PIERRE, S.D. (AP) – South Dakota has reported three flu deaths, the first deaths of the season.

The South Dakota Department of Health says one death was reported in Deuel County, and two deaths occurred in Mellette County. Those who died were all 50 years or older.

State epidemiologist Dr. Joshua Clayton says the deaths are a reminder that influenza “can be a very serious illness,” and that it’s not too late to get vaccinated for flu this season.

Flu activity is classified as widespread across South Dakota. So far, the state has reported 1,555 lab-confirmed cases of flu and 59 flu-related hospitalizations.