Immunisation provides protection against bacteria and viruses through the development of antibodies to the infecting organism. In Australia, in recent years, there have been epidemics of measles and whooping cough due to incomplete immunisation.
By being immunised, you are protected, but so are your family members and the community – those people to whom you could spread the disease.
When you are vaccinated, by injection or swallowing the medicine, your body produces an immune response in the same way it would to the disease - but without you getting the disease.
The body then keeps proteins, called antibodies, circulating in the blood stream to fight that particular disease. It is important for both adults and children to protect against commonly occurring infections. Without immunisation, many of these infections can cause severe illness and even death.
In Australia, most vaccinations are given by injection into the upper arm, or sometimes leg. Some are taken orally (in the mouth).