Development of a novel DC-targeting vaccine that targets COVID-19 spike protein to control COVID-19 infection [Added supplement: COVID-19 Variant Supplement]

COVID-19 is a coronavirus identified as the cause of an outbreak of respiratory illness that was first detected in Wuhan, China. There is currently no vaccine to prevent COVID-19 infection. The spike protein (SP) of the virus is the key molecule for entry into a cell and is a main target of host protective immune responses. A receptor-binding domain (RBD) located in SP is essential for the infection of COVID-19. Previous studies have demonstrated that RBD of SARS-CoV consists of multiple neutralizing epitopes that induce highly potent neutralizing antibodies. The neutralizing antibody can bind to SARS-CoV and interferes with its ability to infect a cell. These findings suggest that RBD of COVID-19 is an ideal anti-COVID-19 vaccine candidate. Dendritic cells (DCs) are antigen-presenting cells that play critical roles to efficiently present viral antigens to the T cells of the immune system. Therefore, targeting DCs is a promising strategy to improve vaccine effectiveness. Recently, we have developed a highly efficient DC-targeted vaccination technology, and in this study, we will use this vaccination technology to expose the RBD of COVID-19 to host immune system. We will also investigate the potential of this novel vaccine approach to elicit potent immune responses against COVID-19 and SARS-CoV infections in vivo. The success of this proposed study will lay the groundwork for the quick development and production of anti-COVID-19 vaccine candidates, and contribute to a rapid response towards controlling the COVID-19 pandemic in China and worldwide