Well I've been deathly allergic to all animals for my whole life. It's been so devastating to me becasue I'm a huge animal lover. But then Jake starting coming around (he was originally my neighbours' cat)and I seemed to slowly build up a resistance to him. He eventually ended up moving in with us, for the first few days my asthma acted up but after that I was perfectly fine.
I've unfortunately had to give up Jake (divorce) but I have a new furbaby now and my allergies have not acted up one bit. I really believe that you can sort of bulid up an "immunity" over a period of time - sort of like a vaccine.
I cannot imagine life without a kitty now!!!