I really believe the key here is education, education and more education.
(IMHO) There will always be people who think they can get away with not obaying the laws, some still don't get the rabies shots for their animals. With education there are fewer willing to take such risks though.
I think most people already in the dog world are aware, at least to some extent that these vac.s are out there before they get a new pet, so info given with each new dog would be a good thing as a reminder to get their pet to the vet right away and accept the vet's advice about what shots it needs and when.
I think the key here is to educate the general public with billboards just as the animal comunity has done in the north east about spay/neuter. The source of parvo seems to come from shelter dogs that were oops litters or byb dogs and these breeders are not going to change even if the law does, but at least if the first time owner already understands that parvo is a horrible way to die and can be prevented they will know before taking that pup home that it needs more than just a rabies shot.