How long after a puppy receives it's third set of shots can you take it for a walk?

I hear and read different things. The breeder says she should be okay right after, but I have read that it takes about 5-10 days for the full immunity to take effect. Not sure who is correct. It has been 5 days so far and I took my puppy out in the front. The sidewalks are snow covered, so I guess that probably helps, but if I should wait a few more days I will.