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Does Measles Cause Brain Damage? Yes, Here’s How It Happens
Measles outbreaks in the U.S. and globally put children’s brain health at risk.
Posted March 5, 2025 Reviewed by Lybi Ma
Key points
- Measles can cause brain swelling, seizures, and lifelong neurological damage.
- Outbreaks in the U.S. and globally put unvaccinated people, especially children, at serious risk.
- Measles weakens the immune system, increasing the risk of other infections for years.
- Vaccination is a safe and effective of protecting against measles infection and brain damage.
Measles is back in the United States, and parents and mental health professionals need to understand the severe risk this virus poses to the brains of children.
Why Is There a U.S. Measles Outbreak in 2025?
In the first two months of 2025, there have been more measles cases in the US than there were in the entire year of 2023. Most of this surge is due to a large and growing outbreak in a Texas community with long-standing vaccine resistance, which has since spread to unvaccinated individuals in other places. Measles cases have also been reported this year in nine other states.
While this virus is preventable with two doses of a safe vaccine, some parents resist, believing (wrongly) that this is just a benign infection, like the common cold, that does not need to be prevented. Some parents are holding “measles parties,” intentionally exposing their kids to the virus in a mistaken belief that it’s better to be infected than not.
Why Should I Worry About Measles?
Why do infectious diseases and public health experts like me worry so much about measles? First, it spreads like wildfire. People with measles release virus particles into the air simply by breathing, and often days before they show symptoms. These particles can linger in the air for hours, infecting up to 90 percent of unvaccinated individuals who come into contact with them. Second, there is no drug to treat measles; the government and companies never developed a drug because the vaccine was so effective at preventing it. Third, about 20 percent of kids require hospitalization for pneumonia, and one to three kids die, including one so far this year.
While measles is widely known for causing fever and rash, less known is that it can cause severe and lasting neurological damage, affecting vision, hearing, and brain function. Some complications occur during the infection itself, while others emerge weeks, months, or even years later.
How Does Measles Damage the Brain?
Primary Measles Encephalitis. This condition is caused by direct infection of the cells in the brain by the measles virus, usually soon after symptoms appear. It occurs in about 1 in 1000 measles cases. In people who develop encephalitis, it causes death in about 15 percent and leaves another 25 percent alive but with seizures and or long-term learning and memory problems.
Blindness. One of the first symptoms of measles is conjunctivitis. If measles severely inflames the cornea, it can lead to scarring and, eventually, permanent vision loss. In rare cases, measles can also lead to blindness by causing swelling of the optic nerve.
Hearing loss. By damaging the airways, measles can lead to severe ear infections that damage the eardrum or bones in the ear, leading to hearing loss. In cases of measles encephalitis, hearing loss can result from damage to the auditory nerve or brainstem.
How Does Measles Damage the Brain in the Year After Recovery?
Acute Postinfectious Measles Encephalomyelitis. Weeks to months after the symptoms of measles have resolved, patients may develop confusion, ataxia, seizures, and other symptoms of encephalitis. In this situation, the brain damage is mediated by the immune system rather than direct infection of the virus. But the results are unfortunately similar. It causes death in 10 to 20 percent of cases, and the remaining survivors are left with epilepsy or other cognitive deficits.
Measles Inclusion Body Encephalitis. If a child (or adult) is immune-compromised when they get measles, they are at risk of another rare form of encephalitis. They may develop a rash, changes in mental status, and severe, recurrent seizures, often progressing to coma and death.
How Does Measles Damage the Brain Years After Recovery?
Subacute Sclerosing Panencephalitis (SSPE). Some children who are infected with measles before the age of 2 can develop a slow decline in cognition and myoclonic seizures. While some patients appear to get better for a brief period, most eventually develop dementia and then die months to years after the initial onset of symptoms.
Immune System Suppression. Probably one of the most common, but least appreciated, dangers of measles virus infection is how it weakens the immune system—known as immune amnesia. For years after infection, people with measles are highly susceptible to severe bacterial infections of the central nervous systems, including meningitis from Haemophilus influenzae, Streptococcus pneumoniae, or Neisseria meningitidis, even if they were previously vaccinated against these bacteria.
How Do We Convince People to Get the Measles Vaccine?
With the resurgence of measles, everyone who works in healthcare—regardless of whether you are a therapist, physician, social worker, or other provider—should understand the many ways measles can damage the brain and senses. Remind your patients about the dangers of the virus and the safety and effectiveness of the vaccine.
I often remind parents not just of the facts but of the lived experience of those who have lost a loved one to measles, such as the famous children’s author Roald Dahl. His daughter, Olivia, died of measles encephalitis in 1962, two years before the vaccine became available.
“It is not yet generally accepted that measles can be a dangerous illness,” Dahl wrote in 1986. “Believe me, it is. In my opinion, parents who now refuse to have their children immunized are putting the lives of those children at risk.”
