An influenza-associated fatality in Los Angeles County marks the first such death for a person under the age of 65 for the 2016-2017 flu season.

California Department of Public Health (CDPH) Director and State Public Health Officer Dr. Karen Smith announced the news on Thursday.

“As this unfortunate case illustrates, the flu can be deadly and causes thousands of fatalities each year in the United States,” Dr. Smith said. “Fortunately, people can get vaccinated to help keep them from getting sick and spreading the flu to others.”

While this is the first reported death, the CDPH has confirmed that 11 influenza-associated cases have required treatment in an intensive care unit.

Deaths and hospitalizations due to influenza in persons under 65 years of age are monitored the study the seasonal severity of influenza.