A purpose is to provide a vaccine which can prevent porcine edema disease in farms where porcine edema disease is anticipated. Meeting this purpose is a vaccine that is a fusion protein in which Stx2eB and a polypeptide having a coiled-coil forming unit are joined or a multimer of the fusion protein, and by immunizing pigs with this vaccine, it is possible to induce potent neutralizing antibodies and to defend against the onset of porcine edema disease.