Background and objective:
The Italian immunisation schedule includes the main indications for the different types of vaccine, based on the most recent scientific evidences. The purpose of this study is to evaluate the trend of population compliance with mandatory and recommended vaccinations in 2019-2022 in the Messina area after the introduction of the Law 119/2017 and after Covid-19 pandemic.

Methods:
This study analyses the data on the vaccination coverage in the Messina area between 2019-2022, and it compares them with the regional and national ones.The research was started on 1st October 2019 and the data were collected trough the OnVac program at time 0, 12, 24, 36 months stratified according to the type of vaccine, age group and gender.

Results:
Data shows an initial positive trend due to compulsory vaccination, as evidenced by the increased coverage for the hexavalent from one year after the introduction of the law until 2020-2021, followed by a drastic decrease to values below the cut-off. Regarding the flu vaccination, the study records an undulating trend, having an initial decrease in the percentages in 2020, followed by a rise to 80% in 2021 and a new decrease in 2022. It is evident that the maximum vaccination peak occurs thanks to the effect of the Law 119/2017 on compulsory vaccination, followed by a slight positive deflection in the initial phase of the Covid-19 pandemic, and a new collapse in the adhesion of the population, probably linked to the fear of contagion in the health sector.

Conclusion:
In conclusion, considering the pandemic implications, we can state that the vaccination obligation is a valid tool for Public Health, but it reveals ineffective if not integrated with an adequate reorganization of the Regional Health System.