Efficacy and Duration of Immunity of an Inactivated Equine Rabies Virus Vaccine

1. Introduction
The vaccination guidelines of the American Association of Equine Practitioners identify rabies as a core vaccine for horses. There are no published results regarding the efficacy of equine rabies vaccines. Published data would provide valuable information to practitioners when making vaccination recommendations and designing protocols. Using a virulent rabies virus challenge, the efficacy of a new inactivated equine rabies virus vaccine^a  was tested in horses.

2. Materials and Methods
This study was observed by the United States Department of Agriculture as required for registration and licensure, and it was approved by the Institutional Animal Use and Care Committee (IAUCC). Twenty-one horses were vaccinated intramuscularly with a single 1-ml dose of vaccine, and 11 horses served as unvaccinated controls. Vaccinated horses were selected for challenge based on virus-neutralizing antibody titer according to 9CFR 113.209(b)(4) requirements for non-carnivores.¹  Vaccinate and control horses were challenged with virulent rabies virus 14-mo post-vaccination and were observed for clinical signs of rabies. [...]