Amateur Biologists Are New Fear in Making a Mutant Flu Virus Na Son Nguyen/Associated Press WORRY An outbreak of the H5N1 bird flu virus was reported in Vietnam in February. Just how easy is it to make a deadly virus? This disturbing question has been on the minds of many scientists recently, thanks to a pair of controversial experiments in which the H5N1 bird flu virus was transformed into mutant forms that spread among mammals. After months of intense worldwide debate, a panel of scientists brought together by the World Health Organization recommended last week in favor of publishing the results. There is no word on exactly when those papers - withheld since last fall by the journals Nature and Science - will appear. But when they do, will it be possible for others to recreate the mutant virus? And if so, who might they be and how would they do it? Scientists are sharply divided on those questions, as they are on the whole complex of issues surrounding the mutated virus known as mutH5N1. On the question of who, while terrorists and cults have long been a concern in biosecurity circles, some scientists also fear that publication may allow curious amateurs to recreate the mutated virus - raising the risk of an accidental release. Over the past decade, more amateur biologists have started to do genetic experiments of their own. One hub of this so-called D.I.Y. biology movement, the Web site DIYbio.org, now has more than 2,000 members. "I worry about the garage scientist, about the do-your-own scientist, about the person who just wants to try and see if they can do it," Michael T. Osterholm of the University of Minnesota said last week at a meeting of biosecurity experts in Washington. Dr. Arturo Casadevall of the Albert Einstein College of Medicine in New York City, who along with Dr. Osterholm is a member of the scientific advisory board that initially recommended against publishing the papers, agreed. "Mike is right," he said in a telephone interview. Humans are very inventive. Advocates of D.I.Y. biology say such fears not only are wildly exaggerated, but could interfere with their efforts to educate the public. "I am really sick and tired of folks waving this particular red flag," said Ellen D. Jorgensen, a molecular biologist who is president of Genspace, a "community biotechnology lab" in Brooklyn. There are many ways to make a virus. The simplest and oldest way is to get the viruses do all the work. In the 19th century, doctors produced smallpox vaccines by inoculating cows with cowpox viruses. The viruses replicated in the cows and produced scabs, which were then applied to patients, protecting them from the closely related smallpox virus. By the turn of the century, scientists had discovered how to isolate a number of other viruses from animals and transfer them to new hosts. And by midcentury scientists were rearing viruses in colonies of cells, which made their study far easier. Viruses have to infect host cells to reproduce; they cannot replicate on their own. More recently, scientists discovered how to make new viruses - or at least new variations on old ones. The biotechnology revolution of the 1970s enabled them to move genes from one virus to another. Flu vaccines can be made this way. Scientists can move some genes from a dangerous flu strain to a harmless virus that grows quickly in chicken eggs. They inject the engineered viruses into the eggs to let them multiply, then kill the viruses to prepare injectable vaccines. Scientists have also learned how to tweak individual virus genes. They remove a portion of the gene and then use enzymes to mutate specific sites. Using other enzymes, they paste the altered portion back into the virus's genes. Another way to make altered viruses is to harness evolution. In a method called serial passage, scientists infect an animal with viruses. The descendants of those viruses mutate inside the animal, and some mutations allow certain viruses to multiply faster than others. The scientists then take a sample of the viruses and infect another animal. Viruses can change in important ways during this process. If it is done in the presence of antiviral drugs, scientists can observe how viruses evolve resistance. And viruses can become weak, making them useful as vaccines. At the biosecurity meeting in Washington last week, Ron Fouchier, who led the Dutch team that created one of the mutant H5N1 viruses, described part of the experiment.