A spike protein S2 antibody efficiently neutralizes the Omicron variant

The severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)variant B.1.1.529,also named Omicron,is becoming the main circulating strain in many countries worldwide and brings new challenges to preventing COVID-19[1-5].The latest data show that the Omicron variant contains more than 50 mutations.Among them,there are 32 mutations in the spike protein[6],which is the key component that determines the infectivity and antigenicity of the virus.Furthermore,15 mutations are located in the receptor-binding domain(RBD),which is key for viral-cell interactions mediated by angiotensin-converting enzyme 2(ACE-2)[7,8].