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There have been significant outbreaks of measles in Australia in 2025, predominantly in NSW, Victoria and WA.
Australia is one of many countries globally that are falling short of optimal MMR vaccine coverage.
Cases relating to travel to areas with higher rates of measles infection continue to be reported, with recent cases in SA and WA being linked to travel to South-East Asia.
Early vaccination of infants travelling to high-risk regions can be considered, with Australian guidelines supporting vaccination from six months, and some expert discussion about vaccination from as early as four months.
The pros of earlier protection from potentially lethal infection must be weighed against the cons of possible reduced immune response to future MMR vaccines.
It is important to also ensure appropriate coverage has been provided to adult travellers to areas of risk.
Exposure can occur with travel to a high-risk destination. age. For example, a study from the Netherlands found that children vaccinated before 8.5 months of age exhibited faster antibody decay and lost their protective neutralising antibody levels over six years. This led the authors to conclude that routine vaccination of infants under 8.5 months of age may lead to blunted measles-specific antibody responses to subsequent MMR vaccination. 10 Possible explanations are suboptimal vaccine response at a younger age and / or persisting maternal measles antibodies that may interfere with vaccine response.
In relation to children aged less than 12 months and travel, the Australian Immunisation Handbook states that“ infants travelling to countries where measles is endemic, or where measles outbreaks are occurring, may receive [ the ] MMR vaccine from as young as six months of age, after an individual risk assessment”.
A case for early vaccination
Dr Myra Hardy, a paediatric infectious diseases physician and postdoctoral researcher in the Tropical Diseases group of the Infection, Immunity and Global
Health research area at Murdoch Children’ s Research Institute, made the case for considering earlier immunisation at the Southern Cross Australasian Travel and Tropical Medicine Conference held in Melbourne in September 2025.
One of the questions raised by Dr Hardy was: are infants aged under six months really protected by maternal antibodies? The answer seems to be,
frequently not. A systematic review conducted in low- and middle-income participants found measles antibody seroprevalence declined to 30 % at four months and 18 % at seven months. 11 This implies that children aged under six months can be susceptible to infection if travelling to an at-risk destination. The consequences of measles infection can be devastating. In addition to SSPE, other serious complications include pneumonia and encephalitis. 12
Given this, Dr Hardy questioned whether we should be recommending the first dose of MMR earlier than six months if children are travelling to areas of risk. Reasons not to do so include the possibility of reduced long-term immunity, even after boosting, but the counter argument
In addition to sub-acute sclerosing panencephalitis, other serious complications include pneumonia and encephalitis.
is the need to provide timely protection from this potentially fatal disease in settings of increased risk. Of note, in New Zealand the recommendation is that the first dose of MMR can be given from four months if the child is travelling to a measles endemic country. This recommendation followed a major outbreak in 2019-20, which infected more than 2000 people in
New Zealand and spread to Samoa, where 5705 cases and 83 deaths occurred. 13
In practice
Discussion among local travel medicine-interested practitioners following Dr Hardy’ s presentation demonstrates that a substantial number of the Australian-based practitioners are presently offering off-label measles immunisation to children from the age of four months based on individual risk assessment and with informed consent from the parents. The cost to the family is $ 25- $ 30 per dose.
Do not neglect the adults
It is also important to remember and check MMR vaccination status for adult travellers. The Australian recommendation is that travellers born during or since 1966 should have received two doses of measles-containing vaccine. In New Zealand, that recommendation is also for two doses of measles-containing vaccine, but for adults born on / after 1 January 1969. 13
References on request from kate. kelso @ adg. com. au