Interferon?

[WHISKERSxoxo]

Hi everyone,
    I am very curious to know what type of drug Interferon is and how it 
helps FeLV + kitties?  Do most Vets carry this product and if not is it hard 
to get?  Do FeLV cats have to have certain symptoms in order to take this 
product?
    I have 3 positive cats.  2 of which I adopted to save from death and I 
would love to do anything to to make their lives 100%.  
    I work at a Vet here in CT and all 3 Dr. haven't even heard of it.  So I 
would love to give them some new info.  
    All comments are appreciated!
Thanks Terri,MooMoo,Smokey, and Poopsie