I've been browsing the forums for a while and have done tonnes of research, and this is one of the few comments I've felt to reply to and strongly strongly support. Agreed 1000%.Your dog can get parvo even if you never let him outside your yard. As a kid, we had a Pit/Lab who NEVER left our yard. It was fenced in so it wasn't like dogs could just walk where she was. Yet, she got parvo when she was like a year old. It can be carried on your feet, clothes, tires, ect. If you have an older dog, they can also shed the virus without "catching" it. Unless your dog lives in a bubble it is always at risk for -something- even in the "safety" of your house and yard. Also, if you move into a house and the last owner doesn't tell you they had a dog who had parvo within the last year, your dog can still get parvo because it can live in the ground and on surfaces if it's not bleached.
It is more important IMO to socialize in this very important time frame. Obviously there is a need for -some- common sense. It wouldn't be wise to take him to a dog park or let him walk around a pet store, that's playing with fire. (For more disease problems than just parvo.) But walking the dog up and down your street isn't that big of a deal. It's no different than you walking down the street and then walking all over your house and yard and then letting the puppy walk where you walked.
The world is a big scary place to puppies and I firmly believe we need to expose them to how GREAT the world can be at a young age. Some of the lengths people go to, to "protect" their puppies is just ridiculous and then there is all kinds of questions about why the dog is terrified of strangers or has a problem walking on different surfaces when it's older. I've seen people who wouldn't even let their puppies go outside of their house or let people touch their dogs because "they might catch something". You think that puppy isn't going to get whatever germs are on their hand when you shake their hand and then pet your puppy?! I honestly think that's why our mutt got sick in the first place. She wasn't exposed to enough germs to build up immunities to it.