Adverse events following immunization in Ontario's female school-based HPV program.

Background: In September 2007, a school-based human papillomavirus (HPV) vaccination program targeting grade 8 girls (approximately 13 years old) and delivered by public health was implemented in Ontario, Canada. We assessed reports of adverse events following immunization (AEFI) from the school-based program as part of quadrivalent HPV (HPV4) vaccine safety surveillance and to contribute to a comprehensive HPV vaccine program evaluation.

Methods: AEFIs following HPV4 vaccine (Gardasil(®)) administered between September 1, 2007 and December 31, 2011 were extracted from the province's reportable disease system.