Surveillance of adverse events following immunization related to human papillomavirus vaccines: 12 years of vaccinovigilance in Southern Italy

Objectives: Human papillomavirus (HPV) vaccines have proved to be effective in preventing cervical carcinoma. Although their safety profile resembled those of any other vaccine, few clinical studies showed that HPV vaccines might also induce severe adverse events. Methods: The authors aimed to investigate the safety profile of HPV vaccines, by analyzing the individual case safety reports (ICSRs) of a suspected adverse event following immunization (AEFI) concerning HPV vaccines that were sent to the Italian Pharmacovigilance Spontaneous Reporting System (RNF) in the Campania Region from January 2007 to September 2018. Results: During the study period, 82 ICSRs, covering 181 AEFIs, related to HPV vaccines were sent to the RNF in the Campania Region. The mean age of patients who experienced an AEFI after HPV vaccinations was 13 ± 4.5 years. The majority of ICSRs reported AEFIs that were considered as not serious (82%) and that had a favorable outcome (93%). Conclusion: The overall results of the study demonstrated that, except for a few cases, AEFIs related to HPV vaccines reflect those already reported in the summary of product characteristics. The authors did not identify any new safety issues or serious, rare or unexpected AEFIs that were medically confirmed to be related to HPV vaccines.