Canada achieved measles elimination status in 1998. Now, it could lose it

Canada is facing a growing measles outbreak that threatens the country’s measles elimination status set by the World Health Organization. Dr. Sarah Wilson, a public health physician with Public Health Ontario, warns that the risk of losing elimination status is substantial. Ontario is reporting more measles cases weekly than it did over an entire decade prior to the outbreak.

Measles elimination is achieved when a virus is no longer circulating regularly in a specific country or region. It is different from eradication, which occurs when person-to-person transmission is eliminated globally. If sustained transmission of the virus continues for one year or more, a country can lose its elimination status.

The Canadian measles outbreak began in October 2024, and if transmission continues until October 2025, the Pan American Health Organization (PAHO) may revoke Canada’s elimination status. Canada currently has the highest number of measles cases in the Americas, with Ontario and Alberta being the most affected provinces.

Losing elimination status may not directly impact Canadians’ daily lives, but it would signify a setback in the fight against a preventable disease like measles. Dr. Santina Lee, a pediatric infectious disease specialist, emphasizes the importance of using available tools, such as vaccines, to control and prevent the spread of the virus.

PAHO is responsible for verifying measles elimination status in the Americas, a region that was the first in the world to achieve elimination in 2016. However, outbreaks in countries like Venezuela and Brazil led to the loss of elimination status, which was later regained in 2024. Brazil successfully controlled its outbreak through targeted vaccine campaigns and rapid response measures.

Dr. Daniel Salas from PAHO expresses concerns about the potential loss of elimination status in Canada and the increased risk it poses to the region. Measles can have severe consequences, particularly for vulnerable populations, including children under five years old. Vaccination plays a crucial role in preventing measles-related deaths and complications.

Despite the challenges posed by the ongoing outbreak, Canada is preparing for the verification process to regain its elimination status. Dr. Marina Salvadori, a senior medical advisor at the Public Health Agency of Canada, believes that with continued vaccination efforts, Canada can reverse course and achieve herd immunity. However, vaccination rates in Canada have declined in recent years, highlighting the importance of reaching a 95% immunization rate to protect the population effectively.

Cases of measles are primarily affecting unvaccinated or under-vaccinated individuals, making it challenging to control the spread of the virus. Public health officials in affected provinces like Manitoba are expanding vaccine eligibility to curb the outbreak. Dr. Lee emphasizes the importance of addressing vaccine hesitancy and having conversations to understand and address concerns.

In conclusion, Canada’s measles outbreak poses a significant threat to the country’s elimination status. By prioritizing vaccination efforts and addressing vaccine hesitancy, Canada can work towards regaining its measles elimination status and protecting the population from this highly contagious and dangerous virus.