Declining childhood vaccination rates could increase the risk of measles outbreaks in Australia over the next couple of years, an infectious diseases expert has warned.

Despite a high level of immunity in the Australian population, Professor James Wood from University of NSW argues there is a growing concern that measles outbreaks will become more of an issue in years to come.

“It is going to be a present issue for us to be aware of, that measles cases will be occurring,” Professor James Wood from University of NSW told 9news.com.au.

“We probably will see some outbreaks in the next couple of years in Australia, maybe just small ones, and not the scale of the American one.

“The vaccination rate’s creeping down and I haven’t seen it go back up again yet.”

Why has measles come back in the US?

Measles is one of the world’s most contagious infectious diseases and it crosses borders easily.

Two doses of the measles-mumps-rubella (MMR) vaccine offers 97 per cent protection against measles, however rates of childhood vaccination have been in decline worldwide since 2020, partly due to the COVID-19 pandemic and misinformation about vaccine safety.

The disease remains prevalent in parts of Asia, the Middle East and Africa.

In nations where measles has been eradicated, outbreaks occur through infection by unvaccinated international travellers.

In communities with high immunity, the outbreaks are usually limited, however, the recent oubreak in Texas started in a religious community that is opposed to vaccination.

Two school-aged children and one adult have since died amid at least 569 cases in multiple states. None of those who died were vaccinated.

New analysis has found nearly a third of young American children had not received their first MMR shot on schedule by 15 months of age.

Measles outbreaks in Australia

Australia has a high level of immunity in the population due to historically high childhood immunisation rates and natural immunity from exposure in people born before 1966.

The World Health Organization declared measles eliminated in Australia in 2014.

We typically see fewer than 100 cases a year.

But the risk of an outbreak is greater in regions with lower vaccination rates.

Around Byron Bay in NSW’s Northern Rivers, only 83 per cent of two-year-old’s were fully vaccinated (for all vaccines on the childhood immunisation register, including MMR) in December 2024.

“If a case arrives in one of those communities, you know, around Byron at a busy time of year like Easter or something, you do have that potential for an outbreak to occur,” Wood said.

“We don’t give our first vaccine to infants until they’re one year old.

“They get protection from their mothers for a few months but, in any community, kids between about six and 12 months of age are at high risk of bad outcomes from a measles infection and they’re not immune so increasing cases in one part of the community – people don’t just stay in one place – raises the risks for those sort of vulnerable infants.”

Wood said he believes vaccination rates may continue to drop yet.

“It’s a worldwide trend that we’ve seen in Australia and it doesn’t feel like it’s reached its bottom yet.

“Each year we’re seeing a little bit lower, and often these things are maybe a little bit delayed.

“It suggests that we’ve got more little kids around and in the past who are unvaccinated or not sufficiently vaccinated for measles.”

Measles infection can cause serious complications – such as blindness, pneumonia or encephalitis, swelling of the brain – and can even be fatal.

The most well-known symptoms of measles are a flu-like illness, which typically lasts two to four days, and a blotchy red rash.