Canada no longer considered Measles-Free

Canada no longer holds measles elimination status according to a statement issued by the Public Health Agency of Canada (PHAC). This outcome was expected as it has been unable to curb an outbreak that began in October 2024 and spread across Alberta, British Columbia, Manitoba, New Brunswick, Nova Scotia, Ontario, Prince Edward Island, Quebec, Saskatchewan and the Northwest Territories.

More than 5,000 notifications had been recorded as of November 1, 2025.

Because this multi-jurisdictional outbreak has continued for over 12 months, the Pan American Health Organization (PAHO) has confirmed that Canada no longer meets measles elimination criteria, citing sustained transmission of the same virus strain for more than a year.

PHAC is working with federal, provincial, territorial and community partners to increase vaccination coverage, strengthen surveillance and restore elimination status once transmission is interrupted for at least 12 months.

Active measles outbreaks across the Americas

According to the Pan American Health Organisation (PAHO), active outbreaks are continuing in several other countries including Mexico, the United States, Bolivia, Brazil, Paraguay and Belize. Most notifications are in unvaccinated individuals. Twenty-eight deaths have been recorded.

Measles notifications increasing in Australia - could we follow the same trend?

One hundred and thirty-eight cases of measles have been notified to Australia’s surveillance system up until 12 October this year (2025).  There were 43 notifications to this time in 2024.

Over 50 cases have been notified in the last quarter (to 12 October) and 9 cases from Western Australia for a single reporting period of just 2 weeks! This is very disappointing given the level of concern raised by the various state health authorities around Australia.

There were NO cases of measles reported between January 1, 2021, and 10 October 2021 when our international borders were closed!

Are we heading in the same direction as Canada and the United States or will our travellers heed the current warnings and make sure they are fully covered for measles before heading overseas.

Global surveillance and travel risk

This recent report from PAHO and those from European surveillance are important reminders to travellers who might be visiting countries with suboptimal vaccination coverage.  While the risk of exposure might be low in Australia and many other countries, it cannot be taken for granted, even in the Americas and Europe (particularly eastern Europe).

Measles is a highly infectious disease. Over 90% of non-immune individuals exposed to the disease will become symptomatic. 

The global risk of measles has increased over the last 2 years.

Who should check their measles immunisation status?

All travellers, particularly those born after 1966 should be assessed for their current measles immunisation status.  Special attention should be given to infants travelling to high-risk destinations.

Early waning of maternal antibody is an important concern.

Maternal measles antibodies play a very important role in protecting infants from an early bout of measles.  This transfer may not be achieved in premature infants and early measles protection must be considered if the child is at risk.  

The level of protection is also influenced by maternal immunity.  This immunity may be different in mothers with natural immunity and those with vaccine immunity.

In a longitudinal study of 221 infants and their mothers in Belgium, only 29% of the infants born to a vaccinated group were considered protected at 3 months compared to 60% in the naturally immune group.  By 6 months, only 1 out of 31 had protective levels versus 10 out of 41 for the naturally immune group.  Neither group showed immunity at 9 months. See the full study: Early waning of maternal measles antibodies in era of measles elimination: longitudinal study.

It should be noted that mothers with vaccine immunity might receive natural boosting in countries where measles transmission persists.  In those countries where transmission has been interrupted (Australia) natural boosting doesn’t occur.  

Vaccination of infants over 6 months must be a consideration when travelling overseas.

Recommendations for infants, children and adults

• Infants 6–11 months of age should be considered for at least one dose of measles containing vaccine. Most mothers of today have vaccine immunity rather than natural immunity. This provides protection for a shorter period. 
• Preschool children ≥12 months of age should have two doses of MMR vaccine separated by at least 28 days.
• School-age children should have two doses of MMR. 
• Adults born in or after 1966 should have two doses of measles-containing vaccine.
• If administered at ≥12 months of age, one dose of measles-containing vaccine or MMR is 95% effective in preventing measles disease and two doses are 99% effective. One dose of measles-containing vaccine or MMR is approximately 85% effective if administered at 9 months of age.