Addressing Parents' Vaccine Concerns: A Randomized Trial of a Social Media Intervention.

INTRODUCTION: Successful strategies are needed to address parental vaccine hesitancy, a significant public health issue. The study objective was to assess whether an Internet-based platform with vaccine information and interactive social media components improved parents' vaccine-related attitudes.

STUDY DESIGN: A three-arm RCT.

SETTING/PARTICIPANTS: The study was conducted in a large Colorado integrated healthcare organization. Parents were enrolled during September 2013 through October 2015 and followed through November 2016; data were analyzed in 2017. Parents, recruited during pregnancy, were given a survey about vaccine-related attitudes at enrollment (i.e., baseline) and when their child was aged 3-5 months and 12-15 months (Timepoints 1 and 2, respectively). Parental vaccine hesitancy was assessed at baseline.

INTERVENTION: Study participants were randomized to the following: a study website with vaccine information and social media components (VSM arm); a website with vaccine information only (VI); or usual care.

MAIN OUTCOME MEASURES: Change in parental vaccine attitudes over time by baseline degree of vaccine hesitancy.

RESULTS: Among 1,093 study participants, 945 (86.5%) completed all three surveys. Comparing baseline with Timepoint 1 among vaccine-hesitant parents, the VSM and VI arms were associated with significant improvements in attitudes regarding vaccination benefits compared to usual care (VSM mean change 0.23 on a 5-point scale, 95% CI=0.05, 0.40, VI mean change 0.22, 95% CI=0.04, 0.40). Comparing baseline with Timepoint 2 among hesitant parents, the VSM and VI arms were also associated with significant reductions in parental concerns about vaccination risks compared to usual care (VSM mean change -0.37, 95% CI= -0.60, -0.14, VI mean change -0.31, 95% CI= -0.55, -0.07). Self-efficacy around vaccine decision making also improved among vaccine-hesitant parents. No intervention effect was observed among parents not vaccine-hesitant at baseline.

CONCLUSIONS: Among vaccine-hesitant parents, an Internet-based intervention improved parents' attitudes about vaccines.

TRIAL REGISTRATION: This study was registered at www.clinicaltrials.gov NCT01873040.