In recent years, the Americas had proudly maintained a measles-free status, a milestone that underscored the success of vaccination programs and public health efforts across the continent. However, alarming developments now threaten to reverse this hard-won achievement. As of late 2025, health authorities are confronting a resurgence of measles in North America that could soon result in the loss of the region’s measles elimination status. This troubling trend has prompted urgent discussions by the Pan American Health Organization (PAHO) to evaluate the current situation and determine the future of measles control in the region.
Measles elimination status is a significant public health designation indicating that a country or region has interrupted endemic transmission of the measles virus. Specifically, a country is considered to have endemic measles if there is uninterrupted transmission from a single outbreak lasting 12 months or longer. PAHO’s regional verification commission, which rigorously reviews epidemiological and molecular data, vaccination coverage, surveillance systems, and the ability to detect and respond to cases, uses this criterion to evaluate countries’ statuses. If uninterrupted transmission is confirmed, a country loses its elimination status, signaling that the virus is now entrenched within its population.
Canada is currently on the brink of losing this status. Since October 2024, the country has experienced a single measles outbreak with over 5,100 reported cases, far surpassing the threshold that defines endemic transmission. This surge has raised alarms not only within Canada but also across North America. Meanwhile, the United States faces a precarious situation. Earlier in 2025, a significant outbreak in West Texas resulted in 762 cases and was declared over by mid-August. However, ongoing outbreaks in South Carolina and Utah remain under investigation. Should these later outbreaks be linked to the original Texas cases, and if transmission continues beyond January 2026 without containment, the U.S. too risks losing its measles-free status.
This potential loss is particularly concerning given the history of measles control in the Americas. Canada first eliminated measles in 1998, and the United States followed in 2000. By 2016, the entire region was declared measles-free, a landmark achievement in infectious disease control. However, this status was compromised when outbreaks emerged in Venezuela in 2017 and Brazil in 2018, both of which eventually interrupted transmission and restored the region’s measles-free status by late 2024. The current outbreaks in Canada and the U.S. threaten to undo these recent gains, highlighting the fragile nature of disease elimination.
The consequences of measles resurgence are grave. Measles is a highly contagious viral disease that can cause severe complications, including pneumonia, hearing loss, and encephalitis—a dangerous brain inflammation that occurs in approximately one in every 1,000 cases and can result in permanent brain damage or death. In the U.S. alone, over 1,600 measles cases and three confirmed deaths have been recorded in 2025. Experts emphasize that these outcomes are preventable with adequate vaccination coverage.
The resurgence is primarily attributed to gaps in vaccination coverage. Measles is among the most contagious infectious diseases known, with an unvaccinated individual capable of infecting 12 to 18 others. Even with about 84 percent vaccine coverage, each case can still spawn two to three new cases—levels of transmissibility comparable to seasonal influenza or the initial COVID-19 variants. To halt transmission and achieve herd immunity, approximately 95 percent of the population must be vaccinated. Unfortunately, in certain communities, vaccine hesitancy and access issues have resulted in coverage falling short of this threshold.
Public health experts stress that increasing vaccination rates is the key to reversing the trend. Strategies to improve coverage include expanding access to vaccination clinics, enhancing public awareness, and ensuring timely reminders for vaccine schedules. Healthcare providers, including pediatricians and family doctors, play a critical role in addressing parental concerns and misinformation that contribute to vaccine hesitancy. Without these concerted efforts, outbreaks will continue to threaten public health.
The economic case for vaccination is compelling. Kimberly Thompson, founder of Kid Risk, a nonprofit specializing in pediatric risk analysis, estimates that the economic benefits of measles and rubella vaccinations in the U.S. range between $310 billion and $430 billion in avoided treatment costs alone. These figures exclude the additional gains from increased productivity as children and parents miss fewer days of school and work. The return on investment in vaccination programs thus extends far beyond immediate