I'm not sure 'finite' is the right way to think about it. I'd be more inclined to think of infections acting to 'Exercise' the immune system, similar to how jo

I'm not sure 'finite' is the right way to think about it. I'd be more inclined to think of infections acting to 'Exercise' the immune system, similar to how jogging keeps your heart healthy, rather than using up a limited number of immune cells.