Immune and Inflammatory Response in Horse Vaccinated Against Equine Herpesviruses 1 (EHV-1) and 4 (EHV-4) Assessed by Serum Protein Electrophoretic Pattern and Leukocyte Population

Protection against infectious diseases can be obtained with vaccines generating immunogenic response through a combination of humoral and cellular immunity. In this study haematological and serum protein electrophoretic profiles of horses vaccinated against herpesvirus 1 (EHV-1) and 4 (EHV-4) were evaluated. Blood samples were collected from 16 horses before (T0), after 24h, 48h, 72h, 1st week, 2nd week and 3rd week (T1I, T2I, T3I, T7I, T14I and T21I) from the first EHV vaccine-dose administration as well as before (TPREII), and after 24h, 48h, 72h, 1st week, 2nd week, 3rd week and 4th week (T1II, T2II, T3II, T7II, T14II, T21II and T28II) from the EHV vaccine-booster. Total leukocyte values increased at T1I, T1II, T3II and T28II compared to T0 (P < .01). Higher lymphocytes and lower neutrophils values were found after first vaccine-dose and vaccine-booster administration compared to the T0 (P < .01). Monocytes showed higher values at T14II than T0 (P < .01). Higher serum values of total proteins, α1-, α-2-, β1-, β2- and γ-globulins were found in horses after first vaccine-dose and vaccine-booster administration (P < .01). Gathered results suggest that horses vaccinated against EHV1 and EHV-4 exhibited a dynamic change of WBC, lymphocytes, neutrophils and monocytes. Moreover, the analysis of serum electrophoresis pattern suggested that EHV vaccination induced the development of inflammation and antibody response in vaccinated horses as highlighted by the increase of α-, β- and γ-globulin fractions. These changes probably reflect the systemic immunological adaptation of animals to EHV vaccine.