Statement from Christine F. Sizemore, Ph.D., and Anthony S. Fauci, M.D., National Institute of Allergy and Infectious Diseases/ National Institutes of Health
Despite global efforts at prevention and treatment, tuberculosis (TB) continues to claim more than 2 million lives each year. These deaths occur among approximately 8 million new TB cases that develop from a reservoir of an estimated 2 billion individuals infected with the TB bacterium (Mycobacterium tuberculosis).
This year, the occasion of World TB Day, March 24, is clouded by a sobering report from the World Health Organization (WHO) on the global increase of drug-resistant TB, especially in Eastern Europe and Central Asia. The WHO report reminds us that although existing control strategies to combat and treat TB are often successful, M. tuberculosis inevitably develops resistance to anti-TB drugs, underscoring the need for new medications and other strategies to keep pace with this formidable microbial foe. Large numbers of drug-resistant, and sometimes untreatable, TB cases could undermine improvements that the global community has made in tuberculosis control.
Over the past several years, significant advances have been made in our understanding of M. tuberculosis, its disease-causing mechanisms and its interactions with its human hosts. Now, we face the challenge of sustaining a global research infrastructure that enables us to translate these basic research findings into new countermeasures — especially therapies, diagnostics and vaccines — needed to fight a changing and adaptable pathogen.
The development of anti-TB interventions relies on our ability to interpret basic science findings so that we may identify vulnerabilities of M. tuberculosis, against which new drugs or vaccines can be directed, and to find ways to quickly and accurately discern molecular evidence of infection and disease in order that we may develop more sensitive diagnostics. The translation of fundamental knowledge into the products needed to reduce the global burden of TB requires a multidisciplinary approach, involving partners from government and the public and private sectors. At NIAID, we have worked to leverage the intellectual capacity of the academic scientific community; the expertise and advanced technology of industrial partners; and the research resources and reagents that we and others make available to researchers around the world. These assets, along with the participation and endorsement of global partners, are critical to developing new interventions that will allow us to improve existing TB control strategies.
The recent payoffs of a multidisciplinary approach to TB research have been substantial, as evidenced by promising collaborations between NIAID and our public/private sector partners. Recently, two new TB vaccine candidates entered human clinical trials in the United States and the United Kingdom; a third candidate is scheduled to undergo human testing shortly in the United States. These new TB vaccine candidates are the first to be tested in people in the United States in more than six decades. The development of a new and improved TB vaccine is critical, because the currently available TB vaccine, Bacille Calmette-Guérin (BCG), offers protection against TB only in infants and young children, with limited effectiveness against the most contagious form of the disease, TB of the lung. In addition to representing the first step toward development of a new product, the new human studies offer an opportunity to learn more about the protective immune responses against M. tuberculosis. Currently, it is not known with certainty what constitutes an effective immune response against pulmonary TB in humans.
The development of new TB drugs is proceeding apace. A promising drug candidate developed by public/private partners with contributions by NIAID is completing preclinical evaluation and is expected to undergo FDA review later this year for approval to be tested in humans. This candidate is a new member of a class of chemicals known as nitroimidazoles, which have the potential to be effective against both the drug-resistant and drug-sensitive forms of TB.
NIAID and our colleagues also are developing several TB diagnostic strategies that are now ready to be evaluated in humans. These products have the potential to significantly modernize TB diagnosis, especially in resource-poor settings.
The TB research community, public and private funders, as well as volunteers participating in the recent and upcoming TB vaccine, drug and diagnostic trials are to be congratulated for their commitment to facilitating the translation of fundamental knowledge into new products to combat TB. These promising new countermeasures are just the beginning of a new era of TB research, in which we anticipate that further fruitful partnerships will assure a constant stream of new interventions against TB.
Anthony S. Fauci, M.D., is Director of the National Institute of Allergy and Infectious Diseases (NIAID) at the National Institutes of Health. Christine F. Sizemore, Ph.D., is Acting Chief of the Tuberculosis and Other Mycobacterial Diseases Section in the NIAID Division of Microbiology and Infectious Diseases.
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NIAID is a component of the National Institutes of Health, an agency of the U.S. Department of Health and Human Services. NIAID supports basic and applied research to prevent, diagnose and treat infectious diseases such as HIV/AIDS and other sexually transmitted infections, influenza, tuberculosis, malaria and illness from potential agents of bioterrorism. NIAID also supports research on transplantation and immune-related illnesses, including autoimmune disorders, asthma and allergies.
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