On Mar. 25, 2025, Ohio Department of Health (ODH) announced a measles outbreak in Ashtabula County and one confirmed case of a visitor in Knox County who exposed others to measles in Knox and nearby counties.

The ODH and Ashtabula County had identified 10 measles cases. Nine were linked to an adult male reported the previous week as the state’s first measles case of 2025. None of the individuals were vaccinated.

Ohio had 90 cases of measles in 2022, when an outbreak in central Ohio totaled 85 cases. The state had one measles case in 2023 and seven in 2024.

Measles is extremely contagious and can spread to others through coughing and sneezing. It can be brought into Ohio by individuals who travel to places where measles is spreading. If people are not protected against the disease, nine out of 10 people who are exposed will become ill.

The measles vaccine (called MMR as it protects against measles, mumps and rubella) is safe and effective at preventing measles. Two doses of MMR is 97% effective against measles. If you are up to date on measles vaccine, the risk of getting sick is extremely low.

The CDC recommends all children get two doses of MMR vaccine, starting with the first dose at 12 through 15 months of age, and the second dose at 4 through 6 years of age. 

In most instances, adults who were vaccinated against measles as children do not need any additional doses as adults. However, adults who did not receive the MMR vaccine as children or those who are unsure about their vaccination status are encouraged to talk to their healthcare provider for more information. Those born prior to 1957 are likely protected by previous infection.