Immune responses to commercial equine vaccines against equine herpesvirus-1, equine influenza virus, eastern equine encephalomyelitis, and tetanus

• Published in: Veterinary Immunology and Immunopathology Vol. 111; no. 1; pp. 67 - 80
• Main Authors: Holmes, Mark A., Townsend, Hugh G.G., Kohler, Andrea K., Hussey, Steve, Breathnach, Cormac, Barnett, Craig, Holland, Robert, Lunn, D.P.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15-05-2006
• Subjects: animal pathogenic bacteria; Animals; Antibodies, Viral - blood; bacterial infections; Clostridium tetani; Clostridium tetani - immunology; DNA, Viral - chemistry; DNA, Viral - genetics; Eastern equine encephalitis virus; Eastern equine encephalomyelitis virus; Encephalitis Virus, Eastern Equine - immunology; Encephalomyelitis, Equine - immunology; Encephalomyelitis, Equine - prevention & control; Encephalomyelitis, Equine - veterinary; Encephalomyelitis, Equine - virology; Equid herpesvirus 1; Equine herpesvirus 1; Equine influenza virus; Female; gene expression; Herpesviridae Infections - immunology; Herpesviridae Infections - prevention & control; Herpesviridae Infections - veterinary; Herpesviridae Infections - virology; Herpesvirus 1, Equid - genetics; Herpesvirus 1, Equid - immunology; horse diseases; Horse Diseases - immunology; Horse Diseases - prevention & control; Horse Diseases - virology; Horses; immune response; Immunoassay - veterinary; Infectious disease; Influenza A Virus, H3N8 Subtype - immunology; Interferon-gamma - blood; interferons; messenger RNA; Neutralization Tests - veterinary; Orthomyxoviridae; Orthomyxoviridae Infections - immunology; Orthomyxoviridae Infections - prevention & control; Orthomyxoviridae Infections - veterinary; Orthomyxoviridae Infections - virology; Polymerase Chain Reaction; seroconversion; Tetanus - immunology; Tetanus - prevention & control; Tetanus - veterinary; Tetanus - virology; Vaccination; vertebrate viruses; viral diseases of animals and humans; Viral Vaccines - immunology; Viral Vaccines - therapeutic use; Horses; Infectious disease; Vaccination
• ISSN: 0165-2427; 1873-2534; 1365-2567
• DOI: 10.1016/j.vetimm.2006.01.010

Horses are commonly vaccinated to protect against pathogens which are responsible for diseases which are endemic within the general horse population, such as equine influenza virus (EIV) and equine herpesvirus-1 (EHV-1), and against a variety of diseases which are less common but which lead to greater morbidity and mortality, such as eastern equine encephalomyelitis virus (EEE) and tetanus. This study consisted of two trials which investigated the antigenicity of commercially available vaccines licensed in the USA to protect against EIV, EHV-1 respiratory disease, EHV-1 abortion, EEE and tetanus in horses.
Trial I was conducted to compare serological responses to vaccines produced by three manufacturers against EIV, EHV-1 (respiratory disease), EEE, and tetanus given as multivalent preparations or as multiple vaccine courses. Trial II compared vaccines from two manufacturers licensed to protect against EHV-1 abortion, and measured EHV-1-specific interferon-γ (IFN-γ) mRNA production in addition to serological evidence of antigenicity.
In Trial I significant differences were found between the antigenicity of different commercial vaccines that should be considered in product selection. It was difficult to identify vaccines that generate significant immune responses to respiratory viruses. The most dramatic differences in vaccine performance occurred in the case of the tetanus antigen. In Trial II both vaccines generated significant antibody responses and showed evidence of EHV-1-specific IFN-γ mRNA responses. Overall there were wide variations in vaccine response, and the vaccines with the best responses were not produced by a single manufacturer. Differences in vaccine performance may have resulted from differences in antigen load and adjuvant formulation.