Source: Government of Victoria 3
Key messages
- Diphtheria is a serious bacterial infection that can cause severe illness and death.
- Australia is currently experiencing the largest diphtheria outbreak on record, especially in regional and remote areas of the Northern Territory, Western Australia and South Australia.
- There have been no cases identified in Victoria to date.
- Vaccination is the most effective protection against diphtheria. Multiple doses and booster vaccinations are needed to provide and sustain immunity.
- The Victorian Department of Health has expanded eligibility for free diphtheria toxoid containing vaccines (Boostrix®).
- Health professionals should review their patient’s diphtheria vaccination status and offer a free vaccine to those who are eligible.
- People travelling to higher-risk areas to live or work should check their diphtheria vaccination status and consider getting vaccinated if they have not had a diphtheria vaccine in the past 5 years. Some people may be eligible for a free vaccine.
- For the latest list of higher-risk areas, visit Diphtheria | Australian Centre for Disease Control.
What is the issue?
There is an ongoing outbreak of diphtheria in northern and central Australia. Most cases have been reported in Northern Territory and Western Australia with smaller numbers in Queensland and South Australia.
Aboriginal and Torres Strait Islander people have been more impacted.
There have been no cases identified in Victoria to date; however, there remains a small risk of diphtheria being imported into Victoria by travellers returning from higher risk areas.
Diphtheria vaccination eligibility
Diphtheria-containing vaccine is available to many Victorians under the National Immunisation Program (NIP). To provide additional protection during this outbreak, Victoria has expanded eligibility for free diphtheria toxoid containing vaccine (Boostrix®) including for people travelling to higher-risk areas.
A Medicare card is not required to access the state-funded vaccine.
Who is eligible for free vaccination in Victoria
In Victoria, diphtheria toxoid containing vaccine is available free-of-charge for the following groups:
For the latest outbreak information and list of higher risk areas please visit Diphtheria | Australian Centre for Disease Control.
Please note, while the vaccine is free-of-charge, some providers may charge an administration or consultation fee.
Recommendations
For health professionals
- Check the diphtheria vaccination status of patients, especially for those travelling to higher-risk areas. Offer people travelling to higher-risk areas a diphtheria-containing vaccination if they have not had a diphtheria vaccine in the past 5 years.
- Offer free diphtheria toxoid containing vaccine to anyone who is eligible under either the National Immunisation Program or the expanded state-funded campaign (Boostrix®).
- Refer to the Australian Immunisation Handbook for vaccination information, including recommended booster dose intervals available at Diphtheria | The Australian Immunisation Handbook.
For the general public
- Check your Diphtheria vaccination status. For more information on how to do this, visit: How to find your immunisation records | Better Health Channel.
- People travelling to higher-risk areas should check their diphtheria vaccination status and consider getting vaccinated if they have not had a diphtheria vaccine in the past 5 years.
- Speak to your doctor ( GP or Aboriginal Health Services) or local immunisation provider to check if you are eligible for a free vaccine.
Updated 4 June 2026
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Updated 4 June 2026
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