Disease prevention starts with vaccination.

There are three good reasons for vaccinating horses:

  • Vaccination may be the only way to help protect horses from some diseases.
  • Preventing disease through vaccination causes less stress than recovery from infection.
  • Many diseases cause permanent damage or death.

Understand which diseases pose the greatest risk.

Currently, five diseases account for the core vaccinations recommended annually by the American Association of Equine Practitioners (AAEP):1 Click on any disease to learn more.

West Nile Virus Eastern equine encephalitis
Western equine encephalitis Tetanus Rabies

There is a difference between vaccines.

Today, innovative vaccines can use technology that helps them target only the parts of a virus needed for an immune response. Some vaccines also stimulate more than one arm of the immune system to protect the horse.

RECOMBITEK® Brand Equine Vaccines use recombinant canarypox-vectored vaccine technology that gives horses both of these advantages while helping protect against either WNV or equine influenza.



  • The only WNV-EWT combination vaccine that provides advanced technology to help prevent WNV2
  • Only RECOMBITEK rWNV has been tested against natural challenge with WNV-infected mosquitoes3 as well as WNV intrathecal challenge in horses4
  • RECOMBITEK rWNV-EWT is the only combination vaccine labeled to aid in the prevention of disease caused by WNV in horses2,5
  • Combines rWNV with reliable killed EEE and WEE virus vaccines and tetanus toxoid to help prevent four out of five core diseases in a single annual dose*,1,2

*For previously vaccinated horses.


RECOMBITEK® Equine rWNV vaccine

  • Annual vaccination with a single dose*,6
  • Proven to work fast and last throughout the mosquito season3
  • The only commercial vaccine tested against both a natural challenge by WNV-infected mosquitoes3 and intrathecal challenge4
  • Onset of immunity in just 26 days after the initial dose7

Intrathecal challenge.4
Unvaccinated Controls
Clinical signs
(muscle fasciculation)
Histopathology (mild to 
moderate encephalitis)
WNV viremia

Click here to learn about the transmission of West Nile virus.

*For previously vaccinated horses.


RECOMBITEK® Equine Influenza Virus vaccine

  • Proven to significantly reduce viral shedding8 (how the disease is spread)
  • In a study, none of the vaccinated horses shed the virus after challenge infection8
  • Stimulates both humoral and cell-mediated immunity8

Viral Shedding

Merial, the maker of RECOMBITEK, also can help you round out a horse’s vaccination program with vaccines for rabies and Potomac horse fever. With this comprehensive line of products, Merial delivers the effective disease protection and valuable educational tools that benefit clinics as well as the horses in their care.


1Guidelines for Vaccination of Horses. American Association of Equine Practitioners. Available at: Accessed August 3, 2009.
2RECOMBITEK rWNV-EWT product label.
3Data on file at Merial. Study 02-092.
4Data on file at Merial. Study 07-051.
5West Nile-INNOVATOR® + EW, West Nile-INNOVATOR + EWT and West Nile-INNOVATOR + VEWT product labels.
6RECOMBITEK Equine rWNV vaccine product label.
7Siger L, et al. Assessment of the efficacy of a single dose of a recombinant vaccine against West Nile virus in response to natural challenge with West Nile virus-infected mosquitoes in horses. American Journal of Veterinary Research  2004;65(11):1459-1462.
8Paillot R, et al. Antibody and IFN-γ responses induced by a recombinant canarypox vaccine and challenge infection with equine influenza virus. Vet Immuno Immunopathol 2006;112:225-233.

®RECOMBITEK is a registered trademark and ™the HORSE HEAD LOGO is a trademark of Merial Limited.
®West Nile-INNOVATOR is a registered trademark of Fort Dodge Animal Health.