Acknowledging uncertainty about long term effects of the HPV vaccination: effects on HPV vaccination intention

Abstract

Background: Being a relatively new vaccine, there remains uncertainty regarding the potential long term effects of the Human Papillomavirus (HPV) vaccination targeting 12-year-old girls. Therefore, in an experimental web-based study, we investigated the effects of acknowledging versus ignoring this uncertainty. A message in which uncertainty was acknowledged was expected to be more persuasive than a message in which uncertainty was ignored. Methods: 695 mothers of girls-to-be invited to the HPV vaccination round of 2014 were derived from the National Immunization Register. Participants were randomly assigned to one of two conditions: 1) acknowledging or 2) ignoring uncertainty about potential long term effects . Findings: Acknowledging uncertainty resulted in a lower intention towards receiving the HPV vaccination than ignoring it. Discussion: This study implies that it seems better to ignore uncertainty regarding potential long term effects of the HPV vaccination on the short term. However, based on inoculation theory we recommend future communication to acknowledge this uncertainty, because this will build resistance to future counterarguments and therefore has more positive long term effects than when uncertainty is ignored.