Question

what does a vaccine work​

Answer 1

Answer:

A vaccine works by training the immune system to recognize and combat pathogens, either viruses or bacteria. To do this, certain molecules from the pathogen must be introduced into the body to trigger an immune response. These molecules are called antigens, and they are present on all viruses and bacteria.

Hope it helps you in UPSC

Answer 2

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 disease, rather than treat a disease once you have caught it.

Vaccines help develop immunity by imitating an infection. This type of infection, however,does not cause illness, but it does cause the immune system to produce T-lymphocytes and antibodies. Sometimes, after getting avaccine, the imitation infection can cause minor symptoms, such as fever.