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The Australian Centre for Disease Control is working closely with the Western Australian Government, the National Polio Surveillance Program and expert advisory groups to assess the finding and coordinate any necessary response.
Vaccine-derived poliovirus is rare but can occur in parts of the world where oral polio vaccine is still used. Australia does not use oral polio vaccine.
This is the first time this strain has been detected in Australia. Similar detections have occurred in other countries in recent years, including in Europe in 2024 and 2025, without leading to cases of polio.
Early assessment suggests the detection is most likely linked to a person from overseas, based on the type of poliovirus detected. Australia does not use oral polio vaccine or has any known clinical cases.
While this is a significant finding, it does not provide evidence of spread of disease in Australia.
Established preparedness plans mean health authorities are well placed to respond quickly. Since notification on 27 April, public health authorities have been working together to assess the situation and coordinate a proportionate response. The World Health Organization has been notified under the International Health Regulations, and further wastewater testing is underway.
Australian Centre for Disease Control Director-General Professor Zoe Wainer said the detection shows Australia’s disease surveillance and monitoring systems are working.
“Wastewater surveillance is designed to give us early warning, so health authorities can take precautionary action,” Professor Wainer said.
“This is an environmental detection, not a clinical case. No cases of polio have been identified, and there is no evidence of local transmission.
“Australia remains polio-free, but this is a timely reminder to check that you and your children are up to date with routine vaccinations.
“Vaccination is the best protection against polio. If you are unsure whether you or your child needs a polio vaccine or booster, please speak with your GP or immunisation provider.”
The polio vaccine used in Australia is safe and highly effective. It protects against poliovirus types 1, 2 and 3 and cannot mutate into vaccine-derived poliovirus.
The Western Australian Government has increased wastewater testing at the Subiaco wastewater plant to weekly for the next 6 months.
Additional background
Australia was declared free from polio in 2000. This detection does not affect that status.
The last case of poliomyelitis caused by locally acquired wild poliovirus in Australia was in 1972.
There are different types of poliovirus:
- Wild poliovirus type 1 remains endemic in Pakistan and Afghanistan.
- Wild poliovirus types 2 and 3 have been eradicated worldwide, although vaccine-derived outbreaks continue to occur.
- Vaccine-derived poliovirus is a rare strain of poliovirus that has genetically mutated from oral polio vaccine, which is not used in Australia.
In Australia, 93% of children aged 5 years are fully vaccinated against polio. This is below the global target of 95%.
Polio combination vaccine is free under the National Immunisation Program for children aged 2 months, 4 months, 6 months and 4 years. Eligible people under 20 years, and refugees and other humanitarian entrants of any age, can get a free catch-up vaccination.
Parents, carers and young people are encouraged to check immunisation records on the Australian Immunisation Register and seek advice from their GP, Aboriginal health service or immunisation provider.
Read more about polio and polio vaccination.