This is the VOA SpecialEnglish Development Report.
Scientists are preparing to test the safety of a new vaccinemedicine that could protect people against tuberculosis. Earlierthis month, researchers at the World Congress on Tuberculosis inWashington, D.C., announced the testing. It is to begin by the endof this year in San Francisco, California. This will be the firsttime in nearly eighty years that a new vaccine has been testedagainst T-B.
Researchers say the new vaccine isa form of an old vaccine called B-C-G. This vaccine is only partlyeffective in preventing the disease. It is used in developingcountries to prevent severe tuberculosis in children. However, B-C-Gdoes not protect adults from the disease.
About two-million people die from T-B each year. Currently, aboutone-third of the world’s population is infected with the bacteriathat cause tuberculosis. Their infection is inactive. T-B infectioncan remain inactive in a person’s lungs for years, or even alifetime. The disease becomes active in about ten percent of allcases.
T-B causes a high body temperature and coughing. Infected peoplespread the disease by releasing particles from their mouths whenthey cough, sneeze, spit or talk. Someone with active T-B must takemedicine each day for six to nine months to halt progression of thedisease.
The World Health Organization has a five-step program toguarantee that T-B patients take their medicine correctly. Theprogram is called Directly Observed Treatment, Short-Course, orDOTS. Health officials are working hard to expand the program aroundthe world. However, only twenty-seven percent of all tuberculosiscases are discovered and treated within the DOTS program. Healthexperts say a new vaccine to prevent T-B is very important.
The last new drug to treat T-B was created more than forty yearsago. Since that time, different forms of the disease have becomeresistant to drugs currently being used. However, researchersbelieve this is about to change because of the discovery of thegenetic structure of the bacterium that causes the disease.
That discovery four years ago has helped scientists betterunderstand how T-B bacteria work. It also has given researchersinformation to help them develop new drugs and vaccines.
This VOA Special English Development Report was written by JillMoss.