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

Abstract

Impacts• Dogs entering Italy had a higher vaccine failure rate than dogs vaccinated in Italy, raising doubts as to the real compliance with vaccination.• The choice of vaccine and time of sampling may influence the individual's titre level post-vaccination and should be considered when interpreting serological test results.• The legislation regulating the free movement of pets needs to be readdressed if the risk of spreading rabies has to be minimized. SummaryThe current European Union (EU) legislation decrees that pets entering the EU from a rabies-infected third country have to obtain a satisfactory virus-neutralizing antibody level, while those moving within the EU require only rabies vaccination as the risk of moving a rabid pet within the EU is considered negligible. A number of factors driving individual variations in dog vaccine response have been previously reported, including a high rate of vaccine failure in puppies, especially those subject to commercial transport. A total of 21 001 observations collected from dogs (2006)(2007)(2008)(2009)(2010)(2011)(2012) vaccinated in compliance with the current EU regulations were statistically analysed to assess the effect of different risk factors related to rabies vaccine efficacy. Within this framework, we were able to compare the vaccination failure rate in a group of dogs entering the Italian border from EU and non-EU countries to those vaccinated in Italy prior to international travel. Our analysis identified that cross-breeds and two breed categories showed high vaccine success rates, while Beagles and Boxers were the least likely to show a successful response to vaccination (88.82% and 90.32%, respectively). Our analysis revealed diverse performances among the commercially available vaccines, in terms of serological peak windows, and marked differences according to geographical area. Of note, we found a higher vaccine failure rate in imported dogs (13.15%) than in those vaccinated in Italy (5.89%). Our findings suggest that the choice of vaccine may influence the likelihood of an animal achieving a protective serological level and that time from vaccination to sampling should be considered when interpreting serological results. A higher vaccine failure in imported compared to Italian dogs highlights the key role that border controls still have in assessing the full compliance of pet movements with EU legislation to minimize the risk of rabies being reintroduced into a disease-free area.

The “Bio-Crime Model” of Cross-Border Cooperation Among Veterinary Public Health, Justice, Law Enforcements, and Customs to Tackle the Illegal Animal Trade/Bio-Terrorism and to Prevent the Spread of Zoonotic Diseases Among Human Population

“…It is difficult to briefly summarize the results of the laboratory survey performed on the confiscated animals although, it was surprising to discover that (i) almost 100% of the confiscated cat and dog puppies were positive for Toxocara sp., an intestinal zoonotic nematode transmissible to humans; (ii) about 5.5% of the dog and cat puppies were positive to Salmonella sp. ; (iii) serological investigation displayed failure in post-rabies vaccination immunity in about 75% of total analyzed, a percentage even worse than previously described ( 22 ) while Chlamydia psittaci , Canine distemper and Parvovirus have been isolated quite frequently in the target species. Although most zoonoses evolve from wildlife hosts, most of them need an intermediate domestic/pet hosts transmission to be able to spread to human ( 23 – 25 ).…”

Comparative study of rabies antibody titers of dogs vaccinated in Finland and imported street dogs vaccinated abroad

“…Previous studies have demonstrated that the antibody response is influenced by the vaccine product used, the number of vaccine doses, the time between vaccinations and blood sampling, and the age, size, and breed of the dog [8–11]. Studies have suggested a failure of vaccination in imported dogs [12, 13]. Rota Nodari et al [13] found a higher vaccination failure rate in imported dogs (13.15%) than in those vaccinated in Italy (5.89%) and De Benedictis et al [14] reported a vaccination failure rate as high as a 37% in dogs crossing the Italian border from Eastern European countries.…”

“…Studies have suggested a failure of vaccination in imported dogs [12, 13]. Rota Nodari et al [13] found a higher vaccination failure rate in imported dogs (13.15%) than in those vaccinated in Italy (5.89%) and De Benedictis et al [14] reported a vaccination failure rate as high as a 37% in dogs crossing the Italian border from Eastern European countries.…”

“…A young age of the imported dogs is not the reason for the low titers since only two of the imported dogs were under the age of 4 months at the time of vaccination and both had antibody titer > 0.5 IU/mL. Rota Nodari et al [13] demonstrated that the discrepancy in vaccine failure rates for dogs sampled > 75 days after vaccination was still significant between dogs vaccinated in Italy and imported dogs, meaning that even when testing > 75 days after vaccination, the vaccination response was truly different between groups.…”

Investigating Possible Etiologies of Post-Exposure Prophylaxis Failure and Deaths From Rabies Infection: Case Reports

“…A study was conducted on animal vaccines in Italy. The relevant data indicated that the choice of vaccine had a significant impact on the failure or success of the rabies vaccination [14]. The fast and proper care of all wounds, maintaining temperature integrity along a cold chain during transport of vaccines, RIGs, and to perform detailed injection schedule could prevent PEP failure.…”