San Diego County’s measles vaccination coverage among kindergartners remains just below the 95% threshold associated with herd immunity, a concern as measles cases and outbreaks increase across California and the U.S., according to NBC 7 Investigates and updated state and federal surveillance data.

San Diego County schools reported 94.8% of kindergartners had measles, mumps, and rubella (MMR) coverage in the 2023–24 school year, NBC 7 reported, and 46 schools in the San Diego area were below 95% in 2023. County officials said the dip reflects a broader post-pandemic pattern. “We are seeing that trend in San Diego County, and, really, this is a trend across the United States, of decreasing vaccination rates coming after the pandemic,” said Erik Berg, the county’s assistant medical director of epidemiology and immunization services. 

Locally, measles activity has been tied to travel in recent years. San Diego County confirmed four cases in 2024, all associated with international travel, and the first local case of 2025 involved an unimmunized teenager who had recently traveled overseas, county officials said. NBC 7 reported in February 2026 that there “haven’t been any reported cases in 2026 in San Diego.” 

Statewide, the California Department of Public Health reported 25 confirmed measles cases in 2025 and 15 in 2024, and said two localized measles outbreaks were underway in California as of Feb. 16, 2026—the state’s first outbreaks since early 2020. A separate CDPH health alert said California had 9 confirmed cases as of Feb. 2, 2026, with most linked to international travel and none documented MMR immunization. 

Nationally, CDC reported 982 confirmed U.S. cases as of Feb. 19 in 2026 and 2,281 cases in 2025, with 49 outbreaks in 2025 compared with 16 in 2024. The Centers for Disease Control also reported U.S. kindergarten MMR coverage fell from 95.2% (2019–20) to 92.5% (2024–25), leaving about 286,000 kindergartners at risk in 2024–25.