A longitudinal analysis of the effect of nonmedical exemption law and vaccine uptake on vaccine-targeted disease rates

Policy Approaches for Increasing Adolescent HPV Vaccination Coverage: A Systematic Review

CONTEXT

US jurisdictions have enacted a wide range of policies to address low human papillomavirus (HPV) vaccination coverage among adolescents, but it is unclear which policies are effective.

OBJECTIVE

To systematically review the impact of governmental policies on adolescent HPV vaccination coverage.

DATA SOURCES

PubMed, Embase, and Scopus databases.

STUDY SELECTION

Eligible studies, published from 2009 to 2022, evaluated the impact of governmental policies on HPV vaccination coverage among adolescents ages 9 to 18.

DATA EXTRACTION

Two investigators independently extracted data on study sample, study design and quality, policy characteristics, and HPV vaccination outcomes. We summarized findings by policy type: school-entry requirements (SERs), federally-funded policies related to the Vaccines for Children program and Medicaid, educational requirements, and others.

RESULTS

Our search yielded 36 eligible studies. A majority of studies evaluating HPV vaccine SERs found positive associations between SERs and HPV vaccination coverage (8 of 14), particularly for SERs in Rhode Island and Washington, DC. All studies evaluating SERs for other adolescent vaccines observed positive spillover effects for HPV vaccination (7 of 7). Federally-funded policies related to Vaccines for Children and Medicaid were consistently associated with higher HPV vaccination coverage (7 of 9). Relatively few studies found associations between educational requirements and HPV vaccination coverage (2 of 8).

LIMITATIONS

Studies used limited vaccination data sources and non- or quasi-experimental designs. Some studies had no or poorly matched comparison groups.

CONCLUSIONS

Our findings suggest promise for SERs and federally-funded policies, but not educational requirements, for increasing HPV vaccination coverage among adolescents.

A Comprehensive Assessment Of Child Care Vaccination Laws Across The US

All fifty US states and Washington, D.C., require children from birth through age five to be vaccinated against certain communicable diseases as a condition of attending child care settings such as day care, Head Start, preschools, pre-kindergarten, and other early childhood programs. However, the nuances and implementation of these laws vary greatly across jurisdictions. To date, a comprehensive analysis of all child care vaccination laws in the US has not been performed. We have developed the first compilation of child care vaccination laws across the US. This compilation is the culmination of an exhaustive examination of multiple components of the laws, such as which vaccines are required, provisions that enable unvaccinated children to temporarily attend child care until they are fully vaccinated, attendance provisions for unvaccinated students during an outbreak, methods of enforcement of vaccination policy, and child care personnel vaccination requirements. This comprehensive analysis provides a critical and foundational framework to inform policy makers and public health professionals involved in policy planning and implementation and policy research. It provides a benchmark for further evaluation of existing and future vaccination laws and their impact on vaccine coverage rates.

In the Wake of a Pandemic: Revisiting School Approaches to Nonmedical Exemptions to Mandatory Vaccination in the US

Mandatory school vaccination policies with exclusion of unvaccinated students can be a powerful tool in ensuring high vaccination rates. Some parents may object to mandatory vaccination policies, claiming exemptions based on medical, religious, or philosophical reasons. Individual schools, school systems, or local or regional governments have different policies with respect to whether, and what kind of, exemptions may be allowed. In the setting of the current pandemic, questions regarding the acceptability of exemptions have resurfaced, as schools and local governments struggle with how to safely return children to school. Anticipating that school attendance will be facilitated by the development of a vaccine, school systems will face decisions about whether to mandate vaccination and whether to permit exemptions. The American Academy of Pediatrics promulgates policy favoring the elimination of nonmedical exemptions generally in schools. This discussion considers whether schools should eliminate nonmedical exemptions to vaccination as proposed in the American Academy of Pediatrics policy, ultimately concluding that broad elimination of exemptions is not justified and advocating a more nuanced approach that encourages school attendance while promoting vaccination and broader public health goals.

Effects of California Assembly Bill 2109 in Low Vaccination Rate Counties: Are We Looking at the Right Variables?

OBJECTIVES

California Assembly Bill 2109 (AB2109) was passed in 2012 and restricted the obtainment of personal belief exemptions (PBEs) for vaccination requirements for school-aged children. This study examined changes in up-to-date (UTD) vaccination rates, PBEs, and conditionally accepted students (CASs) at 3 time points. The study also examined the association of PBEs and CASs on county and school immunization rates.

DESIGN

This study utilized 6 academic years of immunization data from all kindergartens in California from 2010-2011 to 2015-2016. The years were selected to include data 2 years prior to the introduction of the bill, 2 years prior to implementation, and 2 years after the new legislation went into effect in 2014. Data were analyzed for changes in variables over time at the state, county, and school levels. A Pearson correlation was performed to assess the association between CAS, PBE, and not-UTD rates in low- and high-UTD counties.

RESULTS

Counties with the highest percentage of unimmunized students have significantly higher mean CAS rates than PBE rates (P < .01 for all years). CASs were found to be more highly correlated with students not-UTD with immunizations than PBEs in all years studied (P < .01 for all years) and with far greater effect size in low-UTD counties (<90% UTD rate). There was a small rise in PBEs and a small reduction in UTD rates after AB2109 was signed but a fall in PBE and CAS rates and a rise in UTD rates postimplementation.

CONCLUSION

Many California counties have high levels of CASs at the time of kindergarten entry. The extent to which schools require CASs to complete required vaccinations is not known, which could contribute to the pool of undervaccinated students in California. Public health officials should be vigilant to ensure that schools follow up and enforce the completion of vaccines for conditionally admitted students. This study has policy implications due to the fact that it has been revealed that there is a large undervaccinated population remaining relatively unaccounted for in California despite recent efforts.

State statutes and regulations related to human papillomavirus vaccination

A cross-sectional analysis of human papillomavirus (HPV) vaccine statutes and regulations from states and the District of Columbia in the United States (U.S.) was conducted from September–November 2018 to advance analyses of policy impact on HPV vaccination uptake. A search was conducted using WestlawNext, a legal research database. Statutes and regulations relevant to the study were analyzed and coded based on their legal attributes into ten broad coding questions and several sub-questions. Of the 212 laws identified by the initial search string, 93 (43.9%) reference HPV vaccination in statute or regulation. An additional three laws were added following subsequent review. There was a total of 52 statutes and 44 regulations from 34 states and the District of Columbia. Most laws were related to developing and distributing HPV vaccination materials for parents, and mechanisms to fund and reimburse for the vaccination. This study can be used by policymakers in jurisdictions that are considering establishing HPV vaccination promotion interventions in state law and highlighting the limited statutory and regulatory efforts that have been implemented to promote HPV vaccination. Importantly, this study can also be used to conduct evaluations of the efficacy of statutory and regulatory strategies in increasing HPV vaccination rates.

Impact of school vaccination mandates on pediatric vaccination coverage: a systematic review

BACKGROUND

Mandated vaccination for school attendance is a growing strategy internationally. Our aim was to investigate the effects of implementing school vaccination mandates on pediatric population vaccine coverage.

METHODS

In this systematic review, we searched MEDLINE, Embase, CINAHL, the Education Resources Information Center (ERIC) and the PAIS Index for empirical studies of implementation of a primary or secondary school vaccination requirement published in any language through March 2019 with vaccination rates as an outcome. We sought additional studies by consulting experts, reference lists and grey literature sources. Included studies were too heterogeneous for meta-analysis; thus, we extracted data using a standardized rubric and synthesized the results narratively.

RESULTS

Among the 4232 citations obtained, 20 studies met the inclusion criteria. Eighteen were conducted with US data, 1 with Italian data, and 1 with Australian data. Four studies examined school-entry mandates, and 16 examined adolescent requirements. An uncontrolled before-after design was used in 10 studies, cross-sectional analysis in 7, a retrospective cohort design in 2, and a prospective cohort in 1. In many cases, increased documentation of coverage followed the addition of new requirements. The exception to this was human papillomavirus vaccination mandates, which were highly controversial, in the United States. The studies contained notable risks of bias, with cointerventions rarely acknowledged or accounted for, and subpopulations often excluded. A substantial risk of ecological fallacy existed for most studies.

INTERPRETATION

Vaccination mandates appear largely associated with increased vaccination coverage, but it is not possible to attribute causality to the mandate in most studies. High-quality implementation research that uses whole-population coverage data and takes into consideration cointerventions, confounders, clustering of unvaccinated populations and context is required.

Legal approaches to promoting parental compliance with childhood immunization recommendations

Rates of vaccine-preventable diseases have increased in the United States in recent years, largely due to parental refusals of recommended childhood immunizations. Empirical studies have demonstrated a relationship between nonvaccination rates and permissive state vaccine exemption policies, indicating that legal reforms may promote higher immunization rates. This article reviews relevant data and considers the legal landscape. It analyzes federal and state Constitutional law, concluding that religious and personal belief exemptions to school-entry vaccine mandates are not constitutionally required. It identifies public health, bioethical, and policy considerations relevant to the choice among legal approaches employed by states to promote parental compliance. The article describes a range of legal tools that may help promote parental cooperation with immunization recommendations.

Immunization Mandates, Vaccination Coverage, and Exemption Rates in the United States

Background

Vaccination coverage among children entering kindergarten in the United States is high, but interstate variations exist. The relationship between state immunization laws and vaccination coverage has not been fully assessed. We evaluated associations of state laws on both measles, mumps, and rubella (MMR) and diphtheria, tetanus, and pertussis (DTaP) vaccination coverage and exemptions to school immunization requirements.

Methods

We conducted a retrospective, longitudinal analysis of the effect of state immunization laws on vaccination coverage and exemptions among US kindergarteners from SY 2008 to SY 2014. The primary outcome measures were state-level kindergarten entry vaccination coverage rates for 2-dose MMR and 4-dose DTaP vaccines. Secondary outcome measures included rates of state-level exemptions (ie, medical, religious, philosophical) to school immunization requirements.

Results

We found that state policies that refer to Advisory Committee on Immunization Practices recommendations were associated with 3.5% and 2.8% increases in MMR and DTaP vaccination rates. Health Department–led parental education was associated with 5.1% and 4.5% increases in vaccination rates. Permission of religious and philosophical exemptions was associated with 2.3% and 1.9% decreases in MMR and DTaP coverage, respectively, and a 1.5% increase in both total exemptions and nonmedical exemptions, respectively.

Conclusions

We found higher vaccination coverage and lower nonmedical exemption rates for MMR and DTaP vaccines in states adopting Advisory Committee on Immunization Practices guidelines for school entry. Adherence to these best practices was a successful strategy to increase vaccination coverage and reduce vaccination exemptions.

Examining the spatiotemporal evolution of vaccine refusal: nonmedical exemptions from vaccination in California, 2000-2013

BACKGROUND

Vaccine hesitancy continues to be an issue throughout the United States, as numerous vaccine hesitant parents are choosing to exempt their children from school-entry vaccination requirements for nonmedical reasons, despite the safety and effectiveness of vaccines. We conduct an analysis of how vaccine refusal, measured by the use of nonmedical exemptions (based on personal or religious beliefs) from vaccination (NMEs), evolved across space and over time in California.

METHODS

Using school-entry data from the California Department of Public Health, we examined NMEs for students entering kindergarten in California from 2000 to 2013. We conduct global and local spatial autocorrelation analysis to determine whether NME use became more geographically clustered over the study period and whether the location of local clusters of high use were temporally stable. We conducted a grouping analysis that identified the general temporal trends in NME use over the time period.

RESULTS

The use of NMEs increased from 0.73% of all kindergarteners in 2000 to 3.09% in 2013 and became more geographically clustered over the study period. Local geographic clusters of high use were relatively isolated early in the study period, but expanded in size over time. The grouping analysis showed that regions with high NME use early in the study period were generally few (15% of all US Census tracts) and relatively isolated. Regions that had low initial NME use and moderate to large increases over the study period were located in close proximity to the initial high use regions. The grouping analysis also showed that roughly half of all tracts had 0% or very low NME use throughout the study period.

CONCLUSIONS

We found an observable spatial structure to vaccine refusal and NME use over time, which appeared to be a self-reinforcing process, as well as a spatially diffusive process. Importantly, we found evidence that use of NMEs in the initially isolated regions appeared to stimulate vaccine refusal in geographically proximal regions. Thus, our results suggest that efforts aimed at decreasing future NME use may be most effective if they target regions where NME use is already high, as well as the nearby regions.

Trends in Kindergarten Rates of Vaccine Exemption and State-Level Policy, 2011-2016

Background

Kindergarten-entry vaccination requirements have played an important role in controlling vaccine-preventable diseases in the United States. Forty-eight states and the District of Colombia offer nonmedical exemptions to vaccines, ranging in stringency.

Methods

We analyzed state-level exemption data from 2011 to 2012 through 2015 to 2016 school years. States were categorized by exemption ease and type of exemption allowed. We calculated nonmedical exemption rates for each year in the sample and stratified by exemption ease, type, and 2 trend categories: 2011-12 through 2012-13 and 2013-14 through 2015-16 school years. Using generalized estimating equations, we created regression models estimating (1) the average annual change in nonmedical exemption rates and (2) relative differences in rates by state classification.

Results

The nonmedical exemption rate was higher during the 2013-2014 through 2015-2016 period (2.25%) compared to 2011-2012 through 2012-2013 (1.75%); more importantly, the average annual change in the latter period plateaued. The nonmedical exemption rate in states allowing philosophical and religious exemptions was 2.41 times as high as in states allowing only religious exemptions (incidence rate ratio = 2.41; 95% confidence interval, 1.71-3.41).

Conclusions

There was an increase in nonmedical exemption rates through the 2012-2013 school year; however, rates stabilized through the 2015-2016 school year, showing an important shift in trend.

Seven Foundational Principles of Population Health Policy

In 2016, Keyes and Galea issued 9 foundational principles of population health science and invited further deliberations by specialists to advance the field. This article presents 7 foundational principles of population health policy whose intersection with health care, public health, preventive medicine, and now population health, presents unique challenges. These principles are in response to a number of overarching questions that have arisen in over a decade of the authors' collective practice in the public and private sectors, and having taught policy within programs of medicine, law, nursing, and public health at the graduate and executive levels. The principles address an audience of practitioners and policy makers, mindful of the pressing health care challenges of our time, including: rising health-related expenditures, an aging population, workforce shortages, health disparities, and a backdrop of inequities rooted in social determinants that have not been adequately translated into formal policies or practices among the key stakeholders in population health. These principles are meant to empower stakeholders—whether it is the planner or the practitioner, the decision maker or the dedicated caregiver—and inform the development of practical tools, research, and education.

Variation in Vaccination Data Available at School Entry Across the United States

OBJECTIVES

To compile substate-level data on US school-age children's vaccination rates.

METHODS

For states that did not have suitable data online, in 2015 we submitted information requests to the state health department and followed up with the state's Freedom of Information Act when necessary.

RESULTS

The accessibility, scale, and types of vaccination data varied considerably. Whereas 26 states provided data online, 14 released data only after a Freedom of Information Act request. School or school-district data were available for 24 states, 19 at the county level, 2 at the health department level, and 6 provided no substate-level data.

CONCLUSIONS

Effective vaccination policy requires a robust understanding of vaccination behavior. Some states make it difficult to access data or provide low-resolution data of limited value for identifying vaccination behavior.

A spatiotemporal analysis of non-medical exemptions from vaccination: California schools before and after SB277

Childhood vaccination programs are considered one of the most beneficial public health programs in modern history. In the United States, the increasing use of non-medical exemptions (NMEs) from school entry vaccination requirements has garnered attention and scrutiny in the popular press, academic literature, and policy forums. In 2016, California law SB277 goes into effect, eliminating the NME option for students attending the state's public and private schools. Whereas SB277 is a strong move to increase vaccination coverage within California's schools, the new law contains an important caveat - students already having a valid NME (obtained prior to the 2016 school year) are "grandfathered" in until their next grade checkpoint (seventh grade). Although no new students will enter the California school system with a NME after 2016, the law's grandfather clause will allow NMEs to persist within the state school system until 2022. This analysis demonstrates how the past "build up" of students with pre-SB277 NMEs and the law's grandfather clause will act in combination to affect NME rates across the state after the implementation of SB277. We construct spatially explicit, yearly models of all students (K-12) enrolled in the California school system from 2011 to 2022. Our analysis finds that, although all regions of the state will eventually reach an NME rate of 0% by 2022, SB277's effect will be highly spatially and temporally variable. Some school districts will continue to experience elevated NME rates and increased risk of disease outbreak for years after SB277 is implemented. Our analysis highlights the potential spatially variant consequences of SB277's grandfather clause, providing important information for other states considering similar policy initiatives.

Parents' and staff's support for a childcare agency employee mandatory vaccination policy or agency certification program

BACKGROUND

Vaccine-preventable diseases pose a significant risk to children in childcare. However, few regulations exist regarding childcare staff vaccination. This study aimed to assess support for a childcare agency staff mandatory vaccination policy.

METHODS

Surveys were distributed to staff and parents at 23 St Louis, Mo, childcare agencies during fall 2014. Staff and parents' support for a mandatory vaccination and/or agency certification program were compared using χ(2) tests. Multivariate logistic regression was conducted using a 2-level nested design and controlling for gender, race, age, and income to determine predictive models for support for a mandatory staff vaccination policy and/or agency certification program.

RESULTS

Overall, 354 parents and staff participated (response rate, 32%). Most supported a mandatory staff vaccination policy (80.0%; n = 280) or agency certification program (81.2%; n = 285), and there were no differences between parents versus staff. Determinants of support for a mandatory policy included willingness to receive influenza vaccine annually, belief that vaccines are safe and effective, and support for the policy only if there were no costs.

CONCLUSIONS

There is strong support for some type of childcare agency staff vaccination policy. Implementing such a policy/program should be a collaborative endeavor that addresses vaccine cost and access.

An approach for estimating vaccination coverage for communities using school-level data and population mobility information

Childhood vaccination data are made available at a school level in some U.S. states. These data can be geocoded and may be considered as having a high spatial resolution. However, a school only represents the destination location for the set of students that actually reside and interact within some larger areal region, creating a spatial mismatch. Public school districts are often used to represent these regions, but fail to account for private schools and school of choice programs. We offer a new approach to estimate childhood vaccination coverage rates at a community level by integrating school level data with population commuting information. The resulting mobility-adjusted vaccine coverage estimates resolve the spatial mismatch problem and are more aligned with the geographic scale at which public health policies are implemented. We illustrate the utility of our approach using a case study on diphtheria, tetanus, and pertussis (DTP) vaccination coverage for kindergarten students in California. The modeled community-level DTP coverage estimates yield a statewide coverage of 92.37%, which is highly similar to the 92.44% coverage rate calculated from the original school-level data.

Association Between Vaccine Refusal and Vaccine-Preventable Diseases in the United States: A Review of Measles and Pertussis

IMPORTANCE

Parents hesitant to vaccinate their children may delay routine immunizations or seek exemptions from state vaccine mandates. Recent outbreaks of vaccine-preventable diseases in the United States have drawn attention to this phenomenon. Improved understanding of the association between vaccine refusal and the epidemiology of these diseases is needed.

OBJECTIVE

To review the published literature to evaluate the association between vaccine delay, refusal, or exemption and the epidemiology of measles and pertussis, 2 vaccine-preventable diseases with recent US outbreaks.

EVIDENCE REVIEW

Search of PubMed through November 30, 2015, for reports of US measles outbreaks that have occurred since measles was declared eliminated in the United States (after January 1, 2000), endemic and epidemic pertussis since the lowest point in US pertussis incidence (after January 1, 1977), and for studies that assessed disease risk in the context of vaccine delay or exemption.

FINDINGS

We identified 18 published measles studies (9 annual summaries and 9 outbreak reports), which described 1416 measles cases (individual age range, 2 weeks-84 years; 178 cases younger than 12 months) and more than half (56.8%) had no history of measles vaccination. Of the 970 measles cases with detailed vaccination data, 574 cases were unvaccinated despite being vaccine eligible and 405 (70.6%) of these had nonmedical exemptions (eg, exemptions for religious or philosophical reasons, as opposed to medical contraindications; 41.8% of total). Among 32 reports of pertussis outbreaks, which included 10,609 individuals for whom vaccination status was reported (age range, 10 days-87 years), the 5 largest statewide epidemics had substantial proportions (range, 24%-45%) of unvaccinated or undervaccinated individuals. However, several pertussis outbreaks also occurred in highly vaccinated populations, indicating waning immunity. Nine reports (describing 12 outbreaks) provided detailed vaccination data on unimmunized cases; among 8 of these outbreaks from 59% through 93% of unvaccinated individuals were intentionally unvaccinated.

CONCLUSIONS AND RELEVANCE

A substantial proportion of the US measles cases in the era after elimination were intentionally unvaccinated. The phenomenon of vaccine refusal was associated with an increased risk for measles among people who refuse vaccines and among fully vaccinated individuals. Although pertussis resurgence has been attributed to waning immunity and other factors, vaccine refusal was still associated with an increased risk for pertussis in some populations.

Sociodemographic Predictors of Vaccination Exemptions on the Basis of Personal Belief in California

OBJECTIVES

We examined the variability in the percentage of students with personal belief exemptions (PBEs) from mandatory vaccinations in California schools and communities according to income, education, race, and school characteristics.

METHODS

We used spatial lag models to analyze 2007-2013 PBE data from the California Department of Public Health. The analyses included school- and regional-level models, and separately examined the percentage of students with exemptions in 2013 and the change in percentages over time.

RESULTS

The percentage of students with PBEs doubled from 2007 to 2013, from 1.54% to 3.06%. Across all models, higher median household income and higher percentage of White race in the population, but not educational attainment, significantly predicted higher percentages of students with PBEs in 2013. Higher income, White population, and private school type significantly predicted greater increases in exemptions from 2007 to 2013, whereas higher educational attainment was associated with smaller increases.

CONCLUSIONS

Personal belief exemptions are more common in areas with a higher percentage of White race and higher income.