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.
Authors: Giannetto Claudia, Giudice Elisabetta, Piccione Giuseppe, Castronovo Calogero, Arfuso Francesca
Journal: Journal of equine veterinary science
Summary
# Editorial Summary: Immune Response to EHV-1 and EHV-4 Vaccination in Horses Vaccination against equine herpesviruses triggers a measurable systemic immune response that extends beyond simple antibody production, involving coordinated shifts in white blood cell populations and acute phase proteins. Researchers monitored 16 horses across multiple timepoints following primary and booster EHV vaccination, collecting blood samples up to three weeks post-primary dose and four weeks post-booster to track both haematological parameters and serum protein electrophoresis patterns. Total white blood cell counts increased significantly at 24 hours post-primary vaccination and again at 24 hours and 72 hours post-booster, whilst lymphocyte counts rose whilst neutrophil percentages fell during both vaccination phases—findings consistent with a T-cell mediated immune response—with monocytes remaining elevated two weeks post-booster. Serum protein analysis revealed sustained increases across all globulin fractions (α₁, α₂, β₁, β₂, and γ) following both doses, reflecting simultaneous activation of acute phase inflammatory pathways and adaptive immunity through immunoglobulin production. For practitioners, these results demonstrate that EHV vaccination generates the expected integrated immune response; persistent elevation of acute phase proteins and leukocyte shifts validate that the vaccine is driving appropriate immunological adaptation, though individual horses may exhibit varying magnitudes and timings of response that could influence their protection timeline and clinical monitoring during vaccination programmes.
Read the full abstract on PubMed
Practical Takeaways
- •EHV vaccines trigger measurable systemic immune responses characterized by leukocytosis and globulin elevation; expect transient hematological changes within 24-72 hours post-vaccination
- •The dynamic shift toward lymphocytosis and decrease in neutrophils reflects normal adaptive immune activation rather than infection, confirming vaccine efficacy
- •Vaccination-induced changes in serum proteins and white blood cell populations peak at different timepoints (acute response at 24-72h, monocyte response at 2 weeks), which practitioners should consider when interpreting post-vaccination bloodwork
Key Findings
- •Total leukocyte values significantly increased at 24h, 72h, and 28 days post-vaccination compared to baseline (P < 0.01)
- •Lymphocyte counts increased while neutrophil counts decreased after both primary and booster vaccinations (P < 0.01)
- •Serum protein electrophoresis showed increases in all globulin fractions (α1, α2, β1, β2, γ) following vaccination, indicating inflammatory and antibody responses (P < 0.01)
- •Monocyte values were significantly elevated at 14 days post-booster compared to baseline (P < 0.01)