By DENISE GRADY
The scientists who altered a deadly flu virus to make it more contagious have agreed to suspend their research for 60 days to give other international experts time to discuss the work and determine how it can proceed without putting the world at risk of a potentially catastrophic pandemic.
Suspensions of biomedical research are almost unheard of; the only other one in the United States was a moratorium from 1974 to 1976 on some types of recombinant DNA research, because of safety concerns.
A letter explaining the flu decision is being published in two scientific journals, Science and Nature, which also plan to publish reports on the research, but in a redacted form, omitting details that would let other researchers copy the experiments. The letter is signed by the scientists who produced the new, more contagious form of the flu virus, as well as by more than 30 other leading flu researchers.
“We recognize that we and the rest of the scientific community need to clearly explain the benefits of this important research and the measures taken to minimize its possible risks,” the letter states. At an international meeting next month in Geneva, participants selected by the World Health Organization will consider what to do next. Dr. Anthony Fauci, head of the National Institutes of Health, said the gathering would “address some of these difficult issues on an international scale instead of something restricted to the United States government.”
The scientists say their work has important public health benefits, but they acknowledge that it has sparked intense public fears that the deadly virus could accidentally leak out of a laboratory, or be stolen by terrorists, and result in a devastating pandemic. A national biosecurity panel in the United States has already taken the unusual step of asking the scientists to keep part of their data secret to prevent others from reproducing their work.
Scientists are split regarding the research, with some praising it as important and urging that it be published, and others saying the experiments are so dangerous that they should never have been done.
The experiments involve a type of bird flu virus known as H5N1, which rarely infects people but is highly deadly when it does. The work, paid for by the National Institutes of Health, was done by two separate research teams, at Erasmus Medical Center in Rotterdam, the Netherlands, and at the University of Wisconsin, Madison.
Ron Fouchier, a virologist who conducted the research at Erasmus Medical Center, explained why he and his colleagues decided to pause the research. “It is unfortunate that we need to take this step to help stop the controversy in the United States,” he said. “I think if this were communicated better in the United States it might not have been needed to do this. In the Netherlands we have been very proactive in communicating to the press, politicians and public, and here we do not have such a heated debate.”
Dr. Fauci said that he had never seen the scientific world so polarized, and that led him to urge the researchers to show good faith and flexibility by declaring the moratorium themselves. A concern “looming in the background,” he said, was that biosecurity experts might overreact and impose excessive restrictions on the research.
“I think it’s important research that needs to go forward,” Dr. Fauci said. “I think we need to get greater input on the conditions in which it goes forward.”
Dr. Fauci and others who support the research say it may help explain how flu viruses that start out in animals adapt to humans and become transmissible, and therefore able to cause pandemics. That information, the researchers say, could help them recognize viruses on the way to developing pandemic potential.
Richard H. Ebright, a molecular biologist at Rutgers, is among those who oppose the research because of its risks, and doubts that it could be used to predict pandemics. He said that a moratorium was a good idea, but that this one did not go far enough. He said that the letter did not acknowledge the need for improved “biosafety, biosecurity and oversight,” and that in any case, 60 days would not be enough time to put the needed safeguards in place. The letter noted a “perceived fear” among the public, Dr. Ebright said, and seemed to suggest that the debate would cool down if people would just let the researchers explain that they had done the experiments safely.
Dr. Ebright said experiments with this virus should be done only in laboratories with the highest biosafety rating, BSL4, not in the “enhanced BSL3” in which the work was actually done.
Dr. Fouchier disagreed. He also said that his center did not have BSL4 labs.
Dr. Fauci said various expert groups, including the Centers for Disease Control and Prevention, had determined that enhanced BSL3 was good enough for bird flu research.
Since 1997, when the H5N1 virus was first identified, about 600 people have been infected, and more than half died — an extraordinarily high death rate. The saving grace of H5N1 is that when people do become infected — nearly always from contact with birds — they almost never transmit the disease to other people. But the virus has persisted in the environment, infecting millions of birds, and scientists have warned that if it mutates to become more contagious in people, disaster could ensue.
But what mutations would make the virus more easily transmissible? And how hard, or easy, would it be for those mutations to occur? Hoping to answer those questions, some researchers began experimenting with bird flu, working with ferrets, which are considered the best model for studying flu, because they contract it and get sick in much the same way that people do. Recently, the teams in Rotterdam and Madison announced that they had produced a form of H5N1 with mutations that allowed it to “go airborne,” meaning that it spread through the air from one ferret to another. Presumably, though not certainly, the virus could spread in the same way among people.
Dr. Fouchier said he was surprised by how easy it was to change the virus into the very form that the world has been dreading. Now, scientists around the world will have to grapple with what to do with Dr. Fouchier’s creation.
