Hopes for new sweet itch vaccination

TRIALS on a vaccine for sweet itch have shown a “significant” reduction in symptoms.

The vaccine, developed by a team in Switzerland, is the first to target the response of eosinophils, the white blood cells involved at the site of an allergic reaction.

The treatment blocks equine IL-5 (eIL-5), a protein which acts as the “master regulator” of eosinophils, and was considered to be a “safe” approach, which was “well tolerated” in the test horses.

The study, led by Antonia Fettelschoss-Gabriel, PhD of the University Hospital Zurich, was a double-blind, placebo-controlled randomised trial.

The horses received three monthly subcutaneous injections, followed by a booster. Lesion scores were compared to those recorded monthly in the pretreatment season and in the previous year from March to October.

“Seasonal progression of average lesion scores of placebotreated horses were comparable for both seasons, whereas average lesion scores of vaccinated horses showed strongly improved clinical signs,” the study reported.

Half the test herd showed a 50% improvement in their symptoms compared to the previous year and a quarter had 75% improvement.

Researchers believe the treatment — which could be available from 2020 or 2021 — offers an affordable, effective alternative to those that have already been proposed.