I am glad you asked Seema.I will explain about it now.
Ma'am, what are vaccines ?
Vaccines are a small amount of weak or dead germs that are given orally or injected into the body.
Ma'am how do vaccines work ?
When the vaccine enters the body, the body creates substances capable of fighting these weak germs of that disease.This creates immunity against a particular disease.Examples are Chicken pox,MMR,Polio and Tetanus.
Remember that not all Diseases have vaccine.Now follow me to the next room and I will show you some pictures.
The first tool you see is used to inject vaccinations and the other one is used for oral vaccinations like Polio.