chapter 17 vaccines diagnostics and immune disorders

passive imunization

-injection of immunoglobulin to treat immunodeficient patients

-Does not promote antibodies/t cells

-Breastfeeding -IgA

vaccine

material used to immunize someone

active immunization

weakened, killed, or pieces of a pathogen are injected to promote

what you are relieving when you contract pathogen

Antitoxin

-antibodies that neutralize toxins

-Developed from antibodies

Natural infection

-engages full immune system, downside sometimes -death/health detects

What are the standards for a commercial vaccine?

Should not harm the person being inoculated.

What type of immune response should a commercial vaccine stimulate?

Stimulate B-cell and T-cell response; produce memory.

What type of pathogens do commercial vaccines typically use?

Tend to be killed or death pathogens, barely natural pathogens.

What is the purpose of a commercial vaccine?

Protect against the natural pathogen.

How many boosters should a commercial vaccine require?

Should not require many boosters.

What are two characteristics of a commercial vaccine regarding administration?

Easy to administer with a long shelf life.

What is the first basic type of vaccine?

Killed whole cells or inactivated virus

What is the second basic type of vaccine?

Live, attenuated bacteria or viruses

What is a risk associated with live, attenuated vaccines?

They can revert to the pathogen form

What is the third basic type of vaccine?

Purified components (protein) or infectious agent

What is the fourth basic type of vaccine?

DNA or RNA vaccines

herd immunity

-A large portion of the population is immunized against a specific disease

-Immunizing 3/4th of the population can slow the disease -how? -protects people who aren't

-The amount needed for herd immunity depends on the infectious agent

-Only works for contagious diseases

Hypersensitivity reactions

Type I

Type II

Type III

Type IV

Hypersensitivity reaction type 1

IgE-Mediated.

seasonal allergies

antibody and humoral mediated

2-30min

systemic anaphalyxis, hay fever, asthma, eczema

Hypersensitivity reaction type 2

Antibody mediated cytotoxic

5-8h

humoral mediated

blood transfusion reaction, hemolytic disease of the newborn, autoimmune hemolytic anemia, rheumatic fever

Hypersensitivity Reaction Type III

Immune complex type

2-8 days

systemic reactions, disseminated rash, arthritis, glomerulonephritis

humoral mediated

Hypersensitivity reaction type IV

cell mediated delayed hypersensitivity

24-72h

contact dermatitis, tuebrcular lesions

cell mediated

What is Type I hypersensitivity?

A hypersensitivity reaction that can be mild/localized or immediate and life-threatening.

What is anaphylaxis?

A severe and potentially life-threatening reaction associated with Type I hypersensitivity.

How many stages are there in a Type I hypersensitivity reaction?

There are two stages.

What occurs during the sensitization stage of Type I hypersensitivity?

It is the primary exposure or first encounter with the allergen.

What happens during the degranulation stage of Type I hypersensitivity?

Mast cells degranulate and release histamines upon subsequent exposure to the antigen.

What chemicals are released by mast cells during degranulation?

Histamines and prostaglandins.

What factors influence the severity of a Type I hypersensitivity reaction?

The allergen, route of entry, and number of sensitized mast cells.

What is Type II Hypersensitivity?

It is a hypersensitivity reaction where Ig antibodies bind to cell surface antigens.

What type of antibody is involved in Type II Hypersensitivity?

IgG antibodies.

What happens when IgG binds to cell surface antigens in Type II Hypersensitivity?

Another immune cell attacks the target cell.

What is an example of Type II Hypersensitivity?

Blood group incompatibilities.

What do Type A individuals produce in the ABO blood group system?

Anti-B antibodies.

What do anti-B antibodies do in Type A individuals?

They attack B blood cells and lyse them.

What type of hypersensitivity is characterized by immune complex disease?

Type III Hypersensitivity

What type of antibodies are involved in Type III Hypersensitivity?

IgG

What happens when immune complexes circulate in the bloodstream?

They can become embedded in vessel walls.

What is activated by immune complexes in Type III Hypersensitivity?

Complement system

What do PMNs release in response to activation by the complement system?

Reactive oxygen species (ROS) and proteases

What is the result of the inflammation caused by Type III Hypersensitivity?

Harm to both the antigen and the host

What type of hypersensitivity is mediated by T cells?

Type IV hypersensitivity

What is another name for delayed-type hypersensitivity?

Type IV hypersensitivity

What are the two stages of type IV hypersensitivity?

Sensitization and secondary exposure

What is the role of dendritic cells in type IV hypersensitivity?

Antigen processing and presentation

What happens during the secondary exposure in type IV hypersensitivity?

Memory TH1 cells bind antigen on MHC II and release inflammatory cytokines

What is one possible route of damage in type IV hypersensitivity?

Memory TH1 cells recruit WBCs which cause damage

What is the second possible route of damage in type IV hypersensitivity?

Memory TC cells bind antigen presented on MHC I and directly kill cells

What are immunodeficiency diseases (IDDS)?

Disorders in which part of the immune system is missing or defective.

What types of cells are related to immunodeficiencies?

T cells and/or B cells.

What are primary immunodeficiencies?

Genetic disorders that typically manifest in childhood.

What are secondary immunodeficiencies?

Acquired disorders that can occur at any age.

What infection is known to cause secondary immunodeficiency?

HIV, which can lead to AIDS and decimates the immune system.

What is the effect of immunosuppressive drugs on the immune system?

They can lead to secondary immunodeficiencies.

How can radiation therapy and chemotherapy affect the immune system?

They can cause secondary immunodeficiencies.