U.S. at risk of losing elimination status after year of outbreaks, including in Illinois
One year after a deadly measles outbreak in West Texas, cases continue to surface across the United States, including in Illinois. Ongoing transmission now puts the country at risk of losing its measles elimination status — the designation public health officials use when a disease no longer spreads continuously for at least 12 months.
The U.S. achieved elimination status in 2000, a milestone certified by the Pan American Health Organization, a regional office of the World Health Organization. If transmission continues for 12 consecutive months, the virus is again considered endemic, meaning it spreads routinely within the country.
Vaccination rates have declined since the Covid-19 pandemic. During the 2014-2015 school year, Illinois schools reported 97.8% of students received the measles vaccine. Ten years later, that number had fallen to 95.8%.
“Although vaccination rates in our schools are relatively high, more than 12,000 students in suburban Cook County are not vaccinated for measles, mumps, and rubella,” said Kiran Joshi, MD, chief operating officer of Cook County Department of Public Health. “For each vaccine, the number of unvaccinated students in suburban Cook County schools has almost doubled over the last decade.”
Chicago Public Schools report wide variation in measles, mumps, and rubella (MMR) vaccination coverage. Some schools report 100% vaccination. Many land between 85% and 95%. About 10 schools report coverage below 80%. Brennemann Elementary School on the North Side reported a 69.1% MMR vaccination rate.
Illinois requires certain immunizations for public school attendance, although parents may claim religious or medical exemptions.
A recent poll by KFF (formerly the Kaiser Family Foundation) and the Washington Post found that 1 in 6 parents report skipping some recommended childhood vaccines. The same poll found that overall trust in measles vaccines remains high.
Robert Johnston, PhD, a historian of medicine and politics and professor at the University of Illinois Chicago, is writing a book about vaccine controversies in the U.S. over the past three centuries.
“There’re so many different reasons why people become vaccine-hesitant or vaccine dissidents or outright anti-vaccination,” Johnston says. “There are people who are skeptical of or ambivalent about vaccines. Even more anti-vaccination movements have been filled by people upset about the government mandates around them. Medicine and science are secondary to thorny matters of political theory, democratic obligation, and bodily autonomy.”
One persistent idea is that healthy children can gain “natural immunity” by contracting measles, eliminating the need for vaccination.
In the 1960s, Johnston says, some parents intentionally exposed children to infected playmates so they would develop immunity. Johnston says, “My own mother, who was definitely not a vaccine skeptic, did exactly this with me.”
James Alwine, PhD, a virologist and professor emeritus at the University of Pennsylvania, says that approach is not a safe way to handle a virus like measles.
“You have to be infected, and your immune system has to develop defenses against the invading virus. This takes time,” Alwine says. “During that time, the infecting virus can wreak havoc on you and possibly cause death.”
While kids are especially at risk for hospitalization, adults also can contract measles, especially those who are unvaccinated. In the U.S., roughly 1 in 5 unvaccinated people who get measles end up hospitalized.
Measles can cause encephalitis and severe pneumonia, Alwine says. It can also trigger “immune amnesia,” temporarily erasing immunity to other diseases.
“People think measles is just a childhood disease — you get it, and get over it,” Alwine says. “But the risk is that children can die from it, and unvaccinated adults are also at risk.”
In 2025, the United States recorded 2,144 measles cases, according to the Centers for Disease Control and Prevention. Two children died in the Texas outbreak. Illinois reported 14 cases.
When someone in Cook County tests positive, the Cook County Department of Public Health launches contact tracing. Health officials post exposure notices, issue public alerts, and offer MMR vaccinations.
“In response to the measles outbreak last April, we hosted 15 vaccination clinics at 10 schools and administered 618 school-required vaccinations,” Joshi says. “If you get the MMR vaccine within 72 hours of initially being exposed to measles, you may get some protection from measles or have milder illness.”
The Chicago Department of Public Health also offers free vaccinations at citywide immunization clinics.
As outbreaks spread, Alwine calls measles a “canary in a coal mine.”
“If you start seeing rising measles cases, as we’re seeing now, it is a strong indication that your vaccine rates are well below the levels needed to protect the whole population, especially the youngest and oldest, the people with the weakest immune systems,” Alwine says. “And that means that all the other vaccine-preventable diseases are going to follow.”
U.S. Department of Health and Human Services Secretary Robert F. Kennedy Jr., who oversees the CDC, has publicly questioned vaccine safety, including during his leadership of the Children’s Health Defense, an anti-vaccine nonprofit.
Earlier this month, the CDC updated its recommended immunization schedule, recommending children get vaccinated against 11 diseases, down from 17 in the prior schedule.
In December, Illinois released its own vaccine guidelines, diverging from the new federal recommendations.
“Vaccine politics have been a constant throughout American history,” Johnston says. “They’ve ebbed and flowed, but there’s been a straight throughline. These things never go away, and they particularly come out at moments of high political conflict.”
Public health experts say vaccine debates often intensify when politicians tap into fears about children’s health and government control. As the latest surge is proving, though, measles does not bend to politics. It spreads wherever trust erodes, and vaccination rates fall.
