From the moment a baby is born, they are exposed to many different types of bacteria and viruses.
Some of these can cause life-threatening diseases.
When a child is vaccinated, their immune system produces antibodies that help protect them from infection if they come across the disease in the future.
If a child comes into contact with the disease later on, their immune system recognises it and rapidly produces antibodies to fight it.
Sometimes, a child may get a less serious form of the illness after getting vaccinated, but they usually recover faster and are protected from the more dangerous effects of the disease.
By following the childhood immunisation schedule, parents can ensure their child is protected and help prevent the spread of disease in the community.
For more information, visit health.gov.au/childhoodimmunisation or talk to your health professional.