Since January 2020, Elsevier has created a COVID-19 resource center with free information in English and Mandarin on the novel coronavirus. The resource center is hosted on Elsevier Connect, the company's public news and information website. Elsevier grants permission to make all its COVID-19-related research available in PubMed Central and other publicly funded repositories, including the WHO COVID database, with unrestricted research reuse and analyses, provided that the original source is acknowledged. This permission is granted for free as long as the COVID-19 resource center remains active. The structure, function, and antigenicity of the SARS-CoV-2 spike glycoprotein are discussed. SARS-CoV-2 binds to human ACE2 with high affinity and uses it as an entry receptor to invade target cells. Cryo-EM structures of the SARS-CoV-2 spike glycoprotein in two distinct conformations, along with the inhibition of spike-mediated entry by SARS-CoV polyclonal antibodies, provide a blueprint for the design of vaccines and therapeutics. The SARS-CoV-2 spike glycoprotein harbors a furin cleavage site at the boundary between the S1 and S2 subunits, which is processed during biogenesis and sets this virus apart from SARS-CoV and SARS-related coronaviruses. The cryo-EM structures of the SARS-CoV-2 spike glycoprotein trimer provide a structural framework for vaccine design and understanding the immune response to this virus.Since January 2020, Elsevier has created a COVID-19 resource center with free information in English and Mandarin on the novel coronavirus. The resource center is hosted on Elsevier Connect, the company's public news and information website. Elsevier grants permission to make all its COVID-19-related research available in PubMed Central and other publicly funded repositories, including the WHO COVID database, with unrestricted research reuse and analyses, provided that the original source is acknowledged. This permission is granted for free as long as the COVID-19 resource center remains active. The structure, function, and antigenicity of the SARS-CoV-2 spike glycoprotein are discussed. SARS-CoV-2 binds to human ACE2 with high affinity and uses it as an entry receptor to invade target cells. Cryo-EM structures of the SARS-CoV-2 spike glycoprotein in two distinct conformations, along with the inhibition of spike-mediated entry by SARS-CoV polyclonal antibodies, provide a blueprint for the design of vaccines and therapeutics. The SARS-CoV-2 spike glycoprotein harbors a furin cleavage site at the boundary between the S1 and S2 subunits, which is processed during biogenesis and sets this virus apart from SARS-CoV and SARS-related coronaviruses. The cryo-EM structures of the SARS-CoV-2 spike glycoprotein trimer provide a structural framework for vaccine design and understanding the immune response to this virus.