It's the exact same vaccine...they just put a different label on it. I know with puppy vaccines, you have to admister boosters within a specific time frame (3-4 weeks apart) to get the ideal immune response and build up antibodies sufficiently. So, maybe your vet's thought is since she didn't get her adult rabies booster within one year of her puppy rabies vaccine that she won't get the correct immune response. My personal thought is that she is most likely protect against rabies and doesn't need another vaccine this soon...but not sure how the law would handle it if a problem occured since your vet labeled it as a "one year rabies". I've always wondered how that would hold up since it is the exact same vaccine...if your state requires rabies every three years but your vet still gives "one year" rabies, are you still good for three years according to the law..or only that one year? Anyone know?