Measles cases have doubled in California so far this year compared to last year — and 2026 is barely half over.
California has confirmed 52 measles cases in the first 6½ months of the year; that’s more than double the 25 cases reported in all of 2025. If this pace continues, the number of cases will pass California’s high from 2015, when there were 125 cases in the state and a portion of them were related to a large outbreak at Disneyland.
Of this year’s 52 cases, 49 patients were either unvaccinated or had an unknown vaccination record. Four have had to be hospitalized. Many cases involve children or young adults — 27 cases involved those ages 5 to 19, and 15 cases involved children under 5 years old, according to the California Department of Public Health. L.A. County has tallied seven cases so far this year among its residents.
Nationally, measles cases have nearly eclipsed last year’s total already and the country is poised to hit its highest case level since the late 1980s and early ’90s. As of mid-July, 2,260 measles cases were reported, compared to 2,289 in all of last year. Last year’s tally was the highest in a single year since the devastating 1989-91 measles epidemic, which resulted in more than 55,000 cases and 166 suspected deaths.
The U.S. Centers for Disease Control and Prevention said 93% of confirmed measles cases are associated with outbreaks. There have been 34 new outbreaks reported so far this year.
New measles cases continueto be reported across California at a regular clip, putting unvaccinated people — including babies too young to have received their first immunization — at risk of severe illness and potentially death.
The latest case involved a juvenile who had been living abroad and now lives in Orange County; the child was contagious with measles while passing through Los Angeles International Airport, officials said.
The juvenile arrived on a flight from Cancún, Mexico, on Delta Air Lines Flight 614 on July 16 at 9:45 p.m., the Los Angeles County Department of Public Health said. Mexico is among the top 10 countries worldwide with measles outbreaks, according to the World Health Organization.
People who might have been exposed to the infectious passenger included those who were in the international terminal, around Gate 206, about an hour after the flight’s arrival, and around the flight’s baggage claim area between 10:30 p.m. and 11:30 p.m.
Passengers who sat near the infected passenger, as well as people exposed to the person in a healthcare setting, will be contacted about their exposures, officials with the Los Angeles County and Orange County public health departments said. People are at risk of developing measles from seven to 21 days after their exposure; the last day to monitor for symptoms is Aug. 6.
People who aren’t immunized are at a higher risk to contract measles and should monitor their symptoms, officials said. Those who have been immunized, or have been previously infected, are probably protected against infection “but should still monitor for symptoms,” the L.A. County Department of Public Health said.
“As measles cases increase, it is important that residents take steps to make sure they are fully protected. The MMR vaccine is the safest and most reliable way to prevent measles and protect yourself, your family, and your community,” said Dr. Muntu Davis, the L.A. County health officer, in a statement. “Measles spreads easily and can lead to serious complications, including pneumonia, brain swelling, and even death.”
Another infectious traveler passed through LAX while infected with measles earlier this month. The traveler arrived on British Airways flight 281, from London, at Gate 155 in the international terminal July 3. People at that gate between 3 p.m. and 4 p.m. may have been exposed to measles, as well as people at aboard the Hertz car rental shuttle between 3:30 p.m. and 4:30 p.m.
There have been at least two infants who have contracted measles so far this year in California — both of whom traveled internationally before falling ill. One case was reported in San Francisco, and the other in Orange County. The infants were probably exposed to measles “during international travel, whether in airports, airplanes or otherwise while abroad,” the state Department of Public Health told The Times. “Some but not all of them visited an area with a known measles outbreak.”
Since 2020, the state Department of Public Health has received 11 reports of infants under 1 year of age with measles. Among those, eight had traveled internationally and one traveled to another state where there was a measles outbreak.
“Infants less than 1 year old can contract measles, especially during travel,” the L.A. County Department of Public Health said.
The other two cases involved infants who had not traveled before getting the virus.
Los Angeles County health officials advise that infants age 6 to 11 months who will be traveling internationally, or domestically to areas with measles outbreaks, get the measles vaccine early, which is routinely given after a child turns 1, and then again between the ages of 4 and 6. Infants who get that early dose should still get two additional doses, officials said.
California health officials also recommend that those age 1 to 3 get their second measles vaccine dose early if they’re going to travel internationally.
“Parents can consider several factors when deciding about travel, including whether measles is circulating at their destination, the potential for exposure during travel, and whether their child is eligible for an early MMR dose,” the California Department of Public Health told The Times. “Talking with the child’s pediatrician can help families weigh these considerations and choose what makes the most sense for their situation.”
If parents do decide to give their babies a vaccine to protect against measles, they should try to get the injection at least two weeks before travel.
When the measles vaccine is given at 6 months of age, 76% developed protective antibodies against measles, and when given at 8 to 9 months, 85% developed antibodies, according to UC San Francisco infectious diseases expert Dr. Peter Chin-Hong. “This is in contrast to infants 12 months and older, where more than 95% develop protective antibodies.”
“Measles doesn’t only affect people who travel or live internationally—everyone is at risk if they’re not protected,” said Dr. Anissa Davis, a deputy county health officer in Orange County. “Because measles is highly contagious, it can spread quickly within communities, even among those who haven’t traveled. The best way to protect yourself and your loved ones is to get vaccinated before exposure occurs.”
Health officials are encouraging parents to plan now for updating their kids’ vaccines, with the new school year only a few weeks away.
“The rise in measles cases nationally is a reminder that we cannot let our guard down against serious and highly contagious diseases,” said Dr. Susan Philip, the San Francisco health officer, in a statement.
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