On June 29, 2015, then-governor of California Jerry Brown signed into law California Senate Bill 277. The law, which took effect on July 1, 2016, removed the personal belief/religious exemption to vaccination for children attending public and private schools and daycare centers. SB 277 was followed by SB 276 and its companion bill SB 714 which limited the ability of doctors to grant medical exemptions for childhood vaccinations. Both of those bills were signed into law by California’s Governor Gavin Newsom in 2019.1 2 3
The elimination of all but medical exemptions to vaccination in California during the past eight years, and particularly the state’s oversight authority over the granting of medical exemptions by doctors, has made that state perhaps the strictest (some might say “draconian”) in the country in terms of its childhood vaccination laws. Other states that only allow for medical exemptions to vaccinations for schoolchildren include Connecticut, Maine, Mississippi, New York and West Virginia, but they appear to be less restrictive toward physicians granting them.4 5 6 7
Childhood Vaccination Rates in California Rose After SB 277
As a result of SB 277, the percentage of children entering kindergarten in California who received all the required vaccines went up from 92.8 percent in 2015-2016 to 95.6 percent in 2016-2017. Reportedly due to parents seeking more medical exemptions for their children, the percentage of fully vaccinated kindergartners in the state dropped slightly to 95.1 percent in 2017-2018 and 94.8 percent in 2018-2019 just prior to the declaration of a COVID-19 pandemic in the U.S. in early 2020.8 9 10
During the 2018-2019 school year, 4,812 kindergartners in California received medical exemptions from vaccines. This represented a 70 percent increase from 2016-2017 when SB 277 took effect. “It’s alarming that you’re having increasing numbers of medical exemptions,” said pediatrician James Campbell, MD. “You cannot imagine that that number of additional people now have new medical problems.”10
What probably happened is that many parents in California who were no longer able to obtain vaccine exemptions based on personal belief turned to the only other option they had for protecting their children from a medical procedure they had reason to believe might harm them. Some of these children may have had previous vaccine reactions or severe allergies or immune system problems that caused their parents to be more cautious about vaccination. To understand this concern by parents, you have to take into consideration the childhood autism epidemic that has been especially plaguing California since the 1990s and continues to this day.
According to an article in The Sacramento Bee published on July 18, 2016, autism rates for children attending public schools in California had increased seven-fold since 2001. More than 97,000 public schoolchildren in the state were diagnosed as autistic in 2015-2016—6,500, or seven percent, more than in 2014-2015. In 2016, 1 in 65 kindergartners in California was classified as having autism. Based on data from the California Department of Education, the article noted that the number of autistic students in California had risen by 5,000 to 7,000 every year since 2006.11
In 2011, a study done by the independent public non-profit Lucile Packard Foundation for Children’s Health estimated the number of public schoolchildren with autism in California had risen from 7,508 in 2002 to 59,690 in 2010. In other words, an increase of more than 12-fold from 2002 to 2015-2016.12
So regardless of what health authorities in California may have thought about a possible link between vaccines and autism, the alarming continuing steady rise in childhood autism rates awakened concerns among a growing number of parents regarding vaccines and their side effects. The push by California legislators to eliminate the personal belief exemption to vaccination in 2015 left many parents desperate, searching for doctors willing to provide medical exemptions for their children. The other alternative was to simply pick up and move their families to other states with less oppressive mandatory vaccination requirements.
CDC Estimates 1 in 22 Children With Autism in California
On Mar. 23, 2023, the U.S. Centers for Disease Control and Prevention (CDC) published an analysis in its epidemiological digest Morbidity and Mortality Weekly Report (MMWR) that determined the prevalence of autism spectrum disorder (ASD) among children eight years old in the U.S. to be 1 in 36. The analysis was based on data collected in 2020 by the surveillance program known as the Autism and Developmental Disabilities Monitoring (ADDM) Network in 11 states, including Arizona, Arkansas, California, Georgia, Maryland, Minnesota, Missouri, New Jersey, Tennessee, Utah and Wisconsin. Of these, California had the highest prevalence of ASD, with a whopping 1 in 22 eight-year-old children diagnosed with autism.13 14 15 16
The median age for the first autism diagnosis for eight-year-old children across the ADDM Network was just over four years old. The median age for the first diagnosis was three years old.16
The 1 in 22 autism prevalence rate for California in the 2020 data represented a noticeable increase from the 1 in 26 rate found in the data collected from the ADDM Network in 2018.17 18
There was no autism prevalence data for California reported as part of the ADDM Network analysis in 2016, but if you use the 1 in 65 autism prevalence rate for kindergartners (generally children 5-6 years of age) provided by the California Department of Education for that year to gauge a five-year trend (2016-2020), it is curious to observe the dramatic increase in autism prevalence in the state post-2016—the year SB 277 was implemented.13
Cause of Continuing Rise in Autism Rates Still Unknown
Of course, this is not proof of anything. There is no evidence that the increase in vaccination rates for schoolchildren in California spurred by SB 277 in any way affected autism prevalence rates in the state. Correlation is not causation. But one can certainly speculate, particularly when the reason for the continued yearly increases in the prevalence rates for this neurological condition remains largely a mystery.
“For California in particular, the data are surprising and represent the highest autism prevalence estimates from a region by an epidemiologic study,” said Walter Zahorodny, PhD, director of the New Jersey Autism Study at the Rutgers New Jersey Medical School, who co-authored the analysis of the ADDM Network data from 2020. “The trouble is we don’t understand what the primary drivers of the increase are.”13
Rutgers University acknowledges that it is “difficult to ascertain why ASD prevalence continues to climb.” It recognizes that there are “known risk factors for autism,” which include “age of parents, multiple-gestation birth, prematurity, C-section delivery and care in the intensive care unit after delivery.” But it points out that these “perinatal factors have remained relatively stable even as the rate of ASD has continued to surge.”13
It is often theorized that the rise in autism prevalence rates can be attributed to “better awareness” and more “availability of services.” However, Dr. Zahorodny stated he believed this was “impossible” because the scope and breadth of increase in ASD has reached across all subtypes of the condition—from mild to severe and across all demographic groups. “This is not just a phenomenon of becoming more sensitive to subtly impaired kids,” Dr. Zahorodny said.13