The paper, by flu virologist Yoshihiro Kawaoka of the University of Wisconsin-Madison, reports on how Kawaoka and his team made an H5N1 hybrid that transmits efficiently among mammals.
Here's a look at the twists turns on the paper's route to publication:
August 2011: Kawaoka submits his paper to the journal Nature. It and another paper by Dutch virologist Ron Fouchier are referred to the U.S. National Science Advisory Board for Biosecurity due to concerns the science could be used for ill intent.
Dec. 20, 2011: The U.S. government accepts the NSABB's advice that the papers should be published without the details of how the work was done. The authors and the journals reluctantly agree on the proviso there's a way to share the data on a need-to-know basis.
Feb. 16-17, 2012: After weeks of heated debate about the U.S. decision, the World Health Organization convenes a meeting on the issue. The participants, many of whom are flu scientists, say the papers should be published in full.
Feb. 29: Fouchier says at a meeting of scientists that his study has been misunderstood. He explains his lab-made virus is not lethal to ferrets. The U.S. National Institutes of Health asks the NSABB to reconsider the studies.
March 29-30: The NSABB reconvenes and is warned about the repercussions of blocking publications of the studies. An intelligence briefing suggests there appear to be no risks from publishing the works. The group reverses its position.
April 13: A letter slamming the March 29-30 meeting agenda is leaked. NSABB member Michael Osterholm suggests the agenda was designed to pressure the board to reverse itself.
April 20: The U.S. government announces it accepts the NSABB advice.
April 27: The Dutch government, which has been blocking export of Fouchier's paper, agrees to let him submit his revised manuscript to the journal Science. A publication date hasn't yet been set.
May 2: Nature publishes Kawaoka's paper.