In early 2012 influenza virus researchers around the world decided to stop working on highly pathogenic avian influenza H5N1 virus. This decision came after work from the Fouchier and Kawaoka laboratories revealed the isolation of influenza H5N1 strains that can be passed among ferrets by aerosol. The moratorium on influenza H5N1 virus research has now been lifted, as described in a letter from influenza virologists to Science and Nature.
Lifting the embargo on H5N1 research is an important step forward for understanding what regulates influenza transmission. In my view it was an ill-conceived move, done to quell the growing concern over the adaptation of influenza H5N1 virus to aerosol transmission in ferrets. We now know that these viruses are not lethal for ferrets, and much of the outrage expressed about this work was misguided. In my view the moratorium has accomplished little other than delaying the conduct of important virology research.
According to the influenza virus researchers who signed on to the moratorium, its purpose was to:
…provide time to explain the public-health benefits of this work, to describe the measures in place to minimize pos- sible risks, and to enable organizations and governments around the world to review their policies (for example on biosafety, biosecurity, oversight, and communication) regarding these experiments.
An important consideration is the level of containment that will be required for studying influenza H5N1 transmission. WHO has released recommendations on risk control measures for H5N1 research, and individual countries will decided how to proceed. The US has not yet made a decision on the level of containment needed for H5N1 virus transmission research. Influenza virologists who participated in the moratorium have their own view:
We consider biosafety level 3 conditions with the considerable enhancements (BSL-3+) outlined in the referenced publications (11â€“13) as appropriate for this type of work, but recognize that some countries may require BSL-4 conditions in ac- cordance with applicable standards (such as Canada).
Their last statement forms the crux of the issue on H5N1 transmission research:
We fullyÂ acknowledge that this researchâ€”as with any work on infectious agentsâ€”is not without risks. However, because the risk exists in nature that an H5N1 virus capable of transmission in mammals may emerge, the benefits of this work outweigh the risks.