Antibody Levels of Dogs Vaccinated with Japanese Inactivated Tissue Culture Rabies Vaccine and Their Antibody Responses after Re-vaccination

Abstract

Antibody responses of dogs inoculated with the inactivated rabies vaccine were investigated using the paired sera obtained from 125 dogs in Tokyo, Shizuoka, Gifu, Kyoto, Miyazaki and Kumamoto Prefectures, Japan, in 2005. Ninety of the 100 dogs that had been previously vaccinated within the past year possessed neutralizing antibodies with titers higher than 25 that are considered as being sufficient for protection. The antibody titers of dogs that were above 8 had geometric mean titers (GMT) of 251. Additional vaccination of those dogs resulted in all dogs acquiring neutralizing antibodies higher than 25, and their titers reached a GMT of 750 one month after the booster inoculation. On the other hand, 23 of 25 dogs having no history of rabies vaccination produced neutralizing antibodies with titers having a GMT of 43, ranging from below 8 to 256, one month after vaccination. Notably, no antibodies were detected in sera collected from two of those dogs even after vaccination. The results seem to suggest that the present vaccination regime in which dogs are vaccinated once a year is important in creating and maintaining consistent immunity in vaccinated dogs.