Our dr said 2, which we did with J and will do with Isaac. I've had several mild food allergies, although nothing severe to nuts of any form. I am a bit paranoid with it, so I'll do as I'm told.
Anyway, when Isaac wants what brother is having, I've given him almond or cashew butter. That might be an option, although it's just as much hassle (to do something different) and I don't know how expense compares to soy.
Posted with pp: J has moved to natural PB, too. I'm trying to move away from hydrogenated oils.