The Power of a Story: How Emotions and Numeracy Affect Parental Decisions About the Human Papillomavirus Vaccine

The Human Papillomavirus (HPV) is the most common sexually transmitted infection (CDC, 2021). There are two strains of HPV known for causing cervical, penile, anal, vaginal, and oropharynx (throat) cancers (CDC, 2020). A vaccine is available to prevent these cancer-causing strains of HPV for individuals between the ages of 9-45. Unfortunately, vaccination uptake and completion rates are below the recommended rates to achieve herd immunity. A primary barrier to vaccination is concern about potential adverse events following vaccination. The purpose of the present study is to examine the influence of anecdotal versus statistical information on parents\u27 intentions to vaccinate their children against HPV. Participants (N = 206) were randomly assigned to one of three conditions: 1) read only statistical information about the likelihood of an adverse event after vaccination, 2) statistical information and mostly negative anecdotes about adverse events, or 3) statistical information and mostly positive anecdotes about the benefits of vaccination. The primary outcome measure was behavioral intentions to vaccinate. In addition, risk as feelings were assessed as mediators of association and numeracy was assessed as a moderator of associations. Results indicated that individuals who read negative anecdotes along with statistical information reported less likelihood to vaccinate their child, less reassurance about the benefits of the vaccine, and more worry and uncertainty about the vaccine side effects. Mediation models were tested to examine the possible impact of feelings (i.e., worry, uncertainty, reassurance, and regret) on behavioral intentions. Worry had a mediating effect on the relationship between type of information and behavioral intentions to vaccinate. Overall, the results of this study indicate that negative anecdotes weigh more heavily in decision-making on the HPV vaccine than supported by statistical evidence, and these anecdotes elicit negative feelings (i.e., worry) which are impacting intentions to vaccinate