Effect of memory on the survival probabilities. Effect of the amount of memory on the probability of an individual to survive a re-exposure with the same pathogen. The probability to survive a pathogen with a low basic survival probability, p
(grey) increases faster with an increasing memory response than the survival probability of a pathogen with a higher p
(black). Independent of the basic survival probability, a memory pool with maximal pool size occupied by memory cells specific for one pathogen guarantees survival of an infection with this pathogen.