BIO 220 Ch 15: Adaptive, Specific Immunity and Immunization

What is immunocompetence?

The ability of the body to interact with a wide spectrum of foreign substances.

When does immunocompetence begin and when is it completed?

It begins during fetal development and completion can extend through late puberty.

What is memory in adaptive immunity?

Lymphocytes are programmed to recall their first encounter with an antigen and respond rapidly to subsequent encounters.

What are the two characteristics that define specific (adaptive) immunity?

Specificity and memory.

What is specificity in adaptive immunity?

Antibodies produced against an antigen function only against the antigen that stimulated their production.

What is active immunity?

Immunity that results when a person is challenged by an antigen that stimulates production of antibodies.

What are the characteristics of active immunity?

It creates memory, takes time to develop, and is long-lasting.

What is passive immunity?

Immunity produced when preformed antibodies are donated to an individual.

What are the characteristics of passive immunity?

It does not create memory, acts immediately, and is short-term.

What is natural immunity?

Immunity acquired as part of normal life experiences.

What is artificial immunity?

Immunity acquired through a medical procedure such as vaccination.

What is natural active immunity?

Immunity acquired by getting and recovering from an infection.

What is natural passive immunity?

Immunity acquired through transfer of antibodies from mother to child across the placenta or through breast milk.

What is artificial active immunity?

Immunity acquired through vaccination.

What is artificial passive immunity?

Immunity acquired by receiving preformed antibodies from another source.

What is immunization?

Active immunization in which a person is administered some form of antigen.

What is another term for immunization?

Vaccination.

What is the purpose of immunization?

To expose a person to antigen so they develop active immunity and immune memory.

What is immunotherapy?

The use of immune products such as antibodies to provide protection or treatment.

What is the purpose of immunotherapy?

To provide immediate immune protection through passive immunity.

What is the primary immune response?

The response that occurs during the first exposure to an antigen.

What happens during the primary immune response?

A latent period occurs, IgM appears first, IgG appears later, and antibody levels eventually decline.

Which antibody appears first during a primary immune response?

IgM.

What is the secondary (anamnestic) response?

A response that occurs when the immune system encounters the same antigen again.

What happens during the secondary response?

Memory lymphocytes respond immediately, producing a rapid and sustained antibody response dominated by IgG.

Why are booster vaccinations given?

To provide a quick, potent response against subsequent exposures to infectious agents.

What are the four major preparations used for vaccines?

Live attenuated vaccines, inactivated (killed) vaccines, subunit vaccines, and toxoid vaccines.

What is a live attenuated vaccine?

A vaccine created by reducing the virulence of a pathogen while keeping it viable.

What is an inactivated (killed) vaccine?

A vaccine made from microorganisms that have been killed and cannot reproduce.

What is a subunit vaccine?

A vaccine containing only specific antigenic parts of a pathogen rather than the entire organism.

What is a toxoid vaccine?

A vaccine made from an inactivated bacterial toxin that stimulates immunity against the toxin.

How are most vaccines administered?

By injection.

What are alternative routes of vaccine administration?

Some vaccines are administered orally or nasally.

What is an adjuvant?

A compound added to some vaccines to enhance immunogenicity and prolong retention of antigen.

What is a major requirement for vaccine development?

A vaccine must provide more benefit than risk.

What are common side effects of vaccines?

Local reactions at the injection site, fever, and allergies.

What are rare side effects of vaccines?

Back-mutation to a virulent strain and neurological effects.

What happens if significant adverse effects are detected in a vaccine?

The vaccine is altered or withdrawn.

What is herd immunity?

The reduction in pathogen occurrence because immune individuals do not harbor and spread the pathogen.

How does herd immunity protect non-immunized individuals?

It makes them less likely to encounter the pathogen.

Why is widespread vaccination important?

It increases herd immunity and reduces transmission of infectious agents.