lunes, julio 31, 2006

Custom-Built Pathogens Raise Bioterror Fears

By Joby Warrick
Washington Post Staff Writer
July 31, 2006

In 2002, Eckard Wimmer, a molecular geneticist, startled the scientific world by creating the first live, fully artificial virus in the lab. It was a variation of the bug that causes polio, yet different from any virus known to nature. And Wimmer built it from scratch.

The virus was made wholly from nonliving parts. The most crucial part, the genetic code, was picked up for free on the Internet. Hundreds of tiny bits of viral DNA were purchased online, with final assembly in the lab.

Wimmer intended to sound a warning, to show that science had crossed a threshold into an era in which genetically altered and made-from-scratch germ weapons were feasible. But in the four years since, other scientists have made advances faster than Wimmer imagined possible.

A revolution in biology has ushered in an age of engineered microbes and novel ways to make them. The new technology opens the door to new tools for defeating disease and saving lives. But today, in hundreds of labs worldwide, it is also possible to transform common intestinal microbes into killers. Or to make deadly strains even more lethal. Or to resurrect bygone killers, such the 1918 influenza. Or to manipulate a person's hormones by switching genes on or off. Or to craft cheap, efficient delivery systems that can infect large numbers of people.

"The biological weapons threat is multiplying and will do so regardless of the countermeasures we try to take," said Steven M. Block, a Stanford University biophysicist.

The U.S. Centers for Disease Control and Prevention has declined so far to police the booming gene-synthesis industry, which churns out made-to-order DNA to sell to scientists.

How to Make a Virus

Wimmer's artificial virus looks and behaves like its natural cousin -- but with a far reduced ability to maim or kill -- and could be used to make a safer polio vaccine. But it was Wimmer's techniques, not his aims, that sparked controversy when news of his achievement hit the scientific journals.

As the creator of the world's first "de novo" virus -- a human virus, at that -- Wimmer came under attack from other scientists who said his experiment was a dangerous stunt. He was accused of giving ideas to terrorists, or, even worse, of inviting a backlash that could result in new laws restricting scientific freedom. Wimmer counters that he didn't invent the technology that made his experiment possible. He only drew attention to it. "To most scientists and lay people, the reality that viruses could be synthesized was surprising, if not shocking," he said. "We consider it imperative to inform society of this new reality, which bears far-reaching consequences."

"This," he said, "is a wake-up call."

The global biotech revolution underway is more than mere genetic engineering. It is genetic engineering on hyperdrive. New scientific disciplines such as synthetic biology, practised not only in the United States but also in new white-coat enclaves in China and Cuba, seek not to tweak biological systems but to reinvent them.

The holy grail of synthetic biologists is the reduction of all life processes into building blocks -- interchangeable bio-bricks that can be reassembled into new forms. The technology envisions new species of microbes built from the bottom up: "living machines from off-the-shelf chemicals" to suit the needs of science, said Jonathan Tucker, a bioweapons expert with the Washington-based Center for Non-Proliferation Studies. "It is possible to engineer living organisms the way people now engineer electronic circuits," Tucker said.

Racing to exploit each new discovery are dozens of countries, many of them in the developing world.There's no binding treaty or international watchdog to safeguard against abuse. And the secrets of biology are available on the Internet for free, said geneticist Robert L. Erwin. "It's too cheap, it's too fast, there are too many people who know too much," Erwin said, "and it's too late to stop it."

"Scientists creating new life forms cannot be allowed to act as judge and jury," Sue Mayer, a veterinary cell biologist and director of GeneWatch UK, said in a statement signed by 38 organizations. Activists are not the only ones concerned about where new technology could lead. Numerous studies by normally staid panels of scientists and security experts have also warned about the consequences of abuse. An unclassified CIA study in 2003 titled "The Darker Bioweapons Future" warned of a potential for a "class of new, more virulent biological agents engineered to attack" specific targets. "The effects of some of these engineered biological agents could be worse than any disease known to man," the study said.

It is not just the potential for exotic diseases that is causing concern. Harmless bacteria can be modified to carry genetic instructions that, once inside the body, can alter basic functions, such as immunity or hormone production, three biodefense experts with the Defense Intelligence Agency said in an influential report titled "Biotechnology: Impact on Biological Warfare and Biodefense."

Last fall, a British scientific journal, New Scientist, decided to contact some of these DNA-by-mail companies to show how easy it would be to obtain a potentially dangerous genetic sequence -- for example, DNA for a bacterial gene that produces deadly toxins. Only five of the 12 firms that responded said they screened customers' orders for DNA sequences that might pose a terrorism threat. Four companies acknowledged doing no screening at all. Under current laws, the companies are not required to screen.

"It would be possible -- fully legal -- for a person to produce full-length 1918 influenza virus or Ebola virus genomes, along with kits containing detailed procedures and all other materials for reconstitution," said Richard H. Ebright, a biochemist and professor at Rutgers University. "It is also possible to advertise and to sell the product, in the United States or overseas."


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