U.S. measles cases surpass 4,000: Pennsylvania more than 400 cases beyond the state

U.S. measles cases this year have surpassed 4,000, with over 25 percent of the nation’s reported infections coming from Pennsylvania, according to recently released data from the Centers of Disease Control and Prevention (CDC).

There are currently 4,080 measles cases reported across 47 states and Washington, D.C., the CDC confirmed Friday. Out of these reported infections, 1,105 originated in Pennsylvania measles, surpassing all other states.

The outbreak is the worst commonwealth has seen in more than 35 years and has subsequently sparked a public feud between its governor, Josh Shapiro, and U.S. Health Secretary Robert F. Kennedy Jr. over Pennsylvania’s reported deaths tied to measles.

Forty-two percent of cases across the U.S. in 2026 were among children aged 5 to 19, according to CDC data, while 17 percent are children under 5 and 40 percent are people over 20.

The CDC describes measles as a highly contagious virus but adds that two doses of the MMR vaccine provide the best protection against the illness. The Pennsylvania Health Department states both doses together are 97 percent effective at preventing measles for life.

In New York, the ongoing measles outbreak caused New York Gov. Kathy Hochul (D) to declare her first statewide disaster emergency of 2026 on Monday. The Empire State has reported 97 cases this year, up from 26 in 2025, according to the CDC.

Symptoms typically begin with a high fever, cough, runny nose and watery eyes, health experts say. Three to five days after symptoms begin, a rash may appear on the face, spreading downward.

The health district said the virus can live for up to two hours in an airspace where the infected person coughed or sneezed.

In 2025, three people in the U.S. died from measles — two in Texas and one in New Mexico.