Rabies in vaccinated raccoons from Ontario, Canada

Area of Science:

• Veterinary Virology
• Wildlife Disease Ecology

Background:

• Raccoon rabies, caused by a specific rabies virus variant, posed a significant threat in eastern Ontario from 1999 to 2006.
• Control efforts included trap-vaccinate-release (TVR) and point infection control (PIC) programs.

Purpose of the Study:

• To evaluate the effectiveness of rabies vaccination programs in raccoons.
• To assess the risk of rabies in vaccinated raccoons.

Main Methods:

• Over 43,000 raccoons (Procyon lotor) were vaccinated via injection (Imrab3) as part of control programs.
• Confirmed cases of rabies in vaccinated raccoons were analyzed.

Main Results:

• Two vaccinated raccoons were diagnosed with rabies post-vaccination (at 6 months and 2 weeks).
• One case suggested potential vaccination failure, while the other indicated vaccination of an animal in the late incubation stage.

Conclusions:

• Rabies vaccination in raccoons may not confer complete immunity in all individuals.
• Wildlife rehabilitators and captive raccoon facilities should be aware that vaccinated animals can still contract rabies.