I had an all cats vet where I used to live. Somehow she decided I was safe to be honest with. We had all kinds of informative conversations (including how most vets are drug addicts). She told me to never vaccinate. She says she will only do it if the owner brings it up. She believed that indoor cats do not need vaccines and she said she saw the damages they could do in geriatric cats. If it's doing damage to older cats, it's doing damage to the young ones as well.