Red-
I remember that the doctor started weaning me off the shots- I had shots every week, then every two weeks, then every three weeks. It was a long time ago, but I do remember that much.
The second time around- honestly after six months, I got tired of going twice a week to get shots so I stopped going but I think it was enough to do the trick. I have some allergies now- I take Zyrtec or other over the counter stuff and it helps.