In June 2012, a team of researchers from the University of Wisconsin published a paper in the journal Nature about airborne transmission of H5N1 influenza, or bird flu, in ferrets. The article changed the way the United States and nations around the world approached manmade biological threats.

This was not the researchers’ intent.

The team had altered the virus’s amino acid profile, allowing it to reproduce in mammal lungs, which are a bit colder than bird lungs. That small change allowed the virus to be transmitted via coughing and sneezing, and it solved the riddle of how H5N1 could become airborne in humans.

The U.S. government initially supported the work through grants, but members of Congress, among other critics around the world, responded to the publication of the research with alarm and condemnation. A New York Times editorial described the experiment and similar research conducted in the Netherlands, eventually published in the journal as "An Engineered Doomsday." So the researchers agreed to a voluntary moratorium on their findings. In October, the White House Office of Science and Technology Policy announced that it would halt funding for research into how to make diseases more lethal — so-called “gain-of-function” studies — and asked anyone doing such research on deadly diseases to cease and desist.