Q.29

Question

Why is the immune response after reinfection much faster than the adaptive immune response after the initial infection? 

Step-by-Step Solution

Verified
Answer

Post reinfection, the generation of memory cells makes the immune response much quicker in comparison to the adaptive immune response post the initial infection. 

1Introduction:

An antigen-specific T or B lymphocyte, which does not differentiate into effector cells during the primary immune response, however, which can instantly turn into effector cells upon reexposure to the same pathogen is known as a memory cell. 

2Explanation:

After reinfection, the memory cells will instantaneously divide into plasma cells and CTLs (cytotoxic T lymphocytes) without any kind of input from TH cells or antigen-presenting cells. In comparison, the adaptive immune response to the initial infection needs time for the naïve T and B cells with suitable antigen specificities to be determined and stimulated.