Health authorities across Australia have issued urgent alerts following a dramatic surge in measles infections, driven by summer holiday travel and a worrying decline in childhood immunisation rates.
Vaccination Rates Fall Below Critical Threshold
Data from the National Centre for Immunisation Research and Surveillance (NCIRS) reveals a significant backslide in vaccination coverage. For the first time in a decade, Australia's early childhood vaccination rate has fallen below the 95% threshold required for herd immunity against measles.
Nationally, coverage for two-year-olds has dropped to 89.7%. Furthermore, the number of children receiving their first MMR (measles, mumps and rubella) dose on schedule has fallen by 11.4 percentage points compared to pre-pandemic levels.
This immunity gap has collided with increased international travel, resulting in 168 confirmed measles cases in 2025. This represents a nearly threefold increase from the 57 cases recorded in 2024.
Multi-State Alerts for 'Boxing Day Cluster'
The situation escalated over the festive period, with a growing 'Boxing Day cluster' now linked to seven cases. Health departments in New South Wales and South Australia believe the cluster originated from a single infectious traveller moving through high-traffic public areas.
In South Australia, an infected adult visited Westfield Marion and Event Cinemas on Boxing Day, followed by Cockles Cafe in Port Elliot on 28 December. The trail continued when the person flew from Adelaide to Sydney on Qantas flight QF748 the following day, prompting urgent contact tracing of passengers and airport visitors.
New South Wales has confirmed three recent cases, all involving travellers returning from south-east Asia. Alerts are active for multiple locations in northern Sydney, including the Macquarie Centre, Waitara Family Medical Practice, Westfield Hornsby, and the emergency departments at both Hornsby Ku-ring-gai and Concord hospitals on specific dates.
Highly Contagious Virus Demands Vigilance
The Boxing Day cluster has also reached Western Australia, where two cases – including one child – have been confirmed. Victoria has reported a separate case involving an adult returning from Bali.
Authorities stress the extreme contagiousness of measles. The virus is highly airborne and can linger in a room for up to 30 minutes after an infectious person has left, making unvaccinated individuals highly vulnerable in shared spaces.
Health officials are urging all Australians to verify their vaccination status. Anyone born in or after 1966 who has not had two doses of the MMR vaccine is eligible for a free booster. Typical symptoms begin with a fever, cough, and runny nose, followed several days later by a distinctive red rash.
The rise in cases began before the holidays, with Western Australia recording a steady increase throughout December, reaching 60 cases for the year by late last month. Queensland also issued warnings in mid-December after an infectious traveller arrived on the Gold Coast from Bali.
