Veterynarna biotehnologija – Veterinary biotechnology, 2020, 36, 47-54 [in Ukrainian]. https://doi.org/10.31073/vet_biotech36-04
State Scientific and Research Institute of Laboratory Diagnostics and Veterinary and Sanitary Expertise
ASSESSMENT OF THE SPECIFIC PROTECTION LEVEL OF DOMESTIC CARNIVOROUS ANIMALS AFTER ANTIRABIC VACCINATION
Introduction. Rabies is a lethal disease that can only be prevented by the creation of protective anti-rabies immunity using specific vaccines. In order to prevent the spread of rabies to disease-free territories, a program for the control of post-vaccination antibody titers of pet animals was applied in EU countries in the early 21st century. Therefore, it is necessary to study the individual antirabies immunity in order to evaluate the efficiency of dogs and cats vaccination and revealing the causes of insufficient specific protection level.
The goal of the study was to detect the level of rabies protective antibodies in carnivorous animals and to identify samples with low (0.50–0.87 IU/cm3) and insufficient antibody titers (<0.50 IU/cm3).
Materials and methods. In 2017 it was tested 5970 samples of blood sera from dogs and cats that were submitted to the laboratory for rabies diagnostics at the State Scientific-Research Institute for Laboratory Diagnostics and Veterinary Sanitary Expertise. Sera were tested by the FAVN test. The reaction was performed using the BHK-21 C13 (ATCC CCL-10) cell culture grown in 96-well microplates with a constant dose of CVS-11 virus (ATCC VR 959).
Information on potential risk factors: type, age, date of blood collection after vaccination, type of vaccine, and frequency of immunization were obtained and analyzed for each animal.
Results of research and discussion. The protective titer in 5862 of 5970 serum samples from vaccinated animals was ≥0.5 IU/cm3, 108 (1.8%) samples contained <0.5 IU/cm3 titer of anti-rabies antibodies. The minimum protective antibody titers ranging from 0.5 to 0.87 IU/cm3 were detected in 489 (8.2%) serum samples. The analysis revealed 149 blood sera samples with 0.5–0.87 IU/cm3 titer of anti-rabies antibodies of animals vaccinated with polyvalent vaccines (30.5%) and 340 samples (69.5%) of animals vaccinated with monovalent anti-rabies vaccines of different manufacturers. Insufficient levels of rabies virus antibodies (<0.5 IU/cm3) were detected in 57 samples from animals vaccinated with monovalent vaccines. Low and insufficient levels of rabies virus antibodies were detected in the serum of dogs in 397 (81.2%) and 91 (84.3%) samples, respectively. Among the samples from cats, this percentage was significantly lower – 92 samples (18.8%) were in the range of 0.5–0.87 IU/cm3 and 17 samples (15.7%) with insufficient antibody titers to rabies virus were below 0.5 IU/cm3).
The highest percentage of blood sera with low and insufficient titer of anti-rabies antibodies was detected in young animals up to one year old. In animals over 5 years old, low antibody titers for rabies virus were found in 135 cases (27.6%), and 19 sera contained insufficient level of specific antibodies titer.
Conclusions and prospects for further research. Antibodies of the protective titer (0.5 IU/cm3 and above) were detected in 5862 (98.2%) of tested samples. Insufficient (<0.5 IU/cm3) anti-rabies immunity was detected only in 108 (1.8%) serum samples, and minimum protective values (from 0.5 to 0.87 IU/cm3) in 489 (8,2%) serum samples. The dogs generally had higher percentage of samples with low (81.2%) and insufficient (84.3%) titers of rabies virus antibodies compared to cats – 18.8% and 15.7%, respectively. The obtained results indicated the necessity to study individual immunity of animals with insufficient and low anti-rabies immunity after vaccination.
Keywords: rabies, rabies immunity, rabies antibodies, blood serum.