single tooth replacements. Nevertheless, there is every reason to believe that such an approach would be more satisfactory than present-day crown and bridgework. The implant would be placed directly in the jaw bone and there would be no need to cap the adjacent teeth. Although additional clinical studies are needed, we believe that ultimately dental implants will become the treatment of choice for any and all missing teeth.

FLUORIDATION AND PUBLIC HEALTH

Question. What is the Institute's position on a recently released report by the National Toxicology Program declaring that fluoridation of public water supplies is no danger to public health and is safe and effective in reducing cavities in affected populations?

Answer. The report in question was requested by the Assistant Secretary for Health, who appointed a subcommittee of his Committee to Coordinate Environmental Health and Related Programs (CCHERP) to conduct a major review of the risks and benefits of fluoride. This request followed the release of data from a National Toxicology Program experiment that found "equivocal" evidence of bone cancer in three male rats fed high dosages of fluoride in drinking water and one male rat fed a mid-high dosage. No bone cancers were found in female rats nor in male and female mice. The term "equivocal" means that the cancers could have occurred by chance alone.

The CCHERP report was released in February 1991 and is the most up-to-date and comprehensive of its kind. NIDR concurs with its findings, the most important being that there is no evidence that fluoride causes cancer of any kind in animals or human beings. This conclusion was based on animal experiments (such as the NTP study) and over 50 epidemiological studies, including an extensive review of cancer incidence and mortality in the United States by the National Cancer Institute. Another finding was that dental fluorosis has increased in nonfluoridated communities since the 1940s and may have increased in fluoridated communities. The cause is largely attributed to the wide availability of fluoride products and evidence of inappropriate and excessive use in some situations. Dental fluorosis (a condition that can range from a very mild staining of enamel to a more severe mottling and pitting of the surface) merits continued monitoring, but the fluorosis that has been reported is generally mild and more of a cosmetic than a health problem. The report affirms the safety and efficacy of water fluoridation, stating that it is the most cost effective and equitable (benefiting rich and poor alike) method of preventing tooth decay, and enumerates areas where additional research is needed.

Question. With the increasing use of fluorides in toothpastes and mouth washes, do you feel that a potential exists for fluoride overdoses in some populations?

Answer. It is important to note that dental fluorosis is a condition that affects developing teeth, so the issue raised concerns the oral health of children. NIDR does not recommend that mouth rinses be used by children aged 5 or under because they may swallow the rinse. Parents should also supervise toothbrushing in younger children to ensure that only a small amount of toothpaste is used on the brush. In terms of the population at large, we believe that it is important to document the incidence and prevalence of dental fluorosis and to monitor total fluoride intake from all sources in the environment, both in fluoridated and nonfluoridated areas, and among various age groups. This is one of the many important recommendations in the CCHERP report and in the NIDR Long-Range Research Plan for the Nineties.

NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES

STATEMENT OF DR. ANTHONY 8. FAUCI, DIRECTOR AND ASSOCIATE DIRECTOR FOR HIV RESEARCH

SUMMARY STATEMENT

Senator HARKIN. Now, we turn to the National Institute of Allergy and Infectious Diseases. Dr. Fauci, we have your budget request for $976.7 million, which is about 7.7 percent more than last year. I noticed that $459.3 million, or 47 percent, of your request is devoted to AIDS.

Again, we welcome you back and thank you again for your leadership of your Institute. And we would be delighted to hear your statement at this time.

Dr. FAUCI. Thank you very much, Mr. Chairman.

The National Institute of Allergy and Infectious Diseases is responsible for the conduct and support of basic and clinical research on infectious diseases, many of which cause extraordinary morbidity and mortality throughout the world. One of these, as you mentioned, is the human immunodeficiency virus which causes AIDS. In addition, we conduct and support research on the immune system which is the defense system of the body against the emergence of infections and certain neoplasms. I have come before this committee several times to discuss the research advances in these areas, and they have been truly extraordinary. However, these advances in biomedical technology have created a dilemma with their own new challenges. The public's expectation of what biomedical research can do to alleviate suffering and death caused by human diseases now clearly surpasses our available resources not only in research, but in health care delivery.

One way to bridge this gap is to prevent certain diseases before they occur, and this is particularly feasible with infectious diseases. Historically, vaccines have resulted in the saving of millions of lives and immeasurable financial costs. In this regard, the recent advances in technology have positioned us quite well to develop new vaccines for infections for which we thus far have no vaccines and more effective and safer vaccines for infections for which we already have existing vaccines.

In this regard, this past year basic and clinical research conducted by the NIAID in collaboration with the National Institute of Child Health and Human Development has resulted in the licensing of two new vaccines to protect infants against Haemophilus influenzae type b, the leading cause of bacterial meningitis in young children. This is an important advance, but just a start in NIAID's commitment to perform the basic and clinical research necessary to implement the children's vaccine initiative. The aim of this initiative is to develop an oral vaccine that provides lifelong immunity to the major diseases of childhood throughout the world.

On another note, there has been a disturbing rise in morbidity and mortality due to asthma among inner city children, most of whom are minorities. NIAID recently announced eight awards to establish a network of centers to study this problem. I can tell you more about this later on.

History in general and AIDS in particular has taught us that new and emerging microbes are a constant threat to our survival. NIAID is committed to remain at the forefront of research to strengthen our basic science alert system against this ever-present threat.

PREPARED STATEMENT

In the area of gene therapy, which you have just heard about from some of my colleagues, NIAID intramural scientists have recently demonstrated that a factor secreted by cells called gamma interferon could dramatically restore the genetically determined defective capacity of white blood cells of individuals with chronic granulomatous disease to kill potentially lethal bacteria. This is an important breakthrough in our ability to modify cellular gene function as opposed to replacing absent or defective genes, a manipulation which is akin to gene therapy.

Finally, time does not permit in this opening statement to give a summary of our AIDS activities, but I look forward to discussing this with you in our question period.

Thank you, Mr. Chairman.

[The statement follows:]

STATEMENT OF DR. ANTHONY S. FAUCI

Over the past four decades, the research mission of the National Institute of Allergy and Infectious Diseases (NIAID) has evolved to encompass illnesses ranging from allergies to AIDS, from the common cold to exotic diseases that devastate populations throughout the world. These diverse areas of research are all solidly grounded in the foundation of our Institute, which is basic research on microbes that infect people and on the immune system that protects us against these invaders. This common theme underlies all of our efforts. Today, even as biomedical researchers break new ground in immunology, usher in the era of gene therapy, and design drugs that are highly specific and effective against a wide range of infectious agents, such achievements create a new challenge. can do to alleviate suffering and death caused by human diseases far surpasses

our available resources.

The public's expectations of what biomedical research

How then can NIAID best employ its sophisticated technologies to fulfill its mission of improving public health? The most effective way to narrow the growing gap between expectations and available resources is to prevent diseases before they occur. In the area of infectious diseases, this is best achieved through vaccines.

Our foundation of basic research and our accomplishments in vaccine development make NIAID uniquely positioned to lead the renaissance in vaccinology that is being realized in the decade of the 1990s. Historically, vaccines have dramatically decreased or even completely eliminated infectious diseases that have taken heavy tolls on past civilizations. A classic example is the complete eradication of the scourge of smallpox from the world. Nonetheless, we have realized only a fraction of the full potential of vaccines to prevent a wide array of infections that cause considerable morbidity and mortality throughout the world. Over the past several years. natural products and synthetic peptides of organisms and, most recently, recombinant DNA products have largely replaced whole killed or attenuated organisms that have traditionally been used to make vaccines. approaches have resulted in more specific and potentially less toxic vaccines. Something more theoretical, but with considerable potential, is the

These newer

concept of intracellular immunization, which employs a form of gene therapy to

"immunize" cells against viral infection. It involves inserting into an individual's blood cells a gene encoding for a protein that inhibits the growth of the target virus. This past year, several NIAID-supported researchers identified mutant genes of the AIDS virus that are promising candidates for such a strategy.

Vaccines benefit people of all ages, but their impact on the health of children is particularly important. Many of you may be aware of a new concept

known as the "Children's Vaccine Initiative." First proposed by the executive director of the United Nations Children's Emergency Fund, its goal is lofty: immunize children worldwide with an oral vaccine that provides lifelong immunity to the major infectious diseases of childhood. NIAID is committed to focusing our basic research activities on surmounting the technical obstacles inherent in creating such a vaccine.

In fact, I am pleased to be able to tell you about an important advance in the technology for producing childhood vaccines. In 1990, the FDA licensed two new vaccines to protect infants against Haemophilus influenzae type B (Hib), the leading cause of bacterial meningitis in young children. Each year, more than 700 children die of Hib meningitis, and several thousand suffer long-term neurologic consequences of the disease, including mental retardation and hearing loss. The new vaccines now make it possible to prevent Hib disease in children at highest risk for developing severe disease, those between 2 and 15 months of age.

The Hib vaccines use a new technology with far-reaching implications for protecting young infants against other serious bacterial infections. Because of the immaturity of their immune systems, very young children do not respond to vaccines made from the outer polysaccharide coats of some bacteria. NIAID-, supported extramural investigators and other scientists at the National Institute of Child Health and Human Development overcame this problem by pairing the Hib polysaccharide with a protein that children can respond to at birth. Use of the Hib conjugate vaccines will save an estimated $359 million for every annual cohort of children that is vaccinated. This compares with the $17.4 million NIAID spent on research leading to the development of these

vaccines.

We are continuing our search for an improved pertussis (whooping cough)