vaccines hypersensitivty and immune disorders

Vaccine

Material used to immunize someone

Active immunization

Weakened, killed, or pieces of a pathogen are injected to promote production of specific antibody and T cells

Passive immunization

Injection of immunoglobulin to treat immunodeficient patients

Antitoxin

Antibodies that neutralize toxins

Effective Vaccine

Should not harm person being inoculated, stimulate B-cell and T-cell response, produce memory, protect against the natural pathogen, should not require many boosters, easy to administer with long shelf life

Types of Vaccines

Killed whole cells or inactivated viruses, live, attenuated bacteria or viruses, purified components of infectious agent, DNA or RNA

Herd Immunity

Large portion of population is immunized against specific disease; immunizing 3/4th of population can slow disease

Type I Hypersensitivity

May be mild/localized; some are immediate and life threatening, includes anaphylaxis

Sensitization

Primary exposure in type I hypersensitivity reaction

Degranulation

Subsequent exposure in type I hypersensitivity reaction where mast cells release chemicals

Type II Hypersensitivity

IgG antibody binds to cell surface antigens, causing blood group incompatibilities

Type III Hypersensitivity

Immune complex disease where IgG binds to soluble antigens, overwhelming the system and embedding in vessel walls

Type IV Hypersensitivity

Delayed-type hypersensitivity; only class mediated by T cells

Primary immunodeficiencies

Genetic disorders typically manifesting in childhood

Secondary immunodeficiencies

Acquired at any age, consequence of certain infections (HIV), use of immunosuppressive drugs, or radiation therapy

Allergen

Substance that causes an allergic reaction

Blood group incompatibilities

Occurs when antibodies attack B blood and lyse cells in type II hypersensitivity

Immune complex

Formed when IgG binds to soluble antigens in type III hypersensitivity

Complement activation

Occurs in type III hypersensitivity, activating PMNs and releasing ROS and proteases

Memory TH1 cells

Bind antigen on MHC II; release inflammatory cytokines; recruit WBC which cause damage in type IV hypersensitivity

Memory TC cells

Bind antigen presented on MHC I; directly kill cells in type IV hypersensitivity