Elsevier established a free COVID-19 resource center in January 2020, offering English and Mandarin information on the virus. The center grants permission for free access to research in PubMed Central and other repositories. The article discusses the structure, function, and antigenicity of the SARS-CoV-2 spike glycoprotein. It reveals that SARS-CoV-2 uses ACE2 to enter cells, with similar binding affinity to ACE2 as SARS-CoV. The SARS-CoV-2 spike glycoprotein has a furin cleavage site, distinguishing it from SARS-CoV. Cryo-EM structures of the SARS-CoV-2 spike glycoprotein show multiple conformations, providing insights for vaccine and therapeutic design. SARS-CoV antibodies inhibit SARS-CoV-2 entry, indicating cross-neutralizing potential. The study highlights the structural and functional similarities between SARS-CoV-2 and SARS-CoV, emphasizing the importance of ACE2 as an entry receptor. The research underscores the role of the spike glycoprotein in viral entry and the potential for cross-reactive antibodies in vaccine development. The findings contribute to understanding SARS-CoV-2's pathogenicity and inform strategies for vaccine and therapeutic design.Elsevier established a free COVID-19 resource center in January 2020, offering English and Mandarin information on the virus. The center grants permission for free access to research in PubMed Central and other repositories. The article discusses the structure, function, and antigenicity of the SARS-CoV-2 spike glycoprotein. It reveals that SARS-CoV-2 uses ACE2 to enter cells, with similar binding affinity to ACE2 as SARS-CoV. The SARS-CoV-2 spike glycoprotein has a furin cleavage site, distinguishing it from SARS-CoV. Cryo-EM structures of the SARS-CoV-2 spike glycoprotein show multiple conformations, providing insights for vaccine and therapeutic design. SARS-CoV antibodies inhibit SARS-CoV-2 entry, indicating cross-neutralizing potential. The study highlights the structural and functional similarities between SARS-CoV-2 and SARS-CoV, emphasizing the importance of ACE2 as an entry receptor. The research underscores the role of the spike glycoprotein in viral entry and the potential for cross-reactive antibodies in vaccine development. The findings contribute to understanding SARS-CoV-2's pathogenicity and inform strategies for vaccine and therapeutic design.