This Review provides a guide to the memory cells of the adaptive immune system, comprising memory T cells, memory B cells and plasma cells; it covers their formation, function, heterogeneity, localization, regulation and maintenance, and the crucial technological advances that allowed their discovery.

This Review from Comerford and McColl discusses recent advances that have been made in understanding the biology of the atypical chemokine receptor (ACKR) family. The authors explain how these receptors interact with their ligands to shape immune responses and also highlight potential new additions to the ACKR family.

Compared with many other vaccines, current vaccines against influenza provide only limited protection. Here, the authors describe the challenges and recent attempts at generating T cell-based vaccines. It may be important to combine T cell-based vaccines with antibody-based vaccines to provide long-lasting immunity across influenza virus strains.

An optimal immune response to influenza virus strikes a balance between protective antiviral immune mechanisms and detrimental immunopathology. Here, the authors review the immune mechanisms responsible for each side of this balance and how this may inform future vaccine design.