OBJECTIVES: Neisseria meningitidis can cause invasive meningococcal disease which may lead to severe long-term sequelae and is associated with high case-fatality rates. Meningococcal serogroup B vaccines help protecting against Neisseria meningitidis serogroup B (MenB), which represents the most prevalent serogroup in Italy. MenB vaccination for newborns was introduced in some Italian regions in 2014 and in the national immunization program (NIP) in 2017. Certain Italian regions also included MenB vaccination for adolescents. We investigated MenB vaccination coverage in Italy, for different age groups and dosing schedule.

METHODS: We conducted a retrospective administrative database study from a subset of Local Health Units in Veneto, Friuli-Venezia Giulia, Lazio, Liguria, and Umbria, representing about 20% of the regional population. MenB vaccination coverage per dose and year of vaccination over the 2014-2022 period were estimated for the 2009-2021 birth-cohorts and reported by regions.

RESULTS: Infants (2015-2020 birth cohorts) MenB vaccination rates increased significantly over the 2017-2022 period, from an average of 29.9% to 66.7%, across all five regions. For infants born in 2020 and fully vaccinated by 2022 (2+1 dose), regional MenB vaccination rates range between 50.8% and 80.2%. For children (2012-2019 birth cohorts) and adolescents (2009-2011 birth cohorts) vaccinated in 2022 according to a 2-dose schedule, regional MenB vaccination rates were estimated between 43.5% and 62.2%, and between 5.0% and 28.3%, respectively.

Finally, for infants (2020 birth cohort) vaccinated in 2022 the proportion of those who started the vaccination series with the first dose and completed the series (2+1) within 2 years of age varies among regions, between 76.5% and 93.0%.

CONCLUSIONS: MenB vaccination coverage and adherence to the full vaccination schedule varies significantly among different regions and age groups in Italy. Infant vaccination remains sub-optimal compared to the NIP target of 90%, while child and adolescent vaccination remains low.

Funding: GSK (GSK study identifier: VEO 000707).