Background and Objectives:
The National Immunization Prevention Plan 2017-2019 (extended to 2021) states that Diphtheria, Tetanus, acellular Pertussis (dTap) and Inactivated Poliomyelitis vaccine (IPV) have to be boost between 11 and 18 years of age, mandatorily. Among other vaccines, conjugated quadrivalent meningococcus (Men ACWY) is recommended during adolescence. The present study aimed to investigate dTap-IPV and Men ACWY coverage and potential predictors of the uptake among undergraduate university students in Southern Italy.

Methods:
This cross-sectional survey was conducted through an anonymous online questionnaire that included socio-demographic characteristics, attitudes, and reasons for not having received vaccinations and willingness to receive vaccinations.

Results:
Preliminary findings refer to a sample of 407 respondents with a mean age of 22.8 years (SD±2.9). During adolescence, 88.6% of respondents received dTap-IPV vaccine, 74% had received the Men ACWY and over two-third of the sample received both vaccinations. Among dTap-IPV unvaccinated students, 39.3% declared to be unwilling to receive the vaccine booster because they believed to be not at risk of contracting vaccine preventable infectious diseases (46%), vaccination was not offered to them (41%) and because they were afraid about potential serious side effects (13.6%). Furthermore, the reasons for not getting Men ACWY were the lack of vaccination proposal (59.4%), the fear of serious side effects (20.3%), believing to be not at risk of meningococcal infection (18.8%) and, lastly, because it was not mandatory (10.9%).

Conclusion:
Preliminary results show low perception of the risk of acquiring vaccine-preventable diseases and this represent a key issue to address in order to keep high vaccines’ coverage. Although it is preferable that public acceptance make compulsory vaccination programs unnecessary, the finding that some young adults did not get vaccinated against Men ACWY, since it is not mandatory, highlight the need of better understanding the impact on immunization coverage of different approaches.