Measles Resurgence: A Growing Public Health Concern in the U.S.
Measles cases in the United States have become a significant public health issue over the last two years. According to a Johns Hopkins University tracker using state and local health data, there were 2,295 confirmed measles cases in the U.S. as of July 22. This number exceeds the 2,286 cases reported in 2025.
Concentrated Outbreaks
Reported cases are scattered across the country, but specific areas in Pennsylvania, South Carolina, Florida, Virginia, Utah, Texas, and Arizona have seen more significant outbreaks. Texas had the largest outbreak in 2025 with a total of 803 cases.
Recent data from the CDC, as of July 17, show 34 new outbreaks reported in 2026, compared to 48 in 2025. Most of these cases are linked to local outbreaks, though some originate from international visitors.
Vaccination and Age Groups
Data reveal that 93% of measles patients in both 2025 and 2026 were unvaccinated or had unknown vaccination status. Children and young adults aged 5 to 19 are the most affected groups. There have been no measles-related deaths reported in 2026; however, there were three in 2025.
Transmission and Symptoms
Health officials note that measles spreads through direct contact with infectious droplets or becomes airborne when an infected person breathes, coughs, or sneezes. The virus can remain infectious in the air for up to two hours after an infected person leaves. Symptoms typically appear within one to two weeks, beginning with a high fever, cough, runny nose, and red, watery eyes. Flat red spots appear on the face and spread downwards to the body a few days later. Individuals are most contagious from four days before to four days after the rash appears.
“Measles is so contagious that up to 90% of susceptible people who are exposed to an infected person will become infected,” said Dr. Marc Siegel, emphasizing the importance of community protection.
Community Protection and Vaccine Recommendations
Dr. Marc Siegel, a senior medical analyst, highlights the necessity of maintaining a 95% vaccine coverage rate to achieve herd immunity. The herd immunity threshold relies on how contagious the disease is and how effectively vaccination or prior infection immunity prevents its spread.
The CDC recommends two doses of the MMR vaccine, advocating it as the best defense against measles. The two-dose vaccination is nearly 100% effective, and natural immunity after infection is generally lifelong. Dr. Siegel stresses that this is not about personal choice but community protection, particularly for individuals who cannot receive a live virus vaccine due to being immunocompromised or pregnant.
People showing symptoms of measles or who believe they have been exposed should self-isolate and contact their doctor before visiting a medical center to prevent further spread.