Treating insect-bite hypersensitivity in horses with active vaccination against IL-5

Area of Science:

• Veterinary immunology
• Allergic diseases in animals
• Biologics and immunotherapy

Background:

• Insect-bite hypersensitivity is a common allergic skin disease in horses.
• Lesions are characterized by eosinophil infiltration due to allergic reactions.
• This condition is chronic, seasonal, and difficult to treat.

Purpose of the Study:

• To develop a therapeutic vaccine targeting equine interleukin-5 (eIL-5).
• eIL-5 is identified as the key regulator of eosinophils in horses.
• The goal is to treat insect-bite hypersensitivity by targeting eosinophils.

Main Methods:

• A vaccine was created by linking eIL-5 to a virus-like particle (CMV_TT).
• Thirty-four Icelandic horses were immunized with the eIL-5-CMV_TT vaccine or a placebo.
• The vaccine was administered without adjuvant.

Main Results:

• The vaccine was safe and well-tolerated in horses.
• It successfully induced anti-eIL-5 autoantibodies in most vaccinated horses.
• Vaccinated horses showed significant reductions in clinical lesion scores compared to placebo and previous seasons.

Conclusions:

• This study presents the first successful immunotherapeutic strategy for a chronic equine disease.
• The therapeutic vaccine against eIL-5 demonstrates efficacy in treating insect-bite hypersensitivity.
• This approach may pave the way for similar IL-5 targeting vaccines in human medicine.