OK, I'm a bit confused now about the reasons vaccine reactions occur. I had thought that reactions were caused by the ferret's allergic reaction to a vaccine, and that the allergy would make itself known the first or second time the ferret was vaccinated. But the things that have been written just recently sound more like vaccine reactions are due to particular batches of vaccine, and so there'd be no way of predicting when reactions might occur during a ferret's vaccination history. Does anybody have any comment on this? Confused in Montreal Regina Harrison [Posted in FML issue 1818]