Immunological memory is the basis of protective immunity provided by vaccines and previous infections. Immunological memory can develop from multiple branches of the adaptive immune system, including CD4 T cells, CD8 T cells, B cells, and long‐lasting antibody responses. Extraordinary progress has been made in understanding memory to SARS‐CoV‐2 infection and COVID‐19 vaccines, addressing development; quantitative and qualitative features of different cellular and anatomical compartments; and durability of each cellular component and antibodies. Given the sophistication of the measurements; the size of the human studies; the use of longitudinal samples and cross‐sectional studies; and head‐to‐head comparisons between infection and vaccines or between multiple vaccines, the understanding of immune memory for 1 year to SARS‐CoV‐2 infection and vaccines already supersedes that of any other acute infectious disease. This knowledge may help inform public policies regarding COVID‐19 and COVID‐19 vaccines, as well as the scientific development of future vaccines against SARS‐CoV‐2 and other diseases.