Review the safety and efficacy of vaccines under the condition of COVID-19 epidemic.

SARS-Cov-2, a new strain of coronavirus that has never been found in humans before, has become one of the biggest public health issues in the 21st century. By March 2021, more than 100 million people around the world had been diagnosed with the disease. Confirmed cases of COVID-19 have ranged from mild symptoms to severe or even fatal. In the early stage of the disease, fever, fatigue, dry cough is the main clinical manifestations. About half of the patients developed dyspnea more than one week later, and the severe cases rapidly progressed to acute respiratory distress syndrome. Thus, the development of the COVID-19 vaccine is important because of the impact and damage caused by the virus worldwide. This paper will first introduce some information related to the vaccine, such as the safety and efficacy of the vaccine. Then, It will illustrate data on some COVID-19 vaccines that are on the market or still in development with comparison and analysis. [ABSTRACT FROM AUTHOR]