Vaccine hesitancy: An overview on parents' opinions about vaccination and possible reasons of vaccine refusal.

Vaccine hesitancy has increased worldwide with a subsequent decreasing of vaccination rates and outbreaks of vaccine-preventable diseases (i.e. measles, poliomyelitis and pertussis) in several developed countries, including Italy. We conducted a survey to investigate the attitudes of a parents' sample about vaccinations by the distribution of questionnaires in six lower secondary schools of the Italian city of Messina. Regarding vaccinations carried out on children, the declared vaccination coverage rates ranged widely between good coverage percentages for some vaccinations (Measles-Mumps-Rubella, Diphtheria-Tetanus-Pertussis), and very low coverage rates for others, especially for "new" vaccinations (HPV, meningococcal, pneumococcal). The vaccinations carried out correlated negatively with both parents' age and their level of education. Moreover, a favourable parents' opinion was strongly influenced by a favourable opinion of the physician, while an unfavourable parents' opinion seemed conditioned by a direct or indirect knowledge of people harmed by vaccines. In addition, our data show that parents do not often know or partially know the real composition of the vaccines and the diseases prevented by vaccinations. Data analysis shows that parents are, theoretically, favourable towards vaccinations but have little knowledge of such practices, sometimes not being unaware of the types of vaccines administrated to their children. Health education and communication of correct information are certainly the cornerstones to improve the situation and to fight the widespread and non-grounded fears about vaccines.