GPs urged to remind patients of measles jabs as millions may be unprotected

It found that susceptibility was highest among infants who were too young to receive their full measles vaccination schedule and those born from the late 1970s onwards.

Every birth cohort from 1977 onwards had at least 5% of its population estimated to be susceptible.

It is the first study to combine national immunisation register data with multiple serosurveys (studies that test blood samples to measure population immunity levels) to produce a detailed analysis of measles susceptibility across all age groups.

Led by the National Centre for Immunisation Research and Surveillance (NCIRS) the study, published in the Australian and New Zealand Journal of Public Health found 6.7% of the population were susceptible to measles as of 2019, having either not been vaccinated or not having a second dose of the vaccination.

Experts warn that these immunity gaps may now be wider as childhood vaccination coverage has continued to decline.

Immunisation Foundation Australia founder and director Catherine Hughes said people may be surprised to find out they had only had one dose of the measles vaccination, rather than two, leaving them exposed to the disease.

“When people find out they may only have had one measles dose, the reaction is almost always the same: surprise, then worry that they've done something wrong. but they haven't,” she said.

“Many were children before the second dose became routine in the early 1990s, or grew up while the schedule was changing around them.”

Ms Hughes said GPs should treat the matter as ordinary housekeeping and routinely ask patients about measles vaccinations.

“What we hear from people is that they'd happily get a catch-up dose, they've just never been asked,” she said

Ms Hughes said travel consults or flu shot appointments provided good opportunities to raise the topic.

“Whatever prompt or reminder system a practice already uses for other overdue care, measles could sit alongside it,” she said.

“If someone can't confirm two doses, an extra one is safe and free, and once it's given it goes onto the Australian Immunisation Register so that person never has to wonder again.”

The findings come as global measles outbreaks increase and imported cases continue to reach Australia.

Data from the National Notifiable Diseases Surveillance System shows national measles notifications have risen sharply since 2022 – from single figures to 181 in 2025, with 113 cases recorded so far in 2026.

Last year WA recorded 62 cases of measles, the highest in several years. So far five cases have been recorded in the state so far in 2026.

Epidemiologist and data analyst at NCIRS Zoë Croker was lead author of NCIRS' study.

“Australia remains a measles elimination success story, but our findings show we're closer to the minimum level of population protection needed to prevent outbreaks than many people might expect," she said.

"While we have maintained our measles elimination status since 2014, protection isn’t shared evenly across the population, and the margin for error is relatively small. 

“Importantly, population immunity may now be slightly lower than our 2019 estimate, given that childhood vaccination rates have declined since the COVID-19 pandemic.

“Measles is one of the most contagious diseases known. Even relatively small immunity gaps in communities can create opportunities for the virus to spread when cases are imported from overseas.”

Among the cohorts with higher immunity gaps are parents raising young families who are among Australia's most frequent overseas travellers, increasing the chances of measles being introduced into households and communities.

The study also found that people aged 15-35 years accounted for half of the measles cases reported in Australia between 2008 and 2022.

Associate director at NCIRS and senior author of the study Associate Professor Frank Beard said there were likely to be communities, regions or groups where immunity gaps were substantially higher than the national average, raising the risk of local outbreaks if measles is introduced.

Several high-income countries, including Canada, Spain and the United Kingdom, have recently lost their measles elimination status amid rising global outbreaks and international travel.

"What’s happened overseas is a reminder that elimination status isn’t guaranteed – it has to be actively maintained. That means keeping our population immunity as high as possible," A/Prof Beard said.