Pennsylvania Measles Outbreak: 1,222 Cases and What to Know
Updated: 2 days ago
Written and medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Quick Answer
The Pennsylvania measles outbreak has reached 1,222 confirmed cases across 42 counties, with 225 people hospitalized and 5 confirmed measles-associated deaths, as of the October 14, 2026 state update. Almost every case was in unvaccinated people. The most important step is making sure your family has had two doses of the MMR vaccine [1].
The Pennsylvania measles outbreak has grown to 1,222 confirmed cases across 42 counties, with 225 people hospitalized and 5 confirmed measles-associated deaths, according to the state Department of Health's October 14, 2026 update. [1] A sixth death, in Franklin County, is under review. [2] Almost every case has been in people who were not vaccinated: only 4 cases (less than 1%) were in vaccinated people. [1] The most important step you can take is simple: make sure you and your family have had two doses of the MMR (measles, mumps and rubella) vaccine.
What the research says
Two vaccine doses give very strong protection. A Cochrane review of 138 studies covering more than 23 million participants found that the vaccine was 95% effective at preventing measles after one dose and 96% after two doses. The same review found no link between the MMR vaccine and autism (rate ratio 0.93, in 1,194,764 children) (Di Pietrantonj et al., Cochrane Database of Systematic Reviews, 2020) [9].
About 1 in 5 people in a large US outbreak needed hospital care. In the 2025 West Texas outbreak, 60 of 325 confirmed patients (18.5%) were hospitalized. Among the 54 whose records were reviewed, 72.2% had pneumonia, 70.4% needed extra oxygen, and all were unvaccinated or had unknown vaccination status. Most (88.9%) had no underlying medical conditions (Wang et al., MMWR Morbidity and Mortality Weekly Report, 2026) [10].
Big outbreaks start in communities with low vaccination rates. A CDC report on early 2025 found 800 US cases by April 17, about a 180% jump over all of 2024. Overall, 96% of patients were unvaccinated or had unknown vaccination status, 11% were hospitalized, and three died (Mathis et al., MMWR Morbidity and Mortality Weekly Report, 2025) [11].
Key takeaways
The Pennsylvania measles outbreak began in late April 2026 and has reached 1,222 cases in 42 counties as of October 14, 2026. [1] [3]
Nearly 20% of people with measles in Pennsylvania have been hospitalized. [1]
Two documented doses of the MMR vaccine give about 97% protection, and people with two documented doses do not need another dose. [1] [7]
If you are exposed and not immune, the MMR vaccine can still help if given within 72 hours, and immune globulin can be given within 6 days. [7]
Measles is contagious from about 4 days before to 4 days after the rash appears, and the virus can stay in the air for up to two hours. [1]
How big is the Pennsylvania measles outbreak?
The Pennsylvania measles outbreak is still growing. The state Department of Health added 86 new cases between October 9 and October 14 alone. [1] Nationally, the CDC counted 4,080 confirmed measles cases in 2026 as of October 8, with 414 hospitalizations, about 10% of cases. [5]
Measure | Pennsylvania (as of Oct 14, 2026) |
|---|---|
Confirmed cases | 1,222 |
Counties with cases | 42 |
Hospitalizations | 225 (nearly 20%) |
Confirmed measles-associated deaths | 5 (a sixth under review) |
Cases in vaccinated people | 4 (less than 1%) |
The confirmed deaths include two infants, an 18-year-old and a 40-year-old woman. [2] The state notes that measles kills about 1 to 3 of every 1,000 people who catch it. [3]
There is some encouraging news. Pennsylvania providers usually give about 25,000 MMR doses a month. They gave more than 56,000 in September and more than 23,000 in just the first two weeks of October. [1] The state health secretary has said new cases are not rising as quickly as before, but that it is still too early to say the spread is slowing. [4]
Why is measles so dangerous?
Measles is a highly contagious virus. [6] It spreads through the air when an infected person breathes, coughs or sneezes. [1] Symptoms start 7 to 21 days after exposure. They begin with fever, cough, runny nose and red, watery eyes, and a few days later a rash starts on the head and spreads downward. [1]
Measles can cause serious complications [8]:
Measles can also weaken the immune system's memory of past infections, so children may need some routine vaccines again. [8] A rare, fatal brain disease called SSPE can appear years later, mostly in children infected before age 2.
Who is protected, and who should check their MMR status?
The MMR vaccine is the main protection against measles, and adults with only one dose or no records should check their status with a provider or pharmacist. Here is how protection compares by vaccination status, based on CDC figures [7]:
Children routinely get their first MMR dose at 12 to 15 months and their second at 4 to 6 years. [7] Most adults need at least one dose or other proof of immunity, and some higher-risk adults need two. [7] Pennsylvania advises adults who have only one dose, or who cannot find their records, to talk with a health care provider or pharmacist. [1]
Babies under 12 months are usually too young for routine vaccination. [7] During outbreaks, health departments may advise an early extra dose for some infants, so parents in affected areas should ask their pediatrician. [6]
What should you do if you are exposed to measles?
If you are exposed to measles and unsure of your immunity, call your doctor ahead, ask about post-exposure protection and watch for symptoms for 21 days.
Call ahead. Phone your doctor, clinic or local health department before you go in, so you do not expose others in a waiting room.
Ask about post-exposure protection. The MMR vaccine given within 72 hours of exposure, or immune globulin (antibodies) given within 6 days, can lower the chance of getting sick. [7] A Cochrane review found that at least one vaccine dose after exposure was 74% effective at preventing measles in children (low-certainty evidence). [9]
Watch for symptoms for 21 days. Look for fever, cough, runny nose, red eyes and rash. [1]
Stay home if symptoms start. People are contagious from about 4 days before until 4 days after the rash appears. [1]
Pennsylvania residents with questions can call the state Department of Health hotline at 877-PA-HEALTH (877-724-3258). [1]
What does the Pennsylvania measles outbreak mean for the rest of the US?
Measles was declared eliminated in the United States in 2000 thanks to high two-dose MMR coverage. [11] Large outbreaks usually begin when the virus is brought in by a traveler and then reaches a close-knit community where many people are unvaccinated. [11] The Pennsylvania measles outbreak follows that pattern, and national case counts in 2026 have now passed 4,000. [5]
Nationally, CDC researchers note that high population immunity keeps the overall risk of widespread spread low. [11] The best protection for your family, and for babies and people with weak immune systems who cannot be vaccinated, is making sure everyone eligible has had two MMR doses.
Frequently asked questions
How many cases are in the Pennsylvania measles outbreak?
As of October 14, 2026, Pennsylvania reported 1,222 confirmed measles cases in 42 counties, 225 hospitalizations and 5 confirmed measles-associated deaths, with a sixth death under review. [1] [2]
I had two MMR shots as a child. Do I need a booster?
No. The Pennsylvania Department of Health and the CDC say people with two documented MMR doses are considered protected and do not need another dose. [1]
Can vaccinated people still get measles?
Rarely. Two doses are about 97% effective, so a small number of vaccinated people can still be infected. [7] In Pennsylvania, only 4 of 1,222 cases were in vaccinated people. [1]
Does the MMR vaccine cause autism?
No. A large Cochrane review that included more than 1.1 million children found no link between the MMR vaccine and autism. [9]
What are the first signs of measles?
Measles usually starts with fever, cough, runny nose and red, watery eyes. [1] [8] A few days later, a rash appears on the head and spreads down the body. [1]
Health information, not medical advice. This article is for general education and does not replace advice from your own doctor. If you think you or your child has measles, call your doctor or local health department before visiting a clinic.
Sources
Pennsylvania Department of Health. Pennsylvania Department of Health Provides Statewide Update on Measles Outbreak as Cases Reach 1,222 in 42 Counties. Pennsylvania Department of Health. October 14, 2026. https://www.pa.gov/agencies/health/newsroom/pa-department-of-health-provides-statewide-update-on-measles-out10
Steinzor P. Coroner Reports Pennsylvania's Sixth Measles-Associated Death. AJMC. October 14, 2026. https://www.ajmc.com/view/coroner-reports-pennsylvanias-sixth-measles-associated-death
Pennsylvania Department of Health. Pennsylvania Department of Health Provides Statewide Update on Measles Outbreak as Cases Reach 1,078 in 41 Counties. Pennsylvania Department of Health. October 7, 2026. https://www.pa.gov/agencies/health/newsroom/pa-department-of-health-provides-statewide-update-on-measles-out9
McFarlane L. Pa. Health Secretary Bogen says MMR vaccines up despite ongoing measles outbreak in state. WVIA News. October 14, 2026. https://www.wvia.org/news/local/2026-10-14/pa-health-secretary-bogen-says-mmr-vaccines-up-despite-ongoing-measles-outbreak-in-state
Mahatole S. US Measles Cases Rise to 4,080, CDC Says. Reuters (republished by GV Wire). October 9, 2026. https://gvwire.com/2026/10/09/us-measles-cases-rise-to-4080-cdc-says/
Pennsylvania Department of Health. Measles. Pennsylvania Department of Health. Accessed October 16, 2026. https://www.pa.gov/agencies/health/diseases-conditions/infectious-disease/measles
Centers for Disease Control and Prevention. Measles Vaccine Recommendations. Centers for Disease Control and Prevention. Updated March 3, 2026. https://www.cdc.gov/measles/hcp/vaccine-considerations/index.html
Mayo Clinic Staff. Measles: Symptoms and causes. Mayo Clinic. April 23, 2025. https://www.mayoclinic.org/diseases-conditions/measles/symptoms-causes/syc-20374857
Di Pietrantonj C, et al. Vaccines for measles, mumps, rubella, and varicella in children. Cochrane Database of Systematic Reviews. 2020;4(4):CD004407. PMID 32309885. https://doi.org/10.1002/14651858.CD004407.pub4
Wang D, et al. Characteristics of Patients Hospitalized with Measles During an Outbreak - West Texas, January-March 2025. MMWR Morbidity and Mortality Weekly Report. 2026;75(20):252-257. PMID 42207686. https://doi.org/10.15585/mmwr.mm7520a1
Mathis AD, et al. Measles Update - United States, January 1-April 17, 2025. MMWR Morbidity and Mortality Weekly Report. 2025;74(14):232-238. PMID 40273019. https://doi.org/10.15585/mmwr.mm7414a1
About the author: Dr. Baraa Alnahhal, MD, is a medical doctor and the founder of Rinnit. Dr. Baraa Alnahhal reviews new medical research and translates it into clear, evidence-based health information for everyday readers.
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