Factors associated with the success of rabies vaccination of dogs in Sweden

Abstract

BackgroundUnited Kingdom, Ireland, Malta and Sweden maintain their national provisions for a transitional period regarding rules concerning rabies vaccination and individual serological test for rabies neutralizing antibodies. The purpose of vaccinating dogs against rabies is to establish pre-exposure immunity and protect individual animals from contracting rabies.The aim of the study was to investigate factors associated with reaching the internationally accepted threshold antibody titre of 0.5 IU/mL after rabies vaccination of dogs.MethodsThe study was a prospective single cohort study including 6,789 samples from Swedish dogs vaccinated with commercially available vaccines in Sweden, and the dog's antibody responses were determined by the OIE approved FAVN test. Information on potential risk factors; breed, age, gender, date of vaccination, vaccine label and the number of vaccinations, was collected for each dog. Associations between the dependent variable, serological response ≥ 0.5 IU/mL or < 0.5 IU/mL and each of the potential risk factors were investigated using logistic regression analysis.ResultsOf 6,789 vaccinated dogs, 6,241 (91.9%) had an approved test result of ≥ 0.5 IU/mL. The results of the multivariable logistic regression analysis showed that vaccinating with vaccine B reduced the risk of having antibody titres of < 0.5 IU/mL by 0.2 times compared with vaccination using vaccine A. Breed size was found significant as an interaction with number of vaccinations and age at vaccination as an interaction with day of antibody testing after last vaccination. In summary, larger breeds were at higher risk of having antibody titres of < 0.5 IU/mL but if vaccinated twice this risk was reduced. Moreover, there were a increased risk for dogs < 6 months of age and > 5 years of age to have antibody titres of < 0.5 IU/mL, but this was affected by number of days from vaccination till testing.ConclusionsThe probability of success of rabies vaccinations of dogs depends on type of vaccine used, number of rabies vaccinations, the breed size of the dog, age at vaccination, and number of days after vaccination when the antibody titres are tested. The need for a booster vaccination regimen is recommended for larger breeds of dog.

Rabies Vaccination: Higher Failure Rates in Imported Dogs than in those Vaccinated in Italy

“…In agreement with previously reported findings (Mansfield et al., ; Kennedy et al., ; Zanoni et al., ; Berndtsson et al., ), young dogs in our study showed a lower probability of achieving a positive outcome, with a steadily increasing success rate in adult dogs up to the age of 9 and declining thereafter. This finding is not unexpected, based on the dog immune system development and senescence (Day, , ) and previously reported evidence that rabies vaccination induces a significantly lower response in old dogs than in adult ones (12.1 ± 1.3 and 3.15 ± 0.8 years, respectively) (HogenEsch et al., ).…”

“…Of interest, it also includes an analysis of the observations collected from dogs entering the Italian border both from EU and non‐EU countries. Findings from our study are generally in agreement with those reported in the literature, identifying sex as the only variable not associated with serological response to rabies vaccination in dogs (Cliquet et al., ; Mansfield et al., ; Kennedy et al., ; Zanoni et al., ; Berndtsson et al., ).…”

The weight of obesity on the human immune response to vaccination

“…To our knowledge, this was the first study to correlate a poor rabies-specific vaccine-induced immune response in obese humans. These data supported an animal study that indicated larger breeds of dogs had an increased risk for inadequate vaccine-induced rabies-specific antibody levels [83]. …”

Safety and serological response to a matrix gene-deleted rabies virus-based vaccine vector in dogs

“…The age, size and breed of the dog and the type of vaccine, number of vaccinations and the interval(s) between vaccination influence the quantity and persistence of RABV-specific immunity (18–20). Based on these variables, the frequency of dogs that seroconvert after a single inoculation with inactivated RABV-based vaccines above 0.5 IU/ml varies widely from study to study and can range from 50% to >90% (18, 20–22). In dogs that do respond to vaccination with inactivated RABV-based vaccines, antibody titers peak around 2–4 weeks post-immunization and then rapidly decline (23).…”