One of the good, professional breeders on YT had a bad experience with parvo that closed down her breeding program for a good while so she could decon her entire home, etc. She will not let anyone come see pups until they are fully vaccinated.
I aquired my Huey from a byb-actually a friend who bred her dog-which I know now is not the right place to get a yorkie, but didn't know at the time (he was a gift). Since she wasn't a real breeder, she didn't have any rules in place and since she lived a couple of miles from where we had our weekend getaway, we got to visit every weekend (including the day after he was born) and any other time we wanted until we took him home at the ripe old age of 7 1/2 weeks
-once again, ignorance is bliss...