The first Pennsylvania measles case of 2025 has been confirmed. Yale School of Public Health Dean Megan L. Ranney, MD, MPH, joined CNN on March 3 to discuss this case and the growing measles outbreak in Texas.
Measles
Measles is an airborne virus that is typically characterized by a rash and fever. The virus is highly contagious and can cause serious health complications, especially in children.
Symptoms and How It Spreads
Symptoms appear 17 to 21 days after exposure to the disease. Symptoms include high fever (may spike to more than 104° F), cough, red eyes, runny nose, and fatigue, followed by a red rash that typically starts on the head or face and spreads across the body.
Severe complications may include pneumonia (the most common cause of measles-related death), encephalitis (brain inflammation that may cause seizures or permanent brain damage), severe dehydration from persistent diarrhea, and blindness (especially in malnourished individuals with Vitamin A deficiency). Around 1 in 5 unvaccinated people in the U.S. who get measles is hospitalized. 1 to 3 of every 1,000 children who become infected with measles will die. Measles can also lead to immune amnesia, which increases your vulnerability to other diseases.
Measles Can Spread in Several Ways:
- Airborne transmission (coughing or sneezing). Measless can live in the air for up to two hours.
- Direct contact with contaminated surfaces
- Person-to-person contact
A person with measles is contagious four days before and four days after the rash appears. Measles is so contagious that if one person has it, up to 90% of the people close to that person who are not immune will also become infected. This is a major concern in populations where herd immunity for measles – 95% of people vaccinated – isn't achieved.
Who is Most Vulnerable?
Infants under 12 months who haven’t yet been vaccinated, children under 5, pregnant women, and immunocompromised individuals are highly vulnerable to measles and should take extra precautions during an outbreak.
Treatment and Prevention
The best protection against measles is the measles, mumps, and rubella (MMR) vaccine. Two doses of MMR vaccine are 97% effective at preventing measles. One dose is 94% effective. While it is uncommon for someone who is fully vaccinated to develop measles, breakthrough infections can occur, especially in communities experiencing an outbreak where high levels of measles are circulating.
2025 Measles Outbreak
In 2025, an outbreak of Measles cases in several states was reported. The outbreak has been most prevalent in West Texas and New Mexico, particularly where vaccination rates are low.
Featured YSPH Involvement: Virtual Medical Operations Center Special Reports
Students in the Yale School of Public Health’s Public Health Emergencies: Disaster Planning and Response course have been putting together Special Reports twice a week to provide up-to-date, comprehensive data on the ongoing measles outbreak for both responders and the public.
The Virtual Medical Operations Centers (VMOC) briefs are a service learning project designed to teach students how to gather information and communicate effectively during emergencies such as natural disasters, outbreaks, and adversarial events.
Students gain valuable insight into the importance of collaboration and teamwork in disaster response. They learn that situational awareness is crucial in managing public health emergencies. The reports compile diverse information from a variety of sources—including status reports, maps, news articles, and online content—into a single, accessible document designed for wide distribution. These reports save Emergency Operations Centers (EOCs) and reporting agencies working on the ground precious time and allow them to utilize high quality information they may not have the resources to find themselves.
Key features of this report include:
- Comprehensive Overview: Each report provides situation updates, maps, relevant news, and web resources.
- Accessibility: Designed for easy reading, wide distribution, and interactive use.
- Collaboration: The “unlocked" format enables free, seamless sharing, copying, and adaptation by other responders.
The students learn by doing, quickly discovering how and where to find critical information, and presenting it in an easily understood manner.
This Virtual Medical Operation Center Special Report on the West Texas measles outbreak was created by students in our EHS 581 class, Public Health Emergencies: Disaster Planning and Response, as a service-learning project