The Los Angeles County Department of Public Health this week reported the death of a school-aged child due to a rare complication occurring from a measles infection they experienced as an infant.

In a statement Thursday, the health department said the child had become infected before they were eligible to receive the measles vaccine. Their death was due to subacute sclerosing panencephalitis (SSPE).

The department described SSPE as a “rare, progressive brain disorder that is a late complication of infection from the measles virus.” It affects roughly one in 10,000 people who get measles, but this rate jumps to 1 in 600 for those who get measles when they are an infant.

“SSPE usually develops two to ten years after the initial measles infection after the patient seemed to fully recover. It is characterized by a gradual and worsening loss of neurological function with death occurring one to three years after the initial diagnosis,” added the agency.

In light of the death, the agency encouraged Los Angeles County households to ensure that all members are protected against measles.

Children typically receive their first dose of the measles vaccine at 12-15 months and receive their second dose when they are between four and six-years-old.

This death comes just weeks after the measles outbreak in West Texas was declared over. More than 700 cases were ultimately confirmed in the Texas outbreak, causing two deaths of school-aged children who were unvaccinated and had no underlying conditions.

“This case is a painful reminder of how dangerous measles can be, especially for our most vulnerable community members,” Muntu Davis, Los Angeles County Health Officer, said in a statement.

“Infants too young to be vaccinated rely on all of us to help protect them through community immunity. Vaccination is not just about protecting yourself—it’s about protecting your family, your neighbors, and especially children who are too young to be vaccinated.”