Measles Outbreak 2026: US Confirms First Deaths as Cases Hit 2,777 — What You Need to Know

The United States measles outbreak of 2026 has become the nation’s worst in more than three decades, with the CDC now reporting 2,777 confirmed measles cases across 45 states — and the first measles deaths of the year. Pennsylvania confirmed two fatalities in unvaccinated individuals, the state’s first measles deaths in 35 years. Public health officials are urging families to check their MMR vaccination status as cases continue to climb at an accelerating pace.

Measles outbreak 2026: what the latest CDC numbers show

The Centers for Disease Control and Prevention added 211 new infections in its latest weekly update — more than double the 101 cases added the week before. The key figures paint a stark picture:

• 2,777 confirmed cases in 2026 across 45 states, plus New York City and Washington, DC
• 36 outbreaks reported this year, defined as three or more related cases
• 2,289 cases were recorded in all of 2025 — a record at the time, now surpassed
• 94% of cases are in people who are unvaccinated or have unknown vaccination status
• Only 16 cases this year were linked to international travel; the rest were locally acquired
• 19% of cases involve children aged 5 and under, while 66% involve children and teens
• 7% of patients have required hospitalization

Pennsylvania remains the current hotspot, reporting 89 of the newest cases. South Carolina leads the nation with 670 cases, followed by Utah with 526 and Pennsylvania with 393.

First US measles deaths of 2026 confirmed in Pennsylvania

On August 25, the Pennsylvania Department of Health confirmed two measles-associated deaths in Lancaster County — the state’s hardest-hit county. Both individuals were unvaccinated. It is the first measles death recorded in the United States in 2026, and Pennsylvania’s first in 35 years.

“Because measles was largely eliminated in the Commonwealth for more than three decades, people are not familiar with this disease and don’t fully understand the potential severity of the illness,” said Debra Bogen, MD, Pennsylvania’s Secretary of Health. “The measles, mumps, and rubella (MMR) vaccine is safe and provides the best protection we have against measles.”

Last year, three people — including two children — died of measles in the US, the first measles deaths in the country in more than a decade.

Why is measles spreading again?

Measles was declared eliminated in the United States in 2000, meaning the disease was no longer continuously circulating. That status is now in jeopardy. Falling vaccination rates are the primary driver:

• The national MMR vaccination rate among kindergarteners fell from 95.2% in 2019–2020 to 92.4% in 2025–2026
• The proportion of children with vaccine exemptions rose to 4.2%, up from 3.6% the previous year
• Measles is one of the most contagious diseases known — one infected person can spread it to up to 9 out of 10 unprotected people nearby

Measles spreads through the air when an infected person coughs or sneezes, and the virus can linger in a room for up to two hours after they leave. In November, international health officials will meet to decide whether the US retains its measles elimination status.

Measles symptoms and complications

Symptoms typically appear 7 to 14 days after exposure and include:

• High fever, often above 103°F (39.4°C)
• Cough, runny nose, and red, watery eyes (conjunctivitis)
• A characteristic red rash that begins at the hairline and spreads downward over the body
• Tiny white spots inside the mouth (Koplik spots)

A person is contagious from four days before the rash appears until four days after. Complications are serious and can include pneumonia, brain swelling (encephalitis), and permanent hearing loss. Children under 5 and adults over 20 face the highest risk of severe illness. Measles can also cause “immune amnesia,” wiping out immune memory and leaving survivors vulnerable to other infections for months or years.

MMR vaccine: the best protection

The MMR vaccine remains the cornerstone of measles prevention:

• One dose is 93% effective at preventing measles; two doses are 97% effective
• The American Academy of Pediatrics recommends routine vaccination at 12–15 months, with a second dose at 4–6 years
• Infants as young as 6 months can receive an early dose when traveling to outbreak areas
• Adults born after 1957 who have not been vaccinated or had measles should receive at least one dose; those in high-risk settings should have two

When enough people are vaccinated, herd immunity protects the most vulnerable — including babies too young to be immunized and people with weakened immune systems.

Frequently asked questions about the 2026 measles outbreak

Q: How contagious is measles?
A: Extremely. Measles is one of the most transmissible infectious diseases known. If one person has it, up to 90% of unvaccinated people close to them will become infected. The virus stays airborne in a room for up to two hours after the infected person leaves.

Q: I was vaccinated as a child. Do I need a booster?
A: Most people who received two doses of MMR as children are protected for life and do not need a booster. If you are unsure of your status, a blood test can confirm immunity, and your healthcare provider can advise based on your risk.

Q: What should I do if I think I was exposed to measles?
A: Contact your healthcare provider immediately — do not walk into a clinic or emergency room unannounced, as you could expose others. If you are unvaccinated, a dose of MMR within 72 hours of exposure may provide some protection, and immune globulin can help in certain high-risk cases.

Q: Is the MMR vaccine safe?
A: Yes. The MMR vaccine has been used safely for more than 50 years. Serious side effects are extremely rare. Extensive research has found no link between the MMR vaccine and autism.

Q: Why is this outbreak worse than recent years?
A: The surge reflects declining routine childhood vaccination rates, rising vaccine exemptions, and pockets of unvaccinated communities where the virus can spread rapidly once introduced.

Bottom line

The 2026 measles outbreak is a public health emergency that has already cost lives. With the US on the verge of losing its elimination status, health authorities are clear: the MMR vaccine is safe, effective, and the single best tool for stopping this outbreak. If you or your children are unvaccinated or behind schedule, now is the time to catch up.