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

Exploring the impact of the New York State repeal of nonmedical vaccination exemptions on student enrollment, absenteeism, and school workload: Perspectives from a survey of school administrators

In June 2019, New York State (NYS) adopted Senate Bill 2994A eliminating nonmedical vaccine exemptions from school entry laws. Since student noncompliance with the law required school exclusion, we sought to evaluate the law's effects on student enrollment and absenteeism, and school workloads related to its implementation. In November 2019, we sent an electronic survey to NYS (excluding New York City) schools. Due to the COVID-19 pandemic, outreach was curtailed in March 2020 with 525 (14%) of 3,759 eligible schools responding. To account for non-response, results were analyzed using inverse probability weighting. After weighting, 39% (95% CI: 34%, 44%) of schools reported enrollment changes and 31% (95% CI: 26%, 36%) of schools reported absenteeism related to the law. In addition, 95% (95% CI: 93%, 98%) of schools reported holding meetings and/or preparing correspondence about the law, spending a mean of 14 (95% CI: 11, 18) hours on these communication efforts. Schools in the highest pre-mandate nonmedical exemption tertile (vs. lowest) were more likely to report enrollment and absenteeism changes, and higher workloads. While our results should be interpreted with caution, changes in student enrollment, absenteeism, and school workloads may represent important considerations for policymakers planning similar legislation.

Preventable Disease, the Case of Colorado: School District Demographics and Childhood Immunizations

The objective of this study was to evaluate the impact of selected sociodemographic factors on childhood vaccination hesitancy and to define their role according to specific exemptions. This population-based cohort study utilized vaccination rate and sociodemographic data from 1st to 12th grade from 2017 to 2021 for all school districts in Colorado. Data included immunization status and exemptions for each vaccine, race, ethnicity, and free and reduced meal status. Data were evaluated through dimensional analysis and Generalized Linear Mixed Models. School districts with a higher representation of White students had lower immunization rates and use more personal exemptions while school districts with larger Hispanic populations and higher proportions of free and reduced lunches had higher vaccination rates and used more religious exemptions. Black and Pacific Islander populations had higher rates of incomplete vaccination records while Asian American population displayed increased vaccination compliance. Colorado is a robust example of how socioeconomic and cultural differences are important factors with a direct influence on vaccination rates. Future childhood vaccination campaigns and legislation should consider complex socioeconomic and cultural factors.

Partisan Polarization of Childhood Vaccination Policies, 1995‒2020

Objectives. To examine trends in partisan polarization of childhood vaccine bills and the impact of polarization on bill passage in the United States. Methods. We performed content analysis on 1497 US state bills (1995-2020) and obtained voting returns for 228 legislative votes (2011‒2020). We performed descriptive and statistical analyses using 2 measures of polarization. Results. Vote polarization rose more rapidly for immunization than abortion or veterans' affairs bills. Bills in 2019-2020 were more than 7 times more likely to be polarized than in 1995-1996 (odds ratio [OR] = 7.04; 95% confidence interval [CI] = 3.54, 13.99). Bills related to public health emergencies were more polarized (OR = 1.76; 95% CI = 1.13, 2.75). Sponsor polarization was associated with 34% lower odds of passage (OR = 0.66; 95% CI = 0.42, 1.03). Conclusions. State lawmakers were more divided on vaccine policy, but partisan bills were less likely to pass. Bill characteristics associated with lower polarization could signal opportunities for future bipartisanship. Public Health Implications. Increasing partisan polarization could alter state-level vaccine policies in ways that jeopardize childhood immunization rates or weaken responsiveness during public health emergencies. Authorities should look for areas of bipartisan agreement on how to maintain vaccination rates. (Am J Public Health. Published online ahead of print August 25, 2022:e1-e9. https://doi.org/10.2105/AJPH.2022.306964).

Understanding the Role of Psychosocial Factors in Pakistani Parents' Hesitancy to Vaccinate Their Kids: The Mediating Role of Knowledge and Mistrust of Science about the COVID-19 Vaccine

Vaccination is a vital component in the battle against outbreaks of infectious diseases. Recognizing parents’ reluctance to vaccinate their children is even more critical now, given the ongoing threat of a COVID-19 pandemic. Conspiracy theories, vaccination safety concerns, parental efficacy and risk perception, and a lack of confidence in science all influence intention. To investigate how these variables interact with vaccination behavior against COVID-19, we developed a model with psychosocial factors serving as the predictor and mistrust in science and vaccine knowledge serving as the mediator. In order to validate the model, the parents’ intentions regarding their children’s vaccination with COVID-19 were used. The study included 454 Pakistani parents who completed an online questionnaire assessing their intention to vaccinate their children. We analyzed the data using structural equation modeling (SEM). A significant level of vaccine hesitation is due to belief in vaccine conspiracy theories, and vaccine safety concerns were investigated. A surprising correlation exists between risk perception and vaccination intentions, followed by parental self-efficacy. It is significant to note that vaccine knowledge mediated conspiracy beliefs, risk perceptions, and intentions fully but partially mediated parental self-efficacy. Conspiracy theories were mediated by a mistrust in science, while perceptions of risk and vaccine safety were partially mediated. The findings of this research were used to develop sensible policy reforms and public health campaigns to encourage vaccination against both common infections such as measles, human papillomaviruses, or pertussis, and novel diseases such as COVID-19.

Revisiting the 2014-15 Disneyland measles outbreak and its influence on pediatric vaccinations

The 2014-15 Disneyland measles outbreak that began at the California theme park in December 2014 sparked an international conversation regarding measles, vaccine hesitancy, and vaccine policies. The outbreak capped a year with the highest number of measles cases reported in two decades and came amidst increasing trends in nonmedical vaccine exemptions in California and elsewhere. Because of its sensational story line and spread among unvaccinated populations, the outbreak received a high level of media coverage that focused on vaccine hesitancy as a primary driver of the outbreak. This media coverage and the ostensible public support for vaccines that followed led some to hypothesize that the outbreak might have a "Disneyland effect," or a positive influence on the uptake of pediatric measles vaccine. This article reviews the facts of the outbreak and its context, and explores the evidence for the Disneyland outbreak causing an influence on U.S. pediatric vaccine-related beliefs and behaviors.

Evaluating Michigan's Administrative Rule Change on Nonmedical Vaccine Exemptions

OBJECTIVES

Vaccine hesitancy is a growing threat to health in the United States. Facing the fourth highest vaccine exemption rate in the United States in 2014, Michigan changed its state Administrative Rules, effective January 1, 2015, requiring parents to attend an in-person vaccine education session at their local health department before obtaining a nonmedical exemption (NME). In this article, we evaluate the longer-term impact of this policy change on the rate, spatial distribution, and sociodemographic predictors of NMEs in Michigan.

METHODS

Using school-level kindergarten vaccination data from Michigan from 2011 to 2018, we evaluated sociodemographic predictors of NMEs before and after this Administrative Rule change using Bayesian binomial regression. We measured the persistence and location of school district-level geographic clustering using local indicators of spatial association.

RESULTS

Immediately after the rule change, rates of NMEs fell by 32%. However, NME rates rebounded in subsequent years, increasing by 26% by 2018, although income disparities in NME rates decreased after the rule change. Philosophical, religious, and medical vaccine exemptions exhibited distinct geographic patterns across the state, which largely persisted after 2015, illustrating that NME clusters remain a concern despite this rule change.

CONCLUSIONS

Although Michigan's Administrative Rule change caused a short-term decline in NME rates, NME rates have risen dramatically in the following 4 years since the policy was implemented. Michigan's administrative effort to require parental education at the local health department before receiving an exemption did not cause a sustained reduction in the rate or spatial distribution of NMEs.

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.

Addressing Parental Vaccine Hesitancy and Other Barriers to Childhood/Adolescent Vaccination Uptake During the Coronavirus (COVID-19) Pandemic

Routine childhood immunizations are proven to be one of the most effective public health interventions at controlling numerous deadly diseases. Therefore, the CDC recommends routine immunizations for children and adolescent populations against vaccine-preventable diseases e.g., tetanus, pertussis, diphtheria, etc. This current review sought to examine barriers to pediatric vaccine uptake behaviors during the COVID-19 pandemic. We also explored the implications for parental vaccine hesitancy/delay during an ongoing health crisis and proposed recommendations for increasing vaccine confidence and compliance. Our review determined that the receipt for vaccinations steadily improved in the last decade for both the United States and Tennessee. However, this incremental progress has been forestalled by the COVID-19 pandemic and other barriers i.e. parental vaccine hesitancy, social determinants of health (SDoH) inequalities, etc. which further exacerbate vaccination disparities. Moreover, non-compliance to routine vaccinations could cause an outbreak of diseases, thereby, worsening the ongoing health crisis and already strained health care system. Healthcare providers are uniquely positioned to offer effective recommendations with presumptive languaging to increase vaccination rates, as well as, address parental vaccine hesitancy. Best practices that incorporate healthcare providers' quality improvement coaching, vaccination reminder recall systems, adherence to standardized safety protocols (physical distancing, hand hygiene practices, etc.), as well as, offer telehealth and outdoor/drive-through/curbside vaccination services, etc. are warranted. Additionally, a concerted effort should be made to utilize public health surveillance systems to collect, analyze, and interpret data, thereby, ensuring the dissemination of timely, accurate health information for effective health policy decision-making e.g., vaccine distribution, etc.

The landscape of childhood vaccine exemptions in the United States

Once-eliminated vaccine-preventable childhood diseases, such as measles, are resurging across the United States. Understanding the spatio-temporal trends in vaccine exemptions is crucial to targeting public health intervention to increase vaccine uptake and anticipating vulnerable populations as cases surge. However, prior available data on childhood disease vaccination is either at too rough a spatial scale for this spatially-heterogeneous issue, or is only available for small geographic regions, making general conclusions infeasible. Here, we have collated school vaccine exemption data across the United States and provide it at the county-level for all years included. We demonstrate the fine-scale spatial heterogeneity in vaccine exemption levels, and show that many counties may fall below the herd immunity threshold. We also show that vaccine exemptions increase over time in most states, and non-medical exemptions are highly prevalent where allowed. Our dataset also highlights the need for greater data sharing and standardized reporting across the United States.

Parental Hesitancy About Routine Childhood and Influenza Vaccinations: A National Survey

BACKGROUND AND OBJECTIVES

The World Health Organization has designated vaccine hesitancy as 1 of the 10 leading threats to global health, yet there is limited current national data on prevalence of hesitancy among US parents. Among a nationally representative sample of US parents, we aimed to (1) assess and compare prevalence of hesitancy and factors driving hesitancy for routine childhood and influenza vaccination and (2) examine associations between sociodemographic characteristics and hesitancy for routine childhood or influenza vaccination.

METHODS

In February 2019, we surveyed families with children using the largest online panel generating representative US samples. After weighting, we assessed hesitancy using a modified 5-point Vaccine Hesitancy Scale and labeled parents as hesitant if they scored >3.

RESULTS

A total of 2176 of 4445 parents sampled completed the survey (response rate 49%). Hesitancy prevalence was 6.1% for routine childhood and 25.8% for influenza vaccines; 12% strongly and 27% somewhat agreed they had concerns about serious side effects of both routine childhood and influenza vaccines. A total of 70% strongly agreed that routine childhood vaccines are effective versus 26% for influenza vaccine (P < .001). In multivariable models, an educational level lower than a bachelor's degree and household income <400% of the federal poverty level predicted hesitancy about both routine childhood and influenza vaccines.

CONCLUSIONS

Almost 1 in 15 US parents are hesitant about routine childhood vaccines, whereas >1 in 4 are hesitant about influenza vaccine. Furthermore, 1 in 8 parents are concerned about vaccine safety for both routine childhood and influenza vaccines, and only 1 in 4 believe influenza vaccine is effective. Vaccine hesitancy, particularly for influenza vaccine, is prevalent in the United States.

Centers for Disease Control and Prevention's School Vaccination Assessment: Collaboration With US State, Local, and Territorial Immunization Programs, 2012-2018

Objectives. To describe the ongoing collaboration of the Centers for Disease Control and Prevention's (CDC's) school vaccination assessment with state, local, and territorial immunization programs to provide data to monitor school entry vaccination.Methods. Departments of health and education partner to collect data from public school, private school, and homeschooled kindergartners in the 50 US states, the District of Columbia, 2 cities, and the US territories. Immunization programs submit vaccination coverage and exemption data to the CDC, and the CDC reports these data annually via multiple sources.Results. Among the 50 states and the District of Columbia, the number of programs using a census for vaccination coverage data increased from 39 to 41 during the school years 2012-2013 to 2017-2018 (which for most states was August or September through May or June), and the number using a census to collect exemption data increased from 40 to 46. The number of states that reported sharing their local-level vaccination coverage data online increased from 11 in 2012-2013 to 31 in 2017-2018.Conclusions. Coverage data can be used to address undervaccination among kindergartners to work with communities and schools that are susceptible to vaccine-preventable diseases. As more states publish local-level data online, access to improved data provides the public more valuable information.

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.

Getting Personal: How Childhood Vaccination Policies Shape the Landscape of Vaccine Exemptions

Background

State-mandated school entry immunization requirements in the United States play an important role in achieving high vaccine coverage, but variations in vaccine exemption policies result in a patchwork of vaccine coverage across the country.

Methods

In this study, we evaluate epidemiological effects and spatial variations in nonmedical exemption (NME) rates in the context of vaccine policies. We first analyze the correlation between NME rates and vaccine coverage for 3 significant childhood vaccinations. Furthermore, we assess the effects of policy changes in a subset of states, using a correlative approach at the state level and performing a clustering analysis at the county level.

Results

We find that higher rates of exemptions are associated with lower vaccination rates of school-aged children in all cases. In a subset of states where exemption policy has recently changed, we show that the effects on statewide NME rates vary widely and that decreases in NMEs can lead to an increase in other types of exemptions. Finally, our clustering analysis in California, Illinois, and Connecticut shows that policy changes affect the spatial distribution of NMEs.

Conclusions

Our work suggests that vaccination policies have significant impacts on patterns of herd immunity. Our findings can be used to develop evidence-based vaccine legislation.

Characterizing the vaccine knowledge, attitudes, beliefs, and intentions of pregnant women in Georgia and Colorado

Vaccine coverage for maternal vaccines is suboptimal; only about half of pregnant women received influenza and Tdap vaccines in 2018. We explored knowledge, attitudes, beliefs, intentions, and trust regarding maternal and infant vaccines among pregnant women. Between June 2017 and July 2018, we surveyed 2196 pregnant women recruited from geographically and socio-demographically diverse prenatal care practices in Georgia and Colorado (56% response rate). Fifty-six percent of pregnant women intended to receive both influenza and Tdap vaccines during pregnancy and 68% intended to vaccinate their baby with all recommended vaccines on time. Attitudinal constructs associated with intention to vaccinate include confidence in vaccine safety (ORs: 16–38) and efficacy (ORs: 4–19), perceived risk of vaccine-preventable diseases (ORs: 2–6), social norms (ORs: 4–10), and trust in sources of vaccine information. Women pregnant with their first child were less likely than women who had prior children to intend to vaccinate themselves and their children, more likely to be unsure about their intentions to receive both maternal and infant vaccines, and less likely to report feeling they had enough knowledge or information about vaccines and vaccine safety (p < .01). This demonstrates an opportunity for vaccine education to increase vaccine confidence and informed decision-making, especially among first-time pregnant women.

Understanding the impact of state vaccination laws on exemption rates

PURPOSE OF REVIEW

This review summarizes the current state of school-entry vaccination requirements and related exemption policies in the United States and examines recent changes to these policies.

RECENT FINDINGS

With recent infectious disease outbreaks in the United States, there has been heightened awareness on unvaccinated individuals, and the state-level policies that allow individuals to be exempted from school-entry vaccination requirements. Between 2015 and 2017, there have been eleven states that have altered their policies regarding school-entry vaccination requirements and related reporting for which no formal evaluations have been published. One policy change during that period, California SB 277, which became law in 2016, reduced the nonmedical exemption and increased the childhood vaccination coverage rate in that state, though with some evidence of exemption replacement through the use of medical exemptions. Through September 2019, five additional state law changes have been enacted.

SUMMARY

The large number of heterogeneous changes to state-level policies for school-entry vaccination requirements in recent years need rigorous evaluation to identify best practices for balancing public health authority and parental autonomy while seeking to achieve the highest level of infectious disease prevention for children.

Evidence-based strategies to increase vaccination uptake: a review

PURPOSE OF REVIEW

To summarize evidence-based strategies for improving pediatric immunization rates including physician behaviors, clinic and public health processes, community-based and parent-focused interventions, and legal and policy approaches RECENT FINDINGS: Studies continue to show the effectiveness of audit and feedback, provider reminders, standing orders, and reminder/recall to increase immunization rates. Provider communication strategies may improve immunization rates including use of a presumptive approach and motivational interviewing. Centralized reminder/recall (using a state Immunization Information System) is more effective and cost-effective compared to a practice-based approach. Recent work shows the success of text messages for reminder/recall for vaccination. Web-based interventions, including informational vaccine websites with interactive social media components, have shown effectiveness at increasing uptake of pediatric and maternal immunizations. Vaccination requirements for school attendance continue to be effective policy interventions for increasing pediatric and adolescent vaccination rates. Allowance for and ease of obtaining exemptions to vaccine requirements are associated with increased exemption rates.

SUMMARY

Strategies to increase vaccination rates include interventions that directly impact physician behavior, clinic and public health processes, patient behaviors, and policy. Combining multiple strategies to work across different settings and addressing different barriers may offer the best approach to optimize immunization coverage.

Religious Vaccine Exemptions in Kindergartners: 2011-2018

BACKGROUND

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

The 2016 California policy to eliminate nonmedical vaccine exemptions and changes in vaccine coverage: An empirical policy analysis

BACKGROUND

Vaccine hesitancy, the reluctance or refusal to receive vaccination, is a growing public health problem in the United States and globally. State policies that eliminate nonmedical ("personal belief") exemptions to childhood vaccination requirements are controversial, and their effectiveness to improve vaccination coverage remains unclear given limited rigorous policy analysis. In 2016, a California policy (Senate Bill 277) eliminated nonmedical exemptions from school entry requirements. The objective of this study was to estimate the association between California's 2016 policy and changes in vaccine coverage.

METHODS AND FINDINGS

We used a quasi-experimental state-level synthetic control analysis and a county-level difference-in-differences analysis to estimate the impact of the 2016 California policy on vaccination coverage and prevalence of exemptions to vaccine requirements (nonmedical and medical). We used publicly available state-level data from the US Centers for Disease Control and Prevention on coverage of measles, mumps, and rubella (MMR) vaccination, nonmedical exemption, and medical exemption in children entering kindergarten. We used county-level data individually requested from state departments of public health on overall vaccine coverage and exemptions. Based on data availability, we included state-level data for 45 states, including California, from 2011 to 2017 and county-level data for 17 states from 2010 to 2017. The prespecified primary study outcome was MMR vaccination in the state analysis and overall vaccine coverage in the county analysis. In the state-level synthetic control analysis, MMR coverage in California increased by 3.3% relative to its synthetic control in the postpolicy period (top 2 of 43 states evaluated in the placebo tests, top 5%), nonmedical exemptions decreased by 2.4% (top 2 of 43 states evaluated in the placebo tests, top 5%), and medical exemptions increased by 0.4% (top 1 of 44 states evaluated in the placebo tests, top 2%). In the county-level analysis, overall vaccination coverage increased by 4.3% (95% confidence interval [CI] 2.9%-5.8%, p < 0.001), nonmedical exemptions decreased by 3.9% (95% CI 2.4%-5.4%, p < 0.001), and medical exemptions increased by 2.4% (95% CI 2.0%-2.9%, p < 0.001). Changes in vaccination coverage across counties after the policy implementation from 2015 to 2017 ranged from -6% to 26%, with larger increases in coverage in counties with lower prepolicy vaccine coverage. Results were robust to alternative model specifications. The limitations of the study were the exclusion of a subset of US states from the analysis and the use of only 2 years of postpolicy data based on data availability.

CONCLUSIONS

In this study, implementation of the California policy that eliminated nonmedical childhood vaccine exemptions was associated with an estimated increase in vaccination coverage and a reduction in nonmedical exemptions at state and county levels. The observed increase in medical exemptions was offset by the larger reduction in nonmedical exemptions. The largest increases in vaccine coverage were observed in the most "high-risk" counties, meaning those with the lowest prepolicy vaccine coverage. Our findings suggest that government policies removing nonmedical exemptions can be effective at increasing vaccination coverage.

Analysis of State-Specific Differences in Childhood Vaccination Coverage in Rural India

There is little research on state-level differences in child health outcomes in India. The aim of this study was to identify state-level characteristics that relate to childhood immunizations. Most state-level characteristics came from the 2011 Indian Census. Individual-level data and other state-level characteristics were obtained from the 2007⁻2008 District Level Household and Facility Survey. Predictors of full vaccination were assessed with logistic regression models. Among 86,882 children 12⁻36 months, 53.2% were fully vaccinated. Children living in bigger households (≥7 members), born in non-institutional settings, and female had lower odds of complete vaccination. Individuals living in states in the mid-range of poverty had lower odds of full vaccination compared to those in lower or higher poverty states (3rd vs. 1st quintile: odds ratio [OR]: 0.36, 95% confidence interval [CI]: 0.30, 0.42). Greater average population per primary health center was associated with decreased odds of full vaccination (5th vs. 1st quintile: OR: 0.37, 95% CI: 0.30, 0.47). Vaccination coverage in India can be explained by a complex interplay of individual- and state-level factors. Solutions to increasing vaccination must be multisectoral and acknowledge the cultural and socio-economic diversity that influences an individual child's vaccination coverage along with within-state disparities.

Current landscape of nonmedical vaccination exemptions in the United States: impact of policy changes

INTRODUCTION

In the United States, high childhood vaccination coverage has reduced the morbidity and mortality due to vaccine-preventable diseases. The success of vaccination programs in achieving this high coverage is due, in part, to vaccination mandates for school entry. All states have such mandates, but there is heterogeneity across the states in the allowance of non-medical exemptions (e.g. religious or personal belief exemptions) to these mandates.

AREAS COVERED

We examine historical trends in non-medical exemption prevalence in the US, discuss recent state-level policy changes that may impact non-medical exemption prevalence, and review recent studies on the association between non-medical exemptions and infectious disease outbreaks.

EXPERT COMMENTARY

State-level implementation of mandates, and related allowances for medical and non-medical exemptions, varies greatly across the United States. Non-medical exemption rates have increased over the last two decades, with an increased risk of disease outbreaks in clusters of children with non-medical exemptions due to differences in state laws. Recent efforts to address non-medical exemption rates range from incorporating additional administrative requirements for exemptions and disallowance of any non-medical exemptions. Continued monitoring is needed to evaluate the impact of these changes on exemption rates, to develop optimal childhood vaccination policy across the United States.

Trends and Characteristics of Proposed and Enacted State Legislation on Childhood Vaccination Exemption, 2011-2017

Objectives. To examine trends and characteristics of proposed and enacted state legislation that would directly affect states' immunization exemption laws.Methods. We performed content analysis of proposed bills in state legislatures from 2011 to 2017. We classified bills as provaccination or antivaccination.Results. State legislators proposed 175 bills, with the volume increasing over time: 92 (53%) bills expanded access to exemptions, and 83 (47%) limited the ability to exempt. Of the 13 bills signed into law, 12 (92%) limited the ability to exempt. Bills that expanded access to exemptions were more likely to come from Republican legislators and Northeastern and Southern states.Conclusions. Although most proposed legislation would have expanded access to exemptions, bills that limited exemptions were more likely to be enacted into law. Legal barriers to exempt one's children from vaccination persist despite vaccine hesitancy, which is encouraging for public health.Public Health Implications. Most vaccine exemption laws introduced in state legislatures would pose threats to the public's health. There is a need for constituents to engage their elected legislators and advocate provaccination policies.

Perceptions of vaccination within a Christian homeschooling community in Pennsylvania

BACKGROUND

More than 1.8 million American children ages 5-17 are being educated at home. The percentage of school-aged children in the United States who are homeschooled increased from 1.7% in 1999 to 3.4% in 2012. Every state has established school-entry vaccination requirements for kindergarten students, but most states exempt homeschoolers from these regulations. The goal of this study was to use qualitative methods to examine the vaccination perceptions and practices of Christian homeschooling families in Pennsylvania.

METHODS

A qualitative study (focus groups) of Christian homeschooling parents representing a diversity of vaccination practices (full, partial/delayed, and no vaccination) was conducted in south-central Pennsylvania in 2017. An analysis using a grounded theory approach identified themes that strongly aligned with constructs from the Health Belief Model.

RESULTS

Many of the perspectives expressed by the study population aligned with those of the general American population, including uncertainty about the risk from vaccine-preventable diseases, concerns about the efficacy and safety of vaccines, and confusion about conflicting vaccine information. The Christian homeschooling parents expressed two especially prominent perceptions: a belief that they had a very low risk of contracting infectious diseases because God has provided them with the natural tools necessary for health and a stronger-than-typical sense of empowerment related to parental decision-making and autonomy. Participants expressed that they were generally open to honest communication about vaccination with physicians who respect parental authority.

CONCLUSIONS

Homeschooling families have diverse vaccination practices. Pediatricians and other healthcare practitioners should not make assumptions about health beliefs in this community, and should instead engage parents in conversations about their risk perceptions and vaccine decisions.

The state of the antivaccine movement in the United States: A focused examination of nonmedical exemptions in states and counties

In a Policy Forum, Peter Hotez and colleagues discuss vaccination exemptions in US states and possible consequences for infectious disease outbreaks.

COMMENTARY: WHAT HEALS AND WHY? CHILDREN'S UNDERSTANDING OF MEDICAL TREATMENTS

Lockhart and Keil have written an interesting monograph focusing on the development of reasoning about medicine, a relatively underexplored area of research with potentially broad implications with respect to the design of more-effective medical interventions. In a set of 15 studies with well over 2,200 participants, they examine how children and adults combine aspects of biological and psychological reasoning to create working models of medicine. Lockhart and Keil explore developmental changes in reasoning about illness and its treatment using medicines in terms of dualism (e.g., psychological vs. physical), spatial proximity, differential timing of effects, potential side effects, and treatment tradeoffs. This commentary highlights the novel contributions of this monograph, examines issues that need additional considerations, and makes suggestions for future research.

Increasing Vaccination: Putting Psychological Science Into Action

Vaccination is one of the great achievements of the 20th century, yet persistent public-health problems include inadequate, delayed, and unstable vaccination uptake. Psychology offers three general propositions for understanding and intervening to increase uptake where vaccines are available and affordable. The first proposition is that thoughts and feelings can motivate getting vaccinated. Hundreds of studies have shown that risk beliefs and anticipated regret about infectious disease correlate reliably with getting vaccinated; low confidence in vaccine effectiveness and concern about safety correlate reliably with not getting vaccinated. We were surprised to find that few randomized trials have successfully changed what people think and feel about vaccines, and those few that succeeded were minimally effective in increasing uptake. The second proposition is that social processes can motivate getting vaccinated. Substantial research has shown that social norms are associated with vaccination, but few interventions examined whether normative messages increase vaccination uptake. Many experimental studies have relied on hypothetical scenarios to demonstrate that altruism and free riding (i.e., taking advantage of the protection provided by others) can affect intended behavior, but few randomized trials have tested strategies to change social processes to increase vaccination uptake. The third proposition is that interventions can facilitate vaccination directly by leveraging, but not trying to change, what people think and feel. These interventions are by far the most plentiful and effective in the literature. To increase vaccine uptake, these interventions build on existing favorable intentions by facilitating action (through reminders, prompts, and primes) and reducing barriers (through logistics and healthy defaults); these interventions also shape behavior (through incentives, sanctions, and requirements). Although identification of principles for changing thoughts and feelings to motivate vaccination is a work in progress, psychological principles can now inform the design of systems and policies to directly facilitate action.