The present invention addresses the problem of providing an adjuvant for a mucous membrane vaccine that is highly safe and induces an adequate immune response in a mucous membrane. By the present invention, an adjuvant for a mucous membrane vaccine is provided which includes a complex protine formed from HA1, HA2, and HA3, which are subcomponents of hemagglutinin (HA) of botulinum toxin.本發明係以提供對黏膜誘導充分的免疫反應,且安全性高的黏膜疫苗用佐劑為課題。依據本發明,提供一種黏膜疫苗用佐劑,其含有由肉毒桿菌(botulinus)毒素之紅血球凝集素(HA)的次組份HA1、HA2、及HA3形成的複合體蛋白質。
