摘要
With the outbreak of the coronavirus disease 2019(COVID-19)pandemic,the importance of vaccines in epidemic prevention and public health has become even more obvious than ever.However,the emergence of multiple severe acute respiratory syndrome coronavirus 2 variants worldwide has raised concerns about the effectiveness of current COVID-19 vaccines.Here,we review the characteristics of COVID-19 vaccine candidates in five platforms and the latest clinical trial results of them.In addition,we further discuss future directions for the research and development of the next generation of COVID-19 vaccines.We also summarize the serious adverse events reported recently after the large-scale vaccination with the current COVID-19 vaccines,including the thromboembolism caused by the AstraZeneca and Johnson&Johnson vaccines.
