Tracking Emerging Public Health Challenges – November 30, 2025 – Measles
“The surging number of measles cases around the world is a stark warning sign that outbreaks of other vaccine-preventable diseases could be next, the World Health Organization warned Friday.
“It’s crucial to understand why measles matters,” said Dr. Kate O’Brien, director of the WHO’s Department of Immunization, Vaccines and Biologicals. “Its high transmissibility means that even small drops in vaccine coverage can trigger outbreaks, like a fire alarm going off when smoke is detected first.”
That is, measles is often the first disease to pop up when vaccination rates overall drop.
“When we see measles cases, it signals that gaps are almost certainly likely for other vaccine-preventable diseases like diphtheria or whooping cough or polio, even though they may not be setting off the fire alarm just yet,” O’Brien said at a media briefing Monday, ahead of the release of the WHO’s Progress Toward Measles Elimination report, published Friday in its Weekly Epidemiological Record.” (1)
“In the wake of a measles outbreak in Canada that has infected thousands of people over the past year, an international health agency revoked the country’s measles-free status on Nov. 10, 2025.”
“The Pan American Health Organization, which serves as the World Health Organization’s regional office for the Americas, made this announcement after the agency’s measles
After having only 16 total cases of measles nationwide between 2020 and 2023, the number of measles cases in Canada jumped to more than 100 in 2024 and more than 5,000 cases in 2025.”
“The World Health Organization uses three labels to describe how well a country is preventing the spread of infectious diseases such as measles. A disease is said to be controlled when public health interventions such as routine childhood vaccinations significantly lower the rate of new infections. A disease is considered to be eliminated from a country when the only cases that happen are small outbreaks linked to international travel. And finally, a disease is deemed eradicated only after several years of no cases occurring anywhere in the world.
To achieve the status of measles elimination, a country must have no ongoing local transmission of the disease for at least one year. It will lose that status if it has a chain of cases that spread from person to person for more than one year.
Once a country has eliminated measles, there is almost no risk from the disease as long as vaccination rates stay high. But when vaccination rates drop, outbreaks will soon start happening.” (2)
Winning against measles: five charts that tell a remarkable 24-year story, by Linda Geddes, https://www.gavi.org/vaccineswork/winning-against-measles-five-charts-tell-remarkable-24-year-story
Measles deaths down 88% since 2000, but cases surge, https://www.who.int/news/item/28-11-2025-measles-deaths-down-88–since-2000–but-cases-surge
“A World Health Organization (WHO) report sets out how far the world has come in tackling measles over the past 24 years.
During that time, Gavi, the Vaccine Alliance, has helped to put measles vaccines within the reach of hundreds of millions of children, helping lower-income countries to build and strengthen routine immunisation, run preventive campaigns and quash outbreaks.
Yet the disease hasn’t gone away. Global coverage with measles vaccines still falls short of the 95% needed to halt transmission and outbreaks continue to flare – not only in the lowest-income settings, but also in wealthier countries where immunity has frayed.
The data shows elimination of measles is possible, but only if coverage gaps are closed everywhere.
Here, we chart the trajectory of measles in the first quarter of the 21st century – and the challenges that remain.” (4)
“A measles outbreak in Arizona and Utah shows no sign of slowing, putting the United States dangerously close to losing its elimination status for the vaccine-preventable disease.
With holiday travel and gatherings approaching, doctors worry that transmission could escalate. If measles continues to spread through Jan. 20, that will mark a year of sustained transmission in the United States. At that point, the disease would no longer be considered eliminated and it would instead revert to being endemic, or constantly present.
The backward step seems highly likely.
“These pockets of communities that have low vaccination rates — if we’re not able to get them vaccinated before the holidays, we are very much at risk of going into 2026 and losing U.S. measles elimination status,” said Dr. Rebecca Sunenshine, medical director of the Health Observatory at Arizona State University.” (3)
“Countries lose their so-called elimination status, as determined by the World Health Organization, after 12 months of sustained transmission. The United States, which has held elimination status for 25 years, will reach that critical deadline at the end of January 2026.
“I wouldn’t call the code yet, but I think the patient’s not looking real good,” said Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota.”” (6)
“As the U.S. continues to face its worst measles outbreak in three decades, another country that has struggled with measles offers a telling case study: the eastern European nation of Romania.
While most countries hardest hit by measles are lower-income countries in the Global South, wealthier countries have also seen significant outbreaks. Romania is one of them. The country ranked fifth on the measles outbreak list last year, reporting 30,692 cases and 23 deaths.” (5)
“The island nations of Cabo Verde, Mauritius and Seychelles have eliminated measles and rubella, becoming the first sub-Saharan countries to attain this milestone, the World Health Organization announced.
Cabo Verde has fully funded its immunization programme since 1998 and maintained coverage above 90% for 2 decades. Strong political engagement on immunization, especially towards measles and rubella immunization has been critical in ending the local transmission of the two diseases. The country has not had a confirmed measles case since 1999. The last confirmed rubella cases were in 2010.
In Mauritius, no measles cases have been reported since 2019 and all recent suspected measles and rubella cases were adequately investigated and discarded as non-measles and non-rubella cases. The country responded to a 2018–2019 measles outbreak with renewed vaccination and surveillance efforts. By 2024, measles-mumps-rubella vaccination coverage at national level reached 98% for the first dose and 96% for the second dose. “ (7)
1.Surging measles cases are ‘fire alarm’ warning that other diseases could be next, By Erika Edwards, https://www.nbcnews.com/health/health-news/surging-measles-cases-are-fire-alarm-warning-diseases-rcna246035
2.Canada loses its official ‘measles-free’ status, By Kathryn H. Jacobsen, https://www.gavi.org/vaccineswork/canada-loses-its-official-measles-free-status
3.Measles outbreak in Arizona and Utah could spell the end for U.S. elimination status, By Aria Bendix and Erika Edwards, https://www.nbcnews.com/health/health-news/measles-outbreak-arizona-utah-us-elimination-status-rcna244841
4.The story of measles in five charts, by Linda Geddes, https://www.gavi.org/vaccineswork/story-measles-five-charts?gad_source=1&gad_campaignid=12319817265&gbraid=0AAAAADibICMHLGADpDIboQnawVe_y14A5&gclid=CjwKCAiA86_JBhAIEiwA4i9Ju_iUTbUMCaNfA-g6b3KpzERCArw1FYU7u8cW94x611IcDUogtHKaVxoCswMQAvD_BwE
5.Are there lessons for the U.S. in this European country’s struggle with measles?, by Michal Ruprecht, https://www.newsbreak.com/connecticut-public-560505/4359857328985-are-there-lessons-for-the-u-s-in-this-european-country-s-struggle-with-measles
6.Texas Measles Strain Continues to Spread, Officials Say, By Apoorva Mandavilli and Teddy Rosenbluth, https://www.nytimes.com/2025/11/17/health/measles-us-elimination-status-outbreaks.html?smid=nytcore-ios-share&referringSource=articleShare
7.Africa: Measles and rubella eliminated in Cabo Verde, Mauritius and Seychelles, Robert Herriman, https://outbreaknewstoday.substack.com/p/africa-measles-and-rubella-eliminated
curated by Jonathan M. Metsch, Dr.P.H.
Clinical Professor of Environmental Medicine, Icahn School of Medicine at Mount Sinai