The US declared measles gone in 2000. Next week it may be told the virus has moved back in

Twenty-six years after the United States declared measles eliminated, a group of experts is deciding whether the virus has quietly re-established itself.

The Pan American Health Organization’s Regional Monitoring and Re-Verification Commission began its annual meeting in Washington on Tuesday and sits until Friday, US time. It is reviewing measles reports from all 35 member countries in the Americas, covering 2025 and the first half of 2026, and will make recommendations country by country.

PAHO director Jarbas Barbosa makes the final decision. US Centers for Disease Control and Prevention director Erica Schwartz has said she expects it early next week.

Three countries are under the closest watch: the United States, Mexico and Guatemala. Peru and Bolivia are also considered at risk.

What would actually change?

On paper, very little at first. Elimination status is a public health milestone, not a legal trigger. Dr Schwartz has said that if the US loses it, the CDC will keep “doing the same exact thing that we’ve been doing today”.

What it would signal is bigger. Losing the status means health authorities accept that measles is no longer just arriving with travellers and fizzling out, but circulating continuously inside the country, the same way it did before mass vaccination.

“It would be a disappointment, not a shock,” said Matt Ferrari, an epidemiologist at Penn State University.

How bad is it?

PAHO has counted 57,666 confirmed measles cases in 17 countries and territories across the Americas between January and October 2026. In the US, nearly 7,500 cases and 11 deaths have been reported since President Donald Trump began his second term in early 2025.

The US Department of Health and Human Services, led by Robert F. Kennedy Jr., has said national vaccination rates were already falling before Mr Kennedy took office.

“Whether or not the US loses its measles elimination status, we have a huge problem with measles,” said Noel Brewer of the University of North Carolina, who chairs an independent US vaccine advisory panel.

Has anyone won it back?

Yes, and it takes years. Brazil lost its elimination status in 2019 and regained it in 2024 after a sustained vaccination drive. Canada lost its status in November 2025, after the virus had circulated there for more than 12 months.

What does this mean for Australians?

Measles is one of the most contagious diseases known, and Australia, which the World Health Organization verified as having eliminated measles in 2014, keeps that status largely by stopping chains of infection that start with travellers. More countries where the virus circulates freely, including the United States, which hundreds of thousands of Australians visit each year, raises the odds of more imported cases.

The practical step for travellers is the same as it has always been: check that you have had two doses of a measles vaccine before you fly, and see a doctor if you are unsure.