You don't really have to. I have to have my degree and have passed my boards and maintain my continuing education credits. I also have to have a state criminal background check, A federal FBI fingerprinting check, and a child abuse check that requires every address I have lived in and every person I have lived with since 1975. I have to have a two-step TB test, a recent tetinus shot, hep-b vaccine, MMR, drug screen, current cpr certification and references. You can also check my license status on-line to see if I have any confirmed instances of abuse, neglect, or criminal activity.
Doctors are very similar in their requirements.
Government is very good at regulating thins except politicians.
But that is no indication of how good a nurse you are. There are some pretty dumb nurses out there, as well as teachers. Touting a government check isn’t saying much. The government can’t even keep track of who’s here legally/illegally.