Introduction to California School Vaccine Rates
Despite having some of the nation’s strictest school vaccination laws, California reported a decline last year in the share of kindergarten students who were immunized against measles, including in 16 counties where students no longer have herd immunity against one of the most contagious diseases.
Decline in Vaccination Rates
New data from the California Department of Public Health show that last year, 96.2% of California students in transitional kindergarten and kindergarten were vaccinated against measles, mumps and rubella in the 2023-24 school year, down from 96.5% the year before. And 93.7% of kindergarten students were up to date on all their immunizations, down from 94.1% in the same period the previous year. Data on vaccination rates for first-grade students, which are usually higher, were not yet available.
Risks Associated with Declining Immunization Rates
California’s childhood vaccination rates are still higher than in the U.S. overall. But public health experts say the declining immunization rate creates two main risks: that measles could spread here amid the deadly outbreak that began in Texas, and that the immunization rate could continue to fall.
The COVID-19 Pandemic and Vaccine Hesitancy
The COVID-19 pandemic worsened trust in public health institutions, experts say, and there’s growing concern that deep political discord, along with widespread disinformation online, will only make it harder to reverse the downward trend.
Herd Immunity and Disease Prevention
A 95% vaccination rate, sometimes called “herd immunity,” is generally considered the gold standard of disease prevention. That threshold not only prevents infections from ripping through a community, but also protects those who are not able to get vaccinated because they are pregnant, immunocompromised or have other serious health issues.
Measles and Its Consequences
“Measles is so infectious,” said Dr. Chad Vercio, division chief of general pediatrics at Loma Linda University Children’s Health in San Bernardino County, where about 93.5% of kindergarten students were immunized against measles last year. When fewer people are vaccinated against the disease, he said, “the likelihood that someone who’s not been vaccinated gets infected becomes so much higher.” Measles is most often associated with a high fever and rash, but more severe cases can cause pneumonia or encephalitis. The disease kills about one to three people for every 1,000 infected and leads to hospitalization in 1 in 5 cases, Vercio said.
California’s Vaccine Laws
California’s vaccine laws, which were tightened in the wake of the 2014-15 measles outbreak at Disneyland, make it difficult for parents to send children to school without a series of standard childhood vaccines, including the shots known as DTaP, short for diphtheria, tetanus and pertussis; and MMR, short for measles, mumps and rubella.
Vaccine Hesitancy and Misinformation
Vercio said he and other local pediatricians have seen a “significant” increase in vaccine hesitancy since the start of the pandemic, including parents who refuse to discuss immunizations with their doctors after encountering misinformation online about vaccines, including the debunked connection between vaccines and autism.
County-Level Vaccination Rates
Last year, nearly two-thirds of California’s counties reported immunization rates for all childhood diseases below 95%, with 14 counties falling below 90%, according to the health department data. The immunization rate for measles was higher, but 16 counties — or more than 1 in 4 — still reported a rate below 95%. The lowest immunization rates were in Northern California. In Glenn and El Dorado counties, fewer than 80% of kindergarten and transitional kindergarten students were fully vaccinated, and fewer than 81% against measles. Sutter County reported the lowest vaccination rate overall at 73%, and 75.8% for measles.
Regional Variations
Southern California has generally fared better. Of the nearly 130,000 kindergarten students in Los Angeles County, more than 97% received two or more doses of the MMR shot last year, the data show. And Orange County reported a 97.4% immunization rate for its nearly 44,000 kindergarten students. But San Diego County, which has the second-largest number of kindergarten students after L.A. County, saw its immunization rate slip just below the 95% herd immunity benchmark to 94.8%.
Barriers to Vaccination
Michelle Corson, a spokeswoman for the Kern County Public Health department, said in a statement that a “mistrust of healthcare providers and systems, along with the spread of vaccine misinformation” has contributed to vaccine hesitancy. She said some residents also face other barriers in accessing healthcare, including lack of insurance or transportation challenges.
Vulnerability to Measles
Many counties with relatively low vaccination rates have a higher share of students in independent study or home-school programs that do not involve classroom instruction or who receive special education services at school even if they’re not fully vaccinated. Kern County said 9% of kindergarten students were enrolled in such programs. In El Dorado County, nearly 20% of students were, while in tiny Sutter County, which has the state’s lowest vaccination rate overall, that share surged to nearly 1 in 4 of the county’s kindergarten students.
Conclusion
The decline in vaccination rates in California is a concerning trend that puts vulnerable populations at risk of contracting measles and other preventable diseases. Public health experts and policymakers must work together to address the root causes of vaccine hesitancy and ensure that all children have access to life-saving vaccines.
FAQs
Q: What is the current vaccination rate for measles in California?
A: The current vaccination rate for measles in California is 96.2% for kindergarten students.
Q: What is the threshold for herd immunity?
A: The threshold for herd immunity is 95%.
Q: What are the risks associated with declining immunization rates?
A: The risks associated with declining immunization rates include the spread of measles and other preventable diseases, as well as the protection of vulnerable populations such as pregnant women, immunocompromised individuals, and those with serious health issues.
Q: What can be done to address vaccine hesitancy?
A: Addressing vaccine hesitancy requires a multi-faceted approach that includes education, outreach, and access to healthcare services.
Q: What is the role of government in promoting vaccination?
A: The government plays a critical role in promoting vaccination by implementing and enforcing vaccination laws, providing funding for public health programs, and educating the public about the importance of vaccination.
