California measles cases surge past 2023 total — And it’s only June

Los Angeles, California – Measles—once considered a relic of the pre-vaccine era—has returned to the public health stage with alarming force. California, like much of the United States, is now grappling with a disease most health officials thought had been functionally eliminated.

So far this year, California has reported 17 measles cases—surpassing the total for all of 2023. Nationwide, more than 1,200 confirmed cases have been recorded, already rivaling 2019’s total and reaching levels not seen since the early 1990s. The Centers for Disease Control and Prevention warns that this may undercount the actual spread, as some cases remain untested due to stigma or a lack of awareness.

The scale of the current outbreak—and the fact that measles is entirely preventable—has prompted many physicians and public health officials to sound the alarm.

“This is a really, really unusual time to see this many deaths—and seeing previously healthy children with a vaccine-preventable death in the United States,” said Dr. Erica Pan, California’s public health officer.

Measles is not a mild illness. It is one of the most contagious viruses known, capable of remaining airborne for hours after an infected person has left a room. It can cause viral pneumonia, encephalitis, and a long-term degenerative brain condition known as SSPE. This year, three people in the U.S.—two children in Texas and one adult in New Mexico—have already died from complications related to measles. One infant in Canada, born prematurely to an unvaccinated mother, died earlier this month.

The common denominator in nearly all cases is a lack of vaccination. According to the CDC, 95% of measles cases so far this year involved unvaccinated individuals or people with unknown immunization status. Vaccination rates remain high in California—about 96% of kindergartners are immunized—but certain counties, such as Kern and Santa Cruz, fall below the 95% threshold required for herd immunity.

Outbreaks have been most severe in states like Texas and New Mexico, especially among close-knit, undervaccinated religious communities. But California has had its own history of vulnerability. In 2008, an unvaccinated child returning from Europe sparked an outbreak in San Diego that spread to other unvaccinated children and infants too young to be vaccinated. A 2015 outbreak linked to Disneyland prompted the state to tighten vaccination requirements; however, the underlying risks persist.

Health experts are again urging early vaccination in vulnerable communities and emphasizing that the MMR vaccine has a proven safety record spanning decades. For a disease declared eliminated in the U.S. in 2000, its resurgence represents a failure not of science, but of trust—and the cost is being measured in ICU beds.