All about Vaccines that you need to know..

 What is vaccines? Why is this so useful? How do this function? These are the most common queries that has been developing in the present situation of COVID-19. So lets discuss about it.

 What is vaccines?

 Vaccines are the preparation of killed or living microorganisms which produce immunity when administered into the body. In simple meaning it's insertion into the body increase the immunity to fight against diseases.

 History of vaccination:

    About 3000 years ago the first vaccine was developed against the diseases Small pox  developed by Edward Jenner spread in India and Egypt. Edward Jenner observed the milkmaids who  contracted cowpox did not get smallpox lead him to discover the practice of vaccination against smallpox.

To understand about vaccination we must understand about antigen and antibody.

Antigen:  When the pathogen(diseases causing factor) enters into the human body it releases a toxic chemical to destroy human defense  system and this toxic substance is called antigen

Antibody:  When pathogen produce antigen our blood also defense against and try to destroy that antigen by releasing a very specific chemical called antibody.

In simple antigen makes us ill and anti body fights against antigen to make us well.

There are different types of Immunity.

Types of vaccines:

1)       Killed vaccine: These vaccines are prepared by killing the pathogenic organisms by heat or Uv – rays or alcohol.

Eg: Typhoid  vaccine, cholera vaccine

2)      Toxoid vaccine: These vaccine are prepared by destroying the toxic property of the toxins produced by organism but retaining its antigenic property.

eg: Tetanus toxoid.

3)      Attenuated living vaccines:  The pathogen is made weakened to make it non- virulent

eg: Oral polio vaccine, Bacille Calmette Guerin, Mumps,Measles

4)      Antibodies as vaccine: Serum is used after a person or animal has been exposed to infection. This serum contains antibodies against the pathogens.

Application of vaccines:

a)      Develop immunity against infectious diseases

b)      Destroy or kill the disease causative organisms.