My old vet told me point blank that if I intend to keep my cats indoors permanently, there is no reason to vaccinate them. However, since all of my cats are rescues and semi-feral, I vaccinated them in the beginning b/c I worried that one or more of them would bolt outdoors and not return. That wasn't the case, though. Also, when my RB Pidge had to go in for a lion cut, she had to be sedated b/c she was 20 years old at the time and it was considered surgery. (She was too stiff to groom herself properly and it hurt her to be brushed so she became terribly matted.) By the time I got her caught up on her shots, it was quite expensive b/c the groomers at my vet's would not groom her until she had all her shots. My RB Puddy would be terribly sick for 3 or 4 days afterwards so I stopped the shots altogether. Be that as it may, I still do not immunize my cats and my vet feels that's why they live so long. I don't know how true that is but I'm just sayin'.