New Issue: Orbital Catastrophe Ahead? Read Now

Child’s Death Shows How Measles in the Brain Can Kill Years after an Infection

A child in Los Angeles County has died from a rare but always fatal brain disorder that develops years after a measles infection. Experts underscore the need for vaccination to protect the most vulnerable

MRI scan showing subacute sclerosing panencephalitis with advanced and diffuse cortical atrophy, signified by the ventriculomegaly and markedly enlarged sulci, highlighted in orange

An MRI scan showing subacute sclerosing panencephalitis, a complication of measles infection.

Science Source

A school-aged child in Los Angeles County has died from a rare but always fatal complication from a measles infection they acquired when they were an infant who was too young to be vaccinated. The first dose of the vaccine is typically not administered until one year of age. Experts say the death underscores the need for high levels of vaccination in a population to protect the most vulnerable against the disease, as well as from side effects that can occur long after the initial illness has passed.

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

The child who died suffered from subacute sclerosing panencephalitis (SSPE), a progressive brain disorder that usually develops two to 10 years after a measles infection. The measles virus appears to mutate into a form that avoids detection by the immune system, allowing it to hide in the brain and eventually destroy neurons.


On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.


“It’s just a virus that goes unchecked and destroys brain tissue, and we have no therapy for it,” said Walter Orenstein, an epidemiologist and professor emeritus at Emory University, to Scientific American earlier this year.

People with SSPE experience a gradual, worsening loss of neurological function and usually die within one to three years after diagnosis, according to the Los Angeles County Health Department. The disorder affects only about one in every 10,000 people who contract measles. But the risk may be as high as about one in 600 for those who are infected as infants.

“There is no treatment for this. Children who suffer from this will always die,” said Paul Offit, director of the Vaccine Education Center and an attending physician in the Division of Infectious Diseases at Children’s Hospital of Philadelphia, in a previous interview with Scientific American. Offit, who had measles himself in the 1950s, has seen five or 10 cases of SSPE in his career.

SSPE is one of several side effects of measles that go beyond the coughing, runny nose and characteristic rash of the original infection. Measles can also cause encephalitis, a faster-occurring brain inflammation, in one in every 1,000 people who are infected because the virus causes the immune system to attack a protein produced by certain brain cells. This inflammation kills about one in five people who develop it.

Measles also causes “immune amnesia”: the virus seems to attack the immune system’s B cells, which remember previous pathogens the body has been exposed to, resulting in reduced immunity. There is some evidence this effect can last for a couple of years, making those who get measles more susceptible to other infectious diseases.

These side effects are of particular concern because the measles virus is highly contagious—an order of magnitude more than seasonal influenza. With measles, viral particles emitted by coughing or sneezing can linger in a room for hours after the infected person has left. One infected person infects 15 more people on average.

A bubble chart shows the rate of infectiousness for three categories: measles, polio and smallpox and covid and flu.

This year the U.S. saw its largest single measles outbreak since the disease was declared eliminated in 2000;the recent outbreak occurred mainly in Texas, New Mexico, Kansas and Oklahoma. Most of those infected were unvaccinated or had an unknown vaccination status. Of those infected, 12 percent were hospitalized, and three died of complications from the infection. The fatal cases included the first death of a child from measles in the U.S. in 22 years.

A dot plot shows state and U.S. median MMR vaccine rates from 2012 to 2023.

Ripley Cleghorn; Source: Centers for Disease Control and Prevention (data)

Measles used to infect three million to four million people in the nation every year until vaccines became available in 1963.

The measles vaccine is administered in two doses: typically, the first is given between 12 and 15 months of age and the second is given at four to six years. One dose is 93 percent effective at protection against infection, and two doses are 97 percent effective.

Contrary to claims by Secretary of Health and Human Services Robert F. Kennedy, Jr., measles cannot be treated by vitamin A or cod liver oil. There is no cure or treatment for the disease beyond treatment of symptoms. The only effective means of combatting measles is widespread vaccination. At least 95 percent of a population must be vaccinated to prevent the spread of the disease and to protect either those who are too young to receive it or those who cannot be vaccinated because of other health conditions.

“Infants too young to be vaccinated rely on all of us to help protect them through community immunity,” Davis said in his recent statement. “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.”

Andrea Thompson is senior editor for Earth and environment at Scientific American, covering the environment, energy and Earth sciences. She has been covering these topics for nearly two decades. Prior to joining Scientific American, she was a senior writer covering climate science at Climate Central and a reporter and editor at Live Science, where she primarily covered earth science and the environment. She has moderated panels, including as part of the United Nations Sustainable Development Media Zone, and appeared in radio and television interviews on major networks. She holds a graduate degree in science, health and environmental reporting from New York University, as well as a B.S. and an M.S. in atmospheric chemistry from the Georgia Institute of Technology. Follow Thompson on Bluesky @andreatweather.bsky.social

More by Andrea Thompson

Subscribe to Support Independent Journalism

Great science journalism requires human expertise, time, effort and creativity. And it costs money. That’s why I and the journalists here at Scientific American hope you’ll join our community.

When you subscribe, you are supporting staff and freelance journalists who are passionate about telling science stories that are true, important and compelling. Our editors and reporters are often experts in their fields, which means they understand the nuances of big discoveries and can untangle the breakthroughs from the hype. With a subscription, you are also supporting rigorous fact-checking to ensure the words we publish are precise and accurate. And you’re supporting original illustrations, graphics and photos that bring you closer to an advanced laboratory, an ice sheet in Antarctica or a space mission in orbit. You’re helping us craft other types of high-quality journalism as well: Our newsletters are carefully written, edited and curated by staffers you have or will come to know and love. Our Science Quickly podcast is based on original reporting, collaboration with editors and scientists and exacting production.

Subscriptions keep this engine running so we can continue to deliver thoughtful, rigorous and independent science journalism to you. In an era of viral misinformation, this work is crucial. If you value what we do, I hope you’ll consider joining us as a subscriber

Thank you,

Jeanna Bryner, Editor in Chief, Scientific American

Subscribe