We are conducting a large, record-based study to assess the risk of Guillain-Barré Syndrome (GBS), a serious demyelinating disease, following immunization with the tetravalent meningococcal conjugate vaccine (Menactra) that is currently recommended for all adolescents. The study was requested by CDC and FDA because of an unexpected number of case reports to the CDC's Vaccine Adverse Event Reporting System (VAERS). The study protocol was designed by the investigators, with input from FDA, CDC, and the vaccine's manufacturer, Sanofi-Pasteur. An external advisory board that includes CDC representation, provides input regarding important decisions. The manufacturer is not participating in the conduct of the study and has no control over the analysis or dissemination of results. The study is derived from five large US health plans with a total membership of approximately 50 million over the study time period. America's Health Insurance Plans (AHIP) serves as liaison between the health plans and the Coordinating Center at the Department of Ambulatory Care and Prevention of Harvard Medical School and Harvard Pilgrim Health Care, and is the contracting organization with the health plans.
Age range
11 Years – 21 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
Guillain-Barré syndrome (GBS), verified through neurologist review of medical records
Timeframe: within 42 days following vaccination