Since 2006, several Italian regions have made the measles, mumps, rubella, and varicella (MMRV) vaccine available to all newborns during their second year of life. In 2011, the Italian Drug Authority (AIFA) recommended that MMRV be discontinued due to an increased risk of febrile seizures following vaccination; however, some regions chose to continue using MMRV, and the Ministry of Health recommended that supplemental monitoring of vaccine safety be ensured. AIFA and Regional Health Authorities are currently in charge of monitoring Adverse Events Following Immunization (AEFIs) in Italy.

The purpose of this research is to present the findings of an MMRV-vaccine surveillance programme for AEFIs in Apulia. We chose MMRV AEFIs that occurred in Apulia between 2009 and 2017 from the AIFA database. We used the WHO causation assessment criteria for serious AEFIs, utilising inpatient information from individual medical records in cases where the patient was hospitalised. 155 MMRV-AEFIs occurred during the 8-year monitoring period, with 26 classed as serious and 22 resulting in hospitalisation. When the causality was assessed, the categorization was “consistent causal association to immunisation” for ten, “indeterminate” for two, “inconsistent causal relationship to immunisation” for thirteen, and “not-classifiable” for one. There were no cases of febrile seizures as a result of immunisation.