I give puppy jabs and the first booster 12 months later, after that... nothing.
My dogs get to mix with lots of other dogs and have visited rescue centres with un-vacc dogs, never had any problems what-so-ever.
10 years ago i took in a rescue pup which quickly developed Parvo, it had been in my house and played with my dogs for 9 days when it died but not one of my dogs got sick.
My eldest lived to 16.
There's so much evidence of auto immune diseases & cancers occuring in over-vaccinated dogs, together with evidence of long term immunity from the starter jabs that i stopped boost