Over the past five years, measles outbreaks have hit more than 100 countries. Canada lost its official measles elimination status this week. The United States could be next.
On July 7, 2025, the U.S. passed a sobering milestone: the number of measles cases across the country reached its highest point in three decades, with 1,281 cases reported — the most since the highly contagious disease was officially eliminated in the U.S. back in 2000. And the year was only half over. As of Nov. 4, that total had risen to 1,681 confirmed cases, according to the U.S. Centers for Disease Control and Prevention (CDC).
To find out where this is heading, look to Canada, which eliminated measles back in 1998. A deadly measles outbreak that began in October 2024 is still raging, with more than 5,100 cases reported since its start. On Nov. 10, 2025, the Pan American Health Organization, the World Health Organization’s (WHO) regional office for the Americas, revoked Canada’s official measles-free status.
Will the U.S. be next?
Childhood vaccination rates have been falling worldwide
Measles elimination is defined as the interruption of endemic measles virus transmission in a specific geographic area for more than 12 months. It’s an epidemiological victory — but elimination can only last as long as vaccination rates remain sufficiently high.
A safe and effective measles vaccine has been in use since the 1960s. But vaccine misinformation and vaccine hesitancy are on the rise in the U.S. and elsewhere, and funding cuts are disrupting efforts to reach children with essential immunizations.
Global childhood immunization rates stalled in 2023, leaving 2.7 million additional children un- or under-vaccinated, compared to pre-pandemic levels in 2019, according to WHO and UNICEF data tracking immunization trends for vaccination against 14 diseases. Measles cases surged in 2023, infecting an estimated 10.3 million people worldwide, up 22 percent from the year before. That year, 107,500 people lost their lives to measles. The overwhelming majority were children under 5.
Both the U.S. and Mexico have had sustained measles outbreaks since early 2025, putting them on track to lose their measles-free status in 2026.
Related: Americans Who Never Forget: Life Without Vaccines
As measles cases surge, here are five things to know:
1. Measles can be deadly.
Measles kills nearly 300 people every day, approximately 12 people every hour, mostly children under 5. Even when children survive a measles infection, the virus can leave them with long-term health effects or permanent disabilities.
In some cases, severe complications can include pneumonia, severe diarrhea, blindness and encephalitis (brain swelling). It can also weaken a child’s immune system and make them more vulnerable to other infections long after recovering from measles, a phenomenon known as immunity amnesia.
Any child who is unprotected from measles through immunization is at risk, with malnourished children and those under 5 most at risk.
2. Measles is one of the most contagious diseases on the planet.
Measles is a highly contagious airborne disease. It can spread easily as infected people breath, cough or sneeze, releasing virus particles into the air and onto surfaces that can remain infectious for up to two hours. Unfortunately, those infected with the virus can start to spread measles to others even before they know they have it — four days before the characteristic measles rash appears.
Once a child is infected with measles, 90 percent of those they come into close contact with will become infected, if they are not already immune.
The measles virus does not recognize borders. Over the past five years, measles outbreaks have hit over 100 countries, including several that had previously eliminated measles altogether.
3. Vaccines are the best way to stop outbreaks and protect children.
Measles vaccines are safe. Two doses of a measles-containing vaccine provide 99 percent protection from measles for life. They are the best way to prevent children from contracting measles and spreading the disease to others. No child should risk serious health complications or death by contracting measles.
Since 1974, measles vaccines have saved nearly 94 million lives. They have protected more people than any other vaccine in the Essential Program on Immunization.
While most countries now include measles vaccines in their immunization schedules, too many children are still unprotected. The story of unvaccinated children is one of inequity, poverty and underserved communities.
4. Low vaccination coverage is contributing to measles outbreaks.
Because measles spreads so quickly, maintaining high vaccination rates across communities is critical to preventing outbreaks. Coverage of 95 percent or greater with two doses of measles-containing vaccine is needed to protect communities from measles outbreaks. All children should be vaccinated against measles.
Currently, the global coverage rate of the first dose of the measles vaccine is 83 percent, and the second dose is just 74 percent, far below the level needed for protection. This leaves room for measles to spread and puts vulnerable groups, including unvaccinated children, at higher risk.
Routine measles vaccination and mass immunization campaigns in countries with high case rates are crucial for ending outbreaks and reducing global measles deaths.
5. A switch to five-dose vials can help governments save more lives.
Measles vaccines are often purchased in ten-dose vials. Once opened, health workers only have a few hours to administer all ten doses to children. Any unused doses will expire and must be thrown away.
Health workers can sometimes be hesitant to open a new vial for only one or two children, knowing the rest of the doses will go to waste. This hesitation and fear of wastage too often leads to unopened vials, leaving children without the shots needed to protect them from measles.
A simple switch from ten-dose to five-dose vials can help increase measles vaccination coverage and reduce wastage.
UNICEF’s role in combatting measles
UNICEF’s mission is to reach every single child with lifesaving vaccines.
Each year, UNICEF delivers around 250 million doses of measles-containing vaccines. These vaccines are essential for protecting children against measles through routine immunization programs and preventative campaigns in over 90 countries. The vaccines are also critical for responding to measles outbreaks, including in conflict and humanitarian settings.
As the world’s largest vaccine buyer, UNICEF leverages its significant purchasing power to secure a reliable and sustainable supply of quality-assured measles-containing vaccines at affordable prices. The measles-containing vaccines are safe and cost-effective in saving children’s lives.
UNICEF is part of the Measles and Rubella Partnership, a private-public partnership including WHO, CDC, United Nations Foundation and American Red Cross that spearheads a global push towards measles and rubella elimination and control.
By continuing to invest in and prioritize vaccines, we can ensure that no child anywhere dies of an illness we know how to prevent.
Right now, the lives of the most vulnerable children hang in the balance as conflicts and crises jeopardize the care and protection that they deserve. Dependable, uninterrupted and effective foreign aid is critical to the well-being of millions of children. Please contact your members of Congress and urge them to support ongoing U.S. investments in foreign assistance.
This story was adapted from UNICEF.org