California: From Governator to Vaccinator

On June 30, California Governor Jerry Brown signed into law Senate Bill 277, removing personal belief and religious childhood vaccine exemptions across the state.[i]  With the new law, California becomes only the third state to limit vaccination exemptions to medical only—joining Mississippi and West Virginia.  This effort, on the heels of a measles outbreak at Disneyland that resulted in more than three hundred cases in seven states (as well as Mexico and Canada),[ii] is seen by many as a signature victory for public health (although not renowned vaccine expert, Jim Carrey). 

While there will undoubtedly be challenges in implementing the law statewide, the true test lies in quantifying its effect and determining the feasibility of similar measures nationwide.  Because California was known, historically, for its relatively lax childhood vaccination policies, the transition to the new, considerably stricter exemption policy provides a near-perfect test case for public health policy.  In order to effect positive change far beyond the state line, the California Department of Public Health (CDPH) needs to accurately measure the social and public health impact of SB 277 and share their experiences with other states seeking to update decades-old immunization policy.

At present, CDPH publishes yearly data, by school, for the number of children who are “up-to-date” on vaccinations, have a “permanent medical exemption” and have a “personal belief exemption”—broken down by those counseled by a healthcare practitioner and those who have not (“religious belief exemption”), after a law passed in 2013 requiring the counseling for non-religious personal belief exemptions.  These data are collected and reported for childcare facilities, at kindergarten enrollment and at seventh grade enrollment for all schools statewide.[iii]  The personal belief and religious exemptions will be phased out over the next several years as children progress to the next checkpoint (kindergarten or seventh grade), and the rates for vaccination and medical exemptions, in conjunction with incidence of vaccine-preventable diseases, will provide a baseline picture of the public health impact of SB 277.  CDPH does not currently collect data on the personal or family history conditions warranting medical exemptions.  In fact, there is currently no official form for documenting medical exemptions; a physician letter to the child’s school—maintained in the student’s file—is sufficient.[iv]  Additionally, CDPH does not publish data on exemptions broken down by individual physicians or providers.

While continuing to collect medical exemption rates and communicable disease incidence data is vital, these data alone may not provide a complete picture of the new law’s impact.  Incidence of vaccine-preventable diseases is expected to steadily decrease over the implementation period; however, it will not necessarily change dramatically.  Students are only assessed for vaccination status in preschool childcare, kindergarten and seventh grade, so it will take several years before all of the existing personal belief exemptions are fully phased out.  Additionally, in the absence of another significant event like the 2014-15 measles outbreak at Disney or the 2010 pertussis epidemic, the decrease in communicable disease cases in the coming year will be primarily driven by a return to baseline levels rather than an increase in vaccination.  The full impact of SB 277 may not be known for years to come, but there are vital data to be collected in the meantime.

Gauging the public reaction to the new law will require careful data collection and monitoring of trends beyond just exemption rates and disease incidence.  The number of medical exemptions alone (by school or provider) will not provide a complete vaccination picture for California.  For example, it is likely that a small but motivated percentage of parents who currently have personal belief exemptions for their children may seek to obtain unwarranted medical exemptions rather than have their children vaccinated.  Schools with recent outbreaks of pertussis or measles may have a high number of medical exemptions for these immunizations due to the number of children who recently had the disease.  Additionally, physicians or practices who specialize in treating immunocompromised children (e.g., HIV or pediatric cancer patients) would likely issue a disproportionate number of exemptions.  CDPH does not currently collect information on the medical conditions provided to justify medical exemptions, and these data, particularly their geographic distribution, may give state and local officials information vital to targeting public health interventions and maintaining herd immunity in schools and communities.  To fully understand changing trends in medical exemptions, California should consider implementing measures to identify the conditions associated with them.  Both of the other states that limit immunization exemptions to medical only have mechanisms in place to provide some measure of oversight for the exemption process.  West Virginia requires the approval of the State Immunization Officer in order to obtain a medical waiver,[v] and physicians in Mississippi must provide the medical condition for exemptions to their District Health Officer.[vi]  CDPH needs to consider ways to collect data on the conditions cited on medical exemptions, even if the state does not intend to manage the exemption process directly.  The California state Health and Safety Code grants local health departments complete access to health information relating to students’ immunization status,[vii] so this may be a mechanism through which to collect these data.  Regardless of how state and local public health officials monitor medical exemptions, data beyond the mere numbers need to be collected and analyzed to measure the full impact of the new policy.

In addition to data collection, CDPH public outreach programs to promote vaccination could strengthen the impact of SB 277.  The state of California should continue offering education for physicians emphasizing the importance of vaccination, providing communication strategies for use with reluctant parents and reinforcing the public health and legal implications of the new law for the practice of medicine.  Additionally, similar education efforts should be targeted at school officials and parents to increase awareness during the implementation of the new policy.  Continued public outreach initiatives are vital to ensuring the positive impact of SB 277.

The new vaccination policy was only recently signed into law, so CDPH is likely still in the early stages of planning with respect to establishing implementation and monitoring protocols.  California is poised to move forward as a leader in public health policy, and CDPH has a tremendous opportunity to accurately quantify the impact of the new policy on statewide public health.  Additionally, from a purely public health perspective, it has an obligation to share this information with other states considering similar measures.  In order to do so, CDPH officials must determine now, prior to the law taking effect in 2016, how best to collect and analyze data.  Some questions to ponder include:

  • How do they intend to identify or limit specific conditions related to medical exemptions? 
  • Will they consider monitoring exemption rates for individual physicians or practices? 
  • How much of these data will be provided to the public and in what form? 

Given the far-reaching implications of this new law on public health practice nationwide, California should be diligent and systematic as this law is implemented.  Active and directed collection of data now will provide a solid foundation for analysis, and a dedicated multi-year effort will ensure that social and public health trends are identified early to facilitate intervention as necessary.  California is in an ideal position to assess the impact of statewide vaccination policy, and it has an opportunity to make a lasting, positive impact on the health of the public across the state and far beyond its borders.


[i] California State Senate. Senate Bill 277. June 30, 2015. Accessed: July 17, 2015.

[ii] Chang, Alicia. Large Measles Outbreak Traced to Disneyland is Declared Over. The Big Story. Associated Press. Accessed: July 17, 2015.

[iii] California Department of Public Health. Immunization Levels in Child Care and Schools. July 9, 2015. Accessed: July 17, 2015.

[iv] Shots for School. Immunizations > Exemptions. Accessed: July 17, 2015.

[v] West Virginia Department of Health and Human Resources. Medical Exemptions Information. Accessed: July 17, 2015.

[vi] Mississippi State Department of Health. Medical Exemption Request. Accessed: July 17, 2015.

[vii] State of California. Health and Safety Code, Section 120375. Accessed: July 17, 2015.