.png){kind=small}
.png){kind=small}
.png){kind=small}
.png)
What’s Happening in California?
As of June 2025, California has already recorded 17 confirmed measles cases, more than in all of 2024 combined. Nationally, there were 378 confirmed cases by March 2025, up from 285 in 2024. This resurgence is part of the largest U.S. measles outbreak in decades.
Why Is This Happening?
- Declining vaccination rates: California kindergartner MMR coverage fell slightly—from 96.5% to 96.2%—but remains above the 95% threshold needed for herd immunity. However, regional pockets (e.g., Sutter County at 75.8%) fall below safe levels.
- International travel: Many cases originated overseas and were brought back by unvaccinated travelers.
- Herd immunity erosion: Measles requires ~95% population immunity to stop outbreaks. Lower regional coverage undermines protection—even with high statewide averages.
Measles 101 – Symptoms, Risks & Prevention
Herd Immunity Explained
When ~95% of a community is vaccinated, measles can't spread easily—even unvaccinated individuals are protected. But coverage gaps allow outbreaks to ignite.
What You Can Do
- Verify MMR vaccination: Ensure you and your children have both doses.
- Check titers: Ask your doctor about immunity testing, especially if born before 1968 or with uncertain vaccine history.
- Screen travel plans: Get an early MMR shot if traveling internationally with young children .
How BASS Can Help
Our Infectious Disease and Primary Care departments at BASS Medical Group offer:
- MMR vaccine administration and booster recommendations
- Immunity testing (measles titers)
- Education and follow-up care for post-exposure or symptomatic individuals
Protect your family with expert care and advice tailored to California residents.
FAQs
Are measles outbreaks unusual in California?
Yes. Measles was declared eliminated in 2000, but outbreaks still occur, usually after virus importation into under-vaccinated communities.
Is one MMR dose enough?
No. One dose provides ~93% protection; two doses bring that to ~97%, which is essential for herd immunity.
If I was vaccinated years ago, am I still immune?
Most are, but some older vaccines (pre-1968) were less effective. A titer test or booster may be recommended when uncertain.
.png)
.png)
.png)