A U.S. government official has refuted criticism of the organization of a meeting held to review controversial bird flu studies.

In a lengthy letter, Dr. Amy Patterson denies that the agenda of the late March meeting was crafted to deliberately steer the participants toward a particular outcome.

The U.S. National Science Advisory Board for Biosecurity met March 29-30 to reconsider two studies that reveal how H5N1 viruses can be mutated to be transmissible among mammals.

The board had earlier suggested the studies should be published without details of how the work was done, but they reversed that position at the March meeting.

In a letter to Patterson sent two weeks later, board member Michael Osterholm slammed the meeting, saying the agenda was designed to result in the eventual outcome.

Patterson says in her response that there was no right answer and adds that organizers didn't receive any requests from Osterholm to add speakers to the agenda.