The coronavirus disease 2019 (COVID-19) caused by the infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)，resulting in more than 82 million confirmed cases and caused around 1.8 million deaths, as of 2 January 2021.

The ongoing pandemic still poses unprecedented global threat to public health system worldwide. On December 31, 2020, the joint prevention and control agency of China Council announced that Sinopharm SARS-CoV-2 inactivated vaccine had been conditionally approved by National Medical Products Administration, and the protection rate was 79.34%.

So far, more than 198 vaccines were currently in preclinical or clinical development. The investigators aimed to initiate an observational cohort of healthy individuals injected with SARS-CoV-2 Vaccine, which will perform a longitudinal, comprehensive analysis of the SARS-CoV-2 vaccine Induced adaptive immune responses.