Feline Immunodeficiency Virus

[tobias]

Is there a test to see if a fiv vaccinated cat actually has contracted fiv? My vet says my cat has fiv, but the cat has been vaccinated against it. I understand that once a cat has been vaccinated against fiv that she will always test positive. How then can the vet say that she has this disease, or not?

I am totally confused and concerned for this cat, and the 3 other indoor/outdoor cats I have here.
(These cats are indoors at night)

Can someone please set me straight on this topic?

Thanks in advance,

Tobias