ReviewA systematic review of interventions for reducing parental vaccine refusal and vaccine hesitancy
Introduction
The success of vaccines in reducing disease-associated mortality is second only to the introduction of safe drinking water [2]. According to estimates by the World Health Organization, vaccines for diphtheria, pertussis, tetanus, and measles save between two and three million lives every year. The continued success of vaccines relies on adequate immunization coverage which in turn requires parental willingness to vaccinate children. There has been an increase in concerns about real or perceived vaccine adverse events among parents in the developed world making them uneasy about the decision to vaccinate their children, described as ‘vaccine hesitancy’ in the literature [3], [4]. This is one of the reasons that may lead parents to seek alternative or delayed vaccination schedules, or they may refuse vaccinations altogether. Individuals who remain unvaccinated put communities at risk of disease outbreaks [5], [6]. Although a large body of literature has called for increasing vaccination rates among parents who refuse to vaccinate their children [5], [6], [7], [8], [9], [10], [11], there is a dearth of studies that evaluate interventions to achieve this goal.
Over the past few years, there has been a paradigm shift in the developed world from efforts to increase access to immunizations, to improving their uptake. With regards to the particular issue of vaccine refusal, many studies have explored parents’ attitudes toward immunization [12], [13], their sources of information [14] for decision making, and their reasons for refusing childhood immunizations. Parents’ beliefs about the contraindications and perceived dangers of immunization contribute to their unwillingness to expose healthy children to inoculums [15], [16], [17], [18]. Research studies on cognitive decision making processes report that parents prefer the risks of errors of omission (contracting a disease naturally) over the risks of errors of commission (suffering from vaccine adverse events) [17], [19]. Parents may also believe that they can control their child's susceptibility to a disease and its outcome [17]. In addition, some parents who are opposed to conventional medicine believe that it is more beneficial for children to recover from diseases than receive vaccines for them [20]. Parents may also refuse on religious grounds [18] or because they hold ethical objections to state laws that mandate vaccines [21]. Despite the existence of this vast knowledge base to help us understand parental concerns, there are few comprehensive and systematic reviews on effective interventions for reducing parental vaccine refusal. We therefore conducted a systematic review to amass and evaluate the literature on interventions to decrease parental vaccine refusal and hesitancy toward recommended childhood and adolescent vaccines.
Section snippets
Search strategy and selection criteria
We conducted a systematic literature search from July through September 2012 in four databases: PubMed, CENTRAL, EMBASE and PsychInfo. An empirical search was run on Google Scholar to identify the commonly used MeSH (Medical Subject Headings) and keywords linked to relevant articles. We selected the following MeSH: parents; caregivers; infant; child; preschool child; adolescent; young adult; vaccination; mass vaccination; immunization programs; Papillomavirus infections/prevention and
Results
Results of the search strategy are summarized in Fig. 1. Thirty studies were included in the final review. Study characteristics are summarized in Summary Table 1. Most studies (13) used a before-after intervention design and the remaining were RCTs (3), NRCTs (7) and evaluation studies (6). Most studies (25) were from the US. For ease of analysis, we categorized interventions into three groups: passage of state laws (introduction of personal belief/philosophical exemption laws for school
Discussion
Our systematic review did not reveal any convincing evidence on effective interventions to address parental vaccine hesitancy and refusal. We found a large number of studies that evaluated interventions for increasing immunization coverage rates such as the use of reminder/recall systems [59], [60], [61], [62], [63], [64], [65], parent [66], [67], [68], [69], [70], [71], community-wide [68], [72], [73], [74], and provider-based [75], [76], [77], [78], [79] education and incentives [80], [81],
Acknowledgments
Alina Sadaf had access to all of the data in the study and takes full responsibility for the integrity of the data and the accuracy of the data analyses. The corresponding author, Saad B. Omer, also had full access to the data and had final responsibility for the decision to submit for publication.
Contributors: Alina Sadaf and Jennifer L. Richards were involved in data collection and interpretation, and manuscript writing. Jason Glanz and Daniel A. Salmon were involved in data interpretation
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