Measles Resurgence in the United States: 2025-2026 Crisis

The United States is experiencing a significant resurgence of measles, with cases in 2025 and 2026 reaching the highest levels since the disease was declared eliminated in 2000. Multiple large outbreaks across several states, declining vaccination rates, and policy changes at federal and state levels have placed the country's measles elimination status under review by international health authorities.

National Case Data and Trends

2025-2026 Case Totals

• In 2025, the U.S. recorded over 2,200 confirmed measles cases across 44 states, the highest annual number since 1991.
• In the first three months of 2026, the U.S. recorded 1,671 measles cases, representing 73% of the total cases from all of 2025.
• As of several reporting periods in early 2026, cumulative case counts reached figures between 1,100 and 1,792, depending on the date.
• The CDC reported approximately 2,267 confirmed cases for 2025 and 2,065 cases as of December 30, 2025.

Demographic Data

Approximately 93-96% of cases were among individuals who were unvaccinated or whose vaccination status was unknown.

• Of cases with known vaccination status:
  • 3% had received one dose of the MMR vaccine.
  • 3-4% had received the recommended two doses.
• 85% of cases in some states (e.g., California) were in individuals under age 20.
• Over 80% of cases nationally among children and teens, with approximately 25% affecting children under five years old.

Mortality and Hospitalization

• Three measles deaths were reported nationally in 2025:
  • Two unvaccinated school-age children in Texas.
  • One unvaccinated adult in New Mexico.
• These were the first U.S. measles fatalities in a decade.
• Approximately 1 in 5 unvaccinated individuals who contract measles require hospitalization.
• Hospitalization rates for some outbreaks ranged between 1-2% to over 10% of infected persons.
• Severe complications reported include pneumonia and encephalitis (brain swelling).

Major State Outbreaks

South Carolina

• An outbreak began in October and became the largest single measles outbreak in the U.S. since the disease was declared eliminated in 2000.
• Total cases reached between 997 and 1,000 by the time the outbreak was declared over.
• The outbreak was primarily concentrated in Spartanburg County in the northwest region of the state.
• Over 500 individuals were reported in quarantine at various points during the outbreak.
• At least 21 hospitalizations were reported.
• State epidemiologist reports indicated some children developed encephalitis.

• South Carolina health officials declared the outbreak over after 42 consecutive days with no new outbreak-related cases.
• State health officials attributed containment to timely investigations, identification of exposures, contact tracing, and voluntary quarantines.

• From October to March, approximately 82,000 measles vaccines were administered in the state, a 30% increase over the previous year.
• Spartanburg County saw a 94% increase in vaccinations.
• Health measures included:
  • Sending nearly 2,300 quarantine letters.
  • Making over 1,670 case investigation calls.
  • Quarantining 874 students across seven school districts.
• Response cost estimated at $2.1 million.

• Spartanburg County's student immunization rate for required vaccines was less than 90%.
• National MMR vaccination rates among kindergartners dropped from 95.2% in the 2019-20 school year to 92.5% in the 2024-25 school year.
• Religious exemptions for school vaccines in the outbreak region more than doubled since 2020.
• Statewide, 4% of school-age students had religious exemptions for the 2025-26 school year.

• A bill introduced in the South Carolina state legislature would prohibit requiring vaccines for children under 2 years old.
• Proponents, including State Sen. Carlisle Kennedy, stated the aim is to protect parental rights.
• Opponents, including pediatricians, argue it would undermine herd immunity.
• A Senate subcommittee advanced the legislation.
• At least eight anti-vaccine bills were introduced in the state as of late October the previous year.

Texas

An outbreak in rural Gaines County infected 762 individuals, including two unvaccinated children who died.

• An outbreak began in late January and concluded in mid-August.
• Official case count: 762 infected individuals, primarily in rural Gaines County.
• Two unvaccinated children died.
• An estimated 182 potential measles cases in Gaines County went unconfirmed in March 2025.

Utah-Arizona Border

• An outbreak beginning in June has resulted in over 600 reported cases.
• Genomic analysis by the CDC indicates transmission may have begun 6 weeks to 14 months before the first confirmed case.
• Actual cases may be at least 6.5 times higher than reported.
• Cases in Utah: 607; cases in Mohave County, Arizona: 282.
• Officials confirmed the Utah outbreak strain is linked to the Texas outbreak.

California

• California recorded at least 40 confirmed measles cases in 2026, the highest single-year total since 2019 (73 cases).
• Three outbreaks identified in 2026:
  • Riverside County: 3 people in a single family.
  • Shasta County: 9 people in a church group.
  • Sacramento and Placer Counties: Ongoing outbreak.
• State's kindergarten vaccination rate: 96.1% in 2024-25.
• California law requires vaccinations for school enrollment with exceptions only for medical reasons.

Oregon

• Oregon's nonmedical vaccine exemption rate for kindergartners reached 9.7% in the 2024-25 school year, a state record.
• The state ranked fourth nationally for nonmedical exemption rates.
• Oregon recorded multiple measles cases in early 2026 following two cases confirmed in Linn County.
• Exposure sites identified in Linn County hospitals.

Florida

• Florida reported approximately 130-134 cases.
• An outbreak centered around Ave Maria University in Collier County, with over 100 cases reported.
• Other cases reported in unspecified locations.

Colorado

• Colorado reported a new outbreak in March in suburban Denver.
• Cases linked to Broomfield High School and Broomfield Heights Middle School.
• The state recorded 35 measles cases in 2025.

Federal Policy and Response

CDC Data Release and Genomic Analysis

• The CDC began publishing advanced genetic data from measles viruses that circulated in 2025.
• The data release was delayed for months due to staffing challenges.
• The CDC partnered with the Broad Institute, which sequenced approximately 1,000 samples from 2025 and 2026.
• The CDC is analyzing whole genomes to determine if major outbreaks are related.
• Preliminary CDC analysis suggests the Texas and subsequent outbreaks are not directly linked.

Leadership Statements and Actions

Health and Human Services Secretary Robert F. Kennedy Jr. has made statements and policy changes regarding vaccines, promoting remedies described as unproven for measles treatment.

• Changes were made to vaccine information on CDC websites, which some medical associations stated are not evidence-based.
• Acting CDC Director Jay Bhattacharya supported a decision to reduce recommended childhood vaccines, which a federal court temporarily invalidated.
• CDC Principal Deputy Director Dr. Ralph Abraham described potential loss of measles elimination status as "the cost of doing business with our borders."
• Centers for Medicare & Medicaid Services Administrator Dr. Mehmet Oz urged Americans to get vaccinated against measles.

International Review

• The Pan American Health Organization (PAHO) is responsible for determining the U.S. elimination status.
• PAHO postponed an initial evaluation from April to November.
• PAHO issued an epidemiological alert due to measles surge across the Americas.
• Canada lost its measles elimination status in November.
• The U.S. is at risk of losing its elimination status, maintained since 2000.

Vaccination Information

Vaccine Efficacy

• Two doses of the MMR vaccine are 97% effective at preventing measles.
• One dose is 93% effective.
• Vaccinated individuals who contract measles typically experience milder illness.

National Vaccination Rates

The herd immunity threshold is 95%. The current national MMR vaccination rate among kindergartners is 92.5%.

• 92.5% of kindergartners received the MMR vaccine in the 2024-25 school year.
• This is a decline from 95.2% in the 2019-20 school year.
• A record 138,000 kindergartners obtained vaccine exemptions for the 2024-25 school year.

Recommended Schedule

• First dose: 12 to 15 months of age.
• Second dose: 4 to 6 years of age.
• Early vaccination can be administered as early as 6 months during outbreaks or for international travel.

Regional Exposure Events

Oregon

The Oregon Health Authority (OHA) reported multiple potential measles exposure locations in the Portland metropolitan area in late March:

• Safeway (2800 S.E. Hawthorne Blvd., Portland):
  • March 26: 8 a.m. – 6 p.m.
  • March 27: 2 p.m. – midnight
  • March 28: 2:20 p.m. – 6 p.m.
  • March 29: 2 p.m. – midnight
• Gresham Winco: March 7 (specific times not provided)
• Providence Portland Medical Center Emergency Waiting Room: March 30
• Lark Café (West Linn): March 27, 12 p.m. – 3 p.m.
• Pho.Com restaurant (Gresham): March 25, 4 p.m. – 6:30 p.m.

Additional exposure sites in Keizer:

• Solar Nails (4910 River Road N.): March 30, 12 p.m. – 4:15 p.m.
• Pho Keizer (3400 River Road N.): March 30, 2:30 p.m. – 5:30 p.m.

Washington, D.C.

DC Health issued a warning for potential measles exposure at the National March for Life rally and concert.

Exposure locations included:

• Ronald Reagan Washington National Airport
• Union Station
• Amtrak Northeast Regional train
• D.C. subway system (Metro)
• Basilica of the National Shrine of the Immaculate Conception
• Catholic University
• Children's National Hospital Emergency Department (February 2)

North Carolina

• Three siblings in Buncombe County contracted measles after a visit to Spartanburg County, South Carolina.
• A child in Polk County was confirmed with measles on December 31, 2025, also after visiting South Carolina.
• Exposure location identified: Mission Hospital Emergency Department waiting room in Asheville (January 4, 2 a.m. – 6:30 a.m.).
• The hospital was cited by CMS for failures in isolating suspected measles patients, exposing at least 26 individuals.

California

• Disneyland exposure: January 28, a child with measles visited the park. No linked cases confirmed as of later reports.
• Los Angeles County: 4 cases among international travelers.
• Orange County: Cases in a young adult and toddler, plus two travelers to Disneyland.

Mexico Outbreak

Case Data

Mexico has reported at least 40 deaths from measles since the start of 2025, with more than 17,000 confirmed infections.

• The outbreak originated in Chihuahua state and spread to all 32 Mexican states.
• Jalisco state became the epicenter in 2026.
• Mexico leads the Americas region in cases, with 1,981 confirmed cases in the current year.

Origin and Spread

• The outbreak is linked to a strain (genotype D8, lineage MVs/Ontario.CAN/47.24) that originated in Canada in 2024, later appeared in Texas, and spread to Mexico via an unvaccinated 9-year-old boy returning from Seminole, Texas.
• First cases appeared in a Mennonite community in Cuauhtemoc, Chihuahua state, with an estimated 30% vaccination rate.
• The virus spread to agricultural laborers, many Indigenous, with low vaccination rates.

Government Response

• Mexico launched a nationwide vaccination campaign, administering about 25 million doses.
• Health teams in Chihuahua vaccinated nearly half of the state's 4 million residents.
• Jalisco mandated face masks in schools in seven Guadalajara neighborhoods for 30 days.

Vaccination Rates

• Vaccine coverage in Mexico fell below 80% by 2023.
• In Chihuahua, about two-thirds of 1-year-olds had received the first measles shot in 2024.

Disease Information

Transmission

Measles is one of the most contagious infectious diseases known.

• Spreads through airborne particles when an infected person breathes, speaks, coughs, or sneezes.
• The virus can remain airborne for up to two hours after an infected person leaves an area.
• Up to 90% of unvaccinated individuals exposed to the virus will contract measles.

Symptoms

• Incubation period: 7 to 21 days.
• Early symptoms: high fever (up to 104 degrees Fahrenheit), cough, runny nose, conjunctivitis (red, watery eyes).
• Koplik spots (tiny white spots inside the mouth) may appear 2-3 days after initial symptoms.
• Characteristic red, blotchy rash appears 3-5 days after symptoms begin, starting on the face and spreading downward.
• Infected individuals are contagious from 4 days before the rash appears until 4 days after it appears.

Complications

• Pneumonia: affects approximately 1 in 20 infected children.
• Encephalitis: affects approximately 1 in 1,000 infected children, can lead to permanent brain damage.
• Death: 1 to 3 per 1,000 infected children.
• Immune amnesia: virus can suppress the immune system, increasing risk of severe disease from other infections.
• Subacute sclerosing panencephalitis (SSPE): rare, fatal degenerative central nervous system disease that can develop 7-10 years after infection.