Question

Which of the following is true about the comparison between primary and secondary immune response?

a) Activated B cells produce a different immunoglobulin isotype produced during the primary immune response from that during the secondary immune response.
b) Activation of naive B cells that recognize the same pathogen as memory B cells is increased during the secondary immune response.
c) While it takes about 2 weeks to clear a pathogen during a primary immune response, the secondary immune response can clear an infection much more rapidly.
d) The primary adaptive immune response to a pathogen is faster due to the lack of need for naive lymphocytes to become activated.

Answer 1

The true statement about the comparison between primary and secondary immune responses is c) secondary immune response can clear an infection much more rapidly than the primary one, taking only a few days as opposed to about two weeks for primary response.

Step-by-step explanation:

When comparing primary and secondary immune responses, an important truth is that the secondary immune response can clear an infection much more rapidly than the primary immune response. After an initial exposure, the primary response takes several days before B cell clones expand and differentiate into plasma cells, resulting in low but effective levels of antibodies. Conversely, the secondary immune response is characterized by a swift and robust production of antibodies, resulting in rapid pathogen clearance, often without the individual even showing symptoms.

Specifically, answer c) is correct in stating that "While it takes about 2 weeks to clear a pathogen during a primary immune response, the secondary immune response can clear an infection much more rapidly." The secondary immune response is facilitated by memory cells leading to high amounts of antibody production with greater efficiency, often preventing the infection establishment altogether.