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 (Time points 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 Time point 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% CI¼0.05, 0.40, VI mean change 0.22, 95% CI¼0.04, 0.40). Comparing baseline with Time point 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% CI¼ –0.60, –0.14, VI mean change –0.31, 95% CI¼ –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…Readmore