Parental Decision-Making on Childhood Vaccination

Vaccine hesitancy, which is resistance to be vaccinated or to delay vaccinations despite having available vaccinating services, is related to a range of psychological and demographic determinants, such as attitudes toward vaccinations, social norms, and trust in science. This group of researchers is on the cusp of work to understand those determinants in parents, who play an important, socially dictated role in vaccine-related decisions. "This high involvement might lead to parents overemphasizing the potential side effects that they know to be vaccine-related, and by amplifying those, parents are more focused on the potential outcomes of vaccine-related decisions, which can yield specific pattern of the outcome bias."

Thus, the researchers propose - and describe in this article - two related studies to investigate factors that promote vaccine hesitancy, protective factors that determine parental vaccination decisions, and outcome bias in parental vaccination intentions. The studies will be conducted across 8 countries in Europe and Asia (Finland, Germany, Hong Kong, the Netherlands, Serbia, Slovenia, Spain, and the United Kingdom), rendering findings that they hope aid with understanding the underlying mechanisms of vaccine hesitancy and paving the way for developing interventions for parents.

In study 1, socio-demographic and psychological variables will be tested for their connection with differences among parents when it comes to making vaccine-related decisions for their children. Since vaccination intention and hesitancy are multi-layered phenomena, chosen measures are narrowed to broadly cover these aspects: parent-specific factors (demographics, knowledge, etc.), vaccine-specific factors (perceived vaccine safety and efficacy, etc.), and external factors (values, norms, policies, requirements, etc.). The article reviews literature that will inform the study's hypotheses, in the following topic areas: trust toward authorities; perceived consensus and norms; freedom of choice, choice overload, and values; perception of danger; and access to information. The sample size will be a minimum of 222 participants in each of the 8 countries, and researchers will use an online battery in a correlation panel design study. The study design is described in detail.

They expect to find the following factors to reinforce the intent to vaccinate one's child: trust toward authorities, perceived social and scientific consensus, availability of relevant information, along with previously identified demographic characteristics and open-minded thinking. At the same time, they hypothesise that vaccine hesitancy, perceived freedom, choice overload, the use of informal sources and susceptibility outcome bias serve as reinforces of delaying or omitting mandatory childhood vaccination.

The second study is an experimental study and will be conducted in Serbia. The sample will be comprised of parents and caregivers that participated in Study 1, and additionally an equal number of non-parents. The researchers will investigate the moderating role of parents' high involvement in the specific domain of vaccination decision making. Involvement will be divided into 3 aspects: the situation decision makers are deciding about; decision makers' role, or who is a protagonist (parents vs. non-parents); and, finally, low and high involvement health situations. Because the importance of the decision is related to susceptibility to cognitive biases, they expect that higher involvement among parents, compared to non-parents, will lead to greater proneness to making biased evaluations in health, but not in non-health related dilemmas (experiment 1). In a similar manner, parents will be more susceptible to outcome bias in both high and low involvement situations than non-parents (experiment 2). However, the researchers expect that in dilemmas where the parents are the protagonists, the outcome bias will be stronger in non-parents (experiment 3). It is hoped that the results will help to clarify the specific role of parents in vaccine decisions and will also contribute to the research about the relationship between vaccine hesitancy and cognitive biases.

Reflecting on the findings they expect to be generated from both studies, the researchers assert: "With such knowledge it would be possible to draft interventions custom-made for parents aimed toward undermining their vaccine hesitancy by establishing better communication channels and better, more effective formation of relevant, informative and non-patronizing messages, addressing their personal dilemmas and fears with respect and understanding. Parents might not be afraid of vaccine-preventable diseases, but it seems they are afraid of vaccines - and the burden of the immunity of our herd lies on their shoulders."