An article similar to this one appeared in the NYT:
Paul A. Offit, a virologist at the Children's Hospital of Philadelphia, said the new reports helped explain why the H5 virus, though it can infect people, does not easily spread from one person to another.
Virologists agree that a flu pandemic will happen sooner or later as one of the 16 types of flu virus in the animal world, probably one that infects birds, will manage to switch hosts, and grow and spread in humans. But they differ over whether H5 is the likeliest candidate to make such a switch. Previous pandemics have been caused only by H1- (the 1918 pandemic), H2- (the 1957 Asian flu) or H3-type viruses (the Hong Kong flu of 1968).
The H5 virus has been present in the human population since the late 1950's, said Dr. Offit of Children's Hospital, but has never acquired the full set of mutations needed to set off a pandemic. Such epidemiological evidence "should make us feel safe that there's a substantial barrier," he said, noting the small number of people who have been infected.
Dr. Offit said it was a good thing to worry about the next flu pandemic, given that about three can be expected every century. "What's not good is to try to sell the public on their fear of pandemic flu being this particular bird flu, since if it's not, crying wolf will lose you credibility," he said.
Peter Palese, a virologist at the Mount Sinai School of Medicine, said he did not believe the H5 virus could infect people except when they were exposed to large doses, for example, by sleeping in the same room as chickens. "I feel strongly that H5 has been around in humans for a long time and never caused a pandemic, suggesting that this is not the virus which is likely to be the next pandemic," he said.
But like Dr. Offit, Dr. Palese said he fully supported plans for better preparations for the next flu pandemic, whatever its source. "People have to understand we are not really prepared should it come," he said.