Q: If vaccines work, why do vaccinated horses still contract flu?
A: Vaccines don’t stop infection entirely, but they increase your horse’s immunity to the infection. This means that the vaccine helps to reduce the severity of the disease and the clinical signs your horse will show. They also minimise transmission of the virus to other horses. Essentially, vaccination will help raise immunity strong enough in some horses to prevent them from getting the disease, and in others it will simply ensure that they suffer from much milder symptoms than an infected, unvaccinated horse – either way it’s worth making sure your horse is up to date with his vaccinations and boosters.