Research progress of nasal mucosal immunization vaccine against COVID-19

Respiratory mucosal immune system is the body's first line of defense against infection.Since the outbreak of novel coronavirus disease 2019 (COVID-19) in 2019,nasal mucosal immune vaccine, with its ability to induce cellular, humoral and mucosal triple immune responses, has become a research hotspot.This article focuses on novel coronavirus, with an understanding of its structure and pathogenesis, a brief introduction to the immune mechanism of nasal mucosa, a summary of the different types of nasal mucosal immune vaccines and their clinical research, aiming to provide some theoretical reference for the development of new vaccines, and exploration of the best methods and strategies to combat COVID-19.