[cpdiii]

You can't create a vaccine for a disease that does not yet exist.

Not necessarily. Dependent on how much the virus mutates and and how much the viral coat (which is a bunch of polysaccharides that surround the virus) has changed. The antibodies we produce for the original virus "MAY" give protection for the new virus.

Cowpox is a good example. It is very similar to small pox but only causes a mild illness in humans. However, if you are exposed to cowpox and develop the mild infection you will have antibodies against smallpox and are immune.

[doc30]

You bring up an important point. However, the key words were "not necessarily." Yes, a vaccine could be made from the curent bird flu, but is the risk of it not working on the mutated strain justified by the cost and time of development? Someone should be gearing up to start vaccination development as soon as the virus is observed to mutate and get the needed resources in place as soon as possible. Need to be ready to acquire lots and lots of live chicken eggs.