Measles cases have surged on a global scale in recent years, with an estimated 10.3 million cases reported worldwide in 2023, marking a 20 percent increase compared to 2022. Outbreaks have been documented across various regions including the United States, Europe, and the Western Pacific, which encompasses Australia.

For instance, Vietnam is facing thousands of cases as of 2024 and 2025.

In Australia, there have been 77 recorded cases of measles in the first five months of 2025, a rise from 57 cases reported in all of 2024. The majority of measles cases in Australia are associated with international travel, occurring primarily in individuals returning from abroad or through local transmission after contact with an infected traveler.

Measles, caused by the Morbillivirus, typically affects children and is preventable through vaccination, which is administered in Australia in two doses at 12 and 18 months.

The current global situation raises questions about the suitability of this vaccination schedule amidst increasing outbreaks.

The disease presents symptoms such as fever, cough, runny nose, and a characteristic rash.

While measles can be mild, it has the potential to cause severe health complications requiring hospitalization and can even be fatal.

Additionally, serious health impacts on the brain and immune system may occur years after the initial infection.

Transmission occurs through tiny respiratory droplets, making measles highly contagious; one infected individual can transmit the virus to 12 to 18 non-immune persons.

To combat the spread of measles effectively, the World Health Organization (WHO) advises that vaccination coverage needs to exceed 95 percent to achieve herd immunity.

Declines in vaccination rates, particularly in the aftermath of the COVID-19 pandemic, are contributing to the resurgence of outbreaks.

Typically, newborns receive passive protection against measles through maternal antibodies conveyed during pregnancy and breastfeeding.

The WHO recommends that children receive two doses of the measles vaccine, with the first dose ideally occurring around nine months in regions with significant measles transmission.

This timing is based on the assumption that maternal antibodies have diminished by that age.

However, if maternal antibodies are still present, the vaccination may not trigger a robust immune response.

Research indicates that administering the vaccine before 8.5 months can lead to a quicker decline in antibody levels.

Thus, the second dose, necessary for 10-15 percent of children who do not generate antibodies from the first dose, is crucial and is typically given 6–9 months following the initial administration.

In Australia, the measles-mumps-rubella (MMR) vaccine is routinely provided at 12 months of age, followed by the measles-mumps-rubella-varicella (MMRV) vaccine at 18 months.

Additional doses can be recommended for infants at higher risk, particularly during outbreaks or when traveling to areas with high transmission rates.

A recent study analyzing measles antibody levels in infants under nine months from low- and middle-income countries found that 81 percent of newborns had maternal antibodies, but this proportion dropped to only 30 percent by four months.

This suggests that maternal antibodies may wane sooner than previously recognized, questioning whether the current schedule still maximizes protection for infants in high-transmission environments.

While Australia maintains a vaccination coverage rate of over 92 percent for two doses of the MMR vaccine by age two, which is below the recommended 95 percent, the overall risk of measles outbreaks currently remains low.

The routine vaccination schedule in Australia—administering the first dose at 12 months and the second at 18 months—is unlikely to be altered.

However, there are discussions regarding the potential for broader availability of an early additional dose for children deemed at higher risk.

New Zealand, for instance, permits vaccination for infants as young as four months before travel to endemic regions.

Modifying Australia’s vaccination strategy would entail considerable logistical challenges and costs.

While lowering the age for the first dose may yield benefits in specific situations, it requires more evidence to ensure that such changes do not compromise long-term immunity against measles.

High vaccination rates remain a global priority, particularly for those born after 1966, who are recommended to receive two doses of the measles vaccine, as individuals born prior to the mid-1960s likely contracted the disease as children, providing them with natural immunity.

Individuals uncertain about their vaccination status can verify their records through the Australian Immunisation Register or seek advice from healthcare professionals.

Catch-up vaccinations are available under the National Immunisation Program.