Immune memory is part of the adaptive immune system, storing useful T and B cells that recognise pathogens you have previously encountered. But also the innate immune system can learn to, for some time, accommodate an altered response after infection. 2/7

This "innate memory" can take two main shapes. It is a short-lived feedback mechanism largely thought to prevent an overactive response and damage to self. But it can also take epigenetic changes, increasing a "recall" response, e.g., quicker expression of antiviral factors. 3/7