The US Food and Drug Administration and Centers for Diseases Control and Prevention are investigating reports of five cases of the nerve disorder Guillain-Barre syndrome in patients adminstered Sanofi-Aventis' bacterial meningitis vaccine Menactra (meningococcal conjugate A, C, Y, and W135). In a statement the agencies said that, although it is not known yet whether the cases were directly related to the vaccine or were just purely coincidental, the information is being shared with the public because of its potentially serious nature.

GBS is a serious neurological disorder that can occur, often in healthy individuals, either spontaneously or after certain infections and is associated with increasing weakness in the legs and arms that can ultimately lead to hospitalisation. Although the rate of GBS is similar to what might be expected to occur in the general population, it is the timing that has raised the alarm, given that symptoms first appeared around two weeks after vaccination.

However, the FDA did point out that clinical studies involving more than 7,000 recipients of Menactra conducted by the company’s vaccines unit, Sanofi Pasteur, before the vaccine’s approval earlier this year [[17/01/05c]], revealed no incidences of GBS. In addition, the CDC carried out a study using certain healthcare organisation databases and found that, to date, no cases of the condition have been reported among 110,000 Menactra recipients.

According to Jesse Goodman, Director of the FDA’s Center for Biologics Evaluation and Research, at the present time there are no changes in recommendations for vaccination; individuals should continue to follow their doctors' recommendations. Sanofi is contacting all customers who have received shipments of Menactra vaccine to inform them of this development.