text: Yes, it has mutated and IS contagious between humans.  For the H5N1 bird flu virus strain to become a serious threat to human health it will need to mutate further. At the moment it does not infect humans easily, it very rarely jumps from human to human. However, if it infects a human who already has the normal human flu, it could then exchange genetic information with the human flu virus and acquire the ability to transmit from human-to-human easily - a new mutation. Then, we could be facing a serious flu pandemic that would spread around the world within a matter of weeks.