DeLisa New Williams remembers when measles spread like wildfire through her elementary school. One day, a kid was out sick. Then suddenly everyone was infected, including her.
“It knocked out the whole classroom,” Williams, 41, said. “And then it moved on to the next.”
That was in the early 1990s in the midst of a massive, nationwide measles outbreak that lasted from 1989 to 1991. Tens of thousands of people were infected, and dozens died. Chicago was hit hard — from 1989 to 1990, over 2,200 children were infected, and 22 died.
These days, Williams is worried for her own children and community. A Sun-Times analysis found less than half of Chicago Public Schools are at a 95% measles vaccination rate, the federal Centers for Disease Control and Prevention’s benchmark for herd immunity. Meanwhile, at least six measles cases in Illinois have been confirmed amid worsening outbreaks elsewhere in Texas and New Mexico. Over 900 cases have been reported across 30 states.
“These babies just got through one pandemic, and we’re trying to make sure our kids are acclimated and getting used to coming back to the classroom,” Williams said.
Before the COVID-19 pandemic, 97% of Chicago Public Schools students overall were vaccinated against measles, one of eight vaccinations required by the state. But as of the 2024-25 school year, that percentage has fallen to 93%, according to data from the Illinois State Board of Education. Each October, Illinois schools submit their students’ vaccination numbers for that school year to the state board.
The CDC says a vaccination rate of 95% provides communitywide immunity and protects vulnerable students, like younger children who have yet to complete the required series of shots, or kids with weakened immune systems.
The Sun-Times analysis of state data found even more troublesome trends at individual schools. About 45% of CPS 644 elementary, high schools and charter schools have vaccination rates at or above 95% this year. That’s down from the rate in 2019, the year before the pandemic, when 90% of schools were at herd immunity.
What’s more, several schools dropped to 80% or below. For example, the rate at Brennemann Elementary School in Uptown went from 98% in 2019 to 69% in 2024. CPS did not make Brennemann’s principal available for comment. Ninety schools saw their rate drop by 10% or more.
But not all schools are struggling. Several are close to herd immunity, 68 schools improved their rates, and seven kept them stable.
Dr. Ravi Jhaveri, the division head of pediatric infectious diseases at Lurie Children’s Hospital, was alarmed by the drop. Measles is an extremely contagious disease: One person with measles can spread the virus to as many as 18 people. The transmission rate for flu is about one to two people. Measles can also be fatal or leave someone with severe and long-term complications from the illness.
“There are lots of opportunities for measles to find vulnerable people, and it’s so contagious, measles will find them if they’re not vaccinated,” Jhaveri said.
That’s why a 95% vaccination rate is crucial, Jhaveri said.
“Our children have missed out on so many years, and now they could miss even more just because people aren’t up on immunizations,” said Williams, who has a first grader and sixth grader at Jane A. Neil Elementary School in Chatham.
A CPS spokesperson did not dispute the Sun-Times’ findings, but said the district’s most recent “internal data” shows “95.6% of CPS students are fully protected against measles.”
The district would not provide that internal data to the Sun-Times.
“Understanding that national declining vaccination coverage and increasing student exemptions would increase the risk for vaccine-preventable outbreaks,” the spokesperson said, the district developed a plan to prevent further declines in vaccination rates.
That plan, which the district said has helped improve vaccine coverage districtwide, includes: frequently communicating with parents and school principals, bringing services to schools with the lowest protection rates and helping with documenting immunization records.
Chicago isn’t alone. Vaccination rates dropped nationwide in the years since the height of the pandemic. They have been slowly recovering, but not at a rate public health experts say is necessary for strong community protection.
The vaccination rate waned for several reasons, experts told the Sun-Times. Misinformation around vaccines increased during the pandemic and continues to flourish, and COVID-era disruptions to regular checkups caused many kids to fall behind on their vaccine schedules.
All states allow medical exemptions from mandated vaccinations. Illinois allows parents to request a religious exemption, but not for personal or philosophical reasons. Since 2015, parents must submit a signed “certificate of religious exemption” detailing why they’re declining which vaccines.
Upping the vaccination rate is the best way to prep for an outbreak, medical professionals and public health experts say. And even a modest uptick in measles vaccinations could prevent millions of infections, according to new research spanning 25 years of vaccination rate data.
‘Just get the shot, OK?’
During the 2018-2019 school year, Neil Elementary was at a 97% vaccination rate for measles. But that rate has dropped in the years since, going as low as 80% in 2021-22 school year.
“This is a parental responsibility we have to take on. It’s on us,” said Williams, who is also the parent chair of her local school council. “It’s not just about protecting our kids. We don’t think about the siblings at home, the elders, the vulnerable people these kids go home to. It’s about looking out for the whole community.
“Just get the shot, OK?”
The Illinois Department of Public Health recently unveiled a measles simulator dashboard to track and monitor cases in real time as a part of the state’s larger effort to prepare for measles outbreaks, a department spokesperson said.
Several factors can affect a school’s vaccination rate, said Jhaveri from Lurie Children’s. The state considers a student as fully vaccinated against measles when they’ve had both doses of the MMR vaccine, which covers measles, mumps and rubella. The first dose is usually given when a child is 12 months to 15 months old. The second dose is given between ages 4 and 7. That first dose alone gives 93% immunity, and two doses supply 97%.
But many kids are behind on that vaccination schedule because they missed regular checkups during the pandemic. At the time, doctors urged their patients to avoid visiting clinics in person to minimize the risk of COVID spreading.
Since then, wait times for appointments at clinics and pediatric offices ballooned and can sometimes take months, he said. Patients on Medicaid in particular are having a tough time getting appointments and often have to travel far for basic care like annual physicals and vaccines.
“We have patients traveling 30, 40 miles to Lurie just to get vaccines,” Jhaveri said.
Outbreaks generally happen when an unvaccinated person contracts measles while traveling abroad and brings it back to their community. But with recent large outbreaks in Texas and New Mexico, the risk of contracting measles while traveling in the U.S. is higher, he said.
Robert F. Kennedy Jr., head of the U.S. Department of Health and Human Services, recently endorsed the MMR vaccine, but has also stoked vaccine hesitancy for years, including during his 2024 presidential campaign and since becoming health secretary under President Donald Trump.
“The public has increased hesitancy around vaccines. They’re flooded with misinformation; there’s decreased trust in the established medical systems,” Jhaveri said.
Maria Diaz, a West Lawn resident and mom of three, isn’t crazy about vaccines. She’s partial to more natural approaches to health care, and she avoids artificial foods and plastic as much as possible.
But she’s had all three of her children vaccinated with the standard vaccines, including measles. She also worries about them getting sick at school. Two of her kids are at CPS schools, Richard Henry Lee Elementary in West Lawn and Thomas Kelly College Prep in Brighton Park. Lee Elementary’s vaccine rate stayed around 98% from 2019 to 2025, while Kelly College Prep dropped from 98% to 93%.
“I did have my kids vaccinated, both because it’s a requirement at school, but also because many of the vaccines are older, like the measles vaccine, so it’s been tested for longer,” Diaz, 47, said.
She said she’s not surprised that people are struggling to get checkups and vaccinations at their regular doctor. She recently tried scheduling appointments with her kids’ pediatrician, and the wait time was over six months.
Bring the shots to school
Howard Ehrman, a former Chicago Department of Public Health deputy commissioner, said he believes vaccinating kids in school would bring rates up. It’s “an access problem,” he said.
“Let’s not turn this into a blame the victim campaign,” Ehrman said, adding that many doctors have stopped offering vaccinations in their offices.
Seventy years ago, when the polio vaccine became available, kids were vaccinated at school, where they likely had a full-time school nurse, said Ehrman. But since then, public health efforts like mass immunizations have become more privatized, affecting working-class families, said Ehrman, who recently joined a news conference held by the People’s Response Network calling on CPS to provide vaccinations at schools for measles, whooping cough, meningitis, pneumonia and other diseases.
Under the Chicago Teachers Union 2019 contract, CPS agreed to hire full-time nurses at every school. And while “significant progress” has been made, Ehrman said, there are still dozens of schools without a full-time nurse. He’s also calling for CPS to fill its chief health officer role, which has been vacant since November.
A Chicago Department of Public Health spokesperson deferred to CPS on the feasibility of implementing a school-based vaccination program.
“CDPH has long supported CPS in vaccination efforts for CPS students, including with on-site vaccination events at CPS schools, and we will continue to participate alongside other vaccine providers in CPS-led vaccination efforts,” the spokesperson said.
A CPS spokesperson said the district offers several ways for students to get vaccinated at schools or partner clinics. CPS operates school-based and mobile clinics that offer vaccinations and physicals. Eligible students can receive free vaccinations through the public health department’s immunization program. Since November 2023, the district has partnered with the federal program, Vaccines for Children, and held over 420 vaccination events at several schools.
After the 1989-91 outbreak, mass immunizations efforts in Chicago and nationwide helped tamp down measles cases. The city’s health department, working with the school district and the city housing authority, supplied free vaccines to schools and housing projects. And by 2000, the U.S. declared measles eradicated from the country.
“Are we going to be proactive?” Ehrman asked. “Or are we going to wait till we have another measles outbreak?”