Abstract

An Zhu53947*

The (Coronavirus Disease 2019) COVID-19 outbreak has caused a public health emergency globally. The SARS-CoV2 that causes COVID-19 belongs to the beta strain of the coronavirus family. It is genetically like MERS-CoV and SARS-CoV. Until now, COVID-19 had infected over 190,000,000 people. The people with the infection usually suffer acute respiratory distress syndrome and cytokine storm in the elder and other populations with chronic diseases, death commonly occurs. As the number of infections is increasing dramatically, and there is still no effective therapy for this disease, to prevent the further outbreak, developing an effective SARS-CoV-2 vaccine is urgently demanded. Currently, several institutions and companies have achieved great success in developing the SARS-CoV-2 vaccine. There have adenovirus vector vaccines, mRNA vaccines, and inactivated virus vaccines available in the market. However, during the fermentation of the pandemic, many variants of SARSCoV-2 occurred, for example, the Delta and Delta plus strain which may have the ability to make the immune escape and dramatically decrease the effectiveness of the vaccines. This literature review will summarize several types of candidates of COVID-19 vaccines in four aspects, i.e., nucleic acid, inactivated virus, subunit protein, and viral vector, to promote further investigation and advertising of the vaccines.