Work with your veterinarian to determine your horse's individual vaccination needs. | Photo: Anne M. Eberhardt/The Horse

A behind-the-scenes look at how your horse’s immune system is best primed for battle. 

If you weren’t felled by polio, your children missed the measles, your barn dodged a flu outbreak, and you’ve never seen a horse tormented by tetanus, you probably can thank vaccination. Superheroes in syringes, vaccines the world over battle forces of evil—or at least those of disease-causing pathogens.

Whether in a human or horse, a vaccine works by stimulating the individual’s own immune system to fight specific agents. The vaccine dons a disease agent (pathogen) disguise and stages a pretend invasion of the body. This drill prepares the body’s immune system to repel real bacterial or viral invaders.

“The basic concept behind any vaccine is that it stimulates the immune system in a manner similar to the normal infectious disease process without causing disease,” says David Horohov, PhD, professor and director of the University of Kentucky’s Gluck Equine Research Center. The ideal vaccine, he says, rallies forces from two sides of the immune response, stimulating a systemic (antibody) response as well as a more local cell-mediated response