what is Hypersensitivity and vaccination

what is Hypersensitivity and vaccination? Types of Hypersensitivity and vaccination? Uses Of Hypersensitivity and vaccination?

Hypersensitivity and vaccination

Hypersensitivity:

It is defined as the reaction of immune system leading to serve and even death indian sensitized animals when we exposed to the same antigen time.

Types of hypersensitivity :


Hypersensitivity is classified into two ways:-

  1.  based on time taken for the reaction
  2.  based on the mechanism of pathogen


1} Based on the time taken for the reaction:

Based on time taken, hypersensitivity is classified into two categories. They Are:-

A} immediate hypersensitivity: when an immune response or manifest in short duration of time within minutes, this type of hypersensitivity is called immediate hypersensitivity.

  1. It involves the interaction of antigen and antibody
  2. It is handled by b cells
  3. It can transfer from one host to another by the transfer of serum
  4. Example: food allergens .




B} Delayed hypersensitivity: the immune response appear slowly only after 24 to 48 hours.

  1. It involves the reaction between antigen and t cells
  2. It is handled by t cells
  3. It can transfer from one host to another by the transfer of t cells.



Based on the mechanism of pathogen:

It is of five types. They are:-

  • Type 1 anaphalaxis hypersensitivity.
  • Type 2 antibody depend toxic hypersensitivity.
  • Type 3 immune complex mediated hypersensitivity.
  • Type 4 cell mediated hypersensitivity.
  • Type 5 stimulatory hypersensitivity.





Type 1: anaphalaxis hypersensitivity:-

  1.  when an antigen enters into an animal for the first time, the animal become sensitized.
  2. whenever the same antigen re enters into the same animal then the animal shows anaphalactic reaction.
  3.  when an antigen enters into animal, the animal produce ige type of antibodies. These antibodies binds the mast cell because due to the presence of ige receptors.
  4.  when same antigen re enters into the sensitized animal that dose is known as shocking dose.
  5.  these antigens binds to the bodies is already bind to the mast cells. The antigen antibody reaction occurs on mast cells. Rupturing of mast cell that releases of histamines. These histamines binds to the histamine receptors that leads to an anaphalaxis.







anaphalaxis hypersensitivity
anaphalaxis hypersensitivity

Type 2: antibody dependent cytotoxic hypersensitivity:-

When an antibody reacts with cell surface antigen then cell becomes cytotoxic.

Example: erythroblastosis foetalis

When rh positive factor marriage rh negative mother first baby is safe.
During the second pregnancy also has rh positive it acts as antigen. Rh antibodies are present in the blood of the mother. Rh antibodies binds to the rh antigen binds to the rh antigens that leads to the blood cells becomes cytotoxic {or} destroy. This disease is known as erythroblastosis foetalis.

Type 3 immune complex mediated hypersensitivity:-


When an enormous amount of antigens enter into the body and enormous amount of antibodies releases from a complex known as immune complex.
These immune complexes are formed on the blood capillaries {or} inside the blood capillaries that leads to the destruction of blood capillaries.
This type of hypersensitivity is known as immune complex mediated hypersensitivity.

Type 4 : mediated hypersensitivity:-


In this type of hypersensitivity antigen binds to the t cells that initiates the release of cytokines and some of the hydrolytic enzymes.
The hydrolytic enzymes degrade the tissue and leads to the type 4 hypersensitivity.

Type 5 stimulatory hypersensitivity:-


In this type of hypersensitivity the antibody binds to the cell surface antigen that leads to stimulation of cells.
In type 2 hypersensitivity cells become cytotoxic but in type 5 hypersensitivity cell become stimulation.
This type of hypersensitivity seen in thyrotoxicosis.
In this disease antibody binds to the cell surface antigen receptor that leads to the over production of thyroxin.
In this type of antibody is IG g.

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