Europe Closing The Gap with New Vaccine Technology

A novel equine influenza vaccine using a specialized second generation ISCOM-Matrix adjuvant has resulted in a product that is not only safe and effective, but also capable of closing the so-called "immunity gap," reported researchers from Intervet/Schering-Plough Animal Health in The Netherlands.

In Europe, veterinarians traditionally administer a course of two vaccines four to six weeks apart in young horses, followed by a booster vaccination five or six months later. Antibody levels against equine influenza tend to decline between the second and third application in young horses. During this time period, referred to as the "immunity gap," these young horses are not adequately protected against influenza.

More frequent vaccination of young horses does not close the immunity gap. Instead, the horses simply have higher vaccination burdens and have an increased chance of vaccine intolerance and side effects.

To close the immunity gap, the Intervet/Schering-Plough research team developed a vaccine that would offer increased protection between the second and third vaccinations. This vaccine employed a specialized adjuvant to improve vaccine efficiency using a second-generation ISCOM-Matrix.

In the two-year commercial history of the vaccine, it proved to be safe in pregnant mares and foals as evidenced by a reduction in clinical signs of influenza and decreased virus shedding.

Experts in the United States attest that while the science behind this vaccine is sound, equine influenza vaccines currently available in North America have already overcome the immunity gap and have comparable efficacy to the European ISCOM-matrix adjuvanted vaccine.

The study, "The first safe inactivated equine influenza vaccine formulation adjuvanted with ISCOM-MATRIX that closes the immunity gap" will be published in an upcoming edition of the journal Vaccine. The abstract is available on Pubmed.

About the Author

Stacey Oke, DVM, MSc

Stacey Oke, MSc, DVM, is a practicing veterinarian and freelance medical writer and editor. She is interested in both large and small animals, as well as complementary and alternative medicine. Since 2005, she's worked as a research consultant for nutritional supplement companies, assisted physicians and veterinarians in publishing research articles and textbooks, and written for a number of educational magazines and websites.

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