It's okay. Don't be afraid. I watched kids that were always being vaccinated for 4.5 years while my kids were not, including all during my dd's pregnancy. Nothing major ever happened, outside of a few runny noses and coughs.
Was it the chicken pox (varicella) vaccine? That can shed, but if you've had chicken pox naturally you should be okay. Your ds will probably be okay too. I think my ds got something from the one boy who had the varicella, but it was only three spots, he never got sick, and they just disappeared. It wasn't a big thing.
This is just some common sense advice, I'm sure you already do this, but I'll put it out there. If you are changing diapers on a recently vaxed kid, just make sure you really wash your hands. Or you can also use gloves (they sell disposable ones pretty cheap) if you can. And make sure when you dispose of it, put it somewhere where it's not going to come back out.
I know the polio virus if the kid gets the OPV version of the shot can be active for 30-60 days. But cleanliness will take care of most of that risk.
Don't worry about the vaxed child playing with your non vaxed childs toys. Or anything that goes in either kids mouths. It's all right. If you are really concerned, put up all the unwashable things when the other child is there, and only have washable things when he is. That way you can wash them when he leaves.
Just wash your hands a lot, and wash your ds's hands a lot too.
It's going to be all right.