Previous vaccine history (with proof) and state law will determine whether the vaccine is valid for 1 or 3 years. (nhspca.org)
A 3 - year rabies vaccine can only be given if proof of previous vaccine is shown. (awanj.org)
Previous vaccine research has failed when the body, even when given an immunity booster, couldn't keep up with the ever - changing virus. (sfchronicle.com)