Three-year duration of immunity in cats vaccinated with a canarypox-vectored recombinant rabies virus vaccine.

Despite the availability of efficacious vaccines for animals and humans, rabies is still a major zoonosis. Prevention of rabies in dogs and cats is key for reducing the risk of transmission of this deadly disease to humans. Most veterinary vaccines are adjuvanted inactivated vaccines and have been shown to provide one to four-year duration of immunity. In response to debates about the safety of adjuvanted vaccines in cats, a non-adjuvanted feline rabies vaccine with one-year duration of immunity claim was specifically developed using the canarypoxvirus vector technology. The objective of this study was to validate a vaccination program based on primary vaccination, revaccination one year later and boosters every three years. Seronegative cats were vaccinated at 12 weeks of age and received a booster vaccination one year later. This vaccination regimen induced a strong and sustained antibody response, and all vaccinated animals were protected against virulent rabies challenge carried out 3 years after vaccination. These results validated 3-year duration of immunity after a complete basic vaccination program consisting in primary vaccination from 12 weeks of age followed by revaccination one year later with a non-adjuvanted canarypox-vectored vaccine.