VACCINES:

Have you are all vaccinated for diseases like Small Pox, Polio, definitely

every one had vaccinated for the small pox is the major disease which causes severe ill effect.

So, Whats are vaccines?

Vaccines are nothing but the preventive aid to the specific disease.

i.e., the causative agent (Bacteria/Virus)which producing the infectious disease are killed or made attenuated to give the host said to be vaccines.

Vaccines are many types, KILLED ,ATTENUATED, specific PROTIEN / other Biomolecules which can able to cause disease.

How the vaccines works after vaccination?

its the interesting, our human system is a perfect machine having good memory, and so intelligent also.

Our immune system have the 2Types of cells, 1.B-Cells,2.T-Cells, both having the property to eradicate the antigen(causative agent) from the host through producing Antibody and secreting other chemicals by the response of antigen.

After meeting r eradicating the T&B-Cells have the memory of structure and nature of  infectious organism, it can easily identify the agent by next time infection.

this is the principle for the vaccination the attenuated or killed infectious agent was given as a vaccine the T&B-Cells catch the memory and made prevention against the disease.

now a days DNA vaccines are also practicing under controlled research, ie, made identifying specific causative agents DNA, and incorporated into the specific host cells to produce the specific protein to enhance the immune system.

examples for vaccines-tetanus toxoid, BCG, POLIO...etc..