What determines how long the immune system will remember a disease?

Question

I already know about certain cells that will remain in your body incase you ever catch the same disease but apparently, your immune system can remember the disease for the rest of your life or 1 week?

In: Biology

Answer 1

You immune system keeps track of everything it has seen FOREVER.

However, the disease its self changes to not look the same. So the mutation rate of the disease changes how long immunity to the disease lasts.