Healthy living


Immunisation is the term used for the process of becoming immune to disease. It protects people against specific diseases by using the body’s natural defence mechanism – the immune response.

What is a vaccination?

A vaccine is the material used to induce immunity against infectious diseases. Vaccination refers to the act of giving a vaccine to a person.

How do vaccines work?

Vaccines help develop immunity by imitating an infection. We come into contact daily with people in many different settings, for example at schools and shopping centres, and during this contact it is easy for infectious diseases to be transmitted. The greater number of people immunised, the less risk of people becoming infected and spreading the disease to others.

Who benefits from vaccines?

In the short term, immunisation protects individuals from a specific infectious disease and its immediate complications. But immunisation may also have long-term protective effects – from cancer and other chronic conditions.

An important feature of immunisation is that it also benefits the entire community. When a significant proportion of people in a community have become immune to a specific disease through immunisation, people who are still susceptible to the disease are less likely to come into contact with someone who is carrying the infectious agent.

What is herd immunity?

If enough people are immunised against a contagious disease it is possible to protect most of the community from the disease. This is called ‘herd’ protection. If you have good herd protection (at least 95% are immunised) then even those who are not able to be immunised, for example very young infants, or people with medical conditions, are protected from the disease.

Where to learn more about immunisation

Public Health | Australian Academy of Science

This publication is provided for education and information purposes only. It is not a substitute for professional medical care. Information about a therapy, service, product or treatment does not imply endorsement and is not intended to replace advice from your healthcare professional. Readers should note that over time currency and completeness of the information may change. All users should seek advice from a qualified healthcare professional for a diagnosis and answers to their medical questions.

Photo of a women in her 30s/40s with a serious expression. Text: Have you been fully vaccinated against measles?