I know there may be issues with MLV, and I have had varied success in the cats I vaccinate when ALL the components are MLV: I´ve landed on the Merial RCP where the calicivirus is inactivated. I Norway we have an all MLV called Nobivac which also has attenuated calici, a friend(breeder) with Birmans has problems with this but not the merial, the only difference I have found is the calici. I´ve not had problems with it in our SVs or BGs (and we have a few + kittens), but because of the Birman problems I´ve played safe with the Merial. I will NOT use killed with adjuvant unless I have to (rabies). Why MLVs should be dangerous to SVs I do not know or understand, but all cats, indeed all animals, may react to MLVs, usually mildly: the intent is, after all, to challenge the immune system, and if the cat has some other kind of infection when given MLV that can be difficult. That is why your vet should check the health of your cat before vaccinating, and it is basically what you pay for in addition to vaccine costs.
Per