News Summary
Recent analysis reveals alarming trends in kindergarten vaccination rates across the U.S., with over two-thirds of counties failing to achieve herd immunity against measles. The decline in immunization rates since 2019 poses a significant risk, with health experts emphasizing the need for at least 95% vaccination coverage to prevent outbreaks. California, despite existing regulations, faces localized vulnerabilities, while trends in vaccine exemptions and home-schooling further exacerbate the issue. Public health officials stress the urgency of ensuring vaccinations are up to date as the school year begins to protect children and communities.
San Diego, California—Alarm is rising across the United States as more than two-thirds of American counties collecting data on kindergarten measles vaccinations are failing to achieve herd immunity, recent analysis reveals. A staggering 77% of these counties have reported declines in immunization rates since 2019, increasing the risk of outbreaks.
The analysis was conducted jointly by NBC News Health & Medical Unit and Stanford University, uncovering concerning trends that suggest a significant gap in childhood vaccination against measles, mumps, and rubella (MMR). Health experts indicate that achieving herd immunity for measles requires at least 95% of children to be vaccinated to effectively prevent the spread of this highly contagious disease.
According to the findings, 68% of the counties with measurable MMR rates fall below this critical threshold. In San Diego County, while 94.8% of kindergartners were vaccinated for the 2023-24 school year, 46 schools reported vaccination rates that linger below herd immunity, highlighting localized vulnerabilities.
Despite having some regulations in place, the state of California is not immune to these trends. Laws mandating vaccinations for children in both public and private schools have seen modest success. However, there is still a marked decline in the percentage of kindergartners with complete vaccinations. Medical exemptions are permitted but strictly regulated, as only children with approved medical reasons can bypass the vaccination requirement.
The Centers for Disease Control and Prevention (CDC) reported significant public health concerns, confirming 1,431 measles cases and 35 outbreaks in the U.S., along with 3 deaths in 2025. The first confirmed measles case this year in San Diego County was recorded from an unvaccinated teenager who traveled abroad, emphasizing the risks associated with low vaccination rates.
The situation is compounded by fluctuating vaccine exemption rates. More than half of American counties have seen the rates of vaccine exemptions double over recent years. This trend could be attributed to the fact that personal-belief exemptions were banned in California in 2016, leading to significant changes in vaccination compliance. Subsequently, medical exemptions dropped to 0.1% in 2023, following stricter verification systems.
Public health officials are also noting an increase in families opting for home-schooling or enrolling their children in small private institutions that do not have to adhere to vaccination mandates. This shift has become increasingly common since the ban on personal-belief exemptions was enacted, raising further concerns about potential outbreaks.
The implications of declining vaccination rates are dire. Measles is notably contagious; an infected individual can transmit the virus to 15 to 18 unimmunized persons. As the school year commences, the California Department of Public Health urges families to ensure vaccinations are up to date, as children will be congregating in close environments, an ideal setting for outbreaks.
This year, the U.S. has already experienced 15 measles deaths, equal to the total of the previous 25 years. The most severe complications from measles are observed in unvaccinated children under five years old and adults over 20, heightening the stakes for public health. Parents have expressed overwhelming concern about the risks presented by unvaccinated children, fearing for the well-being of both their own kids and the community at large.
With vaccination rates continuing to decline, health experts warn of a significant increase in measles cases in the near future if proactive measures are not taken. Vaccination is crucial for preventing outbreaks; therefore, a collective effort is imperative to reverse the downward trajectory and protect public health.
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Additional Resources
- NBC San Diego: Vaccination Rates San Diego
- Wikipedia: Vaccination
- County News Center: First Measles Case of 2025
- Google Search: Measles Outbreaks California
- San Diego Union Tribune: Measles Complications and Death
- Google Scholar: Measles Vaccination Rates
- Times of San Diego: Measles Comeback in California
- Encyclopedia Britannica: Measles
- Los Angeles Times: California School Vaccines and Measles Immunity
- Google News: Vaccination California 2025
Author: STAFF HERE SAN DIEGO WRITER
SAN DIEGO STAFF WRITER The SAN DIEGO STAFF WRITER represents the experienced team at HERESanDiego.com, your go-to source for actionable local news and information in San Diego, San Diego County, and beyond. Specializing in "news you can use," we cover essential topics like product reviews for personal and business needs, local business directories, politics, real estate trends, neighborhood insights, and state news affecting the area—with deep expertise drawn from years of dedicated reporting and strong community input, including local press releases and business updates. We deliver top reporting on high-value events such as Comic-Con International, San Diego County Fair, and San Diego Pride Festival. Our coverage extends to key organizations like the San Diego Regional Chamber of Commerce and United Way of San Diego County, plus leading businesses in biotechnology, healthcare, and technology that power the local economy such as Qualcomm, Illumina, and Scripps Health. As part of the broader HERE network, including HEREAnaheim.com, HEREBeverlyHills.com, HERECostaMesa.com, HERECoronado.com, HEREHollywood.com, HEREHuntingtonBeach.com, HERELongBeach.com, HERELosAngeles.com, HEREMissionViejo.com, and HERESantaAna.com, we provide comprehensive, credible insights into California's dynamic landscape.
