I am VERY paranoid about parvo with my pup and don't take him anywhere other than the following.
He has been to the vets once since I've had him to have the desexing stiches out, and he comes to work, we haven't had another other dogs other than our own for over a year at work. He has been coming now for 3 weeks and there hasn't been a problem (touch wood), he gets to meet other people just no dogs although I still have reservations about people coming in that may have been places that have parvo and will bring it in on their shoes.
He starts puppy school this week and has his last/3rd injection at the end of last week.
I have been told though that because it is so dry parvo doesn't last long out here, don't know if that is fact or fiction.