Question

The immunologic response to pathogens often includes a primary response (the first or initial exposure) which primes the immune system to the pathogen. Upon subsequent exposure to the same pathogen, one will usually not experience any symptoms of illness despite perhaps having experienced symptoms in the initial exposure. Why is the second response to an antigen of a pathogen faster and often, asymptomatic compared to the initial response?

Answer 1

Immunity is the overall ability of the host to fight the disease causing organism.

Innate immunity : it is non - specific that is present at the time of birth.

Acquied immunity is a pathogen specific. It is characterised by memory. This means that our body when encounters a pathogen for the first time produces a response called Primary response . Which is of low intensity.

Subsequent encounter with the same pathogen elicits a highly intensified secondary response. This is ascribed to the fact that our body appears to have memory of the first encounter. Due to the memory of the primary response second response to an antigen of a pathogen faster and asymptomatic compared to the initial response.