ABILITY OF CANINE LYME-DISEASE VACCINE TO PROTECT HAMSTERS AGAINST INFECTION WITH SEVERAL ISOLATES OF BORRELIA-BURGDORFERI

We used flow cytometry to determine levels of borreliacidal antibodies in hamsters after vaccination with a commercially available canine Ly me disease vaccine. In addition, we evaluated the ability of vaccinate d hamsters to resist infection with several isolates of Borrelia burgd orferi. Borreliacidal antibodies could be detected 1 week after a prim ary vaccination, peaked at weeks 3 to 5, and then rapidly declined. On e week after a booster vaccination, borreliacidal activity was detecte d at a dilution of 1:10,240, and it decreased fourfold by week 10 afte r the booster vaccination. Vaccinated hamsters were protected against infection with less than or equal to 10(6) B. burgdorferi 297 organism s during the peak borreliacidal response (5 weeks after primary vaccin ation or 2 weeks after booster vaccination). However, hamsters were no t fully protected from development of Lyme arthritis when the titer of borreliacidal antibodies was <1:5,120. In addition, no significant bo rreliacidal activity was induced against B. burgdorferi C-1-11, LV4, o r BV1, which belong to three other seroprotective groups. These studie s demonstrate that vaccination with the canine Lyme disease vaccine in duces protective antibodies against B. burgdorferi 297. However, signi ficant levels of borreliacidal antibodies are not produced until 5 wee ks after vaccination, and protection is short-lived. In addition, no b orreliacidal activity was induced against other isolates of B. burgdor feri. Because of this, the incorporation of multiple isolates or prote in subunits may be necessary to increase the effectiveness of future v accines.