Category and working mechanisms of SARS-CoV-2 vaccines and their effectiveness in clinical trials

Since the pandemic outbreak of the COVID-19， there had been about 121 million confirmed cases and more than 2.6 million deaths， which had significantly affected the economies and health resources in more than 233 countries and regions. Currently， no effective therapeutic option is available for the COVID-19， andimplementation of public health interventions suffers inconvenience. Consequently， the development of COVID-19 vaccines remains crucial. This review updates the current research progression， advantages and disadvantages of inactivated vaccine， live attenuated vaccine， recombinant subunit vaccine， recombinant virus-vectored vaccine， DNA vaccine， and RNA vaccine for the COVID-19. It warrants joint research and development of vaccines on multiple platforms， which would facilitate better control and prevention of the COVID-19 epidemic.