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Avian Flu Research Resumes

Rachael Moeller Gorman

Avian flu researchers who voluntarily halted their research a year ago are now ready to get back to work. What has changed? Find out...

A year ago, 39 leading influenza researchers voluntarily halted their research because of fears that their experiments might ] lead to acidental or terrorist release of an H5N1 (avian) influenza virus that was highly transmittable in mammals. The group wanted to give governments time to review and update guidelines for influenza work and to allow the public to become better informed of the risks and benefits.

Colorized transmission electron micrograph of Avian influenza A H5N1 viruses Source: Cynthia Goldsmith, CDC

Now, in a letter published concurrently in Science and Nature, the same scientists have lifted that ban in countries with such guidelines (1-2). The United States is not among them.

“[Almost] 40 of the world-leading experts in influenza research seem to think that the benefits [of H5N1 research] outweigh the risks,” said H5N1 researcher Ron Fouchier in a teleconference.

The H5N1 virus was first identified in Asian poultry in the late 1990s. While the virus occasionally infects nearby wild birds and mammals—including humans—it is not transmittable through the air and can’t be passed efficiently from human to human.

Last year, however, two groups led by Ron Fouchier at Erasmus Medical Center in Rotterdam, The Netherlands, and Yoshihiro Kawaoka at the University of Wisconsin, Madison reported building versions of the H5N1 virus that could be transmitted through the air, infecting ferrets in neighboring cages via respiratory droplets (3-4).

But before the papers were even published, an outcry erupted. Fears that the new mutant virus could escape the lab and cause a human pandemic or that terrorists could use the paper as a recipe for a new bioweapon gripped the international community. In an unprecedented step, the US National Science Advisory Board for Biosecurity asked Science not to publish the papers, and Science obliged. In response, avian flu researchers stopped work on their riskiest projects.

Eventually, the security board voted to allow thepapers to be published, which occurred in June 2012. Yesterday, researchers lifted the voluntary moratorium in countries that have addressed concerns, such as ensuring that the work is conducted in safe laboratories under strict protocols, thus making it difficult for the virus to escape.

This move allows researchers in the Netherlands and other European Union countries to resume their research. Fouchier estimates experiments in his Rotterdam lab will re-start in a few weeks. But researchers in the US will wait to resume work until the government finalizes its guidelines.

“The U.S. has been unclear in how long it would take. If the US had said at the NIH meeting in November of last year that it would take another three months, we would probably have waited [to lift the moratorium], but we did not get that answer. It might take another one to three years. So how long do you want us to wait?” said Fouchier.

Until the guidelines are finalized, Kawaoka and other US-based or federally funded researchers cannot continue their work. The US will continue to accept public comments on proposed guidelines governing study of these viruses until January 31.

“We want to resume H5N1 virus transmission studies because we believe this research is important to pandemic preparedness,” said Kawaoka in a teleconference. “Our research to understand how avian viruses adapt to mammals will lead to better surveillance and vaccines.”


1. Fouchier, R. A. M., A. Garcia-Sastre, and Y. Kawaoka. 2013. H5N1 virus: Transmission studies resume for avian flu. Nature advance online publication (January).

2. Fouchier, R. A. M., A. GarcĂ­a-Sastre, Y. Kawaoka, W. S. Barclay, N. M. Bouvier, I. H. Brown, I. Capua, H. Chen, R. W. Compans, R. B. Couch, N. J. Cox, P. C. Doherty, R. O. Donis, H. Feldmann, Y. Guan, J. M. Katz, O. I. Kiselev, H. D. Klenk, G. Kobinger, J. Liu, X. Liu, A. Lowen, T. C. Mettenleiter, A. D. M. E. Osterhaus, P. Palese, J. S. M. Peiris, D. R. Perez, J. A. Richt, S. Schultz-Cherry, J. Steel, K. Subbarao, D. E. Swayne, T. Takimoto, M. Tashiro, J. K. Taubenberger, P. G. Thomas, R. A. Tripp, T. M. Tumpey, R. J. Webby, and R. G. Webster. 2013. Transmission studies resume for avian flu. Science (January).

3. Imai, M., et al. 2012. Experimental adaptation of an influenza H5 HA confers respiratory droplet transmission to a reassortant H5 HA/H1N1 virus in ferrets. Nature 486:420–428.

4. Herfst, S. et al. 2012. Airborne transmission of influenzaA/H5N1 virus between ferrets. Science 336:1534-41.

Keywords:  infectious disease