[nomadking]

Originally Posted by pip08456

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In general, the amount of antibody that is present declines over time after an infection has been cleared.
Sometimes, doctors can still measure antibodies after many years — as is the case with measles; and sometimes the antibodies go away more quickly, he added.
“But one of the really clever things about the immune system is that the cells that make this antibody then persist at some low level and form a population of memory cells that are there and able to respond much more briskly if the same pathogen or invader is encountered again on another occasion,” Kuritzkes said.

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Quickly making lots of antibodies can stop an infection in its tracks. The first time your body fights a virus, it can take up to 15 days to make enough antibodies to get rid of it. With the help of Memory B-cells, the second time your body sees that virus, it can do the same in thing 5 days. It also makes 100 times more antibodies than it did the first time. The faster your body makes antibodies, the quicker the virus can be destroyed. With the help of Memory B-cells, you might get rid of it before you even feel sick. This is called gaining immunity.