Measles Makes a Troubling Comeback in the Americas: A Public Health Crisis Unfolding
After decades of progress in combating one of the world’s most contagious diseases, measles is resurging across the Americas, threatening to undo years of public health achievements. The United States, long considered a global leader in disease control, now faces the potential loss of its measles elimination status—a prestigious designation granted by the World Health Organization that signifies the virus is no longer circulating widely within a country’s borders. This alarming development follows Canada’s recent loss of the same status, highlighting the fragility of public health victories against highly infectious diseases.
The concept of measles elimination represents a significant public health achievement, requiring sustained vaccination efforts and vigilant monitoring. A country is considered measles-free when the virus hasn’t continuously spread among residents for at least 12 months, though imported cases—where someone contracts measles elsewhere and brings it into the country—can still occur without affecting this status. The Americas made history in 2016 by becoming the first WHO region to eliminate measles across all its countries, a remarkable accomplishment that demonstrated what coordinated public health campaigns could achieve. However, this triumph proved short-lived when an outbreak in Venezuela stripped the region of its status in 2018, later spreading to Brazil. Though Venezuela reclaimed its elimination status in 2023 and Brazil followed in November 2024, the regional celebration was cut short by Canada’s announcement.
In October 2024, Canada experienced a measles outbreak that continued for more than 12 months, forcing the Public Health Agency of Canada to announce on November 10 that the country had lost its elimination status. Now, the United States faces a similar threat, with a deadline of January 20, 2026—one year after an outbreak began in West Texas—to bring cases under control. The situation has become increasingly dire, with the CDC documenting 1,753 measles cases and three deaths across 42 states in 2025 alone. Most concerning is that over 90 percent of these cases occurred in unvaccinated individuals, pointing to declining immunization rates as a key factor in the virus’s resurgence.
For public health experts who dedicated their careers to eradicating measles, this reversal is deeply troubling. Dr. William Schaffner, an infectious diseases physician at Vanderbilt University, describes the potential loss of elimination status as “a source of great embarrassment.” Having worked to demonstrate that measles could be eliminated from large geographical areas, Schaffner finds it disheartening to “seemingly turn back the clock and start all over in trying to convince parents that vaccinating their children is very, very important.” The situation represents not just a setback for public health statistics, but a real threat to vulnerable populations.
The importance of measles elimination extends far beyond public recognition or statistical achievements. Measles is extraordinarily contagious, requiring approximately 95 percent of a community to be vaccinated or have immunity from previous infection to prevent spread. This high threshold for community protection makes vaccination especially critical for protecting those who cannot receive vaccines, such as infants under one year old. As Dr. Daniel Salas, executive manager of the Special Program for Comprehensive Immunization at the Pan American Health Organization, explains, even if a country’s entire population isn’t affected by an outbreak, “it’s going to affect some communities, some people, some families.” These impacts can be severe—about one in five unvaccinated people who contract measles in the United States require hospitalization, with some developing serious complications including pneumonia, vision loss, or even deadly brain inflammation that may appear years later. The virus can also cause immune amnesia, effectively erasing the body’s protection against other diseases and leaving patients vulnerable to secondary infections.
The outbreak in West Texas provides a sobering illustration of measles’ destructive potential, with more than 700 cases and two children losing their lives. Dr. Pedro Piedra, a pediatric infectious diseases physician at Baylor College of Medicine, puts this in perspective: “Now think about having millions of children get measles… numbers can escalate very quickly with regards to hospitalization, severity of disease and death.” While vaccination remains the most effective tool for controlling measles, public health officials must contend with both vaccine hesitancy and logistical challenges in delivering immunizations to those who need them most.
Addressing these challenges requires identifying and overcoming the barriers that prevent children from receiving vaccines. Sometimes these are geographical—long distances to health centers—while in other cases, they involve language barriers or cultural and religious beliefs. Community leaders working alongside health experts can help navigate these complex factors, but convincing people of the importance of vaccination has become increasingly difficult as the devastating effects of measles fade from public memory. As Schaffner notes, “If every parent had their eligible children vaccinated very quickly… these outbreaks of measles that we have around the country would be snuffed out immediately. That’s how good this vaccine is, if it’s used.”
Looking ahead, the question becomes whether occasional measles outbreaks will become the new normal. As long as the virus persists somewhere in the world, countries that have achieved elimination remain at risk of imported cases triggering new outbreaks, particularly in communities with low vaccination rates. Only global eradication—completely stopping the virus from infecting anyone anywhere—would permanently end this threat. The statistics paint a concerning picture: while the Americas accounted for just 0.1 percent of global measles cases in 2024, that figure has jumped to more than 7 percent in 2025. “This is alarming for the Americas,” Salas warns. “Because of [ongoing outbreaks] we have increased the percentage of cases globally.”
The situation creates a paradox where vaccines have been so successful that many people have forgotten what they’re being protected against. As Piedra aptly compares it, preparing for measles is like preparing for a hurricane: “You know the strength of a hurricane, but you don’t want to have to go through that to [know that you need to] prepare your home for the possibility of such strong winds.” With vaccination rates declining, the threat continues to grow. That the United States stands on the brink of losing its measles elimination status represents, in Piedra’s sobering assessment, “basically a failing grade for our health care system, for the protection of our children.”
