Vaccines and Immune Disorders

active immunization

Can be acquired via 2 methods: a vaccine, and naturally, when the patient gets infected

passive immunization

Involves the transfer of preformed antibodies to individuals to give immediate but temporary immunity

Ex: antibodies in breast milk given from mother to child

antiserum

Blood serum (from humans or animals) that contains antibodies is transferred to a patient to give temporary immunity

how injected antibodies can protect an individual against invaded pathogen.

Injected antibodies provide immediate protection against pathogens by binding directly to them, which prevents cell entry and marks them for destruction

What is the result of successful (effective) immunization?

Vaccines stimulate the primary immune response without causing disease. It stimulates the production of antibodies and memory B and T cells.

Sophie is playing with Abby who currently has a case of chicken pox. Sophie had chicken pox vaccine two years ago.

Explain the immunological reason why, after playing with Abby, Sophie does not get chicken pox.

Since Sophie received the vaccine previously, the vaccine stimulates production of antibodies to the chicken pox virus, alongside memory B and memory T cells that are specific for the virus. When Sophie gets exposed to the virus again, the circulating antibodies in her body give her immediate protection to the infection. The memory T and B cells are activated, which produce cytotoxic T cells and antibodies that prevent the spread of the chicken pox virus

Attenuated vaccines

a live, weakened version of a pathogen that can’t cause disease.

Primary response

initial exposure to the virus from the vaccine, the immune system familiarizes itself with the virus so it can effectively defend against it faster next time (secondary response)

Inactivated (killed) vaccines

dead, inactivated version of a pathogen

Toxoid vaccines

bacterial toxins (protein) that are inactivated

Subunit vaccines

usually protein vaccines. Instead of an entire microbe, only parts of microbe are used

mRNA vaccines

instruct host cells to synthesize pathogen proteins which stimulate host immune response

herd immunity.

Large percentage of population becomes immune to an infection, providing protection for those that aren’t immune

allergy

An inappropriate/excessive immune response to antigens

The response to antigens that leads to damage

allergen

Antigens that trigger allergic reactions

Type I hypersensitivity

an immediate, IgE-mediated allergic reaction to harmless antigens (pollen, food) that occurs within minutes of exposure.

1. Expressed phase (allergic symptoms occur). Allergen binds to IgE on mast cells and basophils. The allergen also stimulates more production of IgE

2. Mast cells and basophils undergo degranulation

What inflammatory cytokines are released during degranulation?

Histamine - rapidly released

Leukotrienes

Prostaglandins

What do prostaglandins do in type I allergic response?

affect smooth muscle and increase mucus secretion

What do leukotrienes do in type I allergic response?

cause prolonged contraction of smooth muscles and increase mucus production

What do histamines do in type I allergic response?

increases permeability of blood capillaries, blood vessel dilation and itching

anaphylactic shock

Life threatening, rapid drop in blood pressure due to serious allergic reaction

septic shock

a life-threatening, advanced form of sepsis where severe infection causes a body-wide inflammatory response, leading to critically low blood pressure

shock

A life-threatening, generalized state of acute circulatory failure resulting in inadequate delivery of oxygen and nutrients to tissues and cells.

autoimmune disorder

The antibodies and cytotoxic T cells produced by the immune system are incorrectly directed against the body’s own tissues

example of an autoimmune disease

Crohn’s disease - antibacterial antibodies react with the intestinal mucosa

Immunodeficiency diseases

A disease resulting from defective immune mechanisms, categorized into congenital (primary) where the person is born with it

acquired (secondary) where a weak immune system develops throughout their life

how AIDS is an example of an immunodeficiency disease

AIDS is acquired as a result of HIV, making it so the helper T cells are destroyed, rendering the immune system unable to manage immune response. This leaves the body weakened and susceptible to disease.