Some of the challenges we face now are really quite dramatic and call for a lot of technical expertise.
We expected it to move, but not any of us thought it would move quite like this.
We cannot afford to be in any way complacent. The fact that there are human cases of bird flu being reported at quite regular intervals now means that the disease is still quite serious.
Because it is moving and because we believe wild birds are implicated, predicting where it's going to flare up next is a very tricky thing to do, and being able to know the scale of the flare-up is also quite tricky.