Analysis of COVID-19 vaccine products and technologies by oral route

Coronavirus disease 2019 (COVID-19) continues to be prevalent all over the world and mutant strains are constantly appearing, the application of vaccine is still an important method of epidemic prevention and control. Mucosal immunity plays an important role in preventing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) invasion. The currently marketed injectable COVID-19 vaccine mainly activates humoral immunity, but it is difficult to induce effective mucosal immunity, and it is unable to prevent pathogen invasion in the early stage of virus infection. Compared with injection vaccination, inoculation of the COVID-19 vaccine through mucosal routes such as nasal or oral can closely imitate the natural infection pathway of the virus and induce a comprehensive immune response. It is an ideal choice for rapid and extensive vaccination because it has the advantages of simple and convenient use, easy to achieve self-management of vaccinators, reduced demand for professional medical personnel and so on. In this paper, we summarized and analyzed the products and technical platforms of COVID-19 vaccine inoculated by oral route, in order to provide reference for related research work.