Using a site-specific mass spectrometric approach, scientists from the University of Southampton analyze the glycan-processing states of the spike (S) glycoprotein used by SARS-CoV-2 to infect human cells, uncovering details that may help guide the development of vaccines against the virus. The SARS-CoV-2 S gene encodes 22 N-linked glycan sequons per protomer, which likely play a role in protein folding and immune evasion, the scientists write in Science.