The New York Public Health Law reads as follows (see

"Actively immunized" shall mean that the animal has been injected with a rabies vaccine suitable to the species and which meets the standards prescribed by the United States department of agriculture for interstate sale and which was administered according to the manufacturer's instructions under the direction of a duly licensed veterinarian not later than the expiration date on the package. Active immunization shall begin fourteen days following primary vaccination or immediately following a booster vaccination, and continue for the period stated in the manufacturer's instructions.

The CDC's Compendium of Animal Rabies Prevention and Control ( says that, regardless of the animal's age at initial vaccination, a booster vaccination should be administered 1 year later.  Because a rapid anamnestic response is expected, an animal is considered currently vaccinated immediately after a booster vaccination and subsequent boosters should be scheduled according to the labeled duration of the vaccine used.  If a previously vaccinated animal is overdue for a booster, the animal should be revaccinated.