Grass pollen allergens are recognised as a major cause of allergic diseases in humans and animals. Worldwide, at least 40% of allergic patients are sensitised to grass pollen allergens and between 50-90% of hayfever or seasonal allergy sufferers are allergic to grass pollen. ToleroMune Grass is a novel, synthetic, allergen-derived peptide desensitising vaccine, currently being developed for the treatment of grass allergy.