OBJECTIVES: Evidence on repeating vaccination misinformation or “myths” in debunking text is abstract
inconclusive; repeating myths may unintentionally increase agreement with myths or help discredit myths. In this study we aimed to compare the effect of repeating vaccination myths and other text-based debunking strategies on parents’ agreement with myths and their intention to vaccinate their children.
RESULTS: There was no evidence that repeating myths increased agreement with myths compared with the other debunking strategies or the control. Posing questions significantly decreased agreement with myths immediately after the intervention compared with the control (difference: 0.30 points, 99.17% confidence interval: 0.58 to 0.02, P 5 .004, d 5 0.39). There was no evidence of a difference between other debunking strategies or the control at either time point, or on intention to vaccinate.
CONCLUSIONS: Debunking strategies that repeat vaccination myths do not appear to be inferior to strategies that do not repeat myths.