October 20, 2006
The Food and Drug Administration (FDA) and Centers for Disease Control and Prevention (CDC) are updating a previous alert to consumers and health care providers regarding reports of Guillain Barre Syndrome (GBS) following administration of Meningococcal Conjugate Vaccine A, C, Y, and W135 (trade name Menactra), manufactured by sanofi pasteur. In October 2005, FDA and CDC reported 5 cases of GBS following administration of Menactra.
GBS is a serious, rare neurological disorder that can occur, often in healthy individuals, either spontaneously or after certain infections. GBS typically causes increasing weakness in leg, arm and other muscles that can be severe and require hospitalization. GBS usually resolves on its own, however some people may have residual neurological deficits.
To date a total of 15 confirmed cases of GBS among individuals 11-19 years of age occurring within six weeks of vaccination with Menactra have been reported to the Vaccine Adverse Event Reporting System (VAERS). Two additional cases have been confirmed in persons 20 years of age and older. All individuals are reported to be recovering or have recovered. While the cases reported suggest a small increased risk of GBS following immunization with Menactra, the limitations in VAERS, and the uncertainty regarding background incidence rates for GBS require that these findings be viewed with caution. At this time, CDC and FDA cannot determine with certainty whether Menactra does increase the risk of GBS in persons who receive the vaccine and, if so, to what degree (the current data suggests an estimated possible increase of approximately 1.25 GBS cases for every million vaccinnees, but this estimate has many uncertainties).
Menactra prevents meningococcal disease, which is a major cause of bacterial meningitis (an infection of the lining of the brain and spinal cord) and blood stream infections. Meningococcal disease affects approximately 1 in 100,000 people ages 11-19 annually. The infection can be life threatening: 10-14 percent of cases are fatal and 11-19 percent of survivors may have permanent disability.
At the present time, there are no changes in recommendations for vaccination and individuals should continue to follow their doctors' recommendations. CDC's Advisory Committee on Immunization Practices will be reviewing this information at its next meeting, October 25-26, 2006.
FDA and CDC are continuing to monitor the situation and are asking any persons with knowledge of any possible cases of GBS occurring after receiving Menactra to report them to VAERS to help the agencies further evaluate the matter. Individuals can report to VAERS on the web or by phone at 1-800-822-7967.
Studies of more than 7,000 recipients performed by sanofi pasteur before the licensure of the vaccine showed no GBS cases. An analysis of Menactra use within the Vaccine Safety Datalink, a database of vaccine information from eight large managed care organizations, revealed that as of September 20, 2006, a total of 126,506 doses had been delivered and, of those, no cases of GBS have been observed among vaccine recipients ages 11-19 within six weeks of vaccination. Additional, larger studies are being planned to provide a more definitive assessment.