20.16b Serums, Vaccines, and Other Immunizing Agents

anatomic barriers

The most important of these are the (?) such as the skin and mucous membranes that block the entrance of pathogens (disease-causing organisms, including viruses and bacteria).

immune system

If pathogens get past these protective barriers, our (?) comes into play.

antibodies

This system consists of the spleen, lymph nodes, thymus, leukocytes, and proteins called (?) in plasma.

immunity

The ability to respond to pathogens is called (?).

passively acquired

It is (?) when antibodies pass directly into a person, either through artificial routes such as injection or through natural routes such as the placenta or breast milk.

actively acquired

Immunity can also be (?) in response to the presence of a pathogen.

T lymphocytes

Actively acquired immunity occurs when (?) (a type of leukocyte that becomes specialized in the thymus gland) comes in contact with a new pathogen.

T cell configurations

The body produces an infinite variety of (?).

reproduce rapidly

When the pathogen comes into contact with a T cell that is specific to it, that T cell begins to (?).

“memory” cells

Some of these cells become involved in the immune response to the pathogen whereas others act as (?).

cell-mediated immunity

The cells involved in the immune response either directly attack the pathogen (?) or activate the complement system, a complex cascade of events that leads to the immune response.

memory cells

The (?) remain in the body in higher numbers so that the next time this specific pathogen enters the body, a much faster response is possible.

B cells

At the same time, (?) (lymphocytes that differentiate or become more specialized in the body, as opposed to the thymus) that are specific for the invading pathogen begin to produce antibodies for that antigen.

humoral immunity

This process is called (?) or antibody immunity.

complement system

When an antibody contacts its specific antigen, it forms a complex that triggers the (?), leading to the immune response.

Serums and vaccines

(?) can augment the immune system.

serum

A (?) is a solution containing whole antibodies for a specific pathogen.

temporary, passive immunity

The antibodies give the recipient (?).

vaccine

A (?) contains a modified pathogen that does not actually cause disease but still stimulates the development of antibodies specific to it.

attenuated

These pathogens can be either dead or (?) (having a decreased disease-causing ability).

first two years of life

The best age for vaccination against disease is within the (?) because the immune system is fairly immature.

Table 20-29

(?) summarizes the recommended schedule for immunization.

immunosuppressants

Available medications can either suppress the immune system (?) or enhance it (immunomodulators).

rejection

Suppressing the immune system is indicated to prevent the (?) of transplanted organs and grafted skin.

Azathioprine (Imuran)

(?) is a commonly used immunosuppressant that acts by decreasing cell-mediated reactions and suppressing antibody production.

Immunomodulating agents

(?) enhance the natural immune reaction in immunosuppressed patients such as those with HIV.

Zidovudine (Retrovir)

Zidovudine (Retrovir), commonly known as AZT, and several protease inhibitors such as ritonavir (Norvir) and saquinavir (Invirase) are examples of these (?).