Many parents view measles as simply a rash and fever, a temporary inconvenience. But for an unfortunate few, the infection lies dormant in the body, waiting to strike seven to ten years later as Subacute Sclerosing Panencephalitis (SSPE). At first, SSPE appears as personality changes, mood swings, and depression. In the following months, it ravages the brain, causing uncontrolled movements, blindness, seizures, and dementia. Finally, the areas regulating breathing, heart rate, and blood pressure fail, leading to coma and death.
Measles was declared eliminated in the U.S. in 2000 due to widespread vaccination. Elimination, for context, means no continuous disease transmission for over a year. Yet cases and outbreaks have increased since then, driven largely by declining vaccination rates, imported cases from international travel, and unscreened migrants.
In 2023, the CDC reported 59 cases; by 2024, this jumped to 285. As of March 14, 2025, the CDC has already recorded 301 cases across 15 jurisdictions, with two deaths reported. This spike in the first few months of 2025 suggests a trajectory that could surpass previous years, especially with a significant outbreak in Texas boosting the numbers.
Studies show SSPE is rare, occurring in about 1 in 14,000 measles infections. For children infected before age 5, the risk rises to 1 in 5,500, for those under 1, it soars to 1 in 609. These youngest children, unable to receive the measles vaccine until 12 months, face the greatest danger. With 301 cases in 2025 so far, we might expect a handful of SSPE cases in the 2030s.
The good news is that the two-dose MMR vaccine provides near-total protection against measles, breaking the chain that leads to SSPE. No fully vaccinated person has developed SSPE, making it a preventable tragedy. This protection extends through herd immunity, where a highly vaccinated community shields the unvaccinated—such as infants under 12 months or those with compromised immune systems. For measles, which is among the most contagious diseases known, experts estimate 90% to 95% vaccination coverage is needed to maintain this shield.
Today’s outbreaks, from Texas and beyond, signal a fraying of the protective barrier built over generations. Rebuilding it will require educating our families, friends, and neighbors about measles’ deeper risks while showing compassion to those wary from the false promises and punitive rollout of the Covid-19 vaccine, still fresh in their memories.