In a closed-door session this week, a Pan American Health Organization advisory commission is weighing genetic evidence that could strip the United States and Mexico of their measles elimination status. The question turns on a simple but grave fact: whether one strain of the virus has kept circulating for a year or more since outbreaks began across North America in 2024. Measles had been driven back for decades by vaccination, and its return reflects how fragile that protection becomes when childhood immunization rates quietly slip. A final decision rests with PAHO's director and is expected n
US and Mexico Face Loss of Measles Elimination Status as PAHO Experts Convene
Measles has caused about a dozen deaths in the U.S. in two years and at least 50 deaths in Mexico, mostly children under 5, with over 20,500 confirmed cases in Mexico.
Vaccination, not the designation, protects Americans, the CDC director said.
Mark
Why does a label like "elimination status" matter if the outbreaks are happening either way?
Mimi
It's a formal statement that the virus is no longer living in the country, only arriving from outside. Losing it says measles is now spreading here continuously. Dr. Margolius called that moving backward.
Luke
Has the decision been made yet?
Mimi
No. The commission is reviewing genetic evidence, and Director Jarbas Barbosa makes the final call. An announcement is being scheduled for next week.
Luke
So the loss is expected, not confirmed. The source says experts expect it, and that's all.
Mark
What exactly is the commission looking at?
Mimi
Whether the same virus has circulated for a year or more. Dr. Adalja said it's solely based on genetics.
Mark
The CDC says the designation doesn't matter much. Is that fair?
Mimi
Director Erica Schwartz said vaccination protects people, not the label. Critics answer that the moment calls for a louder campaign, and they fault Kennedy's moves on the vaccine schedule.
Luke
Keep in mind that the claim that spacing out the MMR shots would reduce full vaccination is the experts' projection, not a measured result. And the criticism of a muted federal response is attributed to critics, not established fact.
Mimi
Fair. What is measured is the drop to about 92% childhood vaccination, below the 95% experts say is needed.
Mark
And Mexico's numbers?
Mimi
More than 20,500 confirmed cases and 50 deaths, mostly children under 5. The link to the Texas outbreak through a Chihuahua child is what researchers think happened, not something proven.
O Pulso
- A PAHO advisory commission is poring over genetic data to decide whether a single measles strain has spread unbroken for a year or more across North America.
- The U.S. has logged over 5,400 cases this year, its worst measles season since 1991, with eight deaths and vaccination rates sliding toward 92%.
- Mexico has reported more than 20,500 confirmed cases and at least 50 deaths, most of them children under five, as the outbreak tore through its northern border.
- Federal officials insist the designation changes nothing about their response, while doctors and city health leaders call the expected loss a step backward.
- PAHO Director Jarbas Barbosa holds the final call, with an announcement expected next week that could confirm the return of sustained measles transmission.
In a closed-door session this week, a Pan American Health Organization advisory commission is weighing genetic evidence that could strip the United States and Mexico of their measles elimination status. The question turns on a simple but grave fact: whether one strain of the virus has kept circulating for a year or more since outbreaks began across North America in 2024. Measles had been driven back for decades by vaccination, and its return reflects how fragile that protection becomes when childhood immunization rates quietly slip. A final decision rests with PAHO's director and is expected next week, a moment that measures how far a once-conquered illness has crept back into daily life.
This week, behind closed doors, an advisory commission of the Pan American Health Organization is examining genetic data that could decide whether the United States and Mexico still count as places where measles has been eliminated. Experts widely expect the answer to be no. The central question is whether the same virus has circulated continuously for a year or more through the outbreaks that have spread across North America since 2024.
The United States earned its status in 2000, after vaccination campaigns lifted childhood coverage above 97%. That protection has eroded for years, partly through discredited claims linking vaccines to autism, and national coverage has fallen to about 92%, with far lower rates in some communities. The results have been stark. This year's more than 5,400 confirmed cases already double last year's total, driven largely by a large outbreak in Pennsylvania, and eight people have died, the most in more than three decades.
Mexico's toll is heavier still. Cases surged early last year, and researchers believe the outbreak in Chihuahua began when an unvaccinated child traveled to an outbreak in Texas and came home infected. More than 20,500 cases have been confirmed there, along with at least 50 deaths, most of them children under five.
CDC Director Erica Schwartz says the designation will not change federal outbreak response, and that vaccination itself is what protects people. Many public health experts want a far more aggressive push for vaccination and clearer guidance for doctors, and they criticize a federal response they see as muted and politically fraught. The next marker is PAHO's announcement next week.
This week, in a closed-door session, an advisory commission of the Pan American Health Organization is going through genetic data on measles. The question before it is whether the United States and Mexico still count as countries that have eliminated the disease. Experts expect the answer to be no.
The commission is looking at whether the same strain of measles virus has been spreading continuously for a year or more in the outbreaks that have moved through North America since 2024. Dr. Amesh Adalja, an infectious disease physician in the Pittsburgh area and a senior scholar at the Johns Hopkins Center for Health Security, said the call rests solely on genetics. If the evidence shows a year of continuous spread, the commission will find that the virus has returned to sustained circulation. It will give that finding to PAHO Director Dr. Jarbas Barbosa, a former Brazilian health official, who makes the final determination. PAHO officials say an announcement is being scheduled for next week. Last year, the organization took away Canada's measles-free designation, which that country had held since 1998.
The U.S. earned its status in 2000, after decades of vaccination campaigns pushed childhood vaccination above 97%. Health experts say 95% coverage is what's needed so that an infected traveler arriving in a community meets so many vaccinated people that no outbreak starts. Rates have slipped for years, partly because of disproven claims linking the vaccine to autism. Last year the national childhood rate fell to about 92%, and it was far lower in some states and communities. Earlier this year, President Donald Trump said, without evidence, that the MMR vaccine is possibly "quite lethal."
The outbreaks followed. Measles spread widely last year in Texas, Arizona, Utah and South Carolina. This year's more than 5,400 confirmed cases are already double the 2025 total, driven largely by an outbreak in Pennsylvania that has dwarfed the earlier ones. The U.S. has recorded eight measles-associated deaths this year, the most in any year in more than three decades, and it is having its worst year for measles illness since 1991. Over the past two years, about a dozen people have died in the U.S. Before that, deaths from measles were virtually unheard of.
Mexico's toll is heavier. Its vaccine arrived years after the first one was licensed in the U.S. in 1963, and it did not reach elimination status until 2016. Cases began surging early last year. Researchers think the outbreak in the northern border state of Chihuahua began when an unvaccinated Mennonite child from there traveled to Gaines County, Texas, where an outbreak was under way, and returned infected. As of this week, Mexico has reported more than 20,500 confirmed cases and 50 measles-related deaths, most of them children younger than 5. Early this year, the World Health Organization confirmed that Armenia, Austria, Azerbaijan, Spain, the United Kingdom and Uzbekistan had also lost their status.
CDC Director Erica Schwartz said this week that losing the designation will not change how federal officials handle outbreaks. In her statement she said vaccination, not the designation, protects Americans, and that the agency knows where transmission is happening and is working with state and local health departments to reach those communities. Many public health experts want more than that. They call for a stepped-up campaign promoting vaccination and more guidance for doctors, and they fault what they describe as a politically fraught, muted federal response. They blame Health Secretary Robert F. Kennedy Jr., a leading anti-vaccine voice before Trump put him in charge of the nation's health agencies. Kennedy has moved to shrink the childhood vaccination schedule and reshape a key vaccine advisory board, and he has praised Trump's executive order calling for spacing out the measles, mumps and rubella vaccine. Experts say that runs counter to medical groups' recommendations and would likely leave fewer children fully vaccinated.
Dr. David Margolius, director of Cleveland's health department and a leader in a coalition of big-city health departments, called the expected decision "a big deal" and said it represents moving backward. The next marker is PAHO's announcement next week.
Citações Notáveis
The measles elimination designation is not what protects Americans. Vaccination does.— CDC Director Erica Schwartz
It's a big deal. The decision represents us moving backward.— Dr. David Margolius, director of Cleveland's health department
Quer a matéria completa?
Leia o original em The Boston Herald ↗