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.