Mucous membranes are important sites for antigenic invasion and organismal resistance to foreign pathogens,and vaccines that can induce an effective mucosal immune response are of great value in preventing infection by foreign pathogens.However,the development of mucosal vaccines has been hampered by the complexity of the mucosal environment(digestive,respira-tory and genitourinary tracts,etc.),which makes it difficult to induce an effective mucosal immune response for immunization with vaccine antigens via the mucosal route.Mucosal adjuvants can modulate or enhance the mucosal immune response of vaccines,thus providing new opportunities for the development of mucosal vaccines.In this paper,we reviewed the research progress of mucosal adju-vants in terms of bacterial toxins,Toll-like receptor agonists,cytokines or chemokines,and other novel mucosal adjuvants.

Mucous membranes are important sites for antigenic invasion and organismal resistance to foreign pathogens,and vaccines that can induce an effective mucosal immune response are of great value in preventing infection by foreign pathogens.However,the development of mucosal vaccines has been hampered by the complexity of the mucosal environment(digestive,respira-tory and genitourinary tracts,etc.),which makes it difficult to induce an effective mucosal immune response for immunization with vaccine antigens via the mucosal route.Mucosal adjuvants can modulate or enhance the mucosal immune response of vaccines,thus providing new opportunities for the development of mucosal vaccines.In this paper,we reviewed the research progress of mucosal adju-vants in terms of bacterial toxins,Toll-like receptor agonists,cytokines or chemokines,and other novel mucosal adjuvants.