"The development of a TB vaccine requires long-term commitment and
collaboration by governments, TB control programs, scientists, industry and
academia, both nationally and internationally," says Ann Ginsberg, M.D.,
Ph.D., tuberculosis and leprosy program officer at the National Institute of
Allergy and Infectious Diseases (NIAID) and a co-author of the report.
The Blueprint was developed at a TB workshop held in March 1998 by NIAID and
the National Vaccine Program Office. A taskforce convened by the Department
of Health and Human Services now oversees the implementation of the plan.
"The Blueprint serves as a call-to-action and rough battle plan for the
development of a TB vaccine, and demonstrates that a coherent plan is in
place and being followed as current resources allow," says Dr. Ginsberg, who
represents the NIH on the taskforce.
According to the Blueprint, 54 million people become infected worldwide with
TB each year. The only currently available TB vaccine, called BCG, is
largely ineffective and interferes with skin tests used to diagnose the
disease. As a result, BCG vaccine is not recommended for use in the United
States. However, BCG is effective against early childhood tuberculosis and
is recommended by the World Health Organization as part of an immunization
schedule for infants in countries where the disease is rampant.
An ideal vaccine would be safe, long-lasting, inexpensive, not interfere
with skin tests used for diagnosis, protect against development of disease
and possibly even block infection.
Development of a TB vaccine presents a significant challenge. TB bacteria
replicate very slowly, making them difficult to study. And because TB is
highly infectious and dangerous to work with, scientists must use
appropriate safety standards and equipment when working with the bacteria in
The report details three different vaccine concepts currently being
developed: live, attenuated vaccines; subunit vaccines; and naked DNA
vaccines. In one live, attenuated vaccine approach, scientists genetically
modify the TB bacterium in the laboratory, thereby reducing its ability to
cause disease. When inoculated into humans, the weakened bacteria should
induce an immune response but not cause disease. In the subunit vaccine
approach, scientists dissect the TB bacterium and use only a fragment of it
in the vaccine to produce an immune response. In naked DNA vaccines, a
relatively new vaccine strategy, scientists take DNA from the TB bacterium
and modify it so only a small piece of the original genetic material is
left. This modified, naked DNA when inoculated into humans prompts the
body's own cells to generate protective immune responses against the
Once scientists have identified a promising vaccine candidate, they will
study its safety and effectiveness in human clinical trials.
**BACKGROUND ON TB**
TB is a contagious disease spread through the air when a person with active
TB expels M. tuberculosis, the bacterium that causes TB, by coughing,
sneezing, speaking or laughing. Once inhaled, the bacteria travel to the
lungs and attach to air sacs, known as alveoli, where they multiply. The
bacteria may cause active disease, or they may persist at a low level for
years before causing disease, a condition known as latent infection.
Currently, 10 to 15 million people in the United States have latent
infection, and 10 percent of them will develop active disease at some point
in their lives.
TB infection is particularly deadly for people with weakened immune systems,
such as individuals already battling HIV infection. An HIV-positive person
is up to 30 times more likely to develop TB disease, which in turn
accelerates HIV disease. TB is the leading cause of death in HIV-positive
Current TB drug regimens require long treatment periods, and many patients
stop taking the drugs as soon as they start feeling better, which can lead
to the emergence of drug-resistant strains. Population growth, inadequate
public health infrastructure, globalization and international travel, the
growing HIV/AIDS epidemic, and the emergence of multi-drug resistant TB
strains (strains that are resistant to two or more of the most commonly used
drugs to treat TB) all contribute to the growing global TB epidemic.
NIAID supports a comprehensive TB research program and follows the Blueprint
guidelines in conducting vaccine research and other anti-TB treatment
studies. The Blueprint is available on the NIAID Web site at http://www.niaid.nih.gov/publications/blueprint. For more information on TB
and vaccine research, please visit the NIAID publications page at
NIAID, a component of the National Institutes of Health (NIH), conducts and
supports research to prevent, diagnose and treat illnesses such as HIV
disease and other sexually transmitted diseases, tuberculosis, malaria,
asthma and allergies. NIH is an agency of the U.S. Department of Health and
Press releases, fact sheets and other NIAID-related materials are available
on the NIAID Web site at http://www.niaid.nih.gov.