Moral foundations and HPV vaccine acceptance in the United States: State, parental, and individual factors.

Rationale: Appeals to intuitive morality may present a novel approach to addressing vaccine hesitancy.

Objective: To better understand the relationship between morality and vaccination by employing Moral Foundations Theory to studies surrounding the HPV vaccination at multiple different levels of decision making.

Method: We employed three different study modalities which examined moralities link to vaccination by employing Moral Foundations Theory. A state-wide ecological study aimed to understand population level trends. Two randomized control interventional studies were then created to understand the effects of Moral Foundations Theory based interventions on both parents of children and individual decision makers.

Results: We demonstrated a negative association at the state level between the purity moral foundations and HPV vaccination rates (β = -.75, SE 0.23; p < .01) and a positive association between loyalty and HPV vaccination rates (β = 0.62 SE 0.24; p < .05). The parental study built upon this by demonstrating negative association between higher moral purity scores and attitudes towards the HPV vaccine and intention to vaccinate their children (β = -0.27 SE 0.07; p < .001). Our final study demonstrated a Moral Foundations Theory based intervention was associated with an increase in the odds of indicating an intention to receive the HPV vaccination (adjusted Odds Ratio (aOR) 2.59, 95% Confidence Interval (CI) 1.62-4.14). This equates to a 20% increase in the predicted probability of the intention to receive an HPV vaccine (39% CI (36%-42%) vs 60% CI (57%-63%).

Conclusions: Together, these studies demonstrate that moral foundations, specifically the purity foundation, appear to have a strong and consistent relationship with HPV vaccination. They also demonstrate the how moral values-based interventions may serve as a novel approach to increase HPV vaccine uptake with potential to be employed to target vaccine hesitancy more broadly.