Scientists have developed a synthetic airborne compound that, when inhaled, permanently alters the human immune system to make individuals allergic to all forms of animal meat and animal by-products (including dairy, eggs, and gelatin). The allergy is immediate, irreversible, and universal across genetic backgrounds. It is not lethal, but causes highly unpleasant symptoms. While the compound is non-toxic and harmless beyond inducing the allergy, once released it cannot be contained or reversed.