Evaluation of the immune response in Shitou geese (Anser anser domesticus) following immunization with GPV-VP1 DNA-based and live attenuated vaccines

Background: Goose parvovirus (GPV) is a highly contagious and deadly disease for goslings and Muscovy ducklings. Objectives: To compare the differences in immune response of geese immunized with GPV-VP1 DNA-based and live attenuated vaccines. Animals and methods: Shitou geese were immunized once with either 20 μg pcDNA-GPV-VP1 DNA gene vaccine by gene gun bombardment via intramuscular injection, or 300 μg by im injection, or 300 μL live attenuated vaccine by im injection, whereas 300 μg pcDNA3.1 (+) im or 300 μL saline im were used as positive and negative controls, respectively. Each group comprised 28 animals. Peripheral blood samples were collected from 2-210 days after immunization and the proliferation of T lymphocytes, the number of CD4 + and CD8 + T cells and the level of IgG assessed. Statistical analysis was performed using a one-way analysis of variance with group multiple comparisons via Tukey's test. Results: The pcDNA-GPV-VP1 DNA and attenuated vaccine induced cellular and humoral responses, and there were no differences between the 20 and 300 μg group in the responses of proliferation of T lymphocyte and the CD8 + T-cell. However, as to CD4 + T-cell response and humoral immunity, the 20 μg group performed better than the 300 μg group, which induced better cellular and humoral immunity than live attenuated vaccine. Conclusions: This study showed that it is possible to induce both cellular and humoral response using DNA-based vaccines and that the pcDNA-GPV-VP1 DNA gene vaccine induced better cellular and humoral immunity than live attenuated vaccine.