Most virologists feel that the risks are justifiable. "We have set up a laboratory here that has three separate physical barriers," Fouchier insists. The core of the laboratory consists of wardrobe-sized boxes outfitted with glass windows, each containing four cages of ferrets.
Two pairs of black rubber gloves are poking into the boxes. "Before we take swabs from the animals or inject viruses into the nostrils, we put steel gloves on over the rubber gloves," says Fouchier. For security reasons, he is not even willing to provide the exact location of the laboratory.
The low pressure in the boxes provides additional protection, because it is intended to ensure that even in the event of a leak, no viruses will escape. In addition, everything that leaves the boxes is disinfected with acetic acid in a safety area.
"And if I did infect myself, we have isolation wards in the adjacent hospital," Fouchier explains. "It's practically impossible for one of my team members to accidentally take the virus along into the Rotterdam subway."
Nevertheless, not even Fouchier can deny that pathogens have escaped from highly secure laboratories. The "Russian flu" of 1977 may have been triggered by a lab virus. SARS, a respiratory disease, almost returned when laboratory workers became infected with the coronavirus during their work. A scientist in Chicago even died of SARS in 2009.
Hundreds of new virus laboratories have been established worldwide in recent years, and highly dangerous pathogens are used in a large share of these laboratories. "The risk of a virus being released accidentally is considerable," says critic Ebright.
That, says Ebright, is why future research involving bird flu viruses should only be done in laboratories with highest so-called biosafety level, BSL-4. Currently only the second-highest level, BSL-3, is required. During their experiments, Fouchier and Kawaoka only wore lab coats and breathing masks, not the "spacesuits" that virologists wear when they are working with pathogens like the Ebola virus.
'An Early Warning System'
Fouchier would prefer to take things a step further and send his pathogen to other labs around the world. "We are at the very beginning, and we need as many scientists and their ideas as possible, so that we can understand why this new virus is so contagious," he says.
In the end, whether the experiments with Fouchier's super-flu virus will continue or possibly be stopped altogether will probably not be determined by issues of safety, but by their potential benefits.
The situation is clear to Fouchier. Using his killer virus, he wants to find out which mutations in the genome are responsible for the extreme infection rates. "We'll know where to look in the future," says the virologist, who hopes that his research will allow him to develop an "early warning system for pandemics."
But this is precisely what others see as an illusion, noting that the monitoring of poultry and especially pigs, in which new viruses develop with particular frequency, is still far too incomplete. A colleague who knows Fouchier's work very well says that the experiments are "nothing more than a piece of the puzzle."