Equine_vaccination

Equine Vaccination Overview

Date of Document: 30 May 2024Department: Eq Derm Endo and Clinical Practice

Equine Vaccines

Common Vaccines

  1. Equine Influenza

    • A highly contagious viral disease affecting the respiratory tract, which can lead to severe illness, reduced performance, and respiratory complications.

    • Vaccination is crucial due to the high rate of disease transmission, especially in places with close contact among horses (e.g., race tracks, shows).

  2. Tetanus

    • Caused by Clostridium tetani, it is a potentially fatal disease leading to severe muscle stiffness and spasms.

    • Vaccination is vital, especially for working horses and those exposed to wounds.

  3. Equine Herpesvirus (EHV-1, EHV-4)

    • EHV-1 can cause respiratory disease, abortion in pregnant mares, and neurological disease. EHV-4 primarily causes respiratory illness.

    • Vaccination is essential for pregnant mares and during outbreaks to protect against severe complications.

  4. Strangles

    • Caused by Streptococcus equi, it leads to swollen lymph nodes, fever, and in some cases, can result in serious complications like guttural pouch empyema.

    • Vaccination helps control outbreaks, especially in populations of young horses such as foals and yearlings.

  5. Other Considerations

    • Rotavirus: Particularly important in young foals; can cause significant gastrointestinal disease.

    • Equine Arteritis Virus (EAV): A viral infection that can lead to respiratory disease and abortion in mares; vaccination is recommended in endemic areas.

Outbreaks Analysis

Historical Outbreak Data

  • Major Equine Influenza Outbreak: January 2, 2019 - December 31, 2019

    • Observation:

    • Unvaccinated horses were the most significantly affected demographic.

    • Horses that had longer intervals between vaccinations were notably more susceptible to the virus than those that maintained up-to-date vaccinations.

  • Vaccinated Horses Demonstrated:

    • Fewer days shedding the virus, which reduces spread.

    • Fewer clinical signs of illness, which indicates an effective response to vaccination.

    • Recommendation: Horses are advised to be re-vaccinated if it has been more than 6 months since their last Equine Influenza vaccine to maintain effective immunity.

Geographic Spread of Outbreaks

  • Affected Areas: Significant outbreaks were noted within the UK, especially in regions like Scotland and key urban centers like Edinburgh and Belfast.

  • Detection of Outbreaks: Outbreaks spread primarily through aerosol transmission, highlighting the need for stringent biosecurity and vaccination protocols in high-density equine environments.

Immunity Types and Their Durability

Natural Immunity

  • Duration: Short-lived; clinical immunity lasts approximately 1 year, while infection-induced immunity may be even more transient.

  • Response: Generates virus-specific immunoglobulins (Ig), including IgA, IgG1, and IgG2, which offer limited protection against reinfection.

Vaccine-induced Immunity

  • Duration: Short-lived, typically lasting less than or equal to 6 months post-vaccination for many vaccines.

  • Markers: Immunity is monitored through antibody responses to hemagglutinin (HA) and neuraminidase (NA) present in the virus.

  • Responses: The response to parenteral (injected) vaccines primarily produces IgG responses, which are critical for effective immunity.

  • Adjuvants: Vary in their ability to stimulate antibody production at given HA levels; their effectiveness depends on formulation specifics.

Vaccine Administration Guidelines

General Administration Protocol

  • For Equine Influenza Vaccines:

    • The initial series consists of 2 doses administered intramuscularly (I/M), spaced 4-6 weeks apart.

    • A third booster dose is recommended after 6 months.

    • Annual revaccination is suggested for optimal protection, with specifics varying according to guidance from organizations such as the British Horse Association and FEI.

Tetanus Vaccination Schedule

  • Tetanus Toxoid Vaccine:

    • Administered as two I/M injections spaced 4-6 weeks apart.

    • A first booster is due 12 months after initial vaccination; subsequent boosters are recommended every 2 years.

    • In cases of injury, an IM injection of Tetanus antitoxin may be required for immediate short-term protection, which is particularly critical for neonates and horses with wounds.

Specific Vaccines Overview

  1. Equine Herpesvirus (EHV-1 and EHV-4)

    • Characteristics: While primarily causing mild respiratory disease, EHV can result in far more severe outcomes, including abortion in broodmares or neonatal death.

    • Vaccination Schedule: Comprise 2 doses spaced 4-6 weeks apart, followed by 6-monthly boosters, especially recommended for broodmares to ensure protection during gestation.

  2. Strangles Vaccine

    • Vaccination Options:

      • Equilis StrepE: A live vaccine, administered 0.2 ml inside the upper lip every 6 months.

      • StrangVac4: A recombinant protein vaccine given as 2 IM injections 4 weeks apart, then every 6 months; it does not interfere with ELISA tests, allowing reliable disease surveillance.

Resources and Additional Information

Essential Reading:

  • Equine Flu Immune Responses: Vettimes Article

  • Article Reference: Durham, A. (2019) "Choosing an equine influenza vaccine". In Practice, 41: 84-87. Available through NU Search or in PDF format on Moodle.

Additional Resources:

Contact Information

  • Department Email: svzkp@nottingham.ac.uk

  • Browse for additional queries related to equine vaccination, ensuring that the latest protocols and recommendations are followed.

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