Vaccinating large populations of wild mice against the bacterium that causes Lyme disease could one day help reduce the risk of transmission of the infection to horses.

A recent study, supported by the National Institute of Allergy and Infectious Diseases, demonstrated that the vaccination of wildlife hosts might be a promising, ecologically based strategy to help prevent the spread of vector-borne diseases like Lyme disease and West Nile virus.

Lyme disease is caused by Borrelia burgdorferi, a spiral-shaped bacterium spread through the bite of a blacklegged (Ixodes) tick. It is estimated that approximately 50% of adult horses in areas of the northeastern United States have been infected, but fewer than 10% develop clinical signs of the disease. There is no commercially available equine Lyme disease vaccine.

For the study, researchers trapped more than 900 white-footed mice in 12 different forested sites in Connecticut. The mice were immunized with a Lyme vaccine that is currently used in dogs