One Monday morning in September last year, Ron Fouchier, a virologist at the Erasmus Medical Center in Rotterdam, Netherlands, stood at the Intercontinental Hotel in Malta and told an audience of scientists about how he had created one of the world’s most dangerous viruses.
In a secure laboratory built to contain harmful pathogens, Fouchier took the H5N1 bird flu virus and mutated it, through some worryingly simple steps, into an airborne strain that spread swiftly among ferrets in neighboring cages. At first glance, the work might seem bad news for ferrets and little more, but the animals are the best mimic we have for how the virus could infect people, for example through coughs and sneezes.
The work went largely unnoticed until December, when the US government’s biosecurity watchdog, the National Science Advisory Board for Biosecurity (NSABB), raised the alarm. Though bird flu, as the name suggests, is mostly an avian disease, it has killed more than half the people known to have been infected. The only reason it has not become a global killer is that it does not spread easily from person to person. The NSABB declared a paper Fouchier had sent to it — and the US journal Science — too dangerous to publish. The board called for key sections of the report to be deleted, to prevent the recipe for the virus from falling into the hands of bioterrorists.
Fouchier was not alone in having his work black-marked. The NSABB urged similar restrictions on another paper sent to the British journal Nature. In that, Yoshihiro Kawaoka, a virology professor at the University of Wisconsin-Madison, merged bird flu with the highly transmissible swine flu virus to make a hybrid strain that also spread among ferrets through airborne droplets. The swine flu virus, which originated in pigs, went global in humans, but while it killed more than 18,000 in a 2009 pandemic, it was not as lethal as the WHO feared.
The advisory board’s reaction has sparked a rare crisis in science. The US government backed the NSABB, but many researchers say the work must be published in full, arguing public health will benefit. A group convened by the WHO recommended full disclosure, but ordered an urgent review of the security and safety of labs where such viruses are stored. In the meantime, work on mutant bird flu has halted under a voluntary moratorium.
The deadlock could soon be broken. On Thursday, the 23-strong NSABB gathered for a confidential two-day meeting in Washington to review updated versions of both papers, which in Fouchier’s case included fresh evidence that his virus is not as dangerous as some accounts first claimed. Fouchier and Kawaoka were to be brought in to answer queries directly. Whatever the panel’s final recommendations, they were likely to redefine how risky, dual-use research is handled in future.
There are solid scientific grounds for tinkering with the virus. Fouchier and Kawaoka’s experiments address a crucial question: Could bird flu evolve naturally into a form that spreads easily among people? Their work suggests it can. In Fouchier’s study it only took five mutations — all of which have been seen in the wild — for bird flu to become airborne and spread through ferrets. Kawaoka showed bird flu could achieve the same end by picking up other genes when it mixed with swine flu, an event that could happen naturally in pigs.