Pamela Bjorkman is an American structural biologist at Caltech and HHMI who, as a graduate student with Don Wiley, determined the first crystal structure of an MHC (major histocompatibility complex) class I molecule in 1987 — one of the landmark structures in immunology. This structure revealed the peptide-binding groove of MHC, immediately explaining at atomic resolution how immune cells distinguish self from non-self and how viral peptides are presented to T lymphocytes. Her laboratory has since made fundamental contributions to structural studies of antibody–antigen complexes, including seminal structures of anti-HIV antibodies bound to the HIV gp120 and gp41 envelope proteins. Her structural work on the broadly neutralizing antibody VRC01 and its binding mode to the CD4-binding site of HIV informed rational HIV vaccine design strategies. During the COVID-19 pandemic, Bjorkman's lab produced crucial structural analyses of SARS-CoV-2 spike protein–antibody complexes that guided immunogen design and helped explain immune evasion by variants of concern.