The United States has recorded more than 5,000 cases of measles in 2026, marking the highest number of infections the country has seen in 35 years. The Centers for Disease Control and Prevention (CDC) reported 5,182 confirmed cases of the highly contagious disease so far this year. That is more than double the 2,289 cases reported in all of 2025, even though the US declared measles eliminated more than twenty years ago.
Children and teenagers have been hit hardest by the virus, making up about 59 percent of all confirmed patients. According to federal health data, 18 percent of cases are in children under five years old, while 41 percent are between the ages of five and 19. Health experts connect the surge to a steady drop in vaccination coverage. Among US kindergarten children, vaccination rates dropped from 95.2 percent in the 2019–2020 school year to 92.4 percent in 2025–2026. Nearly 5,000 of this year's cases were linked directly to local outbreaks.
At the same time, health officials are arguing over how many people have died from the disease. The CDC officially lists four measles deaths nationwide this year. However, state officials in Pennsylvania, the hardest-hit state with 1,487 cases, have reported six deaths. Pennsylvania counts a measles-associated death when an infected patient dies within 30 days of developing symptoms. In August, the CDC removed two Pennsylvania deaths from its national total after US Health Secretary Robert F. Kennedy Jr. questioned whether measles was the true cause.
Infectious disease experts warn that changing the way deaths are classified goes against longstanding methods used by both the CDC and the World Health Organization. As measles cases also increase in other countries where vaccination rates are falling, health experts emphasize that preventing outbreaks is a shared global responsibility, because lower protection in one area can quickly put people thousands of miles away at risk.