Rabies is required in just about every state and most counties require this vaccination to be yearly and won't recognize the three year.
If anything were to happen, whether the dog bites someone, another dog, or gets attacked by a wild animal, or if you get in trouble with the law, it puts your kid at risk for immediate euthanasia. Most places will npt quarantine an unvaccinated dog, and the only way to test is to remove the animals head and test the brain tissue.
It's safer to have it done. There are low cost vax clinics all over and here in oklahoma city, I can get anyone free spay/neuter and vaccines if they need it. Better safe than sorry, ya know?