A tuberculosis vaccine used only infrequently in this country because health officials considered it unreliable has been found in a study to be surprisingly effective, reducing the risk of the lung disease by 50 percent and death by 71 percent.
BCG is said to be the most widely used vaccine in the world. The World Health Organization recommends BCG as a standard childhood immunization.
U.S. health officials recommend the vaccine only under very limited circumstances because its application poses problems in how health officials track tuberculosis.
One major problem is that anyone who has had BCG vaccine will have a positive tuberculin skin test. The skin test would become meaningless if BCG use became widespread, and health officials would need to rely on chest X-rays and other methods to detect infections.
But the study, conducted by researchers at the Harvard School of Public Health and published in today's Journal of the American Medical Association, seems certain to renew public health policy debates about use of BCG.
It was financed by the Centers for Disease Control and Prevention, which stopped recommending use of BCG for health care workers and other adults at high risk for tuberculosis in 1988. It is now recommended only for "uninfected children who are at unavoidable risk of exposure."
The CDC has declared tuberculosis out of control in the United States and strains of the bacillus that causes TB have become resistant to standard antibiotics.