Even though there are a few more weeks of warm summer weather, Cecile's doctor at the Senior Community Center has recommended that she get a vaccine to protect her health during the upcoming flu season. What cell-mediated component of Cecile's immune system relates to the doctor's recommendation?

The related cell-mediated immune system to the doctor's recommendation is the T-lymphocytes or T-cells

Explanation:

Immunity is defined as the body's ability to protect itself against invading harmful organisms or substances. There are two forms or immune responses by the body, and they include:

1. innate immunity (non-specific immunity): this type of immunity is the one present at birth, they include the skin barriers, phagocytes, mucous membranes, stomach acids (HCl), enzymes etc. This immune response is usually the first line of defense against all invading antigen, hence they are non-speciific.

2. acquired or specific immunity: this type of immune response is specific to an organism or group of organisms of the same species. Acquired immunity are of two types; passive and active

i. passive acquired immunity is gotten as a result of transfer from one organisms that is already immune to another organism. It is a temporal form of acquiring immunity, and it is most commonly gotten through transfer through the placenta, or the transfusion of blood or blood products, where the recipient is protected for weeks or even months.

ii. Active immunity is further divided into antibody- and cell-mediated immunity. In the anti-body mediated immunity, B-lymphocytes manufacture antibodies (chemical immune agents) against antigens and the memory cells store the synthesis pattern, so that for future re-infection, the antibodies are manufactured again.

Now, the second part is the cell-mediated active immunity which is specific to our question. This type of immunity is mediated by T (thymus) lymphocytes or T-cells. T-cells because they originated and grow in the thymus gland. T-cells are further divided into three chief types according to their functions:

a. T-helper cells: this type of T-cells stimulate the activation and activity of other cells to enhance immune response, for example, it stimulates B-cells to produce antibodies or phagocytic macrophages for phagocytosis

b. T-suppressor cells: this helps to down regulate the activities of the immune cells/response, by suppressing its activity. they are beneficial to prevent auto-immune responses, but are detrimental if active in cases of active infection.  

c. T-cytotoxic cells: these cells recognize and destroy infected cells, and also activate phagocytes for phagocytosis or ingested pathogens.

I will recommend that you go and look up pictorial representations of these immune responses and cells, they will help your understanding.