By Jennifer Rigby and Julie Steenhuysen
LONDON/CHICAGO, Nov 11 (Reuters) - Global health experts will determine in the coming days whether the United States has lost its official measles-free status, a public health achievement it has held since 2000 now in jeopardy after outbreaks across the country sickened thousands of Americans.
The decision by the Pan American Health Organization poses a new test for the Trump administration and its top health official, Robert F. Kennedy Jr., who has for years
spread doubts, without scientific evidence, about the safety of measles vaccines.
Public health experts say his actions as US health secretary to reduce the number of childhood immunizations have increased vaccine hesitancy and fueled the country's highest infection rate in more than three decades.
PAHO asked all 35 member states in the Americas to submit measles status reports for review by a panel of outside experts. They will make their recommendations during closed-door deliberations in Washington, where their annual meeting convenes through November 13. Mexico and Bolivia are also on the watch list due to prolonged outbreaks, a PAHO spokesperson said by email on Tuesday.
PAHO Director Jarbas Barbosa will then make the final decision on each country's status and communicate that to the relevant authorities, the spokesperson said. The determination is expected to be made public early next week.
"It feels really concerning, as though everything is falling apart. The US was held up as a model for a lot of vaccine programs," said Helen Bedford, professor of children's health at University College London, who has advised the UK government on vaccination.
"But measles is definitely back in the United States," she said. "And it will take a lot of work to reverse that. And it is tragic, because it's children who are going to suffer at the end of the day."
The US Department of Health and Human Services said in a statement that national vaccination rates declined before Kennedy took office. Dr Erica Schwartz, director of the US Centers for Disease Control and Prevention, this week said the agency works closely with US states to contain outbreaks, with a focus on communities where immunizations have trended lower for decades.
If the US loses its measles-free status, she said, "we're going to be doing the same exact thing that we've been doing today." That includes "reemphasizing that the number one way to prevent measles is the MMR (combined measles, mumps and rubella) vaccine."
MEASLES RISE IN THE US
Since President Donald Trump took office for the second time in early 2025, nearly 7,500 US measles cases and 11 deaths have been reported by state and federal health officials. The highly contagious virus commonly causes symptoms including high fever and a rash, and can lead to serious long-term complications as well as death.
PAHO experts will consider whether US measles transmission has continued uninterrupted for 12 months or longer, based on epidemiological and laboratory evidence.
“Whether or not the US loses its measles elimination status, we have a huge problem with measles,” said Noel Brewer, a public health professor at the University of North Carolina who also chairs an independent US advisory panel on measles.
Brewer presented the CDC's measles status report, and his group's assessment of that information, to PAHO experts on Tuesday. He would not provide details.
Despite efforts by state and federal disease fighters to contain the outbreaks, US infections have more than doubled this year compared to 2025. Based on publicly available data, the Arizona-Utah outbreak, which began in June 2025 and is still going, likely meets that criteria, Brewer said.
Canada, Spain and the UK recently lost measles-elimination status after review by World Health Organization experts. The US dropped out of WHO but remains a member of PAHO, its Americas branch.
Demetre Daskalakis, a former top CDC official who resigned after Kennedy took office, said losing the measles-free status would be a sign of a broader dismantling of the nation's public health system.
“Measles is the great indicator of where the cracks are in our foundation,” he said.
(Reporting by Jennifer Rigby and Julie Steenhuysen; Editing by Michele Gershberg and Bill Berkrot)
