The Pennsylvania Department of Health has announced the fourth death that appears to be linked to the ongoing measles outbreak.

The latest death involved an 18-year-old resident of Mifflin County, in the center of Pennsylvania, according to the county coroner’s office. The cause of death was acute disseminated encephalomyelitis (ADEM), a rare and severe neurological complication of measles.

As of 20 September 2026, Pennsylvania has reported 767 measles cases since the beginning of the year. Nearly 100 new cases were reported last week.

I wrote about the third death last week, and this post will review the information about each of the four deaths related to the Pennsylvania measles outbreak, since I’ve read some disinformation about them.

Deaths from the Pennsylvania measles outbreak

Here are the known deaths in Pennsylvania that have been linked to measles:

• As I wrote above, an 18-year-old died from acute disseminated encephalomyletis, a rare but known complication of measles. Mifflin County Coroner Andrea L. Alcalde announced the death on 15 September 2026. The state said the person was not vaccinated with the MMR vaccine.
• A 40-year-old woman in Jefferson County, Pennsylvania, who had measles and had not been vaccinated with the MMR vaccine died on 12 September 2026. Laboratory tests confirmed that she had measles. The Jefferson County Coroner, Greg Furlong, determined that the immediate cause of death was respiratory failure due to measles. The woman had chronic obstructive pulmonary disease and asthma, which were contributing factors. If she hadn’t contracted measles, neither would have caused her immediate death.
• Lancaster County Coroner Stephen Diamantoni said that a 6-week-old died of measles on 18 August 2026. The infant was born with Amish lethal microcephaly, a rare genetic condition rarely found outside of the Amish community. This may have contributed to the death from measles.
• A newborn (who cannot be vaccinated against measles) tested positive for measles and died hours after birth on 14 August 2026. A pathologist who performed the autopsy determined that the primary cause of death was spleen laceration. However, the Pennsylvania Department of Health stated that measles can cause inflammation of the spleen, making it more susceptible to a life-threatening rupture.

Some people might say, “See, if they didn’t have these other conditions, they wouldn’t have died.” On the other hand, I would respond that they would be alive today if they hadn’t contracted measles.

HHS Secretary Robert F. Kennedy Jr. has an ongoing dispute with Pennsylvania on the classification of these deaths as complications of measles. Deaths from measles do not support his narratives about the MMR vaccine. A qualified HHS Secretary would be out front pushing measles vaccinations to prevent more outbreaks and deaths. Instead, RFK Jr wants to engage in a useless squabble with the state health department.

More children, and, frankly, adults are going to die of measles as a result of declining MMR vaccine coverage. It’s just frustrating.

Complications of measles

I know I write this every time I write about measles, but it bears repeating. Measles is not just an annoying rash; it is a deadly, dangerous disease. And as we see from the deaths in Pennsylvania, it is not just dangerous to unvaccinated children, but also to unvaccinated adults.

According to the CDC, some of the many measles complications are:

• For every 1,000 children who get measles, 1-2 will die from it.
• About 30% of measles cases develop one or more complications.
• Pneumonia is the complication that is most often the cause of death in young children.
• Ear infections occur in about 1 in 10 measles cases and can cause permanent hearing loss.
• Diarrhea is reported in about 8% of cases.
• As many as 1 out of every 20 children with measles get pneumonia.
• About 1 in every 1,000 children with measles develops encephalitis, an inflammation of the brain that can lead to convulsions, deafness, and other long-term neurological deficits. Some of these individuals will develop acute disseminated encephalomyelitis (ADEM), a rare and severe neurological complication of measles.
• A measles infection can result in short- and long-term immune system dysfunction, sometimes called immune amnesia, which can leave the child susceptible to other diseases early in life (which is in direct opposition to claims by anti-vaccine activists that it helps “boost” the immune system). If a child developed immunity to a disease before the measles infection, their immune system will “forget” that immunity, and the child will be susceptible to that infection again.
• About 1-2 children out of 1000 who contract measles may develop subacute sclerosing panencephalitis (SSPE), a rare chronic, progressive encephalitis that primarily affects children and young adults. SSPE results from a persistent measles infection. The disease starts with measles infection, usually before the child reaches their second year. This is usually followed by approximately 6-15 asymptomatic years. Some researchers think the asymptomatic period lasts about 5-8 years after the initial disease. The disease gradually progresses with psychological and neurological deterioration, including personality changes, seizures, and coma. It is always ultimately fatal.

Get vaccinated with the MMR vaccine to prevent all of this.

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