Key factors influencing italian mothers' intention to vaccinate sons against HPV: The influence of trust in health authorities, anticipated regret and past behaviour

The Human Papillomavirus (HPV), which is the most common sexually transmitted infection in the world, is associated with different types of cancer, especially cervical cancer. In Italy in 2017 the Italian Ministry of Health introduced a free HPV vaccination programme for 12-years-old boys. In this study we tested an integrated theory of planned behaviour (TPB) model to explain Italian mothers' intention to vaccinate their sons against HPV. TPB variables plus past behaviour, trust in healthy authorities and anticipated regret were measured by a questionnaire in a sample of 333 Italian mothers of 6-11 years old boys, who were not yet vaccinated against HPV. Results showed that subjective norm was the strongest predictor of mothers' intention followed by anticipated regret, trust in health authorities, perceived behavioural control and attitude. Mediation analysis found that past behaviour influenced intention via attitude. The discussion considers the relevance of these factors in promoting mothers' adherence.