How does immunisation work?

Herd immunity

About immunisation

Immunisation is a proven and effective way to prevent the spread of many infections and diseases.

The World Health Organisation refers to it as one of the great successes of modern medicine and estimates that it prevents between two and three million deaths each year. Before the immunisation campaigns of the 1960s and 1970s, diseases like diphtheria and tetanus killed many children. Today, thanks to widespread immunisation, these diseases are very rare.

Immunisation has been so effective that some diseases like small pox are no longer a threat. Small pox was a disease that had been around for 3000 years and killed 30% of people who caught the virus. Thanks to a global vaccination program led by the World Health Organisation, the last known case was in 1978.

How does immunisation work?

A vaccine is a dead or weakened form of a virus. When you get a vaccine, it stimulates your body’s immune system to produce antibodies which fight and kill the virus. If you come into contact with this virus again, your body will be prepared to fight it. It will recognise the virus and be able to quickly produce the right antibodies to destroy it. You might still get some of the symptoms of the disease, but the severity will be less and for a shorter time.  

When you get vaccinated, you’re not only protecting yourself, you’re also protecting those in the community who can’t get a vaccine. Some people are too young to be immunised or others are too sick or weak. When enough people are immunised against a disease, it will slowly die out as it can no longer spread between people.

What’s the difference between immunisation and vaccination?

Vaccination is the process of getting a vaccine from a needle. It’s usually done by a healthcare professional like a nurse or doctor. 

Immunisation includes both the process of getting the vaccine, as well as becoming immune to the disease.

Do vaccines have side effects?

Any vaccine can potentially cause a side effect, but they are mostly minor and go away after a short period of time. Some examples of common side effects include headaches or mild skin rashes. If you get the flu vaccine, you might experience milder symptoms of the flu like a runny nose, muscle aches, or a sore throat.

Is there a link between vaccines and autism?

As the Department of Health confirms, there is no link between vaccines and autism. Many research studies have proven that vaccines do not cause autism. The idea came about after some studies were published in respected journals suggesting a link. These studies were based on poor quality science and the journals have since unpublished the studies. The researchers behind the studies have also since confirmed they no longer believe there is a link. To find out more, read the Department of Health’s Vaccination and autism factsheet.

What vaccines do you need?

You’ll need different vaccines at different times in your life depending on your situation. You’ll need extra vaccines if you’re going travelling to certain countries or if you’re planning to become pregnant. It’s best to ask your doctor what vaccines you need.

You can also find out more about vaccines recommended for the following groups at the Department of Health:

What vaccines do children need?

If you have children, it’s important that they’re immunised against a range of diseases. You can find out more about vaccines recommend for children at the Department of Health.

In Australia, some of the diseases that babies and children are immunised against include:

  • Chickenpox
  • Mumps
  • Rubella
  • Measles
  • Hepatitis B
  • Polio
  • Whooping cough

If you’re enrolled in Medicare, some vaccines are free through the National Immunisation Program.

You can find out more about vaccinating your child at the Department of Health.

Do you have a question about immunisation?

For general information about immunisation, you can call the National Immunisation Information Line on 1800 671 811. It’s open Monday to Friday from 8:30am to 5pm Australian Eastern Standard Time.

If you need medical advice, it’s best to see your doctor.


All information contained in this article is intended for general information purposes only. The information provided should not be relied upon as medical advice and does not supersede or replace a consultation with a suitably qualified healthcare professional.

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