York Region Public Health Declares Local Measles Outbreak Over

On November 19, 2025, York Region Public Health officially declared the local measles outbreak in the City of Vaughan (Thornhill) over. During the outbreak, which began on September 4, 2025, York Region Public Health investigated nine confirmed cases of measles. There have been no new linked cases of measles in York Region since October 4, 2025.

The local outbreak in York Region was not linked to the large provincial outbreak declared over by the Province of Ontario on October 6, 2025. The Ontario outbreak had 2,375 cases, including 51 pregnant individuals and resulting in nine infants being born with measles, putting them at risk of hearing loss and lasting brain impacts, and one infant dying from this preventable infection.

On November 10, 2025, the World Health Organization officially revoked Canada’s measles elimination status. This is a significant loss after 27 years of maintaining this designation. The highly effective vaccination program allowed us to maintain measles elimination status by preventing ongoing spread of the virus within our borders. With elimination status, cases imported from travel can still occur, but with enough vaccine coverage, they would not spark local outbreaks. Unfortunately, this protection has now diminished in our country, resulting in locally spread infections because not enough people have received this safe and effective vaccine.

Although York Region and Ontario outbreaks are now over, other provinces are still reporting new cases of measles. The virus can also be contracted when traveling to areas where measles is circulating.

Measles is a highly contagious viral infection that spreads very easily through airborne transmission. Getting vaccinated is the best way to protect yourself against measles. The vaccines that protect against measles have been in use for over 50 years and after two doses is over 97% effective in preventing infection. Residents are reminded to ensure their immunization records are up to date.

The measles (MMR) vaccine is free and available to those who are eligible or overdue. If you do not have a primary care provider, York Region Public Health offers measles vaccination appointments for individuals aged 12 months to 55 years old.

For more information or to book a vaccination appointment visit york.ca/Measles.