Highlights•NK cells can kill virus-infected cells and protect against severe infections.•Long-
lived memory NK cells may develop after vaccination or infection.•NK cells are potent
regulatory of antiviral T and B cell responses.•The role of NK cells in human infection is
complex and context-dependent.Natural killer (NK) cells are important in immune defense
against virus infections. This is predominantly considered a function of rapid, innate NK-cell
killing of virus-infected cells. However, NK cells also prime other immune cells through the …