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DEVELOPMENT REPORT - June 17, 2002: New TB Vaccine
to be Tested
By Jill Moss
This is the VOA Special English Development
Report.
Scientists are preparing to test the safety
of a new vaccine medicine that could protect people against tuberculosis.
Earlier this month, researchers at the World Congress on Tuberculosis
in Washington, D.C., announced the testing. It is to begin by the end
of this year in San Francisco, California. This will be the first time
in nearly eighty years that a new vaccine has been tested against T-B.
Researchers say the new vaccine is a form of
an old vaccine called B-C-G. This vaccine is only partly effective in
preventing the disease. It is used in developing countries to prevent
severe tuberculosis in children. However, B-C-G does not protect adults
from the disease.
About two-million people die from T-B each year.
Currently, about one-third of the world's population is infected with
the bacteria that cause tuberculosis. Their infection is inactive. T-B
infection can remain inactive in a person's lungs for years, or even
a lifetime. The disease becomes active in about ten percent of all cases.
T-B causes a high body temperature and coughing.
Infected people spread the disease by releasing particles from their
mouths when they cough, sneeze, spit or talk. Someone with active T-B
must take medicine each day for six to nine months to halt progression
of the disease.
The World Health Organization has a five-step
program to guarantee that T-B patients take their medicine correctly.
The program is called Directly Observed Treatment, Short-Course, or
DOTS. Health officials are working hard to expand the program around
the world. However, only twenty-seven percent of all tuberculosis cases
are discovered and treated within the DOTS program. Health experts say
a new vaccine to prevent T-B is very important.
The last new drug to treat T-B was created more
than forty years ago. Since that time, different forms of the disease
have become resistant to drugs currently being used. However, researchers
believe this is about to change because of the discovery of the genetic
structure of the bacterium that causes the disease.
That discovery four years ago has helped scientists
better understand how T-B bacteria work. It also has given researchers
information to help them develop new drugs and vaccines.
This VOA Special English Development Report
was written by Jill Moss.
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