Personal Belief Exemptions Research Articles

Characteristics Associated With Measles, Mumps, and Rubella Coverage and Exemptions After a School Immunization Law Change in Washington, 2019-2020.

We aimed to better understand the impact of statewide legislation removing personal belief exemptions (PBEs) for the measles, mumps, and rubella (MMR) school immunization requirement and factors associated with resulting health-seeking behaviors. We used chi-squared tests and logistic regression models to determine individual- and school-level characteristics associated with holding a MMR PBE and with post-law MMR immunization status among students linked to the Washington State Immunization Information System. Of students with a MMR PBE pre-law change, 43.0% completed the MMR vaccine series and 40.4% sought another exemption type. Religious exemptions made up most new MMR exemptions signed (71.8%), followed by medical exemptions (18.5%), and religious membership exemptions (9.7%). Students were more likely to complete the vaccine series post-law change if they attended a school with a low school-level MMR exemption rate, a public school, or held a lower number of school-required immunization exemptions. This study confirms previous concerns that parents might replace their PBE with another exemption type; however, nearly half the students in the cohort completed the MMR vaccine series. Our findings suggest that targeted immunization policies can increase MMR coverage 1-year post-law change but must account for a replacement effect when exemption categories are eliminated.

State Policy Removing the Personal Belief Exemption for Measles, Mumps, and Rubella (MMR) School Immunization Requirement, Washington State, 2014-2022.

Objectives. To assess the impact of Washington State's 2019 Engrossed House Bill (EHB) 1638-which removed measles, mumps, and rubella (MMR) personal belief exemptions-on MMR vaccine series completion and exemption rates in K-12 students. Methods. We used interrupted time-series analyses to examine changes in MMR vaccine series completion rates before and after EHB 1638 was passed and the χ2 test for differences in exemption rates. Results. EHB 1638 implementation was associated with a 5.4% relative increase in kindergarten MMR vaccine series completion rates (95% confidence interval = 3.8%, 7.1%; P ≤ .001), and results were similar with Oregon as a control state (no change observed in Oregon; P = .68). MMR exemptions overall decreased 41% (from 3.1% in 2018-2019 to 1.8% in 2019-2020; P ≤ .001), and religious exemptions increased 367% (from 0.3% to 1.4%; P ≤ .001). Conclusions. EHB 1638 was associated with an increase in MMR vaccine series completion rates and a decrease in any MMR exemption. However, effects were partially offset by an increase in religious exemption rates. Public Health Implications. Removal of personal belief exemptions for the MMR immunization requirement only may be an effective approach to increase MMR vaccine coverage rates statewide and among underimmunized communities. (Am J Public Health. 2023;113(7):795-804. https://doi.org/10.2105/AJPH.2023.307285).

Vaccine mandates on childcare entry without conscientious objection exemptions: A quasi-experimental panel study

ObjectivesExamine the effect of No Jab No Play policies, which linked vaccine status to childcare service entry without allowing for personal belief exemptions, on immunisation coverage. Study designImmunisation coverage rates from the Australian Immunisation Register were linked to regional level covariates from the Australian Bureau of Statistics between January 2016 and December 2019. Differential timings of policy rollouts across states were used to assess changes in coverage with the implementation of policies with generalised linear models. Quantile regression and subgroup analysis were also conducted to explore the variation in policy responses. ResultsBaseline mean vaccination rates in 2016 were 93.4% for one-year-olds, 91.2% for two-year-olds and 93.2% for five-year-olds. Increases in coverage post-policy were significant but small, at around 1% across age groups, with larger increases in two and five-year-olds. Accounting for aggregate time trends and regional characteristics, implementation of the policies was associated with improved full immunisation coverage rates for age one (post-year 1: 0.15% [95 %CI–0.23; 0.52]; post-year 2: 0.56% [95 %CI 0.05; 1.07]), age two (post-year 1: 0.49 [95 %CI: 0.00; 0.97]; post-year 2: 1.15% [95 %CI: 0.53; 1.77], and age five (post-year 1: 0.38% [95 %CI 0.08; 0.67]; post-year 2: 0.71% [95 %CI 0.25; 1.16]. The policy effect was dispersed and insignificant at the lowest quantiles of the distribution of immunisation coverage, and smaller and insignificant in the highest socioeconomic areas. ConclusionFindings suggest that No Jab No Play policies had a small positive impact on immunisation coverage. This policy effect varied according to prior distribution of coverage and socio-economic status. Childcare access equity and unresponsiveness in high socioeconomic areas remain concerns.

Approaches to healthcare personnel exemption requests from coronavirus disease 2019 (COVID-19) vaccination: Results of a national survey.

Although a growing number of healthcare facilities are implementing healthcare personnel (HCP) coronavirus disease 2019 (COVID-19) vaccination requirements, vaccine exemption request management as a part of such programs is not well described. Cross-sectional survey. Infectious disease (ID) physician members of the Emerging Infections Network with infection prevention or hospital epidemiology responsibilities. Eligible persons were sent a web-based survey focused on hospital plans and practices around exemption allowances from HCP COVID-19 vaccine requirements. Of the 695 ID physicians surveyed, 263 (38%) responded. Overall, 160 respondent institutions (92%) allowed medical exemptions, whereas 132 (76%) allowed religious exemptions. In contrast, only 14% (n = 24) allowed deeply held personal belief exemptions. The types of medical exemptions allowed varied considerably across facilities, with allergic reactions to the vaccine or its components accepted by 145 facilities (84%). For selected scenarios commonly used as the basis for religious and deeply held personal belief exemption requests, 144 institutions (83%) would not approve exemptions focused on concerns regarding right of consent or violations of freedom of personal choice, and 140 institutions (81%) would not approve exemptions focused on introducing foreign substances into one's body or the sanctity of the body. Most respondents noted plans for additional infection prevention interventions for HCP who received an exemption for COVID-19 vaccination. Although many respondent institutions allowed exemptions from HCP COVID-19 vaccination requirements, the types of exemptions allowed and how the exemption programs were structured varied widely.

COVID-19 vaccine Mandates: An Australian attitudinal study

BackgroundThe rollout of vaccines against COVID-19 is prompting governments and the private sector to adopt mandates. However, there has been little conceptual analysis of the types of mandates available, nor empirical analysis of how the public thinks about different mandates and why. Our conceptual study examines available instruments, how they have been implemented pre-COVID, and their use for COVID-19 globally. Then, our qualitative study reports the acceptability of such measures in Western Australia, which has experienced very limited community transmission, posing an interesting scenario for vaccine acceptance and acceptability of measures to enforce it. MethodOur conceptual study developed categories of mandates from extant work, news reports, and legislative interventions globally. Then, our empirical study asked 44 West Australians about their attitudes towards potential mandatory policies, with data analysed using NVivo 12. ResultsOur novel studies contribute richness and depth to emerging literature on the types and varying acceptability of vaccine requirements. Participants demonstrated tensions and confusion about whether instruments were incentives or punishments, and many supported strong consequences for non-vaccination even if they ostensibly opposed mandates. Those attached to restrictions for disease prevention were most popular. There were similar degrees of support for mandates imposed by employers or businesses, with participants showing little concern for potential issues of accountability linked to public health decisions delegated to the private sector. Participants mostly supported tightly regulated medical exemptions granted by specialists, with little interest in religious or personal belief exemptions. ConclusionOur participants are used to being governed by vaccine mandates, and now by rigorous lockdown and travel restrictions that have ensured limited local COVID-19 disease and transmission. These factors appear influential in their general openness to COVID-19 vaccine mandates, especially when linked explicitly to the prevention of disease in high-risk settings.

Political Will, Vaccines, and Community Immunity.

Political Will, Vaccines, and Community Immunity.

Personal belief exemptions for school-entry vaccinations, vaccination rates, and academic achievement

Nonmedical exemptions from school-entry vaccine mandates are receiving increased policy and public health scrutiny. This paper examines how expanding the availability of exemptions influences vaccination rates in early childhood and academic achievement in middle school. We leverage 2003 legislation that granted personal belief exemptions (PBE) in Texas and Arkansas, two states that previously allowed exemptions only for medical or religious regions. We find that PBE decreased vaccination coverage among Black and low-income preschoolers by 16.1% and 8.3%, respectively. Furthermore, we find that those cohorts affected by the policy change in early childhood performed less well on standardized tests of academic achievement in middle school. Estimated effects on test scores were largest for Black students and economically disadvantaged students.

Historical Origins of the Personal Belief Exemption to Vaccination Mandates: The View from California.

A number of states, starting with California, have recently removed all non-medical exemptions from their laws requiring vaccinations for schoolchildren. California was also one of the earliest states to include a broad non-medical, or personal, belief exemption in its modern immunization law, which it did with a 1961 law mandating polio vaccination for school enrollment, Assembly Bill 1940 (AB 1940). This paper examines the history of AB 1940's exemption clause as a case study for shedding light on the little-examined history of the personal belief exemption to vaccination in the United States. This history shows that secular belief exemptions date back further than scholars have allowed. It demonstrates that such exemptions resulted from political negotiation critical to ensuring compulsory vaccination's political success. It challenges a historiography in which antivaccination groups and their allies led late-nineteenth and early-twentieth century opposition to vaccination mandates while religious groups drove mid-twentieth century opposition. It also complicates the historiographic idea of a return to compulsion in the late 1960s, instead dating this return a decade earlier, to a time when belief exemptions in polio vaccination mandates helped reconcile the goal of a widely vaccinated population with the sacrosanct idea of health as a personal responsibility.

State Vaccine Mandates for COVID-19 – An Emerging Disparity between Childcare Providers and School Teachers

INTRODUCTION: On December 22, 2020, the Advisory Committee on Immunization Practices (ACIP) issued guidelines for the allocation of the coronavirus disease-2019 (COVID-19) vaccine. Childcare providers and K-12 school teachers, as designated ‘frontline essential workers,’ were recommended for early vaccination. Despite ACIP recommendations, some states chose only to prioritize school teachers, sending the message that childcare providers’ occupational risk was less than that of school teachers and other frontline essential workers. More recently, on August 11, 2021, California became the first state to require COVID-19 vaccination of school teachers, but excluded childcare providers. To better understand this emerging disparity, we characterize state vaccine mandates for childcare providers versus school teachers.METHODS: To determine which states had issued legislative and/or regulatory directives requiring vaccination of childcare and/or school personnel (as of November 1, 2021), we reviewed official archives of executive orders for all 50 states and the District of Columbia (DC) and COVID-19 state databases maintained by the National Conference of State Legislatures and the National Academy for State Health Policy. For each state with legislative or regulatory directives, we collected information on issue date and compliance deadline, type (e.g., executive order, public health order), issuer (e.g., governor, public health officer), availability of vaccine exemptions and testing alternatives, and acceptable proofs of vaccination.RESULTS: Ten states (including DC) had issued executive-branch directives requiring either COVID-19 vaccination or routine testing for school teachers, of which only five included childcare providers (no states had issued directives for childcare providers alone). No states had passed legislation requiring COVID-19 vaccination. Three states required COVID-19 vaccination without a routine testing alternative; six states allowed for both vaccination and routine testing to fulfill the directive’s requirement; and one state (New York) required routine testing with opt out vaccination for those who objected. Five states did not specify any exemptions to vaccination, with the rest allowing medical and/or religious belief exemptions and none allowing personal belief exemptions. All states required formal proof of vaccination either in the form of an attestation from a healthcare provider, a signed CDC vaccination card, and/or a record from a state immunization registry; no states allowed for personal attestation to support receipt of vaccination. The results can be found summarized in the table. CONCLUSION: While ten states (including DC) have issued directives requiring either COVID-19 vaccination or routine testing among school teachers, only half include childcare providers. This emerging trend suggests an unwarranted disparity between childcare and school settings in states’ efforts to promote vaccination, as the argument in favor of vaccinating the former is at least as strong as that of the latter for several reasons. First, both staff and children in childcare programs may be at higher risk for contracting COVID-19 than those in schools, given the congregation of infants and young children who are both ineligible for vaccination and possibly less effectively adherent to nonpharmaceutical interventions (e.g., masking, social distancing, handwashing). Second, childcare providers have a lower COVID-19 vaccine uptake compared to school teachers (78% versus 90% as of late Spring 2021). Finally, childcare providers skew more heavily minority, and therefore may be at greater risk for COVID-19-related morbidity and mortality (17.3 and 19.3 percent of childcare personnel are Black and Hispanic versus 12.1 and 13.0 percent of school personnel, respectively). To ensure equitable consideration for the health and safety of childcare providers and school teachers alike, states should consider expanding directives to include childcare providers—as has been done by both New Jersey and Illinois—to bridge the COVID-19 vaccination gap between childcare providers and school teachers.

Impact of governmental regulations on compliance with MMR immunizations in Northern California.

California's Senate Bill 277 (SB277) was mandated to reduce the prevalence of measles by eliminating personal belief exemptions. This study evaluated seven county-level records to determine the impact of SB277 on immunizations among kindergarteners in Northern California. This study used a quantitative postintervention secondary data analysis. This study included three kindergarten schools in seven Northern California counties during three academic years from 2015 to 2019. Sixty-three previously collected school measurements involving 4,626 students were included in a secondary analysis. The study used grouped logistic regression to evaluate the variations in immunization compliance records (2015-16 vs. 2017-18 and 2018-19) among kindergartners in seven counties. This study found no significant differences in (1) overall county-level measures and (2) the likelihood that kindergartners would be current with measles-mumps-rubella (MMR; OR=1.12, CI=0.79-1.62) or be up-to-date with five immunizations (OR=1.08, CI=0.77-1.52) post-SB277 versus pre-SB277. This study showed that SB277 had a small clinical but nonstatistically significant impact on kindergartners' up-to-date with up-to-date rates of compliance with five immunizations and those current with two doses of MMR in seven Northern California counties. Despite the passing of SB277, vaccine-hesitant parents have continued to seek alternatives to immunizations.

Opting Out: Individualism and Vaccine Refusal in Pockets of Socioeconomic Homogeneity

Cases of measles and other highly contagious diseases are rising in the United States. Public health experts blame the rise partly on the spatial concentration of parents declining to vaccinate their children, but researchers have given little attention to theorizing why this clustering occurs in particular communities. We argue that residential and school selection processes create “pockets of homogeneity” attracting parents inclined to opt out of vaccines. Structural features of these enclaves reduce the likelihood of harsh criticism for vaccine refusal and foster a false sense of protection from disease, making the choice to opt out seem both safe and socially acceptable. Examination of quantitative data on personal belief exemptions (PBEs) from school-based vaccination requirements in California schools and districts, as well as findings from parent interviews, provide empirical support for the theory. We discuss substantive implications for lawmakers and public health officials, as well as broader sociological contributions concerning neighborhood effects and residential sorting.

Shouting at each other into the void: A linguistic network analysis of vaccine hesitance and support in online discourse regarding California law SB277.

In 2015, California passed Senate Bill 277 and became the third state in the United States to ban all nonmedical exemptions from school immunization requirements, effectively prohibiting religious and personal belief exemptions. This attracted grassroots opposition and considerable debate among vaccine hesitant factions online. This mixed-methods study used quantitative linguistic analysis, semantic network analysis, and content analysis techniques to examine 2424 online documents drawn from newspapers, blogs, health websites, government information pages, web forums, personal websites, Facebook groups, among others. The study examined which words and phrases were used most frequently by vaccine skeptics, vaccine defenders, and more neutral media accounts to illuminate how groups with different attitudes towards vaccination discuss and disseminate information about vaccines and vaccine policy online. We proposed an innovative methodology for examining online discourse surrounding vaccine hesitance, as well as for studying the online dissemination of misinformation about vaccines. Our findings highlighted discrepancies in the narratives between what vaccine supporters believe causes vaccine skepticism and the issues that vaccine skeptics actually discuss within their own digital spaces. For example, in these exchanges, the importance of parental rights overshadowed that of children's rights; supporters of vaccines brought up autism in more distinct documents than skeptics do; distrust of government regulators and researchers seemed to unite vaccine skeptics and defenders; and politicians, doctors, and even celebrities often served as proxies in heated exchanges about factual evidence, believability, and the importance of expertise in public discourse.

Trends in school-level vaccination coverage from 2015 to 2018: Increases in exemption rates and declines in herd immunity in Arizona

Vaccination enrollment requirements are an important tool used to improve vaccination coverage among school-aged children. However, all states permit varying exemptions that allow students to stay enrolled without receiving some (or all) vaccinations. In Arizona, schools are required to report vaccination data on their kindergarten and 6th grade students annually to the Arizona Department of Health Services (ADHS). We analyzed trends in herd immunity and personal belief exemptions in Arizona schools from 2015 to 2018. We also identified multiple correlates of herd immunity at the school level. Our results demonstrate decreased herd immunity statewide and by school type and an increased rate of personal belief exemptions during this period. These findings contribute to the body of literature suggesting that vaccine hesitancy is growing, resulting in suboptimal vaccination coverage for children. Moreover, this research has several policy implications, especially for states permitting multiple exemption types and lax exemption criteria.

The History of the Personal Belief Exemption.

California’s 2015 elimination of personal belief exemptions to required childhood vaccinations may have set off a trend. In 2019, in response to record-breaking measles outbreaks, lawmakers in at least 10 states attempted to eliminate or restrict the exemption. The moves suggest a possible end for the legal tool, which has a long yet little-examined history. The term “personal belief exemption” first came into popular use in the 1990s, but the idea of granting exemption from compulsory vaccination on the basis of secular convictions dates to the late 19th century. Since then, the exemption has evolved through 4 stages, each prompted by new vaccines or vaccine laws. In each stage, the exemptions reflected political compromise in the lawmaking process and broader struggles over liberties and rights. Smallpox prompted the earliest vaccination mandates, and by the late 19th century, those laws inspired the first personal belief exemptions. California passed its first law requiring smallpox vaccination for school admission in 1889, a time when compulsory schooling and rising smallpox rates had been prompting such laws nationwide.1 The law included a medical exemption, but other states’ laws often omitted exemptions, and the unvaccinated could generally be fined, quarantined, or suspended. On the other side of the Atlantic, meanwhile, England’s 1853 compulsory vaccination law triggered decades of widespread noncompliance and openly hostile antivaccinationism.2 In 1898, the British government responded by adding a “conscience clause” to the law.2 US antivaccinationists and … Address correspondence to Elena Conis, Graduate School of Journalism and Center for Science, Technology, Medicine, and Society, University of California, Berkeley, 121 North Gate Hall, Berkeley, CA 94720. E-mail: econis{at}berkeley.edu

Under the Law: Measles outbreaks motivate change

In response to recent increases in the number of measles cases, some states have tightened their vaccine requirements for school admission, eliminating religious and personal belief exemptions. Julie Underwood traces the history of vaccination requirements and how the court has ruled on challenges to these requirements, which argue that requiring vaccination violates various individual rights. So far, courts have ruled in favor of vaccination requirements, noting that they are intended to promote the general welfare of all.

Personal Belief Exemptions for School-Entry Vaccinations, Vaccination Rates, and Academic Achievement

Nonmedical exemptions from school-entry vaccine mandates are receiving increased policy and public health scrutiny. This paper examines how expanding the availability of exemptions influences vaccination rates in early childhood and academic achievement in middle school. We leverage 2003 legislation that granted personal belief exemptions (PBE) in Texas and Arkansas, two states the previously allowed exemptions only for medical or religious regions. We find that PBE decreased vaccination coverage among black and low-income preschoolers by 16.1% and 8.3%, respectively. Furthermore, we find that those cohorts affected by the policy change in early childhood performed less well on standardized tests of academic achievement in middle school. Estimated effects on mathematics and English Language Arts test scores were largest for black students, especially those residing in economically disadvantaged counties.

Religious Vaccine Exemptions in Kindergartners: 2011-2018.

Forty-five states permit religious exemptions to school immunization laws; 15 allow personal belief exemptions. Updated religious exemption estimates are lacking, and it is unclear if personal belief exemption availability impacts religious exemption rates. We aimed to (1) update religious exemption trends in kindergartners, (2) compare states' proportions of kindergartners with religious exemptions by personal belief exemption availability, and (3) describe whether the proportion of kindergartners with religious exemptions changed in Vermont after it eliminated personal belief exemptions in 2016. We analyzed Centers for Disease Control and Prevention data on exemptions for children entering kindergarten from 2011 to 2018, including 295 state-years in our final analysis. Using a quasi-binomial regression analysis, we compared mean proportions of kindergartners with religious exemptions in states allowing both nonmedical exemptions against states with religious exemptions only, adjusting for policy strength and school year. States with religious and personal belief exemptions were one-fourth as likely to have kindergartners with religious exemptions as states with religious exemptions only (risk ratio 0.25; 95% confidence interval 0.16-0.38). After Vermont's policy change, the mean proportion of kindergartners with a religious exemption increased from 0.5% to 3.7%. States were significantly more likely to have kindergartners with religious exemptions during the 2017-2018 school year compared with the 2011-2012 school year (P = .04). Religious exemption rates appear to be associated with personal belief exemption availability, may be subject to a replacement effect on personal belief exemption elimination, and are increasing. Researchers and policy makers should confirm findings with individual-level studies and reconsider the purpose and nature of religious exemption laws.

8 months to 5 days: what happened when Pennsylvania changed the vaccination regulations for provisional enrollment?

ABSTRACT In March 2017, the Pennsylvania Department of Health reduced the time allowed to demonstrate compliance with school-entry vaccination requirements from eight months to five days. We describe changes in provisional enrollment, vaccine exemptions, and vaccine coverage rates before and after the new regulation. Across Pennsylvania, provisional enrollment decreased from 11.1% in 2016/17 to 2.5% in 2017/18 (77% relative decrease). Personal belief exemptions continued a modest upward trend, similar to previous years, and medical exemptions remained steady. Among kindergartners, coverage with ≥ 2 doses of MMR vaccine and 2 doses of Varicella vaccine increased; similar increases were seen for the MCV and Tdap vaccines among 7th graders. However, improvements in coverage and reductions in provisional enrollment were not consistent across counties. Provisional enrollment in Philadelphia County during the 2017/18 school year (10.4%) did not substantially decrease. The statewide reduction in provisional enrollment suggests that the new regulations accomplished the goal of increasing the proportion of students who are up-to-date on required vaccines at the beginning of the school year without a significant increase in vaccine exemptions. However, the persistence of high provisional enrollment in some counties points to additional barriers to this goal in some schools and regions.

Associations of Statewide Legislative and Administrative Interventions With Vaccination Status Among Kindergartners in California

California implemented 3 interventions to increase uptake of vaccines. In 2014, Assembly bill 2109 tightened requirements for obtaining a personal belief exemption. A 2015 campaign provided educational materials to school staff on the proper application of conditional admission for kindergartners who were not up to date on required vaccinations. In 2016, Senate bill 277 eliminated personal belief exemptions. Prior research has not evaluated these 3 interventions together with regard to the vaccination status of students. To assess the changes in the yearly rates of kindergartners who were not up to date on required vaccinations who were entering school during the period of the interventions, by focusing on geographic clustering and the potential contacts of these kindergartners. Observational study that used cross-sectional school-entry data from 2000-2017 to calculate the rates of kindergartners attending California schools who were not up to date on required vaccinations. Assembly bill 2109, a conditional admission education program, and Senate bill 277. The primary outcome was the yearly rate of kindergartners without up-to-date vaccination status. The secondary outcomes were (1) the modified aggregation index, which was used to assess the potential within-school contacts among kindergartners without up-to-date vaccination status, (2) the number of geographic clusters of schools with rates for kindergartners without up-to-date vaccination status that were higher than the rates for schools located outside the cluster, and (3) the number of schools located inside the geographic clusters. In California between 2000 and 2017, 9 323 315 children started attending kindergarten and 721 593 were not up to date on required vaccinations. Prior to the interventions, the statewide rate of kindergartners without up-to-date status for required vaccinations increased from 7.80% during 2000 to 9.84% during 2013 and then decreased after the interventions to 4.87% during 2017. The percentage chance for within-school contact among kindergartners without up-to-date vaccination status decreased from 26.02% during 2014 to 4.56% (95% CI, 4.21%-4.99%) during 2017. During 2012-2013, there were 124 clusters that contained 3026 schools with high rates of kindergartners without up-to-date vaccination status. During 2014-2015, there were 93 clusters that contained 2290 schools with high rates of kindergartners without up-to-date vaccination status. During 2016-2017, there were 110 clusters that contained 1613 (95% CI, 1565-1691) schools. In California, statewide legislative and educational interventions were associated with a decrease in the yearly rates of kindergartners without up-to-date vaccination status. These interventions also were associated with reductions in the number of schools inside the clusters with high rates of kindergartners without up-to-date vaccination status and the potential for contact among these kindergartners.

Elimination of Nonmedical Immunization Exemptions in California and School-Entry Vaccine Status.

California implemented Senate Bill 277 (SB277) in 2016, becoming the first state in nearly 30 years to eliminate nonmedical exemptions from immunization requirements for schoolchildren. Our objectives were to determine (1) the impacts of SB277 on the percentage of kindergarteners entering school not up-to-date on vaccinations and (2) if geographic patterns of vaccine refusal persisted after the implementation of the new law. At the state level, we analyzed the magnitude and composition of the population of kindergarteners not up-to-date on vaccinations before and after the implementation of SB277. We assessed correlations between previous geographic patterns of nonmedical exemptions and patterns of the remaining entry mechanisms for kindergarteners not up-to-date after the law's implementation. In the first year after SB277 was implemented, the percentage of kindergartners entering school not up-to-date on vaccinations decreased from 7.15% to 4.42%. The conditional entrance rate fell from 4.43% to 1.91%, accounting for much of this decrease. Other entry mechanisms for students not up-to-date, including medical exemptions and exemptions for independent study or homeschooled students, largely replaced the decrease in the personal belief exemption rate from 2.37% to 0.56%. In the second year, the percentage of kindergartners not up-to-date increased by 0.45%, despite additional reductions in conditional entrants and personal belief exemptions. The correlational analysis revealed that previous geographic patterns of vaccine refusal persisted after the law's implementation. Although the percentage of incoming kindergarteners up-to-date on vaccinations in California increased after the implementation of SB277, we found evidence for a replacement effect.