Health officials have given few details about the Wisconsin measles cases. They have not disclosed ages, vaccination status or location of exposure.

Wisconsin has its first confirmed measles cases amid the country’s worst year for the disease since it was declared eliminated 25 years a

Nine cases of measles were found in Oconto County, leading the Wisconsin Department of Health Services to encourage the public to get two doses of the measles, mumps, rubella vaccine, which it says is 97% effective in preventing the disease.