Illinois measles outbreak is over, health department says
The Illinois Department of Public Health has declared the state's measles outbreak officially over.
Eight measles cases, all linked to each other, were identified in southern Illinois in April and May, prompting officials to declare an outbreak. Around the same time two cases in Cook County were also identified, which were not related to the downstate cases or to each other.
IDPH officials said Friday that no new measles cases have been identified in Illinois since May 22. Two incubation periods for the virus, which constitute 42 days each, have passed since the last case was identified, which allows health officials to declare the outbreak over.
The Centers for Disease Control and Prevention has reported the larges number of measles cases across the country in the past 33 years in 2025. Over 90% of those cases have been in unvaccinated children and adults, and so far three deaths have been reported, the same number of American measles deaths reported between 2001 and 2024 combined.
IDPH officials stressed the importance of making sure you and your children are properly vaccinated against measles to prevent infection and spread. The MMR vaccine is typically given to children in two doses, the first between 12 and 15 months old and the second between ages four and six
