Improved influenza viral vector based Brucella abortus vaccine induces robust B and T-cell responses and protection against Brucella melitensis infection in pregnant sheep and goats
Fig 5
Index of infection for sheep and goats challenged with B. melitensis 16M at 113–120 days post-vaccination.
Pregnant sheep and goats in the group I (Flu-BA_Omp19-SOD) were immunized twice concurrently via the subcutaneous and conjunctival routes of administration at an interval of 21 days with vaccines generated from the influenza viral vectors (IVV) subtypes H5N1 (prime vaccination) and H1N1 (booster vaccination). The vaccination of animals of group II (Flu-BA_Omp19-SOD_TV) was carried out in the same way as in group I, but only the vaccine generated from IVV subtypes H5N1 was used, which was administered three times at 21 days intervals. Sheep and goats in the negative control group (IV) were vaccinated with 20% Montanide Gel01 adjuvant in PBS three times at 21 days intervals. Animals in the positive control group (III) were immunized once subcutaneously in the axillary region (right side) with commercial vaccine B. melitensis Rev.1 according to the manufacturer's instructions. Challenge with the virulent strain B. melitensis 16M was performed via the subcutaneous route (106 CFU/animal). The index of infection is the number of animals from which Brucella was isolated from the organs and lymph nodes. The data presented as mean ± standard error; * P <0.0001 vs. appropriate control group IV. Statistical analysis was performed using two-way ANOVA followed by Tukey's multiple comparisons test. P values < 0.05 were considered significant.