Among all the threats to public health, few rank as high as antigenic drift; the continual mutation of flu viruses that can hide them from the immune system and every now and then transforms a nagging pest into a mass killer. So far, bird flu--or H5N1--has never reached the point where it could spread easily among humans. But after a lingering controversy over bioterror fears that kept a study under wraps for months, investigators have revealed how 5 simple genetic "tweaks" could make the virus spread swiftly among humans.
"We now know that we're living on a fault line," Cambridge University's Derek Smith told reporters, according to a Bloomberg report. "It's an active fault line, it really could do something, and now what we need to know is, how likely is that?"
So far only 600 people are known to have been infected with H5N1. But 60% of them died, an extraordinary rate that triggered worldwide fears of a lethal pandemic. And when a U.S. biosecurity group was presented with the new findings late last year, they asked the researchers to keep their work secret, in fear that terrorist groups might use it as a recipe for a new superweapon. The World Health Organization, though, felt that publication was the best way to keep people safe, providing researchers around the world with greater insight into the threat so they could find better vaccines and drugs that could prevent a deadly pandemic.
Two of the 5 mutations have already commonly occurred in H5N1. A third has been seen only once. And the other two have only been seen in other pandemics recorded in the '50s and '60s. But bird flu didn't have to combine with another virus to make it more transmissible.
"There is always a risk," NIAID's Dr. Anthony S. Fauci told reporters. "But I believe the benefits are greater than the risks."