Overview

• Los Angeles County confirmed a school-age child died from subacute sclerosing panencephalitis after contracting measles in infancy before vaccine eligibility.
• SSPE is a rare, progressive brain disorder that typically appears years after measles infection and is almost always fatal with no cure.
• Risk estimates indicate about 1 in 10,000 measles cases develop SSPE overall, rising to about 1 in 600 when the infection occurs in the first year of life.
• The United States has recorded 1,454 measles cases so far in 2025, the largest tally in roughly 25 years, with falling vaccination coverage cited by experts.
• Public health guidance calls for MMR at 12–15 months and 4–6 years, with two doses about 97% effective, and a pre-travel dose advised for infants 6–11 months.