This study aimed to evaluate the hematological and serum protein electrophoretic profiles of horses after inactivated West Nile virus (WNV) vaccine administration. Blood samples were collected from 10 horses before (T0), after 24 h, 48 h, 72 h, 1 week, 2 weeks and 3 weeks (T1I, T2I, T3I, T4I, T5I and T6I) from the first WNV vaccine-dose administration, before the vaccine-booster (TPREII), and after 24 h, 48 h, 72 h, 1 week, 2 weeks and 3 weeks (T1I I, T2II, T3II, T4II, T5II, T6II) from the WNV vaccine-booster. There was a significant increase in lymphocytes and a decrease in neutrophils after both the first vaccine-dose and vaccine-booster administration compared to the baseline values (p < 0.01). Monocytes showed higher values after 72 h, 1 week and 2 weeks from the vaccine-booster (p < 0.01). Higher serum total protein values were found in horses after both the first vaccine-dose and booster administration (p < 0.05). α1-lobulins increased after the vaccine-booster with the highest levels measured at T4II (p < 0.05); α-2- and β-globulin fractions increased throughout the post-vaccine period compared to the baseline values (p < 0.05); and higher γ-globulin values were found before the vaccine-booster (TPREII) and after 24 h, 72 h and 3 weeks from the vaccine-booster (T1II, T3II and T6II). The findings allow us to conclude that the WNV vaccine used in the current study does not alter the overall hemogram picture of horses although it is associated with modulation of leukocyte populations and the serum protein electrophoretic pattern.
Keywords: West Nile virus; equine; hematological parameters; inactivated vaccine; protein electrophoretic fractions; serum total proteins.