I found another reference to this genetic manipulation.
Source: Michael Specter, “Nature’s Bioterrorist,” The New Yorker. February 28, 2005, p. 60.
If the avian epidemic does move widely into human populations, as many scientists have predicted, it will mark the first time the world has been
able to anticipate a pandemic. For thousands of years, people have rarely known the causes of their illnesses; they have certainly never been warned
that an epidemic—whether smallpox, plague, cholera, or influenza—was imminent. Viral genetics has changed that. We can follow the evolution of a
virus on a molecular level and gauge its power. Researchers at the C.D.C. [Centers for Disease Control] have just begun crucial experiments in
specially protected laboratories where they will attempt to juggle the genetic components of the H5N1 virus. There are two ways to do that. First, the
team will infect tissue with both the bird virus and a common human flu virus and see what grows. They will also use the tools of genetics. Molecular
biology now allows scientists to break a virus down to its genes; the researchers will disassemble H5N1 and mix it in a variety of combinations with
human flu viruses. Then they will test the results on animals.