What is vaccines and how do …

A vaccine is a type of medicine that trains the body's immune system so that it can fight a disease it has not come into contact with before . Vaccines are designed to prevent diseases ,rather than treat a disease once you have caught it . To understand how vaccine work it helps to look first at how the immune system works , because vaccine harness the natural activity of your immune system. These molecules are called antigens , and they are present on all viruses and bacteria . By injecting these antigens into the body, the immune system can safely learn to recognise them as hostile invaders , produce antibodies and remember them for the future . If the bacteria or virus reappears , the immune system will recognise the antigens immediately and attack aggresively well before the pathogens can spread and cause sickness.

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Vaccines r dead or weakend suspensions of micro organisms for a particular disease. I am going to explain you with an example of Vaccine of dengue.when Microorganisms are active they cause dengue in our body, but when they are weak or dead, they are harmless. So when these dead pathogen are injected in our body in the form of vaccines, they do not cause any harm to our body but when are immune system recognise is it it starts building antibodies against it and eliminate those suspensions of microorganisms. So in this way our body is not affected by dengue and we have antibodies build against dengue. Thus there is no dangerous of getting affected by dengue .Hope that will help

Vaccines are given to a person to keep away their body from disease causing microorganisms. When they are injected to our body,they get the way to spead all over the body and kill the microbes before they effext us