Learning Objectives for this Presentation:
By the end of the presentation, participants will be aware that there were reports of GBS post MCV4 reported through VAERS. This further led to epidemiological investigation.

Background:
In February 2005, Advisory Committee on Immunization Practices (ACIP) recommended routine vaccination of adolescents with MCV4. As of October 4, 2005, the Vaccine Adverse Event Reporting System (VAERS) received six reports of Guillain Barré Syndrome (GBS) within 14-31 days post vaccination. All cases were among 17-18 year olds.

Objectives:
Describe reports of GBS after administration of MCV4 and some aspects of their investigation.

Methods:
A case definition was designed for identification and classification of GBS cases. Data on these case-patients was collected from the hospitals, reviewed and analyzed. Vaccine dose distribution by state (geographical) and month (time) was assessed.

Results:
There have been six confirmed cases of GBS. Among the patients, one reported two previous episodes of post vaccination GBS in early childhood, while another had an acute illness prior to neurological symptom onset. None had documented alternative infectious etiology. Approximately 2.8 million doses of MCV4 were distributed nationally since March. Cases of GBS were reported from PA, OH, NY, NJ and AZ respectively, which received about 26% of the distributed doses from March to October 2005.

Conclusions:
There is insufficient evidence that MCV4 causes GBS. Meningococcal disease is still a serious risk. However the onset of first symptoms of GBS within six weeks post vaccine administration is concerning. Enhanced surveillance should continue and significant adverse events after MCV4 administration should be reported to VAERS.