Chicken pox cases are up nearly 60% from this time last year, state health officials say.
The majority of those 239 cases were people who hadn’t been vaccinated.
"There's this misconception that because they're not seeing the illness as much as they were in the past, that there isn't a need for immunizations,” says Jennifer Eisner, a spokesperson for the Michigan Department of Health and Human Services.
“But really, what that's showing is that immunizations are effective, and they're still necessary."
Eisner says there’ve been nine outbreaks across seven counties in 2016, most recently in Washtenaw, Monroe, and St. Joseph county.
She says kids and adults can wind up in the hospital from chicken pox – and the virus can reactivate later in life, as shingles.