Biosafety Level 4 CDC scientist Scott Smith manipulates a flask of cells used for experiments with live virus. Biosafety Level 4 is the highest security level. James Gathany/Centers for Disease Control and Prevention

In an unusual move, an international coalition of flu researchers agreed last week to a hiatus on work surrounding a highly contagious, mammal-adapted version of the avian influenza virus. Research on transmissible H5N1 flu will halt, and two manuscripts describing how to modify the virus won’t be published, at least not yet.

The voluntary pause came a few weeks after an American advisory panel recommended censoring the research in the name of security. So it raises an interesting question — is some research just too dangerous to pursue? Not just for the scientists conducting it, but for the public in a post-9/11 world?

Voluntarily pausing science in the name of safety and public solace is certainly not common, but then neither is a potentially groundbreaking study into the mechanisms that could make bird flu more potent and more deadly. The decision, announced in Science and Nature, indicates influenza researchers want to quell public fears, but they also don’t want to censor their work.

Dr. Nancy Cox, chief of the Influenza Division at the Centers for Disease Control, said flu researchers will confer during the hiatus about how to proceed, including making modifications to security procedures or the biosafety requirements for labs doing this work. Flu is dangerous, but it’s not nearly as deadly as some of the other pathogens CDC studies, she noted.

“If you think of Ebola and Marburg, and some other pathogens with a high lethality, which are worked on in the lab and for which there aren’t antivirals and there aren’t vaccines, influenza falls into a little bit different category,” she said.

One of the two main labs at the center of this debate does not have a Biosafety Level 4 facility, the highest security level reserved for the most deadly pathogens. Issues like that will be a topic of discussion during the 60-day break.

“(The hiatus) is unusual, but because there was so much concern about the work, it was an appropriate action on the part of the laboratories that are involved in this type of research,” Cox said.

H5N1 Flu: Colorized transmission electron micrograph of Avian influenza A H5N1 viruses (seen in gold) grown in canine kidney cells (seen in green).  Cynthia Goldsmith/Centers for Disease Control and Prevention

It does have some precedent, however, in a 1975 conference in which scientists agreed to pause research on recombinant DNA. That meeting, known as the Asilomar Conference, was organized to quell public concern, but also to allow scientists to agree among themselves about how best to proceed. At the time, recombinant DNA technology — the process of taking DNA from one organism, and recombining it with DNA from another — was still brand-new and researchers were still uncertain about the risks.            More