Risk of Guillain-Barré Syndrome Following Meningococcal Conjugate (MCV4) Vaccination

Through a partnership that uses the data and other resources of three national and two regional health plans and insurers, we are conducting a multi-site retrospective study of the relationship between immunization with tetravalent meningococcal conjugate vaccine (MCV4) and Guillain-Barré syndrome (GBS) in adolescents (ages 11-21 years of age) over the 42-month period of March 1, 2005 to August 31, 2008. This collaboration has several features of a distributed data network, and so provides an instructive example of the feasibility of large scale population-based post-market evidence development.

Participants include five research organizations that are either part of, or closely affiliated with, a health plan or insurer: HealthCore Inc. (affiliated with WellPoint), Highmark Blue Cross Blue Shield of Pennsylvania, i3 Drug Safety, Aetna, Inc., and Kaiser Permanente Center for Health Research of Hawaii. There is a coordinating center at the Harvard Medical School Department of Ambulatory Care and Prevention at Harvard Pilgrim Health Care.

The organizations provide coverage for approximately 80 million individuals (all ages), of whom the information for approximately 50 million will be available for analysis. Each organization provides scientific, informatics, and management expertise regarding its own population and data, and the overall design and conduct of the study.

This retrospective study uses a hybrid design with three analytic components: 1) characterization of the entire cohort with regard to demographics, eligible time under observation, immunization status, incidence rates of GBS during various categories of person time (never immunized, before immunization, during the 42 days after immunization, etc.), and comorbidities and other covariates, 2) a nested case-control study assessing risk associated with immunization, and 3) a self-controlled case series assessing immunization associated risk.

Cohort analysis