Since the multicomponent meningococcal B vaccine introduction, the Apulian Regional Health Authority implemented postmarketing surveillance program, as provided by Italian laws.From National Pharmacovigilance Network, we selected 4CMenB AEFIs reported in Apulia from 01 January 2014 to 31 December 2019, while the number of 4 cMen B doses administered per year was obtained from the regional immunization database (GIAVA).For each subject who experienced an adverse event following meningococcal B vaccine (AEFIs), a predefined form was filled in.A total of 214 AEFIs (26.5 × 100.000 doses) were reported after any dose of MenB-4 c vaccination of which 58/214 (27.1%) were classified as serious (7.2 × 100,000 doses), 145/214 (67.8%) as not serious (180 × 100,000 doses), and 11/214 (5.1%) as undefined (1.3 × 100,000 doses).The average age of subjects who experimented and AEFI was 30 months. The majority of serious AEFIs were reported in 2- to 11-month-old children (44/57; 77.2%). A total of 31/58 (3.8 × 100,000 doses; 53.4%) serious AEFIs were reported as having a 'consistent causal association' with vaccination. Of these, fever/hyperpyrexia was reported in 21/31 (2.6 × 100,000 doses; 67.7%); hypotonic-hyporesponsive episode was reported in 7/31 (0.9 × 100,000 doses [add %-age]) and was the most frequent adverse event with neurological symptoms. A total of 13/31 (41.9%) serious AEFIs classified as 'consistent causal association' were reported after the first dose of 4cMenB, of these 5/13 (38.5%) children did not complete the vaccination schedule.Our data seemed to confirm, in a large population, the a good safety profile of the universal mass vaccination with 4CMENB.
Keywords: AEFI, post-marketing surveillance; causality assessment; hesitancy; hypotonic-hyporesponsive episode.