Going out on a limb here, but vaccines are for viruses not parasites...

You also can't vaccinate something effectively if they have been infected by the virus.

Thirdly, I am under the train of thought that all fish express diseases such as ich while under stress. As you decrease the amount of stress, and take care of them by improving their current conditions, this parasite, is basically not an issue. From my experience at least.

So either we get rid of one parasite that is expressed when a fish is stressed, or we take better care of the fish

Thoughts?