A measles case was confirmed Thursday, bringing the state’s yearly total to a high of seven, as more Coloradans are rolling up their sleeves for the vaccine. The latest case is a vaccinated Colorado adult from Arapahoe County, according to the state health department. The person had recently traveled internationally.
The vaccinated adult was a passenger on Turkish Airlines Flight 201, from Istanbul, Turkey, which arrived at Denver International Airport on May 13. In total, two passengers on that flight have contracted measles. The other was a case announced Wednesday — a child from Arapahoe County.
The Colorado Department of Public Health and Environment said local public health agencies are contacting passengers and crew on the flight. That includes those who were seated or working close to the person with measles and all lap children on the plane.
If you were a passenger on this flight and have symptoms of measles, the health department says to please contact your local public health agency immediately.
Colorado’s seven cases in five months in 2025 tops the total it recorded during the entire decade from 2014-24, according to the state’s measles website. It reported two cases in 2016, one in 2014, 2015 and 2023, and none last year.
“This is a really good time to review your vaccination status and get vaccinated,” said Dr. Ned Calonge, the state’s chief medical officer. “The way to control measles is with measles, mumps and rubella vaccine. It's safe, it's effective, and it's our best protection.”
Sharp increase in MMR shots
The state reported a sharp increase in MMR vaccinations in recent months and Calonge believes it’s due to Coloradans hearing more news about measles cases, which had become increasingly rare.
“People are getting the message. They are taking this opportunity to get their kids up to date on their shots, which is a good thing,” he said.
“I think it's good that it's publicized,” said Dr. Shen Nagel, a pediatrician with Pediatrics West in Wheat Ridge. “People are paying attention to it.”
He said more parents are asking him about it, some are even a bit overly enthusiastic, he said, sometimes looking to get their kids a shot even ahead of the routine MMR schedule.
He said he’s glad to see parents aware and engaged — and he helps find ways to proceed with the enthusiastic parents.
“If it drives people to get what I think is a very safe vaccine, that's excellent,” Nagel said. “From our standpoint, we have a very safe and effective way to prevent this from happening, prevent what's happening in Texas.”
Texas has recorded more than 700 cases and 94 hospitalizations, according to its state health department.
Two school-aged children died. They lived in the outbreak area, in western Texas. They were not vaccinated and had no known underlying conditions.
Known exposure locations in Colorado
The state health department said, regarding the most recent cases, that anyone who was in a few locations during the dates and times listed may have been exposed to measles. They should monitor for symptoms for 21 days after exposure and consider avoiding public gatherings or high-risk settings.
The MMR vaccine, given within 3 days after exposure, can prevent infection.
Monitoring for symptoms is especially key for people who have not been vaccinated with the MMR vaccine. The health department has detailed lists of the locations where people may have been exposed to the measles.
What to do if you may have been exposed and aren’t feeling well
People exposed to measles typically develop symptoms seven to 21 days after exposure, according to the health department.
If you were at these locations during the exposure window and develop symptoms, immediately contact your health care provider by phone. If you do not have a provider, call an urgent care center or emergency department and explain that you may have been exposed to measles. Health officials say it’s important to call ahead, that helps prevent additional exposures.
Upcoming measles, or MMR, vaccination clinics
CDPHE and the Arapahoe County Public Health Department are offering free MMR vaccination clinics for exposed individuals. No appointment is needed.
CDPHE clinic
- Location: Aurora Community Connection, 9801 E. Colfax Ave., Aurora, 80010 (in the courtyard/plaza behind the building)
- Date: Saturday, May 31, 11 a.m. – 3 p.m.
There’s more information on the health department's measles webpage. It includes up-to-date Colorado measles cases as they are confirmed.
Key information about measles
Measles is preventable, but it is also a highly contagious, airborne respiratory infection. It may be best known for its rash, which usually starts several days later on the face and spreads, and fever. It can cause serious health problems, especially for children younger than 5.
Other symptoms include a cough, runny nose and red eyes.
It passes between people so readily, according to the federal Centers for Disease Control and Prevention, that up to nine out of 10 people nearby will become infected if they are not protected.
The best, most long-lasting protection against all strains of it comes from the MMR (or measles, mumps and rubella) vaccine, according to the CDC.
In rare cases, people who are vaccinated can still get measles — about three out of every 100, according to the state health department — but their symptoms are usually milder, and they are less likely to spread it to others. Measles only spreads from people who show symptoms; it doesn’t spread from people who aren’t feeling sick.
Before that vaccine was introduced, an estimated 48,000 people were hospitalized and 400 to 500 people died in the U.S. each year.
More Coloradans are now getting vaccinated for measles
More Coloradans seem to be responding to news of measles cases in the state by getting vaccines with the MMR vaccine, according to a spokesperson with the state health department.
That includes sharp increases among both children of all ages and adults.
According to data reported to the Colorado Immunization Information System (CIIS), provided by the health department, there have been large increases in the number of measles vaccines administered to 6-to 11-month-olds and people 19 and older in recent months.
Among 6-11-month-olds, more than 2,700 doses were administered between March 1 and May 29, 2025. That’s an 800 percent increase from the number of doses administered from the same last year at 302 doses.
Among people 19 and older, more than 24,000 doses have been administered since March 1; that is a more than 340 percent increase from the number of doses administered from the same period last year —about 5,450 doses.
There has been an 8 percent increase among 12-15-month-olds, a 10 percent increase among 4-6 year-olds, and a 28 percent increase among 7-18-year-olds, compared to last year.
Across all age groups, there has been a 38 percent increase in the number of measles vaccines administered in March-May 2025 (more than 87,800 doses) compared to the same months in 2024 (about 63,500 doses).
Seven Colorado cases in 2025 so far
The Colorado cases recorded so far this year are all connected with international travel. “We're not seeing any, at least at this point, any community transmission within Colorado,” Calonge said.
Colorado recorded its first case of 2025 in an adult in Pueblo County in late March.
A second case was confirmed in Denver in an infant about a week later. Both were unvaccinated.
The third case was in Archuleta County, in south-central Colorado, in an adult with an unknown vaccination history.
In the fourth case, announced last month, Denver’s health department could not verify proof of vaccination for the person; their blood results showed they did not have immunity to measles, a spokesperson said. That case involved an adult, a household contact of the first Denver case identified earlier that month.
Health officials announced a fifth confirmed case late last month, in a vaccinated Denver County adult with recent international travel.
The sixth and seventh cases were both on the Turkish Airlines flight from Istanbul. The sixth is a toddler and remains hospitalized, Calogne said.
The National Picture
A total of 1,088 confirmed measles cases were reported nationally by the Centers for Disease Control and Prevention, as of May 29, 2025, with cases in more than half of the nation.
In all of 2024, the U.S. recorded 285 cases.
There have been three deaths this year.
There have been 14 outbreaks reported in 2025, and most confirmed cases, 90 percent, are associated with outbreaks, a higher rate than in 2024.
