system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What happens when our immune system makes us ”immune” to a disease. And how does it do it?
gpt
The Immune System is incredibly complex, so there really is no ELI5 answer, but in essence you have special immune cells that are designed to recognize foreign/non-native molecules called "antigens". When these antigens are found, the immune cells latch on to the foreign cells and destroy them while simultaneously "remembering" the distinct characteristics of the antigen that it was exposed to so that when/if it sees it again, or another very similar antigen, the immune cells can kill it that much more easily. This ability for the immune system to "learn" is its greatest strength and is now being used to harness the same power to fight endemic genetic diseases like cancer. In fact, the most recent Noble Prize for medicine/physiology was given for this discovery. Former US President Jimmy Carter is probably the most famous patient to have used this immunoglobulin therapy to treat the melanoma which had spread to his brain.