Working Toward a Vaccine for Strangles

Strangles is a highly contagious disease of the upper respiratory tract of horses, caused by the bacterium Streptococcus equi subspecies equi (SEE), and one of the most frequently diagnosed infectious diseases in horses worldwide. Currently, no vaccine available in the United States has strong evidence of being safe and effective, and none is able to differentiate vaccinated horses from horses with natural infection. Earlier studies showed that horses can be safely immunized with, and developed an immune response to, a newly identified protein candidate for a strangles vaccine. In this study, the team will further characterize the safety and immune responses of vaccinating horses with this protein vaccine candidate and determine if antibodies from immunized horses have action against SEE, the causative agent for strangles. Findings will help inform the development of a safe and effective vaccine for horses against strangles.