New breed of trouble

It would take "four to five years before enough transgenic birds could be bred to replace the world's broiler chicken population"

("Virologists hatch plan to beat bird flu", October 28). The threat of bird flu is based on natural genetic mutation, where parts of a flu virus that can be transmitted between humans are combined (in an infected human) with the worst elements of bird flu. Future generations would be better off without a transgenic mutation in place of an entire bird species. The 1918 strains of flu have long gone, but we would be left with the legacy of new breeds of chicken that would have unknown effects on humans and the environment over time.

Gordon Joly London