Cases Are Accelerating as Summer Peaks
The United States has confirmed 2,231 measles cases in 2026 as of July 9, with five months of transmission season remaining and the peak summer and fall period still ahead. The figure, confirmed by the CDC, leaves the country just 58 cases below the full-year 2025 total of 2,289. At the current pace, 2026 is on track to become the worst measles year in the United States since 1992.
The consequences of this acceleration are more than statistical. The Pan American Health Organization (PAHO) has a formal review of the U.S. measles elimination status scheduled for November 2026. The U.S. has held that status since 2000. Elimination requires no uninterrupted domestic transmission for 12 consecutive months, a standard the current data pattern makes increasingly difficult to meet.
Why This Matters
Measles is among the most contagious infectious diseases known. The CDC notes that if one infected person enters a room, up to nine out of ten unprotected people nearby may contract the virus. It spreads through the air when an infected person coughs, sneezes, or breathes, and it can remain infectious in a room for up to two hours after the person leaves.
The practical implication for families is stark: communities where MMR vaccination rates have dropped below the 95% threshold needed for herd immunity can sustain rapid local transmission chains. That threshold has been crossed in dozens of school districts across the country, and kindergarten MMR vaccination rates have declined from 95.2% during the 2019 to 2020 school year to 92.5% in 2024 to 2025, according to CDC estimates cited by Global Biodefense. The same data suggest approximately 286,000 kindergartners entered the 2024 to 2025 school year without adequate measles protection.
What We Know So Far
CDC data updated July 10, 2026 show 2,231 confirmed measles cases reported across 42 jurisdictions — every major U.S. region is affected. The 32 new outbreaks reported in 2026 bring the combined outbreak count from 2025 and 2026 to more than 80. Among the 2,231 confirmed 2026 cases, 93% — or 2,082 of 2,231 — are linked to active outbreak clusters.
Of the 2,231 confirmed cases, approximately 92% involve people who were unvaccinated or whose vaccination status was unknown. Only 4% of cases occurred in people who had received both recommended MMR doses.
Three measles deaths were confirmed during the combined 2025 to 2026 outbreak period — two in unvaccinated children in Texas, one in an adult in New Mexico. No deaths have been confirmed in 2026 to date, according to KFF.
Where the Risk Is Highest
The South Carolina outbreak, the largest single cluster of 2026, exceeded 600 cases before officials declared it over in April after 42 days without a new outbreak-related case. Utah's ongoing outbreak — which began in 2025 — has recorded more than 400 cases in 2026 alone.
Active exposures continue across the country. Nashville, Tennessee confirmed two measles cases with seven exposure sites across Nashville and Murfreesboro spanning late June through early July 2026. The Philadelphia Department of Public Health confirmed on July 11 that a person with measles traveled through Philadelphia International Airport on July 4, 2026, between 7:30 a.m. and 11:15 a.m. Anyone present in Terminals A, B, and C during that window who is not immune should monitor for symptoms through July 25.
The Johns Hopkins Bloomberg School of Public Health's IVAC measles tracker shows the highest caseloads in states including South Carolina, Texas, Utah, Ohio, Michigan, and North Carolina — states that also share characteristics including school districts with MMR vaccination rates well below the 95% herd immunity threshold.
What Doctors and Experts Say
Public health experts at KFF note that the metrics now tracking in 2025 and 2026 are "notably worse" than both the elimination period of 2001 to 2011 and the 2019 outbreak that previously threatened elimination status.
A Common Health Coalition report cited by U.S. News & World Report found that a 1% decrease in childhood MMR vaccination rates could produce 17,000 additional measles cases, 4,000 hospitalizations, and 36 preventable deaths per year. "Vaccination is one of the most powerful investments we can make for the health of our children, but when we fail to maintain high vaccination rates, we all pay the price," the report's authors wrote.
Acting CDC Director Jay Bhattacharya stated in March 2026 that "measles is preventable and vaccination remains the most effective way to protect yourself and those around you" — a statement that reflected a shift in public messaging after earlier, more mixed signals from federal health leadership during the height of the 2025 outbreak.
What the Evidence Shows and What It Does Not
The 2026 measles data are lab-confirmed cases from CDC's national notification system — not estimates. They represent real infections in real people. The 2,231 figure is solid.
What remains formally undetermined is whether PAHO will conclude in November that the United States has lost its measles elimination status. Elimination requires no uninterrupted domestic transmission for 12 consecutive months. Whole-genome sequencing of the D8-9171 measles lineage, which has been circulating since at least January 2025, will be central to that determination, according to researchers at CIDRAP and Johns Hopkins.
MedicalDaily Evidence Check
- Data source: CDC national measles case surveillance, updated July 10, 2026
- Confirmed 2026 cases: 2,231 across 42 jurisdictions
- 2025 full-year total: 2,289
- Cases in unvaccinated or unknown vaccination status individuals: approximately 92%
- 2026 new outbreaks: 32 (in addition to ongoing 2025 outbreaks)
- Elimination status review: PAHO scheduled for November 2026
- What it does not prove: Whether the U.S. has formally lost elimination status; that determination requires formal PAHO review
Who Faces the Greatest Risk
The groups most vulnerable to measles and its complications include:
- Unvaccinated children , who make up the largest share of outbreak-associated cases
- Infants under 12 months , who are too young to receive the MMR vaccine and depend on community immunity and maternal antibodies for protection
- People who received only one MMR dose (two doses are required for full protection)
- Immunocompromised individuals , including cancer patients, transplant recipients, and people on certain medications
- Pregnant women , for whom measles can cause preterm labor and low birth weight
- Adults with unknown or unverifiable vaccination history , particularly those born between 1957 and 1989 who may have received an older, less effective formulation
Communities with kindergarten MMR vaccination rates below 95% face the highest collective risk when an infected traveler introduces the virus.
Symptoms and Warning Signs to Watch For
Measles symptoms typically appear seven to fourteen days after exposure, with a maximum incubation window of 21 days. Initial symptoms include:
- High fever, often reaching 104°F or higher
- Cough
- Runny nose
- Red, watery eyes (conjunctivitis)
- Small white spots inside the mouth (Koplik's spots), which appear before the rash
- A distinctive red rash that begins on the face and spreads downward over the body, usually appearing three to five days after initial symptoms begin
Serious complications — most common in children under five, adults over 20, pregnant people, and immunocompromised individuals — can include pneumonia, encephalitis (brain swelling), permanent hearing loss, and death.
Contact a clinician before going to a medical facility if you suspect measles exposure, so the office can prepare to prevent further transmission in the waiting area.
What You Can Do Now
- Verify your vaccination records and those of your children before the new school year begins. The MMR vaccine requires two doses for full protection.
- Contact your child's pediatrician if vaccination status is uncertain, especially for children born after 1989.
- Adults born between 1957 and 1989 who received only one MMR dose, or who received an older inactivated measles vaccine, should speak with a clinician about whether a booster is recommended.
- Monitor the CDC's weekly measles case counts and any local health department alerts for your county or city.
- If you suspect measles , call your healthcare provider before arriving. The virus can remain airborne for up to two hours in an enclosed space, and an unprotected waiting room creates an exposure risk for others.
- Seek prompt medical attention if a child develops a high fever with a spreading rash, particularly if they have had a recent possible exposure or are unvaccinated.
Cost and Access: What Patients Should Know
The MMR vaccine is widely available, typically covered at no out-of-pocket cost under the Affordable Care Act's preventive services mandate for most insured individuals. Uninsured adults and families can access MMR vaccination at no cost through the Vaccines for Children program, which covers all recommended vaccines for children under 19. Community health centers and local health departments also offer MMR vaccination on a sliding-fee scale for uninsured adults.
What Happens Next
CDC publishes updated confirmed case counts every Thursday. The next major data update is expected by July 17, 2026. With summer travel, camps, and fall school enrollment approaching, public health officials and researchers expect the transmission pace to continue or accelerate before the PAHO November review.
State health departments in high-burden areas — including Texas, Utah, Ohio, Michigan, and South Carolina — are continuing outbreak investigations and vaccination outreach programs.
MedicalDaily will update this story with each weekly CDC count and will report on the November PAHO determination when it is issued.
The Bottom Line
Two years into a measles emergency that is now threatening a 26-year public health milestone, the most important action available to every family in the United States is straightforward: confirm that every child and eligible adult in the household has received two doses of the MMR vaccine. For infants under 12 months who are not yet eligible, protecting the community around them is the only option, which means ensuring every vaccinated adult and older child in their lives is up to date. Do not wait for a local outbreak alert to act.
