Investigating Canadian parents' HPV vaccine knowledge, attitudes and behaviour: a study protocol for a longitudinal national online survey

Vaccine Hesitancy Under the Magnifying Glass: A Systematic Review of the Uses and Misuses of an Increasingly Popular Construct

Resistance to vaccines has hindered attempts to contain and prevent outbreaks of infectious diseases for centuries. More recently, however, the term "vaccine hesitancy" has been used to describe not necessarily outright resistance but also a delay in acceptance or uncertainty regarding vaccines. Given concerns about hesitancy and its impact on vaccine uptake rates, researchers increasingly shifted the focus from resistance to vaccines toward vaccine hesitancy. Acknowledging the urgency to accurately assess the phenomenon, it is critical to understand the state of the literature, focusing on issues of conceptualization and operationalization. To carry out this systematic review, we collected and analyzed all published empirical articles from 2000 to 2021 that explicitly included quantitative self-report measures of vaccine hesitancy (k = 86). Using a mixed-method approach, the review demonstrates and quantifies crucial inconsistencies in the measurement of the construct, lack of clarity in regard to the determination of who should or should not be defined as hesitant, and overreliance on unrepresentative samples. Crucially, our analysis points to a potential systematic bias toward exaggerating the level of hesitancy in the population. Modeling a vaccine hesitancy co-citation network, the analysis also points to the existence of insular academic silos that make it harder to achieve a unified measurement tool. Theoretical and practical implications for academics, practitioners, and policymakers are discussed.

The impact of publicly funded immunization programs on human papillomavirus vaccination in boys and girls: An observational study

Background

Reaching and maintaining high global human papillomavirus (HPV) vaccine uptake has been challenging. The impact of publicly funded HPV immunization programs and the interplay of sociodemographic, psychosocial and policy factors in maximizing vaccination is poorly understood. This observational study examined the impact of introducing publicly funded school-based HPV vaccination programs for boys directly on uptake in boys and indirectly on uptake in girls, while concurrently examining other important sociodemographic and psychosocial factors.

Methods

Data were collected from a national, longitudinal sample of Canadian parents of children aged 9-16 years during August-September 2016 (T1) and June-July 2017 (T2). Participants completed an online questionnaire measuring sociodemographic characteristics, vaccine knowledge and attitudes, health care provider recommendation, and HPV vaccine uptake. Analyses were conducted separately for parents of boys and girls using logistic regression analyses at T1 and T2. Jurisdictions with HPV vaccine funding for boys at both time-points were compared to those with funding at neither time-points and those that introduced funding between time-points.

Findings

The sample included parents of boys (n = 716) and girls (n = 843). In multivariable analyses, jurisdictions with funding for boys at both time-points had higher odds of vaccination (adjusted odds ratio, T1 = 10.18, T2 = 11.42; 95% confidence interval, T1 = 3.08-33.58, T2 = 5.61-23.23) than jurisdictions without funding at both time-points; however, funded jurisdictions did not have higher odds of vaccination compared to jurisdictions that newly introduced funding for boys. Vaccination was associated with consistent determinants in boys and girls including child's age, health care provider recommendation, perceived vaccine harms, and perceived vaccine affordability.

Interpretation

This gender-sensitive analysis highlights the interplay of sociodemographic, psychosocial, and policy factors that can improve HPV vaccination. Publicly funded school-based programs are an impactful strategy to increase vaccine uptake.

Funding

This work was supported by the Canadian Cancer Society Research Institute (#704,036). GKS was supported by the Vanier Canada Graduate Scholarship and Queen Elizabeth II Diamond Jubilee Scholarship programs. The funders of this work had no role in the data collection, analysis, or interpretation, or any aspect pertinent to the study.

Resources for assessing parents' vaccine hesitancy: a systematic review of the literature

The concept of Vaccine Hesitancy has begun to appear in the scientific landscape, referring to the reluctance of a growing proportion of people to accept the vaccination offer. A variety of factors were identified as being associated with vaccine hesitancy but there was no universal algorithm and currently there aren’t any established metrics to assess either the presence or impact of vaccine hesitancy. The aim of this study was to systematically review the published questionnaires evaluating parental vaccine hesitancy, to highlight the differences among these surveys and offer a general overview on this matter. This study offers a deeper perspective on the available questionnaires, helping future researches to identify the most suitable one according to their own aim and study setting.

Effects of a multidisciplinary team-led school-based human papillomavirus vaccination health-promotion programme on improving vaccine acceptance and uptake among female adolescents: A cluster randomized controlled trial

INTRODUCTION

Evidence has consistently shown the high efficacy of human papillomavirus (HPV) vaccines in preventing cervical cancers. However, the HPV vaccine uptake rate in Hong Kong is very low. We will develop and evaluate an innovative, theory-based multidisciplinary team-led school-based HPV vaccination health-promotion program (MDL-SHPVP), engaging female adolescents, parents/guardians, and secondary school personnel in multicomponent educational strategies and interactive discussions.

METHODS AND ANALYSIS

A cluster randomized controlled trial is proposed. We will recruit 2520 female adolescents and their parents/guardians from 18 secondary day schools. The MDL-SHPVP is underpinned by the Health Belief Model and Precaution Adoption Process Model. Multicomponent interventions will be offered, including education sessions with small group dialogues with a registered nurse and trained healthcare and lay volunteers, and educational computer games. A team of volunteers will be established to raise HPV, cervical cancer, and HPV vaccine awareness. Outcomes include adolescents' uptake of the HPV vaccine, adolescents' intention to receive HPV vaccination, vaccine acceptance among parents/guardians, and parents'/guardians' and adolescents' HPV knowledge, attitudes, and beliefs. Data will be collected at baseline, 1 month, and 1 year after intervention. The generalized estimating equations analysis will be used for comparing the outcomes between the 2 groups.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the Joint Chinese University of Hong Kong-New Territories East Cluster Clinical Research Ethics Committee (Ref. no.: 2019.055). We will disseminate the study findings via peer-reviewed publications and presentations at relevant events and international and local conferences.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov NCT04438291.

Using the precaution adoption process model to clarify human papillomavirus vaccine hesitancy in canadian parents of girls and parents of boys

Background: Achieving optimal human papillomavirus (HPV) vaccine uptake can be delayed by parents' HPV vaccine hesitancy, which is as a multi-stage intention process rather than a dichotomous (vaccinated/not vaccinated) outcome. Our objective was to longitudinally explore HPV related attitudes, beliefs and knowledge and to estimate the effect of psychosocial factors on HPV vaccine acceptability in HPV vaccine hesitant parents of boys and girls. Methods: We used an online survey to collect data from a nationally representative sample of Canadian parents of 9-16 years old boys and girls in September 2016 and July 2017. Informed by the Precaution Adoption Process Model, we categorized HPV vaccine hesitant parents into unengaged/undecided and decided not. Measures included sociodemographics, health behaviors and validated scales for HPV and HPV vaccine related attitudes, beliefs and knowledge. Predictors of HPV vaccine acceptability were assessed with binomial logistic regression. Results: Parents of boys and girls categorized as "flexible" hesitant (i.e., unengaged/undecided) changed over time their HPV related attitudes, behaviors, knowledge and intentions to vaccinate compared to "rigid" hesitant (i.e., decided not) who remained largely unchanged. In "flexible" hesitant, greater social influence to vaccinate (e.g., from family), increased HPV knowledge, higher family income, white ethnicity and lower perception of harms (e.g., vaccine safety), were associated with higher HPV vaccine acceptability. Conclusions: HPV vaccine hesitant parents are not a homogenous group. We have identified significant predictors of HPV vaccine acceptability in "flexible" hesitant parents. Further research is needed to estimate associations between psychosocial factors and vaccine acceptability in "rigid" hesitant parents.

Using an integrated conceptual framework to investigate parents' HPV vaccine decision for their daughters and sons

Despite being an effective cancer prevention strategy, human papillomavirus (HPV) vaccination in Canada remain suboptimal. This study is the first to concurrently evaluate HPV vaccine knowledge, attitudes, and the decision-making stage of Canadian parents for their school-aged daughters and sons. Data were collected through an online survey from a nationally representative sample of Canadian parents of 9-16 year old children from August to September 2016. Measures included socio-demographics, validated scales to assess HPV vaccine knowledge and attitudes (using the Health Belief Model), and parents' HPV vaccination adoption stage using the Precaution Adoption Process Model (PAPM; six stages: unaware, unengaged, undecided, decided not, decided to, or vaccinated). 3779 parents' survey responses were analyzed (1826 parents of sons and 1953 parents of daughters). There was a significant association between child's gender and PAPM stage of decision-making, with parents of boys more likely to report being in earlier PAPM stages. In multinomial logistic regression analyses parents of daughters (compared to sons), parents of older children, and parents with a health care provider recommendation had decreased odds of being in any earlier PAPM stage as compared to the last PAPM stage (i.e. vaccinated). Parents who were in the 'decided not to vaccinate' stage had significantly greater odds of reporting perceived vaccine harms, lack of confidence, risks, and vaccine conspiracy beliefs. Future research could use these findings to investigate theoretically informed interventions to specifically target subsets of the population with particular attention towards addressing knowledge gaps, perceived barriers, and concerns of parents.

The vaccine hesitancy scale: Psychometric properties and validation

INTRODUCTION

The SAGE Working Group on Vaccine Hesitancy developed a vaccine hesitancy measure, the Vaccine Hesitancy Scale (VHS). This scale has the potential to aid in the advancement of research and immunization policy but has not yet been psychometrically evaluated.

METHODS

Using a cross-sectional design, we collected self-reported survey data from a large national sample of Canadian parents from August to September 2016. An online questionnaire was completed in English or French. We used exploratory and confirmatory factor analysis to identify latent constructs underlying parents' responses to 10 VHS items (response scale 1-5, with higher scores indicating greater hesitancy). In addition to the VHS, measures included socio-demographics items, vaccine attitudes, parents' human papillomavirus (HPV) vaccine decision-making stage, and vaccine refusal.

RESULTS

A total of 3779 Canadian parents completed the survey in English (74.1%) or French (25.9%). Exploratory and confirmatory factor analysis revealed a two-factor structure best explained the data, consisting of 'lack of confidence' (M = 1.98, SD = 0.72) and 'risks' (M = 3.07, SD = 0.95). Significant Pearson correlations were found between the scales and related vaccine attitudes. ANOVA analyses found significant differences in the VHS sub-scales by parents' vaccine decision-making stages (p < .001). Independent samples t-tests found that the VHS sub-scales were associated with HPV vaccine refusal and refusing another vaccine (p < .001). Socio-demographic differences in the VHS were found; however, effect sizes were small (η² < 0.02).

CONCLUSIONS

The VHS was found to have two factors that have construct and criterion validity in identifying vaccine hesitant parents. A limitation of the VHS was few items that loaded on the 'risks' component and a lack of positively and negatively worded items for both components. Based on these results, we suggest modifying the wording of some items and adding items on risk perceptions.