Illinois reports first measles case of 2026

Illinois’ first measles case of the year has been detected in the southern part of the state, state health officials said Tuesday.

People attending services at Good Shepherd Lutheran Church in Collinsville, Illinois, 15 miles east of St. Louis, on Feb. 8 between 8 a.m. and 12:15 p.m. were potentially exposed to the virus.

The state health agency emphasized that the best protection against measles is the two-dose MMR vaccine, which covers measles, mumps and rubella. The first dose is given when a child is between 12 and 15 months old, giving 93% immunity, and the second dose is given between the ages of 4 and 7, bumping immunity to 97%.

“This first reported case of measles in Illinois in 2026 is a reminder to our Illinois residents that this disease can be prevented with up-to-date vaccination,” said IDPH Director Dr. Sameer Vohra. “With almost a thousand cases in the US so far this year, the IDPH team has been preparing, working closely with local public health and health care partners on strategies to reduce spread and minimize outbreaks. … I recommend that our Illinois residents make sure that they and their family members are up to date on the MMR vaccine and all other age-appropriate immunizations.”

Symptoms can take from one to three weeks to appear after exposure to someone with measles, according to health officials, making it even more likely to spread as measles is also a highly contagious disease, according to the health agency. One person can infect up to 18 individuals. In contrast, the flu’s infection rate is about one to two people.

Because of this, anyone who isn’t vaccinated but is exposed should monitor themselves for symptoms such as rash, high fever, cough, runny nose, and red, watery eyes for 21 days, the state health agency said.

This year's first measles case comes much earlier than last year’s first case, which wasn’t detected until mid-April.

Illinois saw 14 cases in 2025 during its peak — where nearly 1,300 cases cropped up nationwide in a short span, the worst outbreak in more than 30 years — a sharp drop from 2024’s three-month measles outbreak in Chicago, where 64 cases were confirmed.

For more information about measles, contact your health care provider, or visit the Illinois Department of Public Health webpage on measles or the CDC’s measles site.