H7N9 may mutate 8 times faster than regular flu

The new bird flu could be mutating up to eight times faster than an average flu virus around a protein that binds it to humans, a team of research scientists in Shenzhen says.

Dr He Jiankui, an associate professor at South University of Science and Technology of China, said yesterday that the authorities should be alarmed by the results of their research and step up monitoring and control efforts to prevent a possible pandemic.

With genetic code of the virus obtained from mainland authorities, the team scrutinised haemagglutinin, a protein that plays a crucial rule in the process of infection. The protein binds the virus to an animal cell, such as respiratory cells in humans, and bores a hole in the cell's membrane to allow entry by the virus.

The researchers found dramatic mutation of haemagglutinin in one of the four flu strains released for study by the central government. Nine of the protein's 560 amino acids had changed. In a typical flu virus, only one or two amino acids could change in such a short period of time, He said.

"It happened in just one or two weeks. The speed may not have caught up with the HIV, but it's quite unusual for a flu."

The fast mutation makes the virus' evolutionary development very hard to predict. "We don't know whether it will evolve into something harmless or dangerous," He said. "Our samples are too limited. But the authorities should definitely be alarmed and get prepared for the worst-case scenario."