U.S. measles cases reach 4,588 in 2026 as Pennsylvania outbreak keeps growing

The Centers for Disease Control and Prevention says 4,588 confirmed measles cases have been reported in the United States so far in 2026. The count runs through Oct. 22 and was posted in the agency’s weekly update on Oct. 23.

A week earlier, the CDC’s count stood at 4,410 cases as of Oct. 15, according to Reuters, so 178 cases were added in one week. The 2026 total is already about double the 2,289 confirmed cases the CDC recorded for all of 2025.

What the federal numbers show

According to the CDC, 47 jurisdictions have reported 4,570 of this year’s cases. The jurisdictions include 45 states, New York City and the District of Columbia. The other 18 cases were among international visitors. The agency has counted 43 new outbreaks this year, and 96 percent of confirmed cases, or 4,404, are linked to outbreaks.

The CDC lists three measles deaths in 2026. It says that number is subject to change, and that it is working with the Council of State and Territorial Epidemiologists on a standard case definition for deaths caused by measles.

The CDC updates its measles data weekly, using confirmed cases reported to the agency by noon each Thursday.

Pennsylvania at the center

Pennsylvania’s outbreak makes up a large share of the national total. On Oct. 23, the state Department of Health reported 1,338 confirmed cases this year, 21 of them confirmed since Oct. 21. Cases have been found in 44 counties, with Crawford County the newest. The department reported 255 hospitalizations and five confirmed measles-associated deaths. It said four cases, less than 1 percent, were in people who had been vaccinated.

The state’s count has climbed steadily. Its Oct. 19 update listed 1,286 cases in 42 counties and 247 hospitalizations.

On Oct. 13, the CDC said it would send more help to Pennsylvania after the state asked for assistance through the agency’s Epi-Aid emergency response program, according to Reuters. The CDC said it would work with local health officials to investigate the outbreak and limit its spread. The agency noted that Texas, South Carolina, Virginia, Kansas, New Mexico and Wisconsin had previously requested Epi-Aids for their own outbreaks.

Pennsylvania’s five reported deaths are more than the CDC’s national total. Reuters reported that this gap has led to a public disagreement over how measles deaths should be defined and counted. The disagreement is between Pennsylvania Gov. Josh Shapiro and Health and Human Services Secretary Robert F. Kennedy Jr., whose department oversees the CDC.

New York’s emergency order

New York has also stepped up its response. On Oct. 5, Gov. Kathy Hochul declared a State Disaster Emergency through Executive Order No. 65. The order lets paramedics, advanced EMS providers, pharmacists and midwives give measles vaccines, and lets nurses order measles tests. At the time, the state counted 108 cases this year, including 92 since July 15 in under-immunized rural communities spread across 18 counties.

“No one should get seriously ill or die from a vaccine-preventable disease,” Hochul said in announcing the order.

In the same announcement, New York Health Commissioner Dr. James McDonald called the measles, mumps and rubella (MMR) vaccine the best protection against the disease.