Bird-flu vaccine 'may not work on humans'

The bird-flu vaccine currently being manufactured was effective against at least two forms of the virus in experiments with mice, but it is not clear if it would also work for humans, a US health chief says.

US government experiments have shown that the clade 1 vaccine also prevented proliferation of the clade 2 virus, a version seen more recently in Indonesia, Europe and Africa, in mice, said Dr Nancy Cox, of the Centres for Disease Control and Prevention.