for National Geographic News
The war against terrorism may have a new weapon. Indian scientists
announced November 5 that they have developed a safer and cheaper
anthrax vaccine.
The new vaccine is less toxic and longer lasting
than the currently available vaccine, said its developers Rakesh
Bhatnagar, chairman of the Center for Biotechnology at Jawaharlal Nehru
University (JNU), and Yogendra Singh, a scientist at the Center for
Biochemical Technology, New Delhi.
Anthrax is an acute infectious disease caused by the spore-forming bacterium Bacillus anthracis. It occurs commonly among cattle, sheep, goats, camels, and other herbivores but it can also occur in humans when they are exposed to infected animals or tissue from infected animals. It has recently become a weapon in the arsenal of terrorists.
"Four people have died from anthrax infections in the United States over the past several weeks, and in some of these cases, bioterrorism-quality anthrax has been the cause," said Elaine Fuchs, a molecular geneticist at the Howard Hughes Medical Institute in Chicago and president of the American Society of Cell Biology (ASCB).
The human anthrax vaccine on the market today was developed at the behest of the Pentagon, and is only available for use by American troops. The current vaccine requires 18 months to take effect and can have toxic side effects. Many soldiers have opted to face disciplinary action rather than subject themselves to the six-course dose.
"The new research by Dr. Bhatnagar is extremely promising, precisely because his newly-engineered anthrax proteins might avoid the side-effects that plagued the previous vaccine," said Katherine Wilson, a biologist at Johns Hopkins University School of Medicine, Baltimore.
Bhatnagar's work was scheduled to be released at the ASCB annual conference in December. The association decided to break its long tradition of keeping the contents of research papers secret until they have been presented because of the vaccine's potential impact on public health.
Developing a Vaccine
The vaccine is the result of seven years of work, funded in part by the Indian Department of Biotechnology. Led by Bhatnagar, the research team created harmless mutant forms of the three key proteins that together make anthrax fatal. The genes for the mutated proteins were introduced into host organisms, where they reproduced. The mutant proteins were then purified to ensure that reactivity and side effects of the vaccine were minimized.
Once the researchers were confident that they could reproduce the protective antigens on a laboratory scale, Bhatnagar's team took the production to near-industrial scale. A five-liter capacity fermenter can now produce approximately five grams of protective antigen per liter, said Bhatnagar. One gram of the antigen can supply millions of vaccine shots.
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