Humoral and cell-mediated immune responses of foxes (Vulpes vulpes) after experimental primary and secondary oral vaccination using SAG(2) and V-RG vaccines

Humeral and cell-mediated immune responses of 36 captive foxes to two oral vaccines against rabies currently used for foxes in Europe were studied. Th e Street Alabama Dufferin (SAD) mutant Gif (SAG,) vaccine has been selected by double mutation from the SAD virus. The vaccinia recombinant virus (V-R G) expresses the rabies glycoprotein. Both vaccines induce similar humoral and cell-mediated responses after primary and secondary oral administration . We observed a typical anamnestic response, although of a limited duration , after the booster vaccination. Therefore, our results suggested that two successive oral vaccination campaigns should not significantly improve the immunisation of foxes. Lymphocyte in vitro proliferative response to the SA D antigen highlighted the presence in blood of a T-cell specific memory 6 m onths after vaccination. The synthesis of several vulpine cytokines was det ected in peripheral blood mononuclear cells (PBMC) stimulated by SAD antige n via reverse transcription polymerase chain amplification. The data showed a concomitant expression of interleukin (IL)-4 and interferon-gamma in PBM C of vaccinated foxes. No change was detected in the level of IL-2, IL-10 a nd IL-12 synthesis, whereas the pro-inflammatory cytokine tumour necrosis f actor-alpha seemed involved in the activation of naive T lymphocytes. (C) 2 001 Elsevier Science Ltd. All rights reserved.