Victoria and NSW have most recently issued notices about an ongoing risk of measles linked to travel overseas and interstate.
But for children the concern is compounded as the Department of Health says coverage rates have decreased below the 95 per cent aspirational target over the last three years.
These could be due to a number of different factors ranging from borders opening after the pandemic to US President Donald Trump's administration avowed anti-vaccine stance to cost of living pressures.
"We've had ongoing issues with our vaccination coverage, and it mostly has to do with access, not so much as disinformation," Meru Sheel, a University of Sydney professor of infectious diseases, told AAP.
"The vaccine dose is free, but getting to the clinic and the cost of seeing a doctor is can be prohibitive and then there's issues around knowledge and doubts around vaccination."
Cases of measles, a highly infectious viral illness and contagious viral illness through air droplets, have surged in the US reaching record highs in 2025 and more than 900 recorded in 2026 alone.
The World Health Organisation estimates it is 12 times more contagious than influenza with symptoms of coughs, rashes, high fever and red eyes often leading to deadly results.
"What happens in one part of the world impacts many parts of the world," said Dr Sheel.
"What we really need to think about is our ability for checks and balances and ensuring a policy consistent with the evidence, which is where we are."
Measles cases have risen from zero in 2021 due to strict COVID lockdowns to 181 in 2025, according to the National Notifiable Disease Surveillance System.
The National Centre for Immunisation Research and Surveillance reports levels of on-time childhood vaccination remain substantially lower than before the COVID-19 pandemic.
In 2024, one in three children received the first dose of measles-mumps-rubella (MMR) vaccine late, while one in five children received the second dose of a diphtheria-tetanus-pertussis (DTP)-containing vaccine late.
ANU epidemiologist Martyn Kirk said misinformation and disinformation about the safety of vaccines does have an impact on coverage rates as parents turn to social media as an unreliable source of information.
"In general we have seen a decline in childhood vaccination rates but governments have been working very strongly to try and promote it as a healthy and safe way of controlling diseases," he said.
He said measles infections are worse if they occur in people who are very young or pregnant women or for people who have a compromised immune system.
"It's more infectious even than COVID," he said.
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