US measles cases reach 4,080 in 2026, highest level in decades

U.S. measles cases reached 4,080 in October 2026, marking the highest annual infection total in decades. Pennsylvania stands as the epicenter with over 1,100 cases, fueling a dispute between Governor Josh Shapiro and HHS Secretary Robert F. Kennedy Jr. after the state reported five deaths while the CDC recognized only two. Over 95% of cases involve unvaccinated or unknown-status individuals, with children under 19 accounting for most infections.

National measles outbreak overview

• ▪The 2026 U.S. measles total follows a 2025 surge of 2,289 confirmed cases across 48 outbreaks, placing the nation in danger of losing its 2000 disease elimination status.
• ▪A total of 42 separate measles outbreaks have been reported across at least 45 states and Washington, D.C. in 2026, with 96% of confirmed cases linked to outbreaks.
• ▪The U.S. Centers for Disease Control and Prevention reported 4,080 confirmed U.S. measles cases in 2026 as of October 8, marking the highest annual infection total since the early 1990s.

Vaccination status and coverage rates

• ▪U.S. kindergarten MMR vaccination coverage dropped to 92.4% during the 2025-26 school year, down from 95.2% in the 2019-20 school year.
• ▪CDC data showed that 2% of 2026 U.S. measles cases occurred in individuals who received one MMR vaccine dose, and 2% occurred in those who received the full two-dose series.
• ▪Approximately 95% of confirmed U.S. measles cases in 2026 occurred among individuals who were unvaccinated or whose vaccination status was unknown.

Age distribution of cases

• ▪Children aged 5 and younger accounted for 17% of all reported U.S. measles cases in 2026.
• ▪Adults aged 20 and older accounted for 1,635 measles cases in 2026, representing 40% of the total U.S. infections.
• ▪Children and teenagers aged 5 to 19 accounted for the largest share of 2026 U.S. measles cases at 1,716 infections, or 42% of the national total.

Measles hospitalizations

• ▪The CDC reported 414 measles-related hospitalizations in the U.S. in 2026, representing approximately 10% of total confirmed cases.
• ▪Approximately 10% of children under age 5 infected with measles in 2026 required hospitalization, according to CDC data.

Pennsylvania outbreak and response

• ▪Pennsylvania health officials reported over 1,136 measles cases in 2026, accounting for more than 25% of all reported U.S. infections.
• ▪Pennsylvania recorded 219 hospitalizations tied to its measles outbreak as of October 2026.
• ▪An 18-year-old woman in Mifflin County, Pennsylvania died in September 2026 from brain swelling caused by measles complications.
• ▪Pennsylvania health authorities reported that more than 56,000 MMR vaccine doses were administered in September 2026 alongside pop-up clinics in affected areas.

Disputes over measles death reporting

• ▪Pennsylvania health officials reported five measles-associated deaths in 2026, whereas the CDC officially recognized only two nationwide deaths.
• ▪The death toll discrepancy sparked a public feud between Pennsylvania Governor Josh Shapiro and HHS Secretary Robert F. Kennedy Jr. over mortality definitions.
• ▪The CDC transitioned to using mortality data from the National Center for Health Statistics rather than relying directly on state health departments for measles death reporting.

South Carolina outbreak

• ▪The 2026 U.S. outbreak initially centered in South Carolina, which recorded 670 cases before state officials declared its initial surge over in April 2025.
• ▪South Carolina recorded the second-highest number of reported measles infections in the United States in 2026, behind Pennsylvania.

New York cases and emergency declaration

• ▪According to CDC data, New York state reported 26 measles cases in 2025.
• ▪New York Governor Kathy Hochul declared a statewide disaster emergency after New York reported around 100 measles cases through October 2026.

Debatable claims

• ▪Declining kindergarten MMR vaccination coverage is the primary cause of the 2026 US measles surge
• ▪HHS should prioritize boosting MMR vaccination rates over expanding vaccine injury tracking databases
• ▪Continuous nationwide transmission means the United States has lost its measles elimination status