Tailoring educational interventions targeting parental vaccine hesitancy: a systematic review of quantitative studies.

Introduction: Childhood vaccines, such as those to prevent tetanus (DTaP/Tdap), human papillomavirus (HPV) or hepatitis B (Hep B), have proven to be an effective strategy in preventing long-term diseases arising from injuries, such as puncture wounds, cuts or burns (e.g., DTaP/Tdap vaccine) or risky sexual behavior in adolescence (e.g., HPV or Hep B vaccines). However, despite national child immunization policies, parental vaccine hesitancy, defined as a delay in accepting or a refusal of available vaccinations, still represents a major social issue, resulting in reduced adherence to numerous vaccination campaigns. Different types of interventions have been proposed to reduce vaccine hesitancy for childhood vaccines, but mixed results have emerged regarding their effectiveness. In the present systematic review, we aimed to perform a qualitative analysis of existing evidence-based interventions targeting parental vaccine hesitancy. Methods: A systematic search on the PubMed, PsychINFO and Web of Science databases was performed to select the relevant studies, with a timeframe ranging from April 2015 to July 2025. To be included in the study, articles had to focus on educational or psychological interventions to reduce vaccine hesitancy for childhood vaccines, using a quantitative method with pre-post measures to adequately assess the effectiveness of the intervention. Results: Out of 442 identified articles, 11 studies met selection criteria and were included in this review. All the articles focused on parents as the recipients of the intervention, while the target population of vaccines ranged from infants to adolescents. The most frequently targeted vaccine was for HPV prevention, and intervention durations ranged from a single exposure session to interventions spanning approximately 2 years. The types of intervention can be grouped into four main categories: (i) narrative-based; (ii) web-based; (iii) culturally-targeted; (iv) other communication-based. The review provided qualitative evidence on the effectiveness of interventions targeting parental vaccine hesitancy in each of the identified categories, although with considerable variability. Discussion: Despite some positive evidence about effectiveness of interventions for promoting immunization in the developmental population, further well-designed evidence-based studies are necessary to reducing heterogeneity of the available data and generalizing conclusions about effective strategies against vaccine hesitancy.