Exploring California's new law eliminating personal belief exemptions to childhood vaccines and vaccine decision-making among homeschooling mothers in California

Parental perceptions of chickenpox and the varicella vaccine: A qualitative systematic review

BACKGROUND

In countries where varicella vaccination is not on the routine childhood immunisation schedule, such as those in the United Kingdom (UK), chickenpox is an almost universal disease of childhood. Chickenpox can cause serious complications, particularly in infants, pregnant women, and the immunocompromised. In November 2023 the varicella vaccine was recommended for inclusion in the UK routine childhood immunisation schedule. Successful rollout of the vaccine may be hindered by parental concerns about vaccine safety and efficacy, and perceptions of chickenpox as a mild illness.

OBJECTIVE

To examine parental perceptions of chickenpox and varicella vaccination, which may be crucial to effective vaccination campaigns.

DESIGN

Qualitative systematic review and thematic analysis.

METHODS

Six electronic databases were systematically searched for studies published between 2016 and 2023: CINAHL, EMBASE, MEDLINE, PsycInfo, PubMed, and Web of Science. The included studies were appraised against the Critical Appraisal Skills Program checklist for qualitative studies. Thematic analysis was used to analyse qualitative data, through the development of themes.

RESULTS

22 articles were included in this review, and five themes identified: perceptions that chickenpox is a mild illness, that parents have concerns about varicella vaccine efficacy and safety, a notion of natural immunity as superior, social determinants of health influence vaccine decision making, and vaccination is overwhelming perceived as a parental decision.

CONCLUSIONS

Whilst some parents displayed an acceptance and willingness to vaccinate against chickenpox, many expressed concerns, and perceived chickenpox as a routine unworrying childhood illness. Analysis demonstrated a knowledge gap in understanding UK parental opinions regarding chickenpox and varicella vaccination, highlighting the need for research in this area, particularly given ongoing reconsideration for inclusion in the UK vaccination schedule.

REGISTRATION

The review was registered on PROSPERO, registration ID CRD42021236120.

Why Parents Say No to Having Their Children Vaccinated against Measles: A Systematic Review of the Social Determinants of Parental Perceptions on MMR Vaccine Hesitancy

Ongoing outbreaks of measles threaten its elimination status in the United States. Its resurgence points to lower parental vaccine confidence and local pockets of unvaccinated and undervaccinated individuals. The geographic clustering of hesitancy to MMR indicates the presence of social drivers that shape parental perceptions and decisions on immunization. Through a qualitative systematic review of published literature (n = 115 articles; 7 databases), we determined major themes regarding parental reasons for MMR vaccine hesitancy, social context of MMR vaccine hesitancy, and trustworthy vaccine information sources. Fear of autism was the most cited reason for MMR hesitancy. The social drivers of vaccine hesitancy included primary care/healthcare, education, economy, and government/policy factors. Social factors, such as income and education, exerted a bidirectional influence, which facilitated or hindered vaccine compliance depending on how the social determinant was experienced. Fear of autism was the most cited reason for MMR hesitancy. Vaccine hesitancy to MMR and other childhood vaccines clustered in middle- to high-income areas among mothers with a college-level education or higher who preferred internet/social media narratives over physician-based vaccine information. They had low parental trust, low perceived disease susceptibility, and were skeptical of vaccine safety and benefits. Combating MMR vaccine misinformation and hesitancy requires intersectoral and multifaceted approaches at various socioecological levels to address the social drivers of vaccine behavior.

The Use of Adaptive Sampling to Reach Disadvantaged Populations for Immunization Programs and Assessments: A Systematic Review

Vaccines prevent 4-5 million deaths every year, but inequities in vaccine coverage persist among key disadvantaged subpopulations. Under-immunized subpopulations (e.g., migrants, slum residents) may be consistently missed with conventional methods for estimating immunization coverage and assessing vaccination barriers. Adaptive sampling, such as respondent-driven sampling, may offer useful strategies for identifying and collecting data from these subpopulations that are often "hidden" or hard-to-reach. However, use of these adaptive sampling approaches in the field of global immunization has not been systematically documented. We searched PubMed, Scopus, and Embase databases to identify eligible studies published through November 2020 that used an adaptive sampling method to collect immunization-related data. From the eligible studies, we extracted relevant data on their objectives, setting and target population, and sampling methods. We categorized sampling methods and assessed their frequencies. Twenty-three studies met the inclusion criteria out of the 3069 articles screened for eligibility. Peer-driven sampling was the most frequently used adaptive sampling method (57%), followed by geospatial sampling (30%), venue-based sampling (17%), ethnographic mapping (9%), and compact segment sampling (9%). Sixty-one percent of studies were conducted in upper-middle-income or high-income countries. Data on immunization uptake were collected in 65% of studies, and data on knowledge and attitudes about immunizations were collected in 57% of studies. We found limited use of adaptive sampling methods in measuring immunization coverage and understanding determinants of vaccination uptake. The current under-utilization of adaptive sampling approaches leaves much room for improvement in how immunization programs calibrate their strategies to reach "hidden" subpopulations.

A systematic literature review to clarify the concept of vaccine hesitancy

Vaccine hesitancy (VH) is considered a top-10 global health threat. The concept of VH has been described and applied inconsistently. This systematic review aims to clarify VH by analysing how it is operationalized. We searched PubMed, Embase and PsycINFO databases on 14 January 2022. We selected 422 studies containing operationalizations of VH for inclusion. One limitation is that studies of lower quality were not excluded. Our qualitative analysis reveals that VH is conceptualized as involving (1) cognitions or affect, (2) behaviour and (3) decision making. A wide variety of methods have been used to measure VH. Our findings indicate the varied and confusing use of the term VH, leading to an impracticable concept. We propose that VH should be defined as a state of indecisiveness regarding a vaccination decision.

Pro-vaccination Groups Expressing Hesitant Attitudes: A Cross-Sectional Study About the Difference Between Attitudes and Actual Behavior in Israel

Background

Vaccines have contributed to the decline in mortality, morbidity, and even the eradication of various infectious diseases. Over time, the availability of information to the public and the request for public involvement in the health decision-making process have risen, and the confidence in vaccines has dropped. An increasing number of parents and individuals are choosing to delay or refuse vaccines.

Objectives

(1) Identifying hesitant attitudes among pro-vaccination parents; (2) testing the difference between the rate of hesitant attitudes and the rate of hesitancy in practice among pro-vaccination parents; and (3) examining the association of sociodemographic characteristics (gender, age, marital status education and religious affiliation) with the difference between hesitant attitudes and hesitancy in practice among pro-vaccination parents.

Methods

Descriptive cross-sectional survey using an online survey that measured vaccine hesitancy among pro-vaccination parents (n = 558) whose children were in kindergarten (3–5 years), according to a variety of sociodemographic characteristics.

Results

A significant difference was found between the rate of hesitant attitudes and the rate of hesitation in actual vaccination among pro-vaccination and hesitant parents, where despite that 26% of the parents had hesitant attitudes, only 19% hesitated in practice [P = 0.0003]. There was also a significant difference between the rate of hesitant attitudes and the rate of hesitancy in practice among women [P = 0.0056] and men [P = 0.0158], parents between 30 and 39 years of age [P = 0.0008], traditional parents [P = 0.0093], Non-academic parents [P = 0.0007] and parents with BA degree [P = 0.0474].

Conclusion

Pro-vaccination individuals may have hesitant attitudes regarding vaccines. Therefore, it is very important for health authorities to address the public's fears and concerns, including those who are classified as pro-vaccination.

Factors that influence parents' and informal caregivers' views and practices regarding routine childhood vaccination: a qualitative evidence synthesis

BACKGROUND

Childhood vaccination is one of the most effective ways to prevent serious illnesses and deaths in children. However, worldwide, many children do not receive all recommended vaccinations, for several potential reasons. Vaccines might be unavailable, or parents may experience difficulties in accessing vaccination services; for instance, because of poor quality health services, distance from a health facility, or lack of money. Some parents may not accept available vaccines and vaccination services. Our understanding of what influences parents' views and practices around childhood vaccination, and why some parents may not accept vaccines for their children, is still limited. This synthesis links to Cochrane Reviews of the effectiveness of interventions to improve coverage or uptake of childhood vaccination.

OBJECTIVES

- Explore parents' and informal caregivers' views and practices regarding routine childhood vaccination, and the factors influencing acceptance, hesitancy, or nonacceptance of routine childhood vaccination. - Develop a conceptual understanding of what and how different factors reduce parental acceptance of routine childhood vaccination. - Explore how the findings of this review can enhance our understanding of the related Cochrane Reviews of intervention effectiveness.

SEARCH METHODS

We searched MEDLINE, Embase, CINAHL, and three other databases for eligible studies from 1974 to June 2020.

SELECTION CRITERIA

We included studies that: utilised qualitative methods for data collection and analysis; focused on parents' or caregivers' views, practices, acceptance, hesitancy, or refusal of routine vaccination for children aged up to six years; and were from any setting globally where childhood vaccination is provided.

DATA COLLECTION AND ANALYSIS

We used a pre-specified sampling frame to sample from eligible studies, aiming to capture studies that were conceptually rich, relevant to the review's phenomenon of interest, from diverse geographical settings, and from a range of income-level settings. We extracted contextual and methodological data from each sampled study. We used a meta-ethnographic approach to analyse and synthesise the evidence. We assessed methodological limitations using a list of criteria used in previous Cochrane Reviews and originally based on the Critical Appraisal Skills Programme quality assessment tool for qualitative studies. We used the GRADE-CERQual (Confidence in the Evidence from Reviews of Qualitative research) approach to assess our confidence in each finding. We integrated the findings of this review with those from relevant Cochrane Reviews of intervention effectiveness. We did this by mapping whether the underlying theories or components of trial interventions included in those reviews related to or targeted the overarching factors influencing parental views and practices regarding routine childhood vaccination identified by this review.

MAIN RESULTS

We included 145 studies in the review and sampled 27 of these for our analysis. Six studies were conducted in Africa, seven in the Americas, four in South-East Asia, nine in Europe, and one in the Western Pacific. Studies included urban and rural settings, and high-, middle-, and low-income settings. Many complex factors were found to influence parents' vaccination views and practices, which we divided into four themes. Firstly, parents' vaccination ideas and practices may be influenced by their broader ideas and practices surrounding health and illness generally, and specifically with regards to their children, and their perceptions of the role of vaccination within this context. Secondly, many parents' vaccination ideas and practices were influenced by the vaccination ideas and practices of the people they mix with socially. At the same time, shared vaccination ideas and practices helped some parents establish social relationships, which in turn strengthened their views and practices around vaccination. Thirdly, parents' vaccination ideas and practices may be influenced by wider political issues and concerns, and particularly their trust (or distrust) in those associated with vaccination programmes. Finally, parents' vaccination ideas and practices may be influenced by their access to and experiences of vaccination services and their frontline healthcare workers. We developed two concepts for understanding possible pathways to reduced acceptance of childhood vaccination. The first concept, 'neoliberal logic', suggests that many parents, particularly from high-income countries, understood health and healthcare decisions as matters of individual risk, choice, and responsibility. Some parents experienced this understanding as in conflict with vaccination programmes, which emphasise generalised risk and population health. This perceived conflict led some parents to be less accepting of vaccination for their children. The second concept, 'social exclusion', suggests that some parents, particularly from low- and middle-income countries, were less accepting of childhood vaccination due to their experiences of social exclusion. Social exclusion may damage trustful relationships between government and the public, generate feelings of isolation and resentment, and give rise to demotivation in the face of public services that are poor quality and difficult to access. These factors in turn led some parents who were socially excluded to distrust vaccination, to refuse vaccination as a form of resistance or a way to bring about change, or to avoid vaccination due to the time, costs, and distress it creates. Many of the overarching factors our review identified as influencing parents' vaccination views and practices were underrepresented in the interventions tested in the four related Cochrane Reviews of intervention effectiveness.

AUTHORS' CONCLUSIONS

Our review has revealed that parents' views and practices regarding childhood vaccination are complex and dynamic social processes that reflect multiple webs of influence, meaning, and logic. We have provided a theorised understanding of the social processes contributing to vaccination acceptance (or not), thereby complementing but also extending more individualistic models of vaccination acceptance. Successful development of interventions to promote acceptance and uptake of childhood vaccination will require an understanding of, and then tailoring to, the specific factors influencing vaccination views and practices of the group(s) in the target setting. The themes and concepts developed through our review could serve as a basis for gaining this understanding, and subsequent development of interventions that are potentially more aligned with the norms, expectations, and concerns of target users.

Parental attitudes towards mandatory vaccination; a systematic review

Uptake of childhood vaccines is decreasing. While mandatory vaccination schemes can increase vaccine uptake rates, they can also cause backlash among some parents. We conducted a systematic review investigating parental beliefs about vaccine mandates and factors associated with support for mandatory vaccination schemes. We searched Embase, Ovid MEDLINE, Global Health, APA PsycINFO and Web of Science from inception to 17th September 2020. Seventeen studies (five qualitative, twelve quantitative) were eligible for inclusion. We synthesised results of qualitative and quantitative studies separately. As quantitative studies were heterogeneous in the mandatory vaccination schemes and associated factors investigated, there was no scope to conduct a meta-analysis. Instead, data were narratively synthesised, considering risk of bias ratings. Qualitative data were synthesised using meta-ethnography, synthesising themes reported across studies included. Quantitative studies reported that support for mandatory vaccination schemes was reasonably high (73% to 88%). However, due to heterogeneity, there was little evidence for any factors being consistently associated with support for mandatory vaccination. Qualitative studies gave an insight into how parents perceive mandatory vaccination. Studies found that parents perceived mandatory vaccination schemes as an infringement of their rights, and particularly disliked schemes offering financial incentives for vaccination. Nevertheless, some parents felt that schemes limiting access to schooling of unvaccinated children gave them "peace of mind." Results should be taken with caution due to the purposive use of non-representative samples. Before deciding to mandate vaccination, it is important to understand the impact it could have on parental beliefs and attitudes about vaccination.

Universal access to essential medicines as part of the right to health: a cross-national comparison of national laws, medicines policies, and health system indicators

BACKGROUND

Access to essential medicines for the world's poor and vulnerable has made little progress since 2000, except for a few specific medicines such as antiretrovirals for HIV/AIDS. Human rights principles written into national law can create a supportive environment for universal access to medicines; however, systematic research and policy guidance on this topic is lacking.

OBJECTIVE

To examine how international human rights law and WHO's essential medicines policies are embedded in national law for medicines affordability and financing, and interpreted and implemented in practice to promote universal access to essential medicines.

METHODS

This thesis consists of (1) a cross-national content analysis of 192 national constitutions, 71 national medicines policies, and legislation for universal health coverage (UHC) from 16 mostly low- and middle-income countries; (2) a case study of medicines litigation in Uruguay, and (3) a follow-up report of eight right to health indicators for access to medicines from 195 countries.

RESULTS

Some, but not all, of the 12 principles from human rights law and WHO's policy are embedded in national UHC law and medicines policies (part 1). Even the most rights-compliant legislation for access to medicines is subject to the unique and inconsistent interpretation of domestic courts, which may be inconsistent with the right to health in international law (part 2). Many national health systems for which data were available still fail to meet the official targets for eight indicators of access to medicines (part 3).

CONCLUSIONS

International human rights law and WHO policy are embedded in national law for essential medicines and practically implemented in national health systems. Law makers can use these findings and the example texts in this thesis as a starting point for writing and monitoring governments' rights-based legal commitments for access to medicines. Future research should study the effect of national law on access to medicines and population health.

Economic and Behavioral Influencers of Vaccination and Antimicrobial Use

Despite vast improvements in global vaccination coverage during the last decade, there is a growing trend in vaccine hesitancy and/or refusal globally. This has implications for the acceptance and coverage of a potential vaccine against COVID-19. In the United States, the number of children exempt from vaccination for “philosophical belief-based” non-medical reasons increased in 12 of the 18 states that allowed this policy from 2009 to 2017 (1). Meanwhile, the overuse and misuse of antibiotics, especially in young children, have led to increasing rates of drug resistance that threaten our ability to treat infectious diseases. Vaccine hesitancy and antibiotic overuse exist side-by-side in the same population of young children, and it is unclear why one modality (antibiotics) is universally seen as safe and effective, while the other (vaccines) is seen as potentially hazardous by some. In this review, we consider the drivers shaping the use of vaccines and antibiotics in the context of three factors: individual incentives, risk perceptions, and social norms and group dynamics. We illustrate how these factors contribute to the societal and individual costs of vaccine underuse and antimicrobial overuse. Ultimately, we seek to understand these factors that are at the nexus of infectious disease epidemiology and social science to inform policy-making.

Parental vaccine attitudes, beliefs, and practices: initial evidence in California after a vaccine policy change

Senate Bill 277 (SB277) eliminated nonmedical exemptions for school-entry vaccines in California, but the impact of parental vaccine knowledge, attitudes, and beliefs on vaccine decision-making has not been extensively examined within the post-SB277 context. This study generates preliminary understanding and discussion of the vaccination knowledge, attitudes, and beliefs among a pilot population of parents of kindergarten students in California after the implementation of SB277. School officials administered a cross-sectional survey to parents of kindergarten children in California from April to July 2019. Parents reported their perceptions of diseases and vaccines, key immunization beliefs, and confidence in different sources of vaccine information. Most parents (92%) had fully vaccinated their children post-SB277 and generally perceived vaccines to be safe and effective, but about 44% reported they were hesitant about childhood vaccines. The majority of parents (87%) rated vaccine information from their doctor as highly credible. This pilot group of kindergarten parents was generally supportive of vaccination and had fully vaccinated their children, but most parents still harbored concerns and misconceptions about vaccines and about public health authorities. This indicates a disconnect between parental vaccine compliance and confidence, and suggests that educational interventions could impact parental vaccine behavior and decision-making.

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.

Homeschooling parents in California: Attitudes, beliefs and behaviors associated with child's vaccination status

BACKGROUND

Senate Bill 277 (SB277) banned nonmedical exemptions from school-entry vaccination requirements for children attending classroom-based schools in California, but excluded homeschooled children from vaccination requirements. Thus, it was hypothesized that more parents would choose to homeschool to avoid vaccination requirements in response to SB277. There is limited literature on the vaccine attitudes, beliefs, and behaviors among the homeschooling population in the US, despite an overall increase in homeschooling nationwide and documented vaccine-preventable disease outbreaks within the homeschooled child population.

METHODS

Between November 2018 and January 2019, we conducted a cross-sectional online survey among homeschooling parents with at least one child in grades K-8 who is currently enrolled in one of the legally-acceptable mechanisms to homeschool in California: (1) home-based private school satellite program (PSP), or (2) public or charter independent study program (ISP) with no classroom-based instruction.

RESULTS

Among 140 homeschooling parents from 8 schools in California, 71% reported that their youngest child in grade K-8 was up-to-date on immunizations at kindergarten-entry and 56% reported that they made the decision to homeschool their child after the implementation of SB277. Compared to homeschooling parents whose child was up-to-date at kindergarten entry, homeschooling parents whose child was not up-to-date at kindergarten entry reported higher concerns over vaccine safety and effectiveness, more frequently cited immunization mandates as a reason to homeschool, and were more likely to report having considered moving out of California due to immunization mandates.

CONCLUSION

There was variation in vaccine attitudes and beliefs within the homeschooling population in this sample. Immunization mandates were a factor in the decision to homeschool for some parents in this sample, supporting the hypothesis that vaccine-hesitant parents considered homeschooling as a way to avoid immunization mandates such as SB277. Future studies should explore the complexities around vaccine attitudes, beliefs and behaviors among homeschooling populations.