Researchers said Wednesday they want to create a lab version of a deadly emerging bird flu in order to study a strain that might be more infectious to people. Responding to past concerns about such research, the U.S. government said it will require extra safety measures.
The H7N9 bird flu virus has killed 43 people in China. The 22 international researchers from 15 institutions say the infectivity research "is necessary and should be done," a statement in Science magazine said. They promise to follow enhanced lab safeguards. Similar efforts to study a more transmissible flu virus, for H5N1 bird flu, triggered a research moratorium and controversy in 2011.