H7N9 first arose in eastern China this spring. Since then, it has killed 43 people and sickened 90 more. The outbreak is now under control, but the research team says the virus could gain traction again this winter flu season, so they want to do so-called gain-of-function studies to learn more about the virus quickly.
Gain-of-function studies are controversial. While it's normal for international scientists to study disease outbreaks intensely, gain-of-function studies take it another step by making epidemic pathogens more dangerous, if only within labs. When scientists wanted to publish the first gain-of-function studies of H5N1 avian flu in 2011, public outcry led them to stop further studies for more than a year.