Immune Response to Japanese Rabies Vaccine in Domestic Dogs

Abstract

To evaluate the immune response induced by Japanese rabies vaccine for veterinary use as international units (IU), we measured levels of rabies antibody in serum samples from dogs by the rapid fluorescent focus inhibition test (RFFIT). In dogs immunized with a reference vaccine (potency level of 3.1 IU/ml), prepared by the same method as that used to produce commercial vaccine, and its dilutions (1 : 2 or 1 : 4), neutralizing-antibody levels increased to 1.0-2.0 IU/ml over a period of 1 month and then decreased to 0.2-1.5 IU/ml over a period of 1 year after the first vaccination and showed a remarkable increase to 12-47 IU/ml after the second vaccination. Sixty-five (74.7%) of the 87 serum samples from domestic dogs that were tested were seropositive (> or =0.1 IU/ml). However, the seropositive rate in dogs less than 1-year old at the time of vaccination was low (57.1%), and the antibody levels in these dogs were not sufficiently high for the rabies antibody titre in serum to be maintained for 1-year. Levels of rabies antibody in all serum samples were also measured by the virus neutralizing test (VNT), and a strong correlation (r > 0.95) was found between the results of the RFFIT and those of the VNT.

Relationship between Virus-Neutralizing Antibody Levels and the Number of Rabies Vaccinations: a Prospective Study of Dogs in Japan

“…Our results are consistent with previous reports (6,12). We also found that protective VNA levels persisted 2 years after the last vaccination in most multiply vaccinated dogs.…”

“…However, the percentage of dogs that meet recommended virus-neutralizing antibody (VNA) levels in Japan is unknown. Furthermore, few studies have attempted to determine the adequacy of the current annual rabies vaccination program for dogs (6).…”

Rabies Immune Status of Dogs Brought into the Hyogo Prefecture Animal Well-Being Center, Japan

“…In the present study, the seroprevalence of stray and other dogs brought into the Hyogo Prefecture Animal Well-being Center was reported for the first time, although the seroprevalence of Japanese dogs has previously been estimated based on the annual vaccination coverage of registered dogs (http://www.mhlw.go.jp/bunya/kenkou/kekkakukansenshou10/02.html) and by several serological surveys conducted at animal hospitals in some regions or by animal quarantine [7,8,13]. In this study, the incidence of protective immune status in dogs brought into the Center (n=166) was very low (27.7%), although the vaccination coverage of Control programs for rabies have been enforced by the Rabies Prevention Law in Japan since 1950; these included quarantine of imported animals, compulsory registration and vaccination of domestic dogs and capture of stray dogs [1].…”

Compendium of Animal Rabies Prevention and Control, 2011

“…29,[31][32][33] An animal is currently vaccinated and is considered immunized if the initial vaccination was administered at least 28 days previously or booster vaccinations have been administered in accordance with this compendium. Rabies vaccinations may also be administered under the supervision of a licensed veterinarian to animals held in animal control shelters before release.…”