Recent progress in application of nanovaccines for enhancing mucosal immune responses

Mucosal vaccines that stimulate both mucosal and systemic immune responses are desirable, as they could prevent the invading pathogens at their initial infection sites in a convenient and user-friendly way. Nanovaccines are receiving increasing attention for mucosal vaccination due to their merits in overcoming mucosal immune barriers and in enhancing immunogenicity of the encapsulated antigens. Herein, we summarized several nanovaccine strategies that have been reported for enhancing mucosal immune responses, including designing nanovaccines that have superior mucoadhesion and mucus penetration capacity, designing nanovaccines with better targeting efficiency to M cells or antigen-presenting cells, and co-delivering adjuvants by using nanovaccines. The reported applications of mucosal nanovaccines were also briefly discussed, including prevention of infectious diseases, and treatment of tumors and autoimmune diseases. Future research progresses in mucosal nanovaccines may promote the clinical translation and application of mucosal vaccines.