A bird flu virus, H9N2, has the potential to spark a human pandemic, according to a team of researchers.
Experiments suggest that H9N2 has adapted to human cells, but cases of person-to-person transmission have not been reported yet.
The researchers say more surveillance of the virus is needed.
The H9N2 virus has often been ignored because it mostly causes minor disease in birds, but scientists are concerned about the spread of other bird viruses.
Author's summary: H9N2 bird flu strain may cause human pandemic.