| ■ TB Vaccines Losing Effectiveness: Study | 07.03.19 |
| Current tuberculosis vaccines may be losing their effectiveness, says an international study to be published online this week in the journal Proceedings of the National Academy of Sciences. Researchers found that the bacterium -- bacillus Calmette-Guerin (BCG) -- that has been used for nearly 90 years to make all the world's TB vaccines may have evolved to the point where it's no longer able to combat the disease, the Toronto Star reported. The scientists created a current genetic map of BCG and found that it has few of the proteins that typically produce an immune response to TB in humans, the Star reported. The effectiveness of TB vaccines has been questioned for decades and this study shows the urgent need to develop a new vaccine, said one of the researchers. Currently, BCG vaccines are given to more than two million infants a week in parts of the world where TB is endemic, the Star reported. |