You don't know what vaccines are then i will tell you.
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. 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. A vaccine provides a controlled exposure to a pathogen, training and strengthening the immune system so it can fight that disease quickly and effectively in future. By imitating an infection, the vaccine protects us against the real thing.
We are given vaccines to help us to fight of unwanted bactiria and viruses. Most vaccines are given at the hospital. We usually think of vaccines as shots, but not all vaccines are given that way. Some are given orally (by mouth) or in other forms like nasal sprays. But it's impossible to escape the fact that some immunizations are just best given as shots.