Experts are concerned Australia could become âfertile groundâ for measles to take hold if the disease is brought into the country amid outbreaks in the US and south-east Asia.
In the US more than 300 cases have been reported. Two people, including a child, have died in west Texas, the epicentre of the outbreak, which the US Centers for Disease Control and Prevention (CDC) expects to âexpand rapidlyâ.
When five cases of measles were confirmed in Victoria on 14 March the stateâs chief health officer warned global case numbers were rising in Vietnam, Thailand, India, Africa, Europe and the UK, the Middle East, and the US.
Should Australians be concerned about global outbreaks?
The World Health Organization declared measles eliminated from Australia in 2014. However, small outbreaks occur regularly because Australians travel a lot, infectious disease epidemiologist Anita Heywood says.
âWhen a non-immune traveller contracts measles in another country and arrives in Australia infectious [they] can transmit to other non-immune people, resulting in an outbreak,â says Heywood, who is a public health expert at the University of New South Wales School of Population Health
The measles outbreaks in the US and Vietnam are of significant concern because Australia is below the WHOâs recommended 95% vaccination rate target, according to Dr Tim Jones, the chair of the Royal College of General Practitionersâ specific interests group for child and young personâs health. Without it, Jones says, Australia does not haveâherd immunityâ â that is, when enough people are immune to a disease the infection canât spread from one person to another in the community.
Currently, 92.21% of two-year-old children in Australia are vaccinated for measles, which requires two doses of the combined measles, mumps and rubella (MMR) vaccine due at 12 and 18 months, according to a spokesperson for the department of health and aged care.
Prof Margie Danchin, a vaccine expert at the Murdoch Childrenâs Research Institute (MCRI), says she is especially concerned there is âfertile ground where we have deep pockets on under-vaccinationâ.
The rate is lower in regions, including the Richmond Valley in northern NSW (75%), and Queenslandâs Noosa hinterland (70%), Danchin says. There are also pockets of under-vaccination in inner-city Melbourne and Sydney, she says.
Who is vulnerable to an outbreak?
Two doses of the measles vaccine in childhood is about 99% effective in stopping someone from getting measles, infectious diseases physician Sanjaya Senanayake says.
âThis generally is regarded as lifelong protection so boosters arenât recommended,â says Senanayake, who works at the Australian National University Medical School.
However, Danchin says it was only after 1992 that Australia started providing children with two doses of the vaccine, and therefore the most at risk population in Australia includes not only those who are unvaccinated but also adults who have had only one dose.
The other at risk groups are children under one year of age who have not yet received the vaccination, as well as immuno-compromised individuals, including those with cancer or who are taking immuno-suppressive medications, who cannot receive live vaccines, Danchin says.
Jones says children under the age of one who arenât immunised yet have the highest risk of contracting measles and suffering severe complications, including pneumonia and encephalitis, which refers to brain swelling. Neither the six-year-old child nor the adult who died of suspected measles in Texas in the past month were immunised, he says.
How many cases have there been in Australia recently?
During the Covid-19 pandemic when Australiaâs borders were closed, there were no cases in 2021, but since then cases have risen, Danchin says, with 57 cases in 2024 and 28 cases in the first three months of 2025.
In New South Wales, there were 18 cases in 2024, compared with six cases in 2023. In the first three months of 2025 there have already been 13 cases.
Likewise, in Victoria, there have been 13 cases to date in 2025, compared with 16 in 2024, and only four cases in 2023.
Nationally, however, the department of health said year-to-date figures on measles (28) were comparable with the figures for the same period in 2024, higher than the four cases recorded in the same period in 2023 and lower than for the same period in the pre-pandemic year 2019.
How contagious is the measles virus?
Danchin says âthe measles virus is the most infectious virus we know â itâs like a heat-seeking missile. In an under-vaccinated population it will spread quicklyâ.
Jones says âup to nine in 10 susceptible people who are either not immunised, under-immunised or immunocompromised will contract this disease if they are in close contact with a person infected with measlesâ.
âAnother factor that makes this disease hard to contain is that people are most contagious before the most conspicuous signs of measles, such as a rash and spots on the gums and conjunctivitis, become apparent.â
What can those at risk do?
People can check their vaccination records on the Australian Immunisation Register, or ask their GP or their parents about which vaccinations they have received, Senanayake says.
The MMR vaccine is free for all Australians, of any age â and anyone can catch up with missed doses at their GP and in some states, at council immunisation clinics, Heywood says.
For babies aged six to 11 months travelling anywhere where there are outbreaks, Danchin says they can receive an early additional MMR dose, but they will still need the regular vaccinations at 12 and 18 months. In Victoria and NSW, those extra early doses are free, she says.
If immuno-compromised individuals are exposed to the virus, they can access immunoglobulin antibodies pre-formed in an injection within six days of exposure, Danchin says. She says governments could lower the barriers that are stopping some people getting vaccines by offering more clinics on Saturday mornings and after hours and by getting more bulk-billing clinics to offer the vaccine.
