U.S. Measles Cases Reach 35-Year High in 2026

The United States has recorded 2,295 measles cases in 2026 as of July 21, marking a 35-year high and surpassing the 2025 total of 2,289 cases. Fueled by declining MMR vaccination rates among kindergartners—which fell to 92.5%, below the 95% herd immunity threshold—large outbreaks in South Carolina and Utah have driven the resurgence. This surge threatens the nation's official measles elimination status, which has been held since 2000 and is scheduled for formal review in November 2026.

U.S. measles case surge

• ▪The Centers for Disease Control and Prevention reported 2,260 confirmed cases across 44 jurisdictions as of July 16, 2026.
• ▪The 2,295 measles cases recorded in 2026 represent the highest annual total in the United States since 1991.
• ▪The United States recorded 2,295 measles cases in 2026 as of July 21, 2026, surpassing the 2025 total of 2,289 cases.
• ▪South Carolina has reported the highest number of measles cases in 2026 with 670 cases, followed by Utah with 518 cases.

Declining vaccination rates

• ▪The decline in MMR vaccination coverage to 92.5% left approximately 286,000 kindergartners unprotected during the 2024-2025 school year.
• ▪Public health officials state that measles vaccination rates must remain above 95% to maintain herd immunity.
• ▪National MMR vaccination coverage among United States kindergartners fell from 95.2% in the 2019-2020 school year to 92.5% in the 2024-2025 school year.

Measles transmission mechanisms

• ▪Measles is highly contagious, with an unvaccinated person having a 90% chance of contracting the virus upon exposure.
• ▪An infectious person can transmit the measles virus to up to 18 other people, compared to an infection rate of 2 for influenza.

Measles health complications

• ▪Approximately 6% of measles patients in 2026, totaling 146 people, have been hospitalized, with no reported deaths as of July 2026.
• ▪Measles can lead to severe complications including ear infections, pneumonia, and encephalitis, which can cause permanent brain damage or death.
• ▪Measles symptoms include high fever, cough, runny nose, watery eyes, and a red, raised rash appearing seven to 14 days after exposure.

Vaccine safety profile

• ▪The MMR vaccine protects against measles with 97% efficacy when administered in the standard two-dose schedule.
• ▪Rigorous scientific studies have confirmed that the measles vaccine does not cause irritable bowel disease or autism.

Public health response challenges

• ▪Canada lost its measles elimination status in 2025 after endemic transmission of the virus was re-established.
• ▪The United States' measles resurgence occurs while key federal health leadership positions, including the CDC director and surgeon general, remain vacant.
• ▪The Pan American Health Organization's Regional Verification Commission is scheduled to review the United States' measles elimination status in November 2026.