Commuters Alerted To Measles Exposure In August At Chicago Union Station, CDPH Says

The Chicago Department of Public Health traced the measles exposure to an out-of-state traveler who passed through Union Station Aug. 27-28

By Lorraine Swanson, Patch Staff

Sep 11, 2026 1:05 PM CDT

CHICAGO—The Chicago Department of Public Health is alerting commuters of a confirmed measles exposure at Chicago's Union Station, 255 South Canal St., late last month.

The measles exposure occurred Thursday, Aug. 27, after 8 p.m. through Friday, Aug. 28. CDPH traced the exposure to an out-of-state domestic traveler. Union Station has been identified as a public exposure location.

While the exact date and time of the exposure are unknown at this time, CDPH will update its website when more information becomes available.

Meanwhile, individuals who never received the MMR vaccine that protects against three serious viral diseases, including measles, mumps, and rubella.

Commuters who may have been exposed to measles should:

Monitor themselves for symptoms of measles.
- Symptoms include rash, high fever, cough, runny nose and red, watery eyes.
- After exposure to someone with measles, symptoms can take from 7 to 21 days to show up.
People who develop symptoms of measles should stay home and away from others.
Contact a health care provider by phone BEFORE going to a medical office or emergency department, unless you are experiencing a medical emergency. Special arrangements can be made for your evaluation while also protecting other patients and medical staff from possible infection.

Across the United States, Centers for Disease Control and Prevention reports 3,134 confirmed cases, surpassing the full-year 2025 total of 2,289 cases.

Around 8 percent of total patients (248 individuals) have required hospitalization. The CDC also reports that approximately 94 percent of infected individuals are unvaccinated or have an unknown vaccination status; only about 3 percent have received two doses of the MMR vaccine.

Adults born before 1957 are generally considered naturally immune to measles because they lived through widespread exposure before the vaccine existed.

However, if you fall within one of these groups, you may want to consider getting another MMR dose, according to the CDC.

No record of immunity: Adults born in 1957 or later who have no documentation of receiving the MMR vaccine or lab proof of immunity should get at least one dose.
High-risk settings: You may need a second dose if you are a healthcare worker, an international traveler, a student at a post-high school college or university, or live close to an immunocompromised person.
Vaccinated before 1968: Anyone who received a measles vaccine prior to 1968 using an inactivated (killed) vaccine or an unknown type should get revaccinated with a live MMR dose.
Outbreak areas: People notified by public health authorities during an active local outbreak may need an extra dose if they only have one documented shot.

The MMR (Measles, Mumps, Rubella) vaccine is available to all Chicago residents at no cost at CDPH's Immunization Clinics.