Although the article is written about dogs 1st, it is also valid for cats (as mentionned in the article)and humans.

written by Catherine O’ Driscoll
(posted with permission)
A team at Purdue University School of Veterinary Medicine conducted several studies (1,2) to determine if vaccines can cause changes in the immune system of dogs that might lead to life-threatening immune-mediated diseases. They obviously conducted this research because concern already existed. It was sponsored by the Haywood Foundation which itself was looking for evidence that such changes in the human immune system might also be vaccine induced. It found the evidence…..

you may read all the article and more on the subjet on
http://naturalrearing.com/coda/a_science_of_vaccine_damage.html

the book ( 1997 book, What Vets Don’t Tell You About Vaccines) is quite important to read too!!!