Dogs vaccinated with common Lyme disease vaccines do not respond to IR6, the conserved immunodominant region of the VNE surface protein of Borrelia burgdorferi

A 25-amino-acid synthetic peptide (C-6 peptide) derived from an immunodominant conserved region (designated 1R(6)) of the VIsE protein of Borrelia burgdorferi has been identified and used to construct immunoenzyme-based diagnostic procedures. These procedures have excellent sensitivity and specificity. Previous reports have demonstrated the usefulness of the C-6 Peptide as an antigen for the serodiagnosis of human and canine Lyme disease. Results indicated that assays based on the C-6 peptide were nonreactive to sera from vaccinated nonexposed animals. The purpose of the present study was to confirm these results in a controlled trial by testing sera from experimentally vaccinated dogs known to be uninfected. Nine specific-pathogen-free beagles were assigned to one of three vaccine groups, each containing three dogs. Each group received one of three commercial Lyme vaccines: RECOMBITEK Lyme (Merial), LymeVax (Fort Dodge Animal Health), and Galaxy Lyme (Schering-Plough Animal Health). Each animal was administered a total of five doses of vaccine over a period of 39 weeks. Serum samples were collected prior to vaccination and then on a weekly basis from weeks 3 to 18 and from weeks 33 to 43. Selected samples were tested by the immunofluorescence assay (IFA) and the Western blot (WB) assay using whole-cell B. burgdorferi antigen extracts, and the results were compared to those obtained with two immunoenzyme-based procedures formatted by using the C-6 peptide. Serum specimens from all animals were reactive to the IFA and WB assay at week 5 and became highly reactive following the administration of multiple doses of vaccine. All serum specimens were uniformly nonreactive in the C-6 peptide immunoenzyme procedures at all time points throughout the study.