Response to Rabies Vaccine in Kittens Under 12 Weeks of Age

We used a prospective observational study to determine whether the administration of rabies vaccine to kittens under 12 weeks of age would induce protective antibody titers. All 10 enrolled kittens had Rapid Fluorescent Focus Inhibition Tests (RFFIT) titers of less than 0.1 IU/mL prior to vaccination, indicating their susceptibility to the rabies virus at approximately 9 weeks of age. All kittens demonstrated a robust immune response to vaccination (i.e. titers > 0.5 IU/mL) on samples collected 28 days after vaccination. These results suggest that, in the absence of maternally derived antibodies (MDAs), kittens approximately 9 weeks of age would be susceptible to the rabies virus but can also have an excellent immune response following vaccination against rabies virus at the time of surgical sterilization.