North America is experiencing a significant resurgence of measles, with over 2,500 confirmed cases and four reported deaths across the United States, Canada, and Mexico in 2025. Health experts attribute this surge to declining vaccination rates, increased cross-border travel, and the erosion of herd immunity.
Key Factors Contributing to the Outbreak
- Declining Vaccination Rates In the United States, measles vaccination coverage has dropped below the critical 95% threshold required for herd immunity, with current estimates around 91%. Approximately 96% of those infected in the U.S. were unvaccinated. Mexico has also seen a decline in vaccination rates, with only 76% of children under two receiving the measles vaccine in 2023. This decrease has contributed to a sharp rise in cases, particularly in the northern state of Chihuahua.
2. Cross-Border Transmission
The mobility of populations across borders has facilitated the spread of measles. Notably, interconnected Mennonite communities in Canada, the U.S., and Mexico have been identified as significant vectors for transmission due to low vaccination uptake.
3. Erosion of Herd Immunity
Experts warn that the current situation may indicate a global loss of herd immunity to measles. Dr. Paul Offit, a leading immunologist, emphasized that measles is the first vaccine-preventable disease to reappear as communal immunity weakens.
Impact by Country
- United States: The U.S. has reported 935 measles cases in 2025, the highest in 25 years, with Texas being the epicenter. Three deaths have been reported, all among unvaccinated individuals.
Canada: Canada has experienced over 730 cases, marking one of the worst outbreaks since measles was declared eliminated in 1998.
Mexico: Mexico has reported at least 360 cases and one death, with the majority occurring in Chihuahua state. The outbreak has prompted the Mexican Ministry of Health to issue a travel advisory for the U.S. and Canada.
Public Health Responses
Vaccination Campaigns: Mexico has launched a National Vaccination Week to immunize 1.8 million children.
Travel Advisories: Mexico’s health authorities have advised travelers to the U.S. and Canada to ensure they are vaccinated against measles.
International Cooperation: Health departments across North America are collaborating to contain the outbreak, emphasizing the importance of maintaining high vaccination coverage.
Conclusion
The resurgence of measles in North America underscores the critical importance of maintaining high vaccination rates to preserve herd immunity. Public health officials urge individuals to ensure they are up-to-date with their measles vaccinations to prevent further spread of this highly contagious disease.
Source; Al Jazeera
