According to state records, at least 130 Illinois schools report measles vaccination levels of under 90 percent. That is the minimum percentage health officials believe communities must achieve for “herd immunity”—an environment that can prevent a disease from spreading.  

Schools are supposed to lose 10 percent of their state funding when they fall below the 90 percent level of vaccinations. But no school has ever been sanctioned for this violation, according to the Illinois State Board of Education.

Illinois code states that funding “shall be withheld by the regional superintendent until the number of students in compliance”… reaches the “specified percentage or higher.”

But even as measles cases arrive in Illinois, the state’s Board of Education says it has no plans to start enforcing the rules through funding sanctions any time soon.

“We are not looking to penalize a district or remove money from a district,” said ISBE spokesman Matt Vanover. “What we’re looking for is compliance. It’s difficult for educators to remove or exclude a child from education, especially when the child is from a poor or struggling family. Local districts will follow through with initaitves and reminders of their own.”

Still, some doctors believe the state’s purported 90 percent vaccination standard is too low.

“In order for a community to have herd immunity you really need to maintain vaccination rates around 95 percent,” said Dr. Tina Tan, a pediatric infectious disease specialist at Lurie Children’s Hospital in Chicago. “Otherwise, what happens is that when the rates below drop below 95 percent, you can have the reemergence or reappearance of these preventable diseases occurring in individuals that are either not vaccinated or are too young to be vaccinated.”

That’s what happened this week in Illinois when infants at a day care center in northwest suburban Illinois were diagnosed with measles.

All those children were too young to be eligible for the measles, mumps and rubella vaccination (MMR), which is traditionally administered after a child turns 1-year-old. But Cook County health officials say they expect the disease to spread.

“The cat is out of the bag,” Dr. Terry Mason, chief operating officer of the Cook County Department of Public Health said yesterday at a press conference in Oak Forest.

According to the Centers for Disease Control and Prevention one in 20 children who contract measles will also get pneumonia; one in 1,000 may develop encephalitis that could lead to deafness and mental retardation; and for one or two in 1,000, the disease could be fatal.

Thursday, WBEZ contacted schools who, according to the ISBE vaccination site, self-reported measles vaccination rates as low as 27 percent. The schools claimed that the site was showing inaccurate information.

Vanover acknowledges that the self-reported data may be flawed, but says it can’t be fixed.  After the yearly November 17 deadline, “the data becomes locked in for reporting purposes and we don’t have any opportunity to go back and correct it,” he said.

For more updated information, Vanover suggests calling individual districts.

Monica Eng is a WBEZ producer and co-host of the Chewing The Fat podcast. Follow her at @monicaeng or write to her at meng@wbez.org.

WBEZ web producer Chris Hagan contributed to this story.