The purpose of this US FDA post-marketing commitment study is to evaluate the safety of
MenACWY-CRM among 50.000 vaccinated adolescents within a large US Healthcare Maintenance
Organization who received MenACWY-CRM vaccination as part of their routine clinical care. The
pre-specified 26 events of interest are events commonly evaluated in vaccine safety studies
and include certain neurological, immunological, vascular, musculoskeletal and hematologic
disorders. All events are collected retrospectively.