Hi the answer is individuals. Hope this helps.
The clinical manifestation which supports this conclusion is that an injury to the brachial plexus which happens during birth. Erb is termed as a paralysis of the arm which is caused by an injury on upper arm's main nerves to be specifically the C5-C6 nerves.
It arrives most commonly on shoulder dystocia when there is a difficult birth. This paralysis can resolve on its own depending on nature of the damage.
Explanation:
<em>Immunological memory</em> is the property of the immune system to store information about a stimulus so it can mount an effective response if it encounters the same stimulus again being this second response quicker and stronger even after years since the first encounter.
This kind of response is dependent on many subpopulations within T and B lymphocytes and NK cells. When encountering an antigen, B cells recognize it by membrane antibody specifically binding to the antigen and then being activated to expand rapidly with their progeny clones differentiating into plasma and memory B cells, these last ones have a long life span to remain in the body, ready when another encounter with the same stimulus occurs, this is how the basis for effective immunizations happens.
I hope you find this information useful! Good luck!