US and Mexico near losing measles elimination status

A Pan American Health Organization advisory commission is meeting behind closed doors this week to decide whether measles is once more spreading continuously inside the United States and Mexico, a finding that would end the elimination status both countries hold.

The commission is examining genetic evidence to establish whether the same measles virus has circulated for a year or more in the outbreaks that began sweeping North America in 2024, according to an Associated Press report carried by WRAL. Its conclusions go to PAHO Director Dr Jarbas Barbosa, a former Brazilian health official, who makes the final determination. PAHO officials said an announcement is being scheduled for next week.

PAHO removed Canada's measles-free designation last year. Canada had held it since 1998.

"It's a big deal. The decision represents us moving backwards," said Dr David Margolius, director of Cleveland's health department and a leader in a coalition of big US city health departments.

"It's solely based on genetics," said Dr Amesh Adalja, an infectious disease doctor in the Pittsburgh area and a senior scholar at the Johns Hopkins Center for Health Security.

The United States reached elimination status in 2000, after vaccination campaigns pushed the childhood measles rate above 97%. Health experts say 95% coverage is needed so that an infected traveller entering a community does not spark an outbreak. The national rate fell to about 92% last year and is lower in some states and communities.

More than 5,100 confirmed cases have been recorded this year, already double the 2025 tally and driven largely by an outbreak in Pennsylvania. Eight measles-associated deaths this year are the most in more than three decades, and it is the worst year for measles illnesses since 1991. Outbreaks last year hit Texas, Arizona, Utah and South Carolina.

CDC Director Erica Schwartz said the designation would not change how federal officials are tackling the outbreaks. "The measles elimination designation is not what protects Americans. Vaccination does," she said in a statement. "Losing a designation doesn't mean we abandon an evidence-based approach."

Many public health experts say the moment demands a louder vaccination campaign and more guidance for doctors, and fault a muted federal response. They blame Health Secretary Robert F. Kennedy Jr., a leading voice in the anti-vaccine movement before President Donald Trump put him in charge of the country's health agencies. Kennedy has moved to shrink the childhood vaccination schedule, reshape a key vaccine advisory board and praised Trump's executive order calling for spacing out the MMR vaccine. Trump said earlier this year, without evidence, that the MMR vaccine is possibly "quite lethal".

Measles typically begins with a high fever and a rash that starts on the face and neck. Most people recover, but the World Health Organization lists it as one of the leading causes of death among young children, and serious complications including blindness and swelling of the brain are more common in the very young and in adults over 30.